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1.
J Am Chem Soc ; 146(8): 5108-5117, 2024 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-38367279

RESUMO

Enzymes are natural catalysts for a wide range of metabolic chemical transformations, including selective hydrolysis, oxidation, and phosphorylation. Herein, we demonstrate a strategy for the encapsulation of enzymes within a highly stable zirconium-based metal-organic framework. UiO-66-F4 was synthesized under mild conditions using an enzyme-compatible amino acid modulator, serine, at a modest temperature in an aqueous solution. Enzyme@UiO-66-F4 biocomposites were then formed by an in situ encapsulation route in which UiO-66-F4 grows around the enzymes and, consequently, provides protection for the enzymes. A range of enzymes, namely, lysozyme, horseradish peroxidase, and amano lipase, were successfully encapsulated within UiO-66-F4. We further demonstrate that the resulting biocomposites are stable under conditions that could denature many enzymes. Horseradish peroxidase encapsulated within UiO-66-F4 maintained its biological activity even after being treated with the proteolytic enzyme pepsin and heated at 60 °C. This strategy expands the toolbox of potential metal-organic frameworks with different topologies or functionalities that can be used as enzyme encapsulation hosts. We also demonstrate that this versatile process of in situ encapsulation of enzymes under mild conditions (i.e., submerged in water and at a modest temperature) can be generalized to encapsulate enzymes of various sizes within UiO-66-F4 while protecting them from harsh conditions (i.e., high temperatures, contact with denaturants or organic solvents).


Assuntos
Estruturas Metalorgânicas , Compostos Organometálicos , Ácidos Ftálicos , Estruturas Metalorgânicas/química , Zircônio/química , Biomimética , Compostos Organometálicos/química , Peroxidase do Rábano Silvestre
2.
Phytomedicine ; 112: 154569, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36842217

RESUMO

BACKGROUND: Bornyl acetate (BA), a chemical component of essential oil in the Pinus family, has yet to be actively studies in terms of its therapeutic effect on numerous diseases, including autoimmune diseases. PURPOSE: This study aimed to investigate the pharmacological effects and molecular mechanisms of BA on myelin oligodendrocyte glycoprotein (MOG35-55)-induced experimental autoimmune encephalomyelitis (EAE) mice in an animal model of multiple sclerosis (MS), a representative autoimmune disease in central nervous system. METHODS: BA (100, 200, or 400 mg/kg) was orally treated to EAE mice once daily for 30 days after immunization for the behavioral test and for the 16th-18th days for the histopathological and molecular analyses, from the onset stage (8th day) of EAE symptoms. RESULTS: BA mitigated behavioral dysfunction (motor disability) and demyelination in the spinal cord that were associated with the down-regulation of representative pro-inflammatory cytokines (interleukin (IL)-1 beta, IL-6, and tumor necrosis factor-alpha), enzymes (cyclooxygenase-2 and inducible nitric oxide synthase), and chemokines (monocyte chemotactic protein-1, macrophage inflammatory protein-1 alpha, and regulated on activation), and decreased infiltration of microglia (CD11b+/CD45+(low)) and macrophages (CD11b+/CD45+(high)). The anti-inflammatory effect of BA was related to the inhibition of mitogen-activated protein kinases and nuclear factor-kappa B pathways. BA also reduced the recruitment/infiltration rates of CD4+ T, Th1, and Th17 cells into the spinal cords of EAE mice, which was related to reduced blood-spinal cord barrier (BSCB) disruption. CONCLUSION: These findings strongly suggest that BA may alleviate EAE due to its anti-inflammatory and BSCB protective activities. This indicates that BA is a potential therapeutic agent for treating autoimmune demyelinating diseases including MS.


