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1.
J Am Chem Soc ; 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39353058

RESUMO

N-heterocyclic carbenes (NHCs) are recognized for their ability to stabilize various main group radicals; however, NHC-derived, sulfur-based radicals remain rare. In this study, we successfully synthesized and characterized a series of palladium diradical complexes that featured new sulfur-based radical ligands from NHC-carbon disulfide adducts. Spectroscopic and computational characterizations of the palladium complexes confirmed the open-shell singlet ground state, which resulted from the antiferromagnetic coupling of two unpaired electrons on each ligand. Proton nuclear magnetic resonance relaxometry was used to experimentally confirm the presence of these unpaired electrons. Moreover, the redox behavior of the complexes was localized on the ligand center, confirming the redox activity of the ligands. The discovery of this sulfur-based, redox-active radical ligand underscores the versatility and significance of NHC-derived radicals, thereby expanding the repertoire of radical ligands and opening new avenues for advanced material and catalytic systems.

2.
J Am Chem Soc ; 146(33): 22874-22880, 2024 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-39093360

RESUMO

A novel reactivity toward C-F bond functionalization has been developed, which could be designated as fluorine atom transfer (FAT). A photoexcited state of an N-heterocyclic carbene-ligated boryl radical exhibits a transcendent reactivity, capable of activating chemically inert carbon-fluorine bonds through homolysis. Combined experimental and computational studies suggest that the ligated boryl radical species directly abstracts a fluorine atom from the organofluoride substrates to provide valuable carbon-centered radicals.

3.
Microb Cell Fact ; 23(1): 290, 2024 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-39443949

RESUMO

BACKGROUND: Microalgae are potential sustainable resources for the production of value-added chemicals that can be used as biofuels, pharmaceuticals, and nutritional supplements. Arachidonic acid (ARA), a omega-6 fatty acid, plays a crucial role in infant development and immune response, and can be used in cosmetics and pharmaceuticals. Demand for industrial-scale ARA production is continuously increasing because of its broad applicability. To address this demand, there has been a significant shift towards microorganism-based ARA production. To accelerate large-scale ARA production, it is crucial to select suitable strains and establish optimal culture conditions. RESULTS: Here, we isolated a novel microalga Lobosphaera incisa CFRC-1, a valuable strain that holds promise as a feedstock for ARA production. Optimal cultivation conditions were investigated using a high-throughput screening method to enhance ARA production in this novel strain. Out of 71 candidates, four organic carbon substrates were identified that could be utilized by L. incisa CFRC-1. Through flask-scale verification, fructose was confirmed as the optimal organic carbon substrate for promoting microalgal growth, total lipid accumulation, and ARA production. Subsequently, we investigated appropriate substrate concentration and cultivation temperature, confirming that the optimal conditions were 30 g L- 1 of fructose and 27 ℃ of temperature. Under these optimized conditions, biomass and ARA production reached 13.05 ± 0.40 g L- 1 and 97.98 ± 7.33 mg L- 1, respectively, representing 9.6-fold and 5.3-fold increases compared to the conditions before optimization conditions. These results achieved the highest biomass and ARA production in flask-scale cultivation, indicating that our approach effectively improved both production titer and productivity. CONCLUSIONS: This study presents a novel microalgae and optimized conditions for enhancing biomass and ARA production, suggesting that this approach is a practical way to accelerate the production of valuable microalgae-based chemicals. These findings provide a basis for large-scale production of ARA-utilizing microalgae for industrial applications.


