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1.
Chem Eng J ; 432: 134160, 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-34931115

RESUMO

Wearing surgical masks remains the most effective protective measure against COVID-19 before mass vaccination, but insufficient comfortability and low antibacterial/antiviral activities accelerate the replacement frequency of surgical masks, resulting in large amounts of medical waste. To solve this problem, we report new nanofiber membrane masks with outstanding comfortability and anti-pathogen functionality prepared using fluorinated carbon nanofibers/carbon fiber (F-CNFs/CF). This was used to replace commercial polypropylene (PP) nonwovens as the core layer of face masks. The through-plane and in-plane thermal conductivity of commercial PP nonwovens were only 0.12 and 0.20 W/m K, but the F-CNFs/CF nanofiber membranes reached 0.62 and 5.23 W/m K, which represent enhancements of 380% and 2523%, respectively. The surface temperature of the PP surgical masks was 23.9 ℃ when the wearing time was 15 min, while the F-CNFs/CF nanocomposite fibrous masks reached 27.3 ℃, displaying stronger heat dissipation. Moreover, the F-CNFs/CF nanofiber membranes displayed excellent electrical conductivity and produced a high-temperature layer that killed viruses and bacteria in the masks. The surface temperature of the F-CNFs/CF nanocomposite fibrous masks reached 69.2 ℃ after being connected to a portable power source for 60 s. Their antibacterial rates were 97.9% and 98.6% against E. coli and S. aureus, respectively, after being connected to a portable power source for 30 min.

2.
Cellulose (Lond) ; 29(10): 5711-5724, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35615225

RESUMO

The surgical masks have been essential consumables for public in the COVID-19 pandemic. However, long-time wearing masks will make wearers feel uncomfortable and massive discarded non-biodegradable masks lead to a heavy burden on our environment. In this paper, we adopt degradable chitosan@silver (CS@Ag) core-shell fibers and plant fibers to prepare an eco-friendly mask with excellent thermal comfort, self-sterilization, and antiviral effects. The thermal network of CS@Ag core-shell fibers highly improves the in-plane thermal conductivity of masks, which is 4.45 times higher than that of commercial masks. Because of the electrical conductivity of Ag, the fabricated mask can be electrically heated to warm the wearer in a cold environment and disinfect COVID-19 facilely at room temperature. Meanwhile, the in-situ reduced silver nanoparticles (AgNPs) endow the mask with superior antibacterial properties. Therefore, this mask shows a great potential to address the urgent need for a thermally comfortable, antibacterial, antiviral, and eco-friendly mask. Supplementary Information: The online version contains supplementary material available at 10.1007/s10570-022-04582-x.

3.
Metab Eng ; 66: 167-178, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33865980

RESUMO

Over 359 million tons of plastics were produced worldwide in 2018, with significant growth expected in the near future, resulting in the global challenge of end-of-life management. The recent identification of enzymes that degrade plastics previously considered non-biodegradable opens up opportunities to steer the plastic recycling industry into the realm of biotechnology. Here, the sequential conversion of post-consumer polyethylene terephthalate (PET) into two types of bioplastics is presented: a medium chain-length polyhydroxyalkanoate (PHA) and a novel bio-based poly(amide urethane) (bio-PU). PET films are hydrolyzed by a thermostable polyester hydrolase yielding highly pure terephthalate and ethylene glycol. The obtained hydrolysate is used directly as a feedstock for a terephthalate-degrading Pseudomonas umsongensis GO16, also evolved to efficiently metabolize ethylene glycol, to produce PHA. The strain is further modified to secrete hydroxyalkanoyloxy-alkanoates (HAAs), which are used as monomers for the chemo-catalytic synthesis of bio-PU. In short, a novel value-chain for PET upcycling is shown that circumvents the costly purification of PET monomers, adding technological flexibility to the global challenge of end-of-life management of plastics.