Assuntos
Pessoas com Deficiência , Encefalomielite Autoimune Experimental , Transtornos Motores , Esclerose Múltipla , Fármacos Neuroprotetores , Camundongos , Animais , Humanos , Encefalomielite Autoimune Experimental/tratamento farmacológico , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Barreira Hematoencefálica , Transtornos Motores/complicações , Transtornos Motores/tratamento farmacológico , Transtornos Motores/patologia , Esclerose Múltipla/tratamento farmacológico , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico
3.
Orthod Craniofac Res ; 26(3): 371-377, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36305223

RESUMO

OBJECTIVE: This retrospective two-centre study aimed to evaluate the occlusal outcomes in patients undergoing orthognathic surgery with clear aligners. METHODS: A retrospective chart review and occlusal outcomes for 15 patients (10 females and five males) with different types of dentofacial deformities in the anteroposterior, vertical and transverse dimensions, who underwent orthognathic surgery in conjunction with clear aligners were evaluated. Weighed Peer Assessment Rating (PAR) index scores of the pre-treatment and post-treatment digital models were used to assess initial complexity, final occlusal outcomes and degree of improvement with surgery and clear aligners. RESULTS: The mean post-treatment PAR score was 3.5 ± 2.54, which was a statistically significant improvement from the pre-treatment PAR score of 27.63 ± 12.09, an 87% improvement was achieved. All subcategories of the PAR index showed statistically significant improvement except for midline assessment component. CONCLUSIONS: Occlusal outcomes with aligners showed great improvement as indicated with the PAR index scores. Orthognathic surgical cases can be treated efficiently with aligners and future studies should compare occlusal outcomes between orthognathic surgical patients treated with clear aligners and those treated with fixed appliances.


Assuntos
Má Oclusão , Aparelhos Ortodônticos Removíveis , Cirurgia Ortognática , Masculino , Feminino , Humanos , Má Oclusão/cirurgia , Estudos Retrospectivos , Resultado do Tratamento
4.
J Am Chem Soc ; 144(28): 12595-12601, 2022 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-35797453

RESUMO

Mechanochemical syntheses of rotaxanes have attracted considerable attention of late because of the superior reaction rates and higher yields associated with their production compared with analogous reactions carried out in solution. Previous investigators, however, have focused on the demonstration of the mechanochemical syntheses of rotaxanes per se, rather than on studying the solid-phase host-guest molecular interplay related to their rapid formation and high yields. In this investigation, we attribute the lower yields of rotaxanes prepared in solution to the limited concentration and a desolvation energy penalty that must be compensated for by host-guest interactions during complexation that precedes the templation leading to rotaxane formation. It follows that, if the desolvation energy can be removed and higher concentrations can be attained, even weak host-guest interactions can drive the complexation of host and guest molecules efficiently. In order to test this hypothesis, we chose two host-guest pairs of permethylated pillar[5]arene/1,6-diaminohexane and permethylated pillar[5]arene/2,2'-(ethylenedioxy)bis(ethylamine) for the simple reason that they exhibit extremely low binding constants (2.7 ± 0.4 M-1 when 1,6-diaminohexane is the guest and <0.1 M-1 when 2,2'-(ethylenedioxy)bis(ethylamine) is the guest in CDCl3; i.e., ostensibly no pseudorotaxane formation is observed). We argue that the amount of pseudorotaxanes formed in the solid state is responsive to mechanical treatments or otherwise and changes in temperature during stoppering reactions. Compared to the amount of pseudorotaxanes that can be obtained in solution, large quantities of pseudorotaxanes are formed in the solid state because of concentration and desolvation effects. This mechanochemical enhancement of pseudorotaxane formation is referred to as a self-correction in the current investigation. Rotaxanes based on permethylated pillar[5]arene/1,6-diaminohexane and permethylated pillar[5]arene/2,2'-(ethylenedioxy)bis(ethylamine) have been synthesized in much higher yields compared to those obtained in solution, aided and abetted by self-correction effects during mechanical treatments and heating at a mild temperature of 50 °C.