Assuntos
Ácido Araquidônico , Carbono , Microalgas , Microalgas/metabolismo , Microalgas/crescimento & desenvolvimento , Ácido Araquidônico/metabolismo , Ácido Araquidônico/biossíntese , Carbono/metabolismo , Biomassa , Ensaios de Triagem em Larga Escala/métodos , Biocombustíveis , Frutose/metabolismo
4.
J Med Internet Res ; 26: e57566, 2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-38978483

RESUMO

BACKGROUND: The adoption of immersive technology in simulation-based nursing education has grown significantly, offering a solution to resource limitations and enabling safe access to clinical environments. Despite its advantages, there are still diverse reports regarding the effectiveness of immersive technology. It is crucial to verify the effectiveness of immersive technology in nursing education to inform future educational programs. OBJECTIVE: This systematic review aimed to identify the contents of immersive technology-based education for undergraduate nursing students and evaluate the effectiveness of immersive technology compared to traditional teaching methods. METHODS: A literature search was performed using 4 databases: PubMed, CINAHL, Embase, and Web of Science; the latest search was completed on January 19, 2023. The inclusion criteria were as follows: participants were undergraduate nursing students; studies were published in Korean or English; designs included randomized controlled trials (RCTs) or nonrandomized studies; and interventions involved virtual reality (VR), augmented reality (AR), mixed reality, or extended reality. Quality assessment was conducted using Cochrane Risk-of-Bias Tool version 2 for RCTs and the Risk-of-Bias Assessment Tool for Nonrandomized Studies. The main outcomes of the included studies were classified according to the New World Kirkpatrick Model (NWKM), ranging from level 1 (reaction) to level 4 (results). Meta-analysis was conducted using RevMan 5.4 software, and subgroup analysis was conducted due to heterogeneity of the results of the meta-analysis. The Grading of Recommendations, Assessment, Development, and Evaluation approach was adopted for assessing certainty and synthesizing results of the relevant literature. RESULTS: A total of 23 studies were included, with participant numbers ranging from 33 to 289. Of these, 19 (82.6%) studies adopted VR to simulate various nursing scenarios, including disaster training, resuscitation, health assessments, and home health care; 4 (17.4%) studies used AR technologies; and 15 (65.2%) studies involved virtual patients in their scenarios. Based on the NWKM, the main outcome variables were classified as level 1 (usability and satisfaction), level 2 (knowledge, motivation, confidence, performance, attitude, and self-efficacy), and level 3 (clinical reasoning); level 4 outcomes were not found in the selected studies. Results of the subgroup analysis showed that immersive technology-based nursing education is more effective than traditional education in knowledge attainment (standard mean difference [SMD]=0.59, 95% CI 0.28-0.90, P<.001, I2=49%). Additionally, there were significant difference differences between the experimental and control group in confidence (SMD=0.70, 95% CI 0.05-1.35, P=.03, I2=82%) and self-efficacy (SMD=0.86, 95% CI 0.42-1.30, P<.001, I2=63%). CONCLUSIONS: These findings support the effectiveness of immersive technology-based education for undergraduate nursing students, despite heterogeneity in methods and interventions. We suggest that long-term cohort studies be conducted to evaluate the effects of immersive technology-based nursing education on NWKM level 4.


Assuntos
Estudantes de Enfermagem , Humanos , Bacharelado em Enfermagem/métodos , Realidade Virtual
5.
Curr Issues Mol Biol ; 45(8): 6583-6592, 2023 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-37623234

RESUMO

Hyperosmotic stress caused by tear hyposection is a leading cause of dry eye disease. We investigated the prevention of dry eye disease in corneal epithelial cells and in rats that were induced to develop dry eye disease via unilateral excision of their exorbital lacrimal gland using Sargassum horneri extract (AB_SH) and its bioactive component fucoidan. Oral administration of AB_SH (250 mg/kg and 500 mg/kg) and fucoidan (100 mg/kg) was conducted for 7 days. In order to measure tear secretion, phenol red thread tear tests were performed along with corneal irregularity measurements. The apoptotic injury in the cornea and the lacrimal gland was evaluated using TUNEL staining. AB_SH and fucoidan were shown to suppress apoptosis and the expression of apoptosis-related proteins in human corneal epithelial cells under hyperosmotic conditions. Oral administration of AB_SH and fucoidan attenuated tear hyposecretion and corneal irregularity in the lacrimal gland-excised rats. In addition, AB_SH and fucoidan also reduced apoptosis in the cornea and lacrimal gland. This study suggests that S. horneri extract and fucoidan can effectively ameliorate dry eye disease by suppressing the apoptosis of ocular tissues.