Assuntos
Polietilenotereftalatos , Pseudomonas , Hidrolases , Plásticos
4.
Int J Mol Sci ; 20(14)2019 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-31315221

RESUMO

Many reports have shown that grains play an important role in our daily lives and can provide energy and nutrients to protect us from various diseases, and they are considered to be indispensable parts of our lives. It has been reported that some constituents in grains could exert functional effects against HIV infections and multiple cancers. Zymolytic grain can produce some new useful molecules and thus support the cell nutrients in the human body. In this study, the effects of zymolytic grain extract (ZGE) supernatants on the changes of nematode indicators were investigated, including lifespan, self-brood size, and body length in environmental conditions (temperature, ultraviolet radiation or 5-fluoro-2'-deoxyuridine (FUDR) stimuli). We found that, compared to the control group, the ZGE supernatant-feeding group could prolong the lifespan of nematodes under normal conditions. More importantly, ZGE supernatants could improve the ability of nematodes to resist stress. When the concentration of FUDR was 400 or 50 µM, the ZGE supernatant-feeding group could prolong lifespan by an average of 38.4% compared to the control group, and the eggs of the ZGE supernatant-feeding group could hatch and develop into adults. These results indicated that ZGE could protect C. elegans from external stress and thus prolong their lifespan and improve the physiological state of nematodes. Therefore, ZGE supernatant has potential to be used as a nutritional product in antioxidant and anti-aging research.


Assuntos
Grão Comestível/química , Longevidade/efeitos dos fármacos , Tolerância a Radiação/efeitos dos fármacos , Estresse Fisiológico/efeitos dos fármacos , Animais , Caenorhabditis elegans , Extratos Vegetais/farmacologia , Raios Ultravioleta
5.
Molecules ; 24(3)2019 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-30678284

RESUMO

In this study, Candida rugosa lipase (CRL) was immobilized into modified hollow mesoporous silica (HMSS) materials with different hydrophobicity. Among propyl-(C3), phenyl-(C6), octyl-(C8), and octadecyl-(C18) modified HMSS as well as native HMSS, taking advantage of more hydrophobic microenvironment, the HMSS-C18-CRL showed exceptional performance in enzymatic esterification reaction. Using the novel HMSS-C18 with immobilized CRL (HMSS-C18-CRL), we investigated the esterification of phytosterols with polyunsaturated fat acid (PUFA) in a solvent-free system for the production of phytosterols esters. Response surface methodology (RSM) was applied to model and optimize the reaction conditions, namely, the enzyme load (5⁻25%), reaction time (10⁻110 min), molar ratio of α-linolenic acid (ALA)/phytosterols (1:1⁻7:1) and represented by the letters E, T, and M respectively. Best-fitting models were successfully established by multiple regressions with backward elimination. The optimum production was achieved at 70 min for reaction time, 20% based on the weight of substrate for enzyme loading, and 5.6:1 for ALA/phytosterols molar ratio. Under optimized conditions, a conversion of about 90 ± 2% was achieved. These results indicated that HMSS-C18-CRL demonstrates to be a promising catalyst and can be potentially applied in the functional lipid production.


Assuntos
Enzimas Imobilizadas , Ésteres/síntese química , Lipase/química , Dióxido de Silício/química , Análise de Variância , Biocatálise , Ativação Enzimática , Estabilidade Enzimática , Proteínas Fúngicas , Interações Hidrofóbicas e Hidrofílicas , Porosidade , Espectroscopia de Infravermelho com Transformada de Fourier , Especificidade por Substrato
6.
Genome ; 61(1): 15-20, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28961406