Assuntos
Rotaxanos , Etilaminas , Modelos Moleculares , Rotaxanos/química , Temperatura
6.
Sci Adv ; 7(22)2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-34049881

RESUMO

Since the emergence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), various vaccines are being developed, with most vaccine candidates focusing on the viral spike protein. Here, we developed a previously unknown subunit vaccine comprising the receptor binding domain (RBD) of the spike protein fused with the tetanus toxoid epitope P2 (RBD-P2) and tested its efficacy in rodents and nonhuman primates (NHPs). We also investigated whether the SARS-CoV-2 nucleocapsid protein (N) could increase vaccine efficacy. Immunization with N and RBD-P2 (RBDP2/N) + alum increased T cell responses in mice and neutralizing antibody levels in rats compared with those obtained using RBD-P2 + alum. Furthermore, in NHPs, RBD-P2/N + alum induced slightly faster SARS-CoV-2 clearance than that induced by RBD-P2 + alum, albeit without statistical significance. Our study supports further development of RBD-P2 as a vaccine candidate against SARS-CoV-2. Also, it provides insights regarding the use of N in protein-based vaccines against SARS-CoV-2.


Assuntos
Vacinas contra COVID-19/imunologia , COVID-19/prevenção & controle , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , Proteínas Recombinantes de Fusão/imunologia , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Toxoide Tetânico/imunologia , Animais , COVID-19/genética , COVID-19/imunologia , Vacinas contra COVID-19/genética , Chlorocebus aethiops , Proteínas do Nucleocapsídeo de Coronavírus/genética , Feminino , Macaca fascicularis , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Transgênicos , Fosfoproteínas/genética , Fosfoproteínas/imunologia , Domínios Proteicos , Ratos , Proteínas Recombinantes de Fusão/genética , SARS-CoV-2/genética , Células Sf9 , Glicoproteína da Espícula de Coronavírus/genética , Spodoptera , Toxoide Tetânico/genética , Células Vero
7.
PLoS One ; 16(4): e0249399, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33857181

RESUMO

OBJECTIVE: The chest X-ray (CXR) is the most readily available and common imaging modality for the assessment of pneumonia. However, detecting pneumonia from chest radiography is a challenging task, even for experienced radiologists. An artificial intelligence (AI) model might help to diagnose pneumonia from CXR more quickly and accurately. We aim to develop an AI model for pneumonia from CXR images and to evaluate diagnostic performance with external dataset. METHODS: To train the pneumonia model, a total of 157,016 CXR images from the National Institutes of Health (NIH) and the Korean National Tuberculosis Association (KNTA) were used (normal vs. pneumonia = 120,722 vs.36,294). An ensemble model of two neural networks with DenseNet classifies each CXR image into pneumonia or not. To test the accuracy of the models, a separate external dataset of pneumonia CXR images (n = 212) from a tertiary university hospital (Gachon University Gil Medical Center GUGMC, Incheon, South Korea) was used; the diagnosis of pneumonia was based on both the chest CT findings and clinical information, and the performance evaluated using the area under the receiver operating characteristic curve (AUC). Moreover, we tested the change of the AI probability score for pneumonia using the follow-up CXR images (7 days after the diagnosis of pneumonia, n = 100). RESULTS: When the probability scores of the models that have a threshold of 0.5 for pneumonia, two models (models 1 and 4) having different pre-processing parameters on the histogram equalization distribution showed best AUC performances of 0.973 and 0.960, respectively. As expected, the ensemble model of these two models performed better than each of the classification models with 0.983 AUC. Furthermore, the AI probability score change for pneumonia showed a significant difference between improved cases and aggravated cases (Δ = -0.06 ± 0.14 vs. 0.06 ± 0.09, for 85 improved cases and 15 aggravated cases, respectively, P = 0.001) for CXR taken as a 7-day follow-up. CONCLUSIONS: The ensemble model combined two different classification models for pneumonia that performed at 0.983 AUC for an external test dataset from a completely different data source. Furthermore, AI probability scores showed significant changes between cases of different clinical prognosis, which suggest the possibility of increased efficiency and performance of the CXR reading at the diagnosis and follow-up evaluation for pneumonia.