6.
Int J Mol Sci ; 24(10)2023 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-37240055

RESUMO

In cystic fibrosis (CF), pulmonary infection with Pseudomonas aeruginosa is a cause of increased morbidity and mortality, especially in patients for whom infection becomes chronic and there is reliance on long-term suppressive therapies. Current antimicrobials, though varied mechanistically and by mode of delivery, are inadequate not only due to their failure to eradicate infection but also because they do not halt the progression of lung function decline over time. One of the reasons for this failure is thought to be the biofilm mode of growth of P. aeruginosa, wherein self-secreted exopolysaccharides (EPSs) provide physical protection against antibiotics and an array of niches with resulting metabolic and phenotypic heterogeneity. The three biofilm-associated EPSs secreted by P. aeruginosa (alginate, Psl, and Pel) are each under investigation and are being exploited in ways that potentiate antibiotics. In this review, we describe the development and structure of P. aeruginosa biofilms before examining each EPS as a potential therapeutic target for combating pulmonary infection with P. aeruginosa in CF, with a particular focus on the current evidence for these emerging therapies and barriers to bringing these therapies into clinic.


Assuntos
Fibrose Cística , Infecções por Pseudomonas , Humanos , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Antibacterianos/metabolismo , Pseudomonas aeruginosa/metabolismo , Fibrose Cística/tratamento farmacológico , Alginatos/metabolismo , Biofilmes , Adjuvantes Imunológicos/uso terapêutico , Adjuvantes Farmacêuticos/uso terapêutico , Pulmão , Infecções por Pseudomonas/tratamento farmacológico
7.
Curr Issues Mol Biol ; 44(12): 5986-5994, 2022 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-36547068

RESUMO

Esculetin is an antioxidant and anti-inflammatory compound derived from coumarin. Oxidative stress can cause overproduction of reactive oxygen species (ROS), which can lead to the development of chronic kidney failure. In this study, human embryonic kidney 293 (HEK293) cells were treated with tert-butyl hydroperoxide (t-BHP) to determine the antioxidant effects of esculetin. HEK293 cells were treated with t-BHP to validate changes in cell viability, ROS production, and apoptosis, and then treated with esculetin to evaluate the changes. Changes in mRNA and protein levels were analyzed using a proteome kit, PCR, and Western blotting. Esculetin improved HEK293 cell viability and reduced apoptosis caused by t-BHP-induced oxidative stress. At the mRNA and protein levels, esculetin decreased pro-apoptotic factor expression as well as increased anti-apoptotic factor expression. The antioxidant efficacy of esculetin was validated when it inhibited the apoptosis caused by t-BHP-induced oxidative stress in HEK293 cells.

8.
Environ Sci Technol ; 56(17): 12602-12612, 2022 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-35998306

RESUMO

Recent advances in electrochemical desalination techniques have paved way for utilization of saline water. In particular, capacitive deionization (CDI) enables removal of salts with high energy efficiency and economic feasibility, while its applicability has been challenged by degradation of carbon electrodes in long-term operations. Herein, we report a thorough investigation on the surface electrochemistry of carbon electrodes and Faradaic reactions that are responsible for stability issues of CDI systems. By using bare and membrane CDI (MCDI) as model systems, we identified various electrochemical reactions of carbon electrodes with water or oxygen, with thermodynamics and kinetics governed by the electrode potential and pH. As a result, a complete overview of the Faradaic reactions taking place in CDI was constructed by tracing the physicochemical changes occurring in CDI and MCDI systems.