RESUMO

Physalis L., an important genus of the family Solanaceae, includes many commercially important edible and medicinal species. Traditionally, species identification is based on morphological traits; however, the highly similar morphological traits among species of Physalis make this approach difficult. In this study, we evaluated the feasibility of using a popular DNA barcode, the chloroplast psbA-trnH intergenic region, in the identification of species of Physalis. Thirty-six psbA-trnH regions of species of Physalis and of the closely related plant Nicandra physalodes were analyzed. The success rates of PCR amplification and sequencing of the psbA-trnH region were 100%. MEGA V6.0 was utilized to align the psbA-trnH sequences and to compute genetic distances. The results show an apparent barcoding gap between intra- and interspecific variations. Results of both BLAST1 and nearest-distance methods prove that the psbA-trnH regions can be used to identify all species examined in the present study. In addition, phylogenetic analysis using psbA-trnH data revealed a distinct boundary between species. It also confirmed the relationship between species of Physalis and closely related species, as established by previous studies. In conclusion, the psbA-trnH intergenic region can be used as an efficient DNA barcode for the identification of species of Physalis.


Assuntos
Código de Barras de DNA Taxonômico , DNA Intergênico/química , Genes de Cloroplastos , Physalis/classificação , Physalis/genética , DNA de Plantas/química , Variação Genética , Complexo de Proteína do Fotossistema II/genética , Physalis/anatomia & histologia , Reação em Cadeia da Polimerase
7.
Sensors (Basel) ; 17(11)2017 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-29137159

RESUMO

As a new machine learning approach, the extreme learning machine (ELM) has received much attention due to its good performance. However, when directly applied to hyperspectral image (HSI) classification, the recognition rate is low. This is because ELM does not use spatial information, which is very important for HSI classification. In view of this, this paper proposes a new framework for the spectral-spatial classification of HSI by combining ELM with loopy belief propagation (LBP). The original ELM is linear, and the nonlinear ELMs (or Kernel ELMs) are an improvement of linear ELM (LELM). However, based on lots of experiments and much analysis, it is found that the LELM is a better choice than nonlinear ELM for the spectral-spatial classification of HSI. Furthermore, we exploit the marginal probability distribution that uses the whole information in the HSI and learns such a distribution using the LBP. The proposed method not only maintains the fast speed of ELM, but also greatly improves the accuracy of classification. The experimental results in the well-known HSI data sets, Indian Pines, and Pavia University, demonstrate the good performance of the proposed method.

8.
J Nanosci Nanotechnol ; 15(2): 1261-8, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26353642

RESUMO

In the work, a novel multifunctional silica-based nanoplatform (Pd@Ag@SiO2(RITC)-R8) for bioimaging and photothermal therapy (PTT) of cancer cells has been developed. The Pd@Ag nanosheets encapsulated inside silica can act as effective near-infrared (NIR) absorbers for cancer photothermal therapy. Fluorescent dye, rhodamine B isothiocyanate (RITC), was covalently doped into the silica network to provide the capacity for optical imaging. After amine modification, the Pd@Ag@SiO2(RITC)-NH2 can be further conjugated with octaarginine (R8, a cell penetrating peptide) for enhancing the uptake of nanoparticles by cells. Confocal fluorescent images and flow cytometry analysis revealed that R8-conjugated nanoparticles (Pd@Ag@SiO2(RITC)-R8) were taken up by cells more efficiently. Correspondingly, the optical imaging and photothermal therapeutic efficiency of Pd@Ag@SiO2(RITC)-R8 upon cancer cells were also raised due to their higher cellular uptake when compared with that of Pd@Ag@SiO2(RITC)-NH2. Our results indicate that these multifunctional Pd@Ag@SiO2(RITC)-R8 may have great potential for applications in imaging-guided cancer photothermal therapy.