Assuntos
Inteligência Artificial , Pneumonia/diagnóstico , Tórax/diagnóstico por imagem , Adulto , Idoso , Área Sob a Curva , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Curva ROC , Centros de Atenção Terciária , Tomografia Computadorizada por Raios X
8.
J Am Chem Soc ; 142(5): 2541-2548, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-31895548

RESUMO

Aqueous rechargeable zinc batteries (ZBs) have received considerable attention recently for large-scale energy storage systems in terms of rate performance, cost, and safety. Nevertheless, these ZBs still remain a subject for investigation, as researchers search for cathode materials enabling high performance. Among the various candidate cathode materials for ZBs, quinone compounds stand out as candidates because of their high specific capacity, sustainability, and low cost. Quinone-based cathodes, however, suffer from the critical limitation of undergoing dissolution during battery cycling, leading to a deterioration in battery life. To address this problem, we have introduced a redox-active triangular phenanthrenequinone-based macrocycle (PQ-Δ) with a rigid geometry and layered superstructure. Notably, we have confirmed that Zn2+ ions, together with H2O molecules, can be inserted into the PQ-Δ organic cathode, and, as a consequence, the interfacial resistance between the cathode and electrolytes is decreased effectively. Density functional theory calculations have revealed that the low interfacial resistance can be attributed mainly to decreasing the desolvation energy penalty as a result of the insertion of hydrated Zn2+ ions in the PQ-Δ cathode. The combined effects of the insertion of hydrated Zn2+ ions and the robust triangular structure of PQ-Δ serve to achieve a large reversible capacity of 210 mAh g-1 at a high current density of 150 mA g-1, along with an excellent cycle-life, that is, 99.9% retention after 500 cycles. These findings suggest that the utilization of electron-active organic macrocycles, combined with the low interfacial resistance associated with the solvation of divalent carrier ions, is essential for the overall performance of divalent battery systems.

9.
Adv Mater ; 31(51): e1905048, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31693231

RESUMO

Although being incorporated in commercial lithium-ion batteries for a while, the weight portion of silicon monoxide (SiOx , x ≈ 1) is only less than 10 wt% due to the insufficient cycle life. Along this line, polymeric binders that can assist in maintaining the mechanical integrity and interfacial stability of SiOx electrodes are desired to realize higher contents of SiOx . Herein, a pyrene-poly(acrylic acid) (PAA)-polyrotaxane (PR) supramolecular network is reported as a polymeric binder for SiOx with 100 wt%. The noncovalent functionalization of a carbon coating layer on the SiOx is achieved by using a hydroxylated pyrene derivative via the π-π stacking interaction, which simultaneously enables hydrogen bonding interactions with the PR-PAA network through its hydroxyl moiety. Moreover, the PR's ring sliding while being crosslinked to PAA endows a high elasticity to the entire polymer network, effectively buffering the volume expansion of SiOx and largely mitigating the electrode swelling. Based on these extraordinary physicochemical properties of the pyrene-PAA-PR supramolecular binder, the robust cycling of SiOx electrodes is demonstrated at commercial levels of areal loading in both half-cell and full-cell configurations.

10.
Adv Mater ; 31(29): e1901645, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31148271

RESUMO

Despite their unparalleled theoretical capacity, lithium-metal anodes suffer from well-known indiscriminate dendrite growth and parasitic surface reactions. Conductive scaffolds with lithium uptake capacity are recently highlighted as promising lithium hosts, and carbon nanotubes (CNTs) are an ideal candidate for this purpose because of their capability of percolating a conductive network. However, CNT networks are prone to rupture easily due to a large tensile stress generated during lithium uptake-release cycles. Herein, CNT networks integrated with a polyrotaxane-incorporated poly(acrylic acid) (PRPAA) binder via supramolecular interactions are reported, in which the ring-sliding motion of the polyrotaxanes endows extraordinary stretchability and elasticity to the entire binder network. In comparison to a control sample with inelastic binder (i.e., poly(vinyl alcohol)), the CNT network with PRPAA binder can endure a large stress during repeated lithium uptake-release cycles, thereby enhancing the mechanical integrity of the corresponding electrode over battery cycling. As a result, the PRPAA-incorporated CNT network exhibits substantially improved cyclability in lithium-copper asymmetric cells and full cells paired with olivine-LiFePO4 , indicating that high elasticity enabled by mechanically interlocked molecules such as polyrotaxanes can be a useful concept in advancing lithium-metal batteries.