Assuntos
Carbono , Purificação da Água , Eletroquímica , Eletrodos , Cloreto de Sódio , Purificação da Água/métodos
9.
Mar Drugs ; 20(5)2022 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-35621932

RESUMO

Two new pyrrolosesquiterpenes, glaciapyrroles D (1) and E (2) were discovered along with the previously reported glaciapyrrole A (3) from Streptomyces sp. GGS53 strain isolated from deep-sea sediment. This study elucidated the planar structures of 1 and 2 using nuclear magnetic resonance (NMR), mass spectrometry (MS), ultraviolet (UV), and infrared (IR) spectroscopic data. The absolute configurations of the glaciapyrroles were determined by Mosher's method, circular dichroism spectroscopy, and X-ray crystallography. Under 366 nm UV irradiation, the glaciapyrroles were systematically converted to the corresponding photoglaciapyrroles (4-6) via photoisomerization, resulting in the diversification of the glaciapyrrole family compounds. The transformation of the glaciapyrrole Z to E isomers occurred in a 1:1 ratio, based on virtual validation of the photoisomerization of these olefinic compounds by 1H-NMR spectroscopy and liquid chromatography/mass spectrometry (LC/MS) analysis. Finally, when encapsulated in poly(lactic-co-glycolic acid) nanoparticles, glaciapyrrole E and photoglaciapyrrole E displayed significant inhibitory activity against influenza A virus. This is the first report of antiviral effects from glaciapyrrole family compounds, whose biological functions have only been subjected to limited studies so far.


Assuntos
Streptomyces , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Streptomyces/química
10.
J Korean Med Sci ; 37(6): e45, 2022 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-35166081

RESUMO

BACKGROUND: The objective of this study was to investigate the trend of self-injurious behavior (SIB) among persons who were directly impacted by coronavirus disease 2019 (COVID-19), especially those with pre-existing mental disorders. METHODS: Using the National Health Insurance Service-COVID-19 database cohort, the monthly SIB rate was calculated by COVID-19 subgroups (i.e., positive for COVID-19 test, negative for COVID-19 test, and non-COVID-19 test [control]). In addition, moderated regression analysis was utilized to examine the statistical difference of SIB (suicide attempt and non-suicidal self-injury using ICD-10 code) trend between COVID-19 subgroups and with and without pre-existing mental disorder. RESULTS: A total of 328,373 persons were included in the cohort study. Of these, 212,678 had been tested for COVID-19, and 7,713 of them were confirmed positive. During the pandemic peak, the "negative for COVID-19" group showed a large increase (P = 0.003) in SIB rates compared to the control group, the "positive for COVID-19" group showed a decreasing trend, but not significant (P = 0.314). Among those who were tested for COVID-19, those with pre-existing mental disorders showed an increasing trend of SIB compared to those without pre-existing mental disorders, however statistically insignificant (P = 0.137). CONCLUSION: Our results suggest that people who are tested for COVID-19 are at a high risk of SIB during the peak COVID-19 pandemic. Therefore, screening for suicide risk and psychological interventions is needed for these high-risk groups.


Assuntos
COVID-19/epidemiologia , SARS-CoV-2 , Comportamento Autodestrutivo/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , COVID-19/psicologia , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
11.
Sensors (Basel) ; 22(7)2022 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-35408424

RESUMO

Despite the widespread application of Autonomous Vehicles (AV) to various services, there has been relatively little research carried out on pedestrian-AV interaction and trust within the context of service provided by AV. This study explores the communication design strategy promoting a pedestrian's trust and positive attitude to driverless services within the context of pedestrian-AV interaction using non-verbal social cues. An empirical study was conducted with an experimental VR environment to measure participants' intimacy, trust, and brand attitude toward AV. Further understanding of their social interaction experiences was explored through semi-structured interviews. As a result of the study, the interaction effect of social cues was found, and it was revealed that brand attitude was formed by the direct effects of intimacy and trust as well as the indirect effects of intimacy through trust's mediation. Furthermore, 'Conceptual Definition of Space' was identified to generate differences in the interplay among intimacy, trust, and brand attitude according to social cues. Quantitative and qualitative results were synthesized to discuss implications considering the service context. Practical implications were also addressed suggesting specific design strategies for utilizing the sociality of AV.