Assuntos
Nanopartículas Metálicas/uso terapêutico , Microscopia de Fluorescência/métodos , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/patologia , Fotoquimioterapia/métodos , Sobrevivência Celular/efeitos dos fármacos , Corantes Fluorescentes/química , Ouro/uso terapêutico , Células HeLa , Humanos , Hipertermia Induzida/métodos , Teste de Materiais , Oligopeptídeos/química , Oligopeptídeos/farmacocinética , Tamanho da Partícula , Radiossensibilizantes/química , Radiossensibilizantes/uso terapêutico , Rodaminas/química , Dióxido de Silício/química , Prata/uso terapêutico , Resultado do Tratamento
9.
Int J Mol Sci ; 16(9): 21975-88, 2015 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-26378526

RESUMO

The over-collection and habitat destruction of natural Dendrobium populations for their commercial medicinal value has led to these plants being under severe threat of extinction. In addition, many Dendrobium plants are similarly shaped and easily confused during the absence of flowering stages. In the present study, we examined the application of the ITS2 region in barcoding and phylogenetic analyses of Dendrobium species (Orchidaceae). For barcoding, ITS2 regions of 43 samples in Dendrobium were amplified. In combination with sequences from GenBank, the sequences were aligned using Clustal W and genetic distances were computed using MEGA V5.1. The success rate of PCR amplification and sequencing was 100%. There was a significant divergence between the inter- and intra-specific genetic distances of ITS2 regions, while the presence of a barcoding gap was obvious. Based on the BLAST1, nearest distance and TaxonGAP methods, our results showed that the ITS2 regions could successfully identify the species of most Dendrobium samples examined; Second, we used ITS2 as a DNA marker to infer phylogenetic relationships of 64 Dendrobium species. The results showed that cluster analysis using the ITS2 region mainly supported the relationship between the species of Dendrobium established by traditional morphological methods and many previous molecular analyses. To sum up, the ITS2 region can not only be used as an efficient barcode to identify Dendrobium species, but also has the potential to contribute to the phylogenetic analysis of the genus Dendrobium.


Assuntos
Código de Barras de DNA Taxonômico , DNA Intergênico , DNA de Plantas , Dendrobium/classificação , Dendrobium/genética , Filogenia , Variação Genética
11.
IEEE Trans Cybern ; 53(10): 6649-6662, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36395126

RESUMO

Spatial-spectral classification (SSC) has become a trend for hyperspectral image (HSI) classification. However, most SSC methods mainly consider local information, so that some correlations may not be effectively discovered when they appear in regions that are not contiguous. Although many SSC methods can acquire spatial-contextual characteristics via spatial filtering, they lack the ability to consider correlations in non-Euclidean spaces. To address the aforementioned issues, we develop a new semisupervised HSI classification approach based on normalized spectral clustering with kernel-based learning (NSCKL), which can aggregate local-to-global correlations to achieve a distinguishable embedding to improve HSI classification performance. In this work, we propose a normalized spectral clustering (NSC) scheme that can learn new features under a manifold assumption. Specifically, we first design a kernel-based iterative filter (KIF) to establish vertices of the undirected graph, aiming to assign initial connections to the nodes associated with pixels. The NSC first gathers local correlations in the Euclidean space and then captures global correlations in the manifold. Even though homogeneous pixels are distributed in noncontiguous regions, our NSC can still aggregate correlations to generate new (clustered) features. Finally, the clustered features and a kernel-based extreme learning machine (KELM) are employed to achieve the semisupervised classification. The effectiveness of our NSCKL is evaluated by using several HSIs. When compared with other state-of-the-art (SOTA) classification approaches, our newly proposed NSCKL demonstrates very competitive performance. The codes will be available at https://github.com/yuanchaosu/TCYB-nsckl.