11.
Int J Radiat Biol ; 95(5): 527-536, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30753094

RESUMO

PURPOSE: The purpose of this study is to evaluate the global scientific publication of biological research of low dose radiation for the past 30 years and provide the insights into the characteristics of research activities and major topics regarding biological effects of low dose radiation exposure. MATERIALS AND METHODS: We bibliometrically investigated the biological research publication of radiation exposure less than 100 mSv. References published from 1987 to 2016 were achieved from the Scopus database and filtered by several criteria such as publication types, research fields, and radiation dose range. RESULTS: Total 753 references were assembled for the bibliometric analysis on the biological studies of radiation effect less than 100 mSv. It provided fundamental knowledge of research, including production tendency, contribution, impact journals, and major research themes. Based on the keyword analysis, we found that specific topics on the biological response to radiation exposure have been changed from the examination of low dose radiation-induced phenomena to the investigation of how to induce a physiological response. In addition, featured articles showed the various views on the biological effects of radiation less than 100 mSv in 30 years publication, depending on radiation doses and types. CONCLUSIONS: Continuous studies in large programs of low dose radiation led to the increment of research achievements in accordance with societal needs in radiation safety regulation for health protection. Our findings can surely help radiation researchers to gain insights and penetration in low dose risk research for radiation protection, and establish a further research direction.


Assuntos
Bibliometria , Publicações , Doses de Radiação , Radiobiologia , Internacionalidade
12.
J Am Chem Soc ; 140(35): 10937-10940, 2018 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-30089358

RESUMO

Conjugated microporous polymers (CMPs) offer a unique structure integrating π-conjugated backbone into a porous network for the simultaneous transport of charges and materials. However, tuning electronic properties of CMPs so far has been limited to an approach of varying the monomers, and the precious metal catalysts are inevitably needed for the C-C coupling reaction. Here, we present a powerful strategy to synthesize CMPs and precisely tune their optical band gap and surface area through metal-free in situ cyclization reaction controlled by the acid strength of acid catalysts. Notably, the optical band gap of CMPs showed a linear relationship with the p Ka of acid catalysts, which provides us with the ability to obtain the desired band gap between 2.07 and 3.35 eV, falling in the range of the visible solar spectrum. Moreover, CMPs exhibited excellent textural properties such as microporosity and high specific surface area.

13.
Vaccine ; 36(24): 3468-3476, 2018 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-29739720

RESUMO

The Middle East respiratory syndrome coronavirus (MERS-CoV) is a highly pathogenic and zoonotic virus with a fatality rate in humans of over 35%. Although several vaccine candidates have been developed, there is still no clinically available vaccine for MERS-CoV. In this study, we developed two types of MERS-CoV vaccines: a recombinant adenovirus serotype 5 encoding the MERS-CoV spike gene (Ad5/MERS) and spike protein nanoparticles formulated with aluminum (alum) adjuvant. Next, we tested a heterologous prime-boost vaccine strategy, which compared priming with Ad5/MERS and boosting with spike protein nanoparticles and vice versa, with homologous prime-boost vaccination comprising priming and boosting with either spike protein nanoparticles or Ad5/MERS. Although both types of vaccine could induce specific immunoglobulin G against MERS-CoV, neutralizing antibodies against MERS-CoV were induced only by heterologous prime-boost immunization and homologous immunization with spike protein nanoparticles. Interestingly, Th1 cell activation was induced by immunization schedules including Ad5/MERS, but not by those including only spike protein nanoparticles. Heterologous prime-boost vaccination regimens including Ad5/MERS elicited simultaneous Th1 and Th2 responses, but homologous prime-boost regimens did not. Thus, heterologous prime-boost may induce longer-lasting immune responses against MERS-CoV because of an appropriate balance of Th1/Th2 responses. However, both heterologous prime-boost and homologous spike protein nanoparticles vaccinations could provide protection from MERS-CoV challenge in mice. Our results demonstrate that heterologous immunization by priming with Ad5/MERS and boosting with spike protein nanoparticles could be an efficient prophylactic strategy against MERS-CoV infection.