Assuntos
Pedestres , Confiança , Atitude , Sinais (Psicologia) , Humanos , Comportamento Social
12.
Molecules ; 28(1)2022 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-36615236

RESUMO

Screening of the antiviral and virucidal activities of ethanol extracts from plants endemic to the Republic of Korea revealed the inhibitory activity of a 70% ethanol extract of the whole plant of A. pseudoglehnii (APE) against influenza virus infection. Two chlorophyll derivatives, ethyl pheophorbides a and b, isolated as active components of APE, exerted virucidal effects with no evident cytotoxicity. These compounds were effective only under conditions of direct incubation with the virus, and exerted no effects on the influenza A virus (IAV) surface glycoproteins hemagglutinin (HA) and neuraminidase (NA). Interestingly, virucidal activities of ethyl pheophorbides a and b were observed against enveloped but not non-enveloped viruses, suggesting that these compounds act by affecting the integrity of the viral membrane and reducing infectivity.


Assuntos
Antivirais , Aster , Vírus da Influenza A , Animais , Antivirais/química , Antivirais/isolamento & purificação , Antivirais/farmacologia , Etanol/química , Glicoproteínas de Hemaglutininação de Vírus da Influenza , Vírus da Influenza A/efeitos dos fármacos , Neuraminidase , Aster/química , Cães , Células Madin Darby de Rim Canino
13.
Molecules ; 27(24)2022 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-36558102

RESUMO

Esculetin is a coumarin-derived compound with antioxidant and anti-inflammatory properties. The current study aims to evaluate the therapeutic implications of esculetin on retinal dysfunction and uncover the underlying mechanisms. Tert-butyl hydroperoxide (t-BHP) at a concentration of 300 µM was used to induce oxidative stress in human retinal pigment epithelial cell line (ARPE-19) cells. Esculetin at concentrations below 250 µM did not cause cytotoxicity to ARPE-19 cells. Cell viability analysis confirmed that t-BHP induced oxidative injury of ARPE-19 cells. However, ARPE-19 cells were protected from t-BHP-induced oxidative injury by esculetin in a concentration-dependent manner. As a result of the TUNEL assay to confirm apoptosis, esculetin treatment reduced the number of TUNEL-positive cells. Esculetin down-regulated the expression levels of Bax, Caspase-3, and PARP and up-regulated the expression level of Bcl2. Collectively, this study demonstrates that esculetin exerts potent antioxidant properties in ARPE-19 cells, inhibiting t-BHP-induced apoptosis under the regulation of apoptotic factors.


Assuntos
Antioxidantes , Estresse Oxidativo , Humanos , Antioxidantes/farmacologia , Antioxidantes/metabolismo , terc-Butil Hidroperóxido/metabolismo , Apoptose , Células Epiteliais/metabolismo , Pigmentos da Retina/metabolismo , Epitélio Pigmentado da Retina/metabolismo , Sobrevivência Celular
14.
Molecules ; 27(9)2022 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-35566278

RESUMO

Exposure to particulate matter is a causative factor of dry eye disease. We aimed to investigate the beneficial effect of eye drops containing aucubin on dry eye disease induced by urban particulate matter (UPM). Dry eye was induced in male SD rats (6 weeks old) by topical exposure to UPM thrice a day for 5 d. Eye drops containing 0.1% aucubin or 0.5% aucubin were topically administered directly into the eye after UPM exposure for an additional 5 d. Tear secretion was evaluated using a phenol red thread tear test and corneal irregularity. The oxidative damage in the lacrimal gland was evaluated using TUNEL and immunohistochemical staining. The topical administration of aucubin significantly attenuated UPM-induced tear hyposecretion (control group: 9.25 ± 0.62 mm, UPM group: 4.55 ± 0.25 mm, 0.1% aucubin: 7.12 ± 0.58 mm, and 0.5% aucubin: 7.88 ± 0.75 mm) and corneal irregularity (control group: 0.00 ± 0.00, UPM group: 3.40 ± 0.29, 0.1% aucubin: 1.80 ± 0.27, and 0.5% aucubin: 1.15 ± 0.27). In addition, aucubin also reduced the UPM-induced apoptotic injury of lacrimal gland cells induced by oxidative stress through the increased expression of HMGB1 and RAGE. These findings indicate that the topical administration of aucubin eye drops showed a beneficial effect against UPM-induced abnormal ocular changes, such as tear hyposecretion and lacrimal gland damage. Therefore, our results reveal the pharmacological activities of aucubin in dry eye disease.