12.
Cancers (Basel) ; 15(2)2023 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-36672495

RESUMO

Ferroptosis exhibits a potent antitumor effect and dihydroorotate dehydrogenase (DHODH) has recently been identified as a novel ferroptosis defender. However, the role of DHODH inhibition in cervical cancer cells is unclear, particularly in synergy with cisplatin via ferroptosis. Herein, shRNA and brequinar were used to knock down DHODH and directly inhibit DHODH, respectively. Immunohistochemistry and Western blotting assays were performed to measure the expression of proteins. CCK-8 and colony formation assays were employed to assess the cell viability and proliferation. Ferroptosis was monitored through flow cytometry, the malondialdehyde assay kit and JC-1 staining analyses. The nude mouse xenograft model was generated to examine the effect of combination of DHODH inhibition and cisplatin on tumor growth in vivo. The expression of DHODH was increased in cervical cancer tissues. DHODH inhibition inhibited the proliferation and promoted the ferroptosis in cervical cancer cells. A combination of DHODH inhibition and cisplatin synergistically induced both in vitro and in vivo ferroptosis and downregulated the ferroptosis defender mTOR pathway. Therefore, the combination of DHODH inhibition and cisplatin exhibits synergistic effects on ferroptosis induction via inhibiting the mTOR pathway could provide a promising way for cervical cancer therapy.

13.
Cancers (Basel) ; 15(6)2023 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-36980687

RESUMO

A significant burden is placed on the lives of females due to cervical cancer, which is currently the leading cause of cancer death among women. Preferentially expressed antigen in melanoma (PRAME) belongs to the CTA gene family and was found to be abnormally expressed among different types of cancers. Our previous research also indicated that PRAME was highly expressed in cervical cancer compared with normal tissues. However, the roles and detailed mechanisms of PRAME have not been explored in cervical cancer. In the present study, the expression of PRAME in cervical tissues and cells was detected by immunohistochemistry (IHC), qRT-PCR, and Western blotting. Additionally, CCK-8, BrdU, scratch, transwell, and flow cytometry assays were conducted to explore the function of PRAME in regulating the malignant biological behaviors of cervical cancer cells. Nude mice were used to confirm the role of PRAME in tumor growth in vivo. Furthermore, the Wnt inhibitor MSAB was used to verify the role of PRAME in regulating the Wnt/ß-catenin pathway both in vitro and in vivo. The results of IHC, qRT-PCR, and Western blotting showed that PRAME was highly expressed in cervical cancer tissues and cells. PRAME knockdown attenuated cell growth, migration, and invasion; induced G0/G1 arrest; and increased cell apoptosis in C33A and SiHa cells through Wnt/ß-catenin signaling regulation. However, the upregulation of PRAME exhibited the opposite effects accordingly, which could be partly reversed via MSAB treatment. The growth rate of xenograft tumors was enhanced when PRAME was overexpressed via Wnt/ß-catenin signaling activation. Taken together, PRAME is associated with cervical cancer occurrence and progression mediated by Wnt/ß-catenin signaling, suggesting that PRAME might be a factor in manipulating cervical carcinogenesis and a potential therapeutic target.

14.
J Invest Dermatol ; 143(1): 26-36.e8, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-35940223

RESUMO

Skin photoaging is a complicated pathological process and is mainly due to UV irradiation, especially UVB irradiation. Damage induction by UVB is a complex process, involving intricate molecular mechanisms. The formation of bulky photoproducts in the DNA globally affects transcription and splicing and results in the dysfunction of keratinocytes. In this study, we show that δ-catenin is predominantly distributed in keratinocytes of the skin epidermis and functionally accelerates cell proliferation and DNA repair. Ex vivo protein profiling reveals that δ-catenin upregulates the phosphorylation of RSK2Ser-227 by enhancing the interaction between PDK1 and RSK2 and thereby induces the nuclear accumulation of YB1 to promote proliferation and DNA repair. Moreover, δ-catenin overexpression induces in vivo keratinocyte proliferation and DNA repair in UVB-irradiated mouse skin. Notably, acidic fibroblast GF/FGFR1 is identified as one of the key upstream signalings of δ-catenin by inducing δ-catenin stabilization. The involvement of δ-catenin in keratinocyte proliferation and DNA repair may suggest δ-catenin as a target for the treatment of UVB damage.


Assuntos
Envelhecimento da Pele , Camundongos , Animais , Envelhecimento da Pele/genética , delta Catenina , Queratinócitos/metabolismo , Raios