Assuntos
Adenovírus Humanos/imunologia , Infecções por Coronavirus/prevenção & controle , Imunização Secundária/métodos , Ativação Linfocitária/efeitos dos fármacos , Coronavírus da Síndrome Respiratória do Oriente Médio/efeitos dos fármacos , Glicoproteína da Espícula de Coronavírus/imunologia , Adenovírus Humanos/genética , Adjuvantes Imunológicos/administração & dosagem , Compostos de Alúmen/administração & dosagem , Animais , Anticorpos Neutralizantes/biossíntese , Anticorpos Antivirais/biossíntese , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Feminino , Humanos , Esquemas de Imunização , Imunogenicidade da Vacina , Imunoglobulina G/biossíntese , Camundongos , Camundongos Endogâmicos BALB C , Coronavírus da Síndrome Respiratória do Oriente Médio/genética , Coronavírus da Síndrome Respiratória do Oriente Médio/imunologia , Nanopartículas/administração & dosagem , Nanopartículas/química , Glicoproteína da Espícula de Coronavírus/administração & dosagem , Glicoproteína da Espícula de Coronavírus/genética , Células Th1/efeitos dos fármacos , Células Th1/imunologia , Células Th1/virologia , Células Th2/efeitos dos fármacos , Células Th2/imunologia , Células Th2/virologia , Vacinas Virais/administração & dosagem , Vacinas Virais/genética , Vacinas Virais/imunologia
14.
Int J Radiat Biol ; 94(7): 685-693, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29775393

RESUMO

PURPOSE: Since the 2011 Fukushima nuclear power plant accident, Korean radiation experts have agreed that reliable data on health risks of low-dose radiation (LDR) are needed to ease the anxiety of lay people. The intent of this study was to devise a sustainable biological program suited for the research environment in Korea and aimed at the health effects of radiation exposures <100 millisieverts (mSv). To address pressing public concerns over LDR risk, we investigated the current understanding of LDR effects by analyzing the previous reports of international authorities for radiation protection and research publications that appeared after the Chernobyl accident. A research program appropriate for societal and scientific inclinations of Korea was then devised based on input from Korean radiation scientists. CONCLUSIONS: After review by our advisory committee, program priorities were set, calling for an agenda that focused on dose-response relationships in carcinogenesis, health span responses to lifestyle variations, and systemic metabolic changes. Our long-term biological research program may contribute scientific evidence to reduce the uncertainties of LDR health risks and help stakeholders formulate policies for radiation protection.


Assuntos
Exposição à Radiação/efeitos adversos , Proteção Radiológica , Medição de Risco , Humanos , Doses de Radiação , Pesquisa
15.
Ecotoxicol Environ Saf ; 157: 292-299, 2018 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-29627413

RESUMO

Inevitable exposure to ionizing radiation from natural and human-made sources has been increasing over time. After nuclear disasters, such as the Fukushima accident, the public concerns on health risk of radiation exposure because of radioactive contamination of the environment have increased. However, it is very difficult to assess the biological effects of exposure caused by environmental radiation. A reliable and rapid bioassay to monitor the physiological effects of radiation exposure is therefore needed. Here, we quantitatively analyzed the changes in cell shape in Drosophila epidermis after irradiation as a model for biomonitoring of radiation. Interestingly, the number of irregularly shaped epithelial cells was increased by irradiation in a dose-dependent manner. A dose-response curve constructed with the obtained data suggests that the measurement of the number of irregular shaped cell in the epidermis is useful for the assessment of radiation dose. In addition, a comparison of the variation in the different samples and the data scored by different observers showed that our evaluation for cellular morphology was highly reliable and accurate and would, therefore, have immense practical application. Overall, our study suggests that detection of morphological changes in the epithelial cells is one of the efficient ways to quantify the levels of exposure to radioactive radiation from the environment.