Assuntos
Síndromes do Olho Seco , Aparelho Lacrimal , Animais , Modelos Animais de Doenças , Síndromes do Olho Seco/tratamento farmacológico , Glucosídeos Iridoides , Aparelho Lacrimal/metabolismo , Masculino , Soluções Oftálmicas/farmacologia , Material Particulado/efeitos adversos , Ratos , Ratos Sprague-Dawley
15.
Curr Issues Mol Biol ; 43(3): 2059-2067, 2021 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-34889900

RESUMO

A declined salivary gland function is commonly observed in elderly people. Advanced glycation end products (AGEs) are believed to contribute to the pathogenesis of aging. Although physical exercise is shown to increase various organ functions in human and experimental models, it is not known whether it has a similar effect in the salivary glands. In the present study, we evaluated the AGEs burden in the salivary gland in the aging process and the protective effect of physical exercise on age-related salivary hypofunction. To accelerate the aging process, rats were peritoneally injected with D-galactose for 6 weeks. Young control rats and d-galactose-induced aging rats in the old group were not exercised. The rats in the physical exercise group ran on a treadmill (12 m/min, 60 min/day, 3 days/week for 6 weeks). The results showed that the salivary flow rate and total protein levels in the saliva of the d-galactose-induced aging rats were reduced compared to those of the young control rats. Circulating AGEs in serum and secreted AGEs in saliva increased with d-galactose-induced aging. AGEs also accumulated in the salivary glands of these aging rats. The salivary gland of aging rats showed increased reactive oxygen species (ROS) generation, loss of acinar cells, and apoptosis compared to young control mice. However, physical exercise suppressed all of these age-related salivary changes. Overall, physical exercise could provide a beneficial option for age-related salivary hypofunction.


Assuntos
Envelhecimento/metabolismo , Galactose/metabolismo , Produtos Finais de Glicação Avançada/metabolismo , Glândulas Salivares/metabolismo , Animais , Biomarcadores , Produtos Finais de Glicação Avançada/sangue , Condicionamento Físico Animal , Ratos , Espécies Reativas de Oxigênio/metabolismo , Glândulas Salivares/patologia , Glândulas Salivares/fisiopatologia , Salivação
16.
Nat Mater ; 19(4): 436-442, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31932671

RESUMO

Despite the growing demand for hydrogen peroxide it is almost exclusively manufactured by the energy-intensive anthraquinone process. Alternatively, H2O2 can be produced electrochemically via the two-electron oxygen reduction reaction, although the performance of the state-of-the-art electrocatalysts is insufficient to meet the demands for industrialization. Interestingly, guided by first-principles calculations, we found that the catalytic properties of the Co-N4 moiety can be tailored by fine-tuning its surrounding atomic configuration to resemble the structure-dependent catalytic properties of metalloenzymes. Using this principle, we designed and synthesized a single-atom electrocatalyst that comprises an optimized Co-N4 moiety incorporated in nitrogen-doped graphene for H2O2 production and exhibits a kinetic current density of 2.8 mA cm-2 (at 0.65 V versus the reversible hydrogen electrode) and a mass activity of 155 A g-1 (at 0.65 V versus the reversible hydrogen electrode) with negligible activity loss over 110 hours.