Assuntos
Forma Celular/efeitos da radiação , Drosophila/efeitos da radiação , Células Epiteliais/efeitos da radiação , Exposição à Radiação/análise , Monitoramento de Radiação/métodos , Animais , Relação Dose-Resposta à Radiação , Drosophila/ultraestrutura , Células Epiteliais/ultraestrutura , Doses de Radiação , Radiação Ionizante
16.
Chem Soc Rev ; 47(6): 2145-2164, 2018 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-29411809

RESUMO

Silicon (Si) anode is among the most promising candidates for the next-generation high-capacity electrodes in Li-ion batteries owing to its unparalleled theoretical capacity (4200 mA h g-1 for Li4.4Si) that is approximately 10 times higher than that of commercialized graphitic anodes (372 mA h g-1 for LiC6). The battery community has witnessed substantial advances in research on new polymeric binders for silicon anodes mainly due to the shortcomings of conventional binders such as polyvinylidene difluoride (PVDF) to address problems caused by the massive volume change of Si (300%) upon (de)lithiation. Unlike conventional battery electrodes, polymeric binders have been shown to play an active role in silicon anodes to alleviate various capacity decay pathways. While the initial focus in binder research was primarily to maintain the electrode morphology, it has been recently shown that polymeric binders can in fact help to stabilize cracked Si microparticles along with the solid-electrolyte-interphase (SEI) layer, thus substantially improving the electrochemical performance. In this review article, we aim to provide an in-depth analysis and molecular-level design principles of polymeric binders for silicon anodes in terms of their chemical structure, superstructure, and supramolecular interactions to achieve good electrochemical performance. We further highlight that supramolecular chemistry offers practical tools to address challenging problems associated with emerging electrode materials in rechargeable batteries.

17.
PLoS One ; 13(1): e0190901, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29304080

RESUMO

A majority of patients with orofacial cleft deformity requires cleft repair through a bone graft. However, elevated amount of bone resorption and subsequent bone graft failure remains a significant clinical challenge. Bisphosphonates (BPs), a class of anti-resorptive drugs, may offer great promise in enhancing the clinical success of bone grafting. In this study, we compared the effects of systemic and local delivery of BPs in an intraoral bone graft model in rats. We randomly divided 34 female 20-week-old Fischer F344 Inbred rats into four groups to repair an intraoral critical-sized defect (CSD): (1) Control: CSD without graft (n = 4); (2) Graft/Saline: bone graft with systemic administration of saline 1 week post-operatively (n = 10); (3) Graft/Systemic: bone graft with systemic administration of zoledronic acid 1 week post-operatively (n = 10); and (4) Graft/Local: bone graft pre-treated with zoledronic acid (n = 10). At 6-weeks post-operatively, microCT volumetric analysis showed a significant increase in bone fraction volume (BV/TV) in the Graft/Systemic (62.99 ±14.31%) and Graft/Local (69.35 ±13.18%) groups compared to the Graft/Saline (39.18±10.18%). Similarly, histological analysis demonstrated a significant increase in bone volume in the Graft/Systemic (78.76 ±18.00%) and Graft/Local (89.95 ±4.93%) groups compared to the Graft/Saline (19.74±18.89%). The local delivery approach resulted in the clinical success of bone grafts, with reduced graft resorption and enhanced osteogenesis and bony integration with defect margins while avoiding the effects of BPs on peripheral osteoclastic function. In addition, local delivery of BPs may be superior to systemic delivery with its ease of procedure as it involves simple soaking of bone graft materials in BP solution prior to graft placement into the defect. This new approach may provide convenient and promising clinical applications towards effectively managing cleft patients.