17.
Microb Cell Fact ; 20(1): 43, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33588824

RESUMO

BACKGROUND: Nannochloropsis is a marine microalga that has been extensively studied. The major carotenoid produced by this group of microalgae is violaxanthin, which exhibits anti-inflammatory, anti-photoaging, and antiproliferative activities. Therefore, it has a wide range of potential applications. However, large-scale production of this pigment has not been much studied, thereby limiting its industrial application. RESULTS: To develop a novel strain producing high amount of violaxanthin, various Nannochloropsis species were isolated from seawater samples and their violaxanthin production potential were compared. Of the strains tested, N. oceanica WS-1 exhibited the highest violaxanthin productivity; to further enhance the violaxanthin yield of WS-1, we performed gamma-ray-mediated random mutagenesis followed by colorimetric screening. As a result, Mutant M1 was selected because of its significant higher violaxanthin content and biomass productivity than WS-1 (5.21 ± 0.33 mg g- 1 and 0.2101 g L- 1 d- 1, respectively). Subsequently, we employed a 10 L-scale bioreactor to confirm the large-scale production potential of M1, and the results indicated a 43.54 % increase in violaxanthin production compared with WS-1. In addition, comparative transcriptomic analysis performed under normal light condition identified possible mechanisms associated with remediating photo-inhibitory damage and other key responses in M1, which seemed to at least partially explain enhanced violaxanthin content and delayed growth. CONCLUSIONS: Nannochloropsis oceanica mutant (M1) with enhanced violaxanthin content was developed and its physiological characteristics were investigated. In addition, enhanced production of violaxanthin was demonstrated in the large-scale cultivation. Key transcriptomic responses that are seemingly associated with different physiological responses of M1 were elucidated under normal light condition, the details of which would guide ongoing efforts to further maximize the industrial potential of violaxanthin producing strains.


Assuntos
Biomassa , Mutação , Estramenópilas , Estramenópilas/genética , Estramenópilas/crescimento & desenvolvimento , Estramenópilas/isolamento & purificação , Xantofilas/metabolismo
18.
Microb Cell Fact ; 19(1): 97, 2020 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-32345276

RESUMO

BACKGROUND: For decades, plastic has been a valuable global product due to its convenience and low price. For example, polyethylene terephthalate (PET) was one of the most popular materials for disposable bottles due to its beneficial properties, namely impact resistance, high clarity, and light weight. Increasing demand of plastic resulted in indiscriminate disposal by consumers, causing severe accumulation of plastic wastes. Because of this, scientists have made great efforts to find a way to biologically treat plastic wastes. As a result, a novel plastic degradation enzyme, PETase, which can hydrolyze PET, was discovered in Ideonella sakaiensis 201-F6 in 2016. RESULTS: A green algae, Chlamydomonas reinhardtii, which produces PETase, was developed for this study. Two representative strains (C. reinhardtii CC-124 and CC-503) were examined, and we found that CC-124 could express PETase well. To verify the catalytic activity of PETase produced by C. reinhardtii, cell lysate of the transformant and PET samples were co-incubated at 30 °C for up to 4 weeks. After incubation, terephthalic acid (TPA), i.e. the fully-degraded form of PET, was detected by high performance liquid chromatography analysis. Additionally, morphological changes, such as holes and dents on the surface of PET film, were observed using scanning electron microscopy. CONCLUSIONS: A PET hydrolyzing enzyme, PETase, was successfully expressed in C. reinhardtii, and its catalytic activity was demonstrated. To the best of our knowledge, this is the first case of PETase expression in green algae.


Assuntos
Hidrolases/genética , Microalgas/enzimologia , Polietilenotereftalatos/metabolismo , Biocatálise , Hidrolases/metabolismo , Hidrólise , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Polietilenotereftalatos/química , Propriedades de Superfície
19.
Pak J Pharm Sci ; 33(1): 129-134, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32122840