Assuntos
Transplante Ósseo , Fissura Palatina/cirurgia , Difosfonatos/administração & dosagem , Animais , Fissura Palatina/tratamento farmacológico , Feminino , Osteoclastos/efeitos dos fármacos , Ratos , Ratos Endogâmicos F344 , Microtomografia por Raio-X
18.
Am J Physiol Lung Cell Mol Physiol ; 313(5): L916-L929, 2017 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-28798253

RESUMO

Radiation-induced pulmonary fibrosis (RIPF) is one of the most common side effects of lung cancer radiotherapy. This study was conducted to identify the molecular mechanism responsible for RIPF. We revealed that the transcriptional level of cytochrome P450 2E1 (CYP2E1) was elevated by examining expression profile analysis of RIPF mouse models. We also confirmed that CYP2E1 regulated levels of endoplasmic reticulum (ER) stress and reactive oxygen species (ROS) in alveolar epithelial type II (AE2) cells and lung fibroblasts. Inhibition of CYP2E1 via its siRNA or inhibitor significantly attenuated epithelial-to-mesenchymal transition and apoptosis of AE2 cells, as well as myofibroblast formation induced by radiation. Finally, the effects of a CYP2E1 inhibitor on development of RIPF were evaluated by in vivo studies. Taken together, the results of the present study suggest that CYP2E1 is an important mediator of RIPF development that functions by increasing cellular ER stress and ROS levels.


Assuntos
Citocromo P-450 CYP2E1/farmacologia , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Fibrose Pulmonar/tratamento farmacológico , Pneumonite por Radiação/tratamento farmacológico , Espécies Reativas de Oxigênio/metabolismo , Animais , Apoptose/efeitos dos fármacos , Retículo Endoplasmático/efeitos dos fármacos , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Humanos , Pulmão/metabolismo , Camundongos Endogâmicos C57BL , Estresse Oxidativo/efeitos dos fármacos
19.
Science ; 357(6348): 279-283, 2017 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-28729506

RESUMO

Lithium-ion batteries with ever-increasing energy densities are needed for batteries for advanced devices and all-electric vehicles. Silicon has been highlighted as a promising anode material because of its superior specific capacity. During repeated charge-discharge cycles, silicon undergoes huge volume changes. This limits cycle life via particle pulverization and an unstable electrode-electrolyte interface, especially when the particle sizes are in the micrometer range. We show that the incorporation of 5 weight % polyrotaxane to conventional polyacrylic acid binder imparts extraordinary elasticity to the polymer network originating from the ring sliding motion of polyrotaxane. This binder combination keeps even pulverized silicon particles coalesced without disintegration, enabling stable cycle life for silicon microparticle anodes at commercial-level areal capacities.

20.
PLoS One ; 12(2): e0171777, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28166286

RESUMO

Expert's risk evaluation of radiation exposure strongly influences the public's risk perception. Experts can inform laypersons of significant radiation information including health knowledge based on experimental data. However, some experts' radiation risk perception is often based on non-conclusive scientific evidence (i.e., radiation levels below 100 millisievert), which is currently under debate. Examining perception levels among experts is important for communication with the public since these individual's opinions have often exacerbated the public's confusion. We conducted a survey of Korean radiation researchers to investigate their perceptions of the risks associated with radiation exposure below 100 millisievert. A linear regression analysis revealed that having ≥ 11 years' research experience was a critical factor associated with radiation risk perception, which was inversely correlated with each other. Increased opportunities to understand radiation effects at < 100 millisievert could alter the public's risk perception of radiation exposure. In addition, radiation researchers conceived that more scientific evidence reducing the uncertainty for radiation effects < 100 millisievert is necessary for successful public communication. We concluded that sustained education addressing scientific findings is a critical attribute that will affect the risk perception of radiation exposure.


Assuntos
Exposição Ocupacional , Percepção , Vigilância em Saúde Pública , Doses de Radiação , Radiação , Pesquisadores/psicologia , Análise Fatorial , Humanos , Exposição Ocupacional/efeitos adversos , República da Coreia/epidemiologia , Medição de Risco , Inquéritos e Questionários
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