RESUMO

EGHB010 is a standardized herbal formula of the rhizome mixture of Paeonia lactiflora Pallas and Glycyrrhiza uralensis Fisch. Neovascularization in the retina is a common pathophysiology of diabetic retinal microvasculopathy and exudative macular degeneration. In this study, we evaluated the inhibitory effects of EGHB010 on abnormal retinal angiogenesis in a hyperoxia-induced neovascular retinopathy model. Vascular endothelial growth factor (VEGF)-mediated vascular tube formation was assayed in human umbilical vascular endothelial cells (HUVECs). Experimental angiogenesis in the retinas was induced by exposing C57BL/6 pups to hyperoxic environment (75% oxygen) on postnatal day 7 (P7) and then returning them to normal oxygen pressure on P12. EGHB010 (50 and 100 mg/kg/day) was administered intraperitoneally for 5 days (P12 - P16). Retinal flat mounts were prepared to measure the extent of retinal neovascularization on P17. The incubation of HUVECs with EGHB010 (1-25 µg/mL) resulted in the inhibition of VEGF-mediated tube formation in a dose-dependent manner. EGHB010 at doses of 50 and 100 mg/kg/day inhibited the formation of retinal neovascular tufts by 31.15±2.28% and 59.83±2.92%, respectively. Together, our results indicate that EGHB010 is a potent anti-angiogenic agent and may have potential for the control of abnormal retinal vessel growth in patients with ischemic retinopathy.


Assuntos
Neovascularização Retiniana/prevenção & controle , Inibidores da Angiogênese/farmacologia , Animais , Animais Recém-Nascidos , Células Cultivadas , Relação Dose-Resposta a Droga , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/fisiologia , Humanos , Hiperóxia/fisiopatologia , Camundongos , Neovascularização Retiniana/fisiopatologia , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Fator A de Crescimento do Endotélio Vascular/farmacologia
20.
Alcohol Clin Exp Res ; 43(5): 842-849, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30779437

RESUMO

BACKGROUND: Previous studies have indicated that alcohol use disorder (AUD) and other psychiatric disorders increase the risk of suicide mortality. However, little research has investigated the concomitant effect of comorbid psychiatric disorders on suicide mortality. This study aimed to investigate the effect of comorbid AUD on suicide mortality of individuals with another psychiatric disorder using a national data sample. METHODS: We used the National Health Insurance Service-National Sample Cohort data from 2002 to 2013. We selected individuals with specific psychiatric disorders based on the International Classification of Diseases, 10th revision (F10-F48). Overall, the study included 741,601 participants. We utilized a prioritization process to identify the primary diagnosis for those with multiple diagnoses. All-cause mortality rates and suicide rates per 100,000 person-year (days) and the standardized mortality ratio (SMR) were calculated. Then, we compared the suicide-specific SMR of 3 different groups: (i) specific psychiatric disorder versus general public; (ii) specific psychiatric disorder comorbid with AUD versus general public; and (iii) specific psychiatric disorder comorbid with AUD versus specific psychiatric disorder without comorbid AUD. RESULTS: Patients with any specific psychiatric disorder showed higher suicide-specific SMR compared to the general population. Being comorbid with AUD further increased the risk of suicide among psychiatric patients. In particular, patients with bipolar affective disorders, organic mental disorders, or depressive disorders comorbid with AUD had about 2 to 4 times higher suicide-specific SMR compared to those without AUD (bipolar affective disorder: SMR = 3.01, 95% confidence interval (CI) [1.49, 4.54]; organic mental disorder: SMR = 3.43, 95% CI [1.05, 5.81]; depressive disorder: SMR = 2.06, 95% CI [1.52, 2.61]). CONCLUSIONS: Our data indicate that having a psychiatric disorder increases the risk of committing suicide. More importantly, comorbid AUD further increases this risk of suicidal death for certain psychiatric disorders. This shows the importance of determining whether patients with psychiatric disorders have comorbid AUD to prevent suicide.


Assuntos
Alcoolismo/mortalidade , Transtornos Mentais/mortalidade , Programas Nacionais de Saúde/tendências , Suicídio/tendências , Adulto , Alcoolismo/diagnóstico , Alcoolismo/psicologia , Estudos de Coortes , Comorbidade , Feminino , Seguimentos , Humanos , Masculino , Transtornos Mentais/diagnóstico , Transtornos Mentais/psicologia , Pessoa de Meia-Idade , Mortalidade/tendências , República da Coreia/epidemiologia , Suicídio/psicologia , Adulto Jovem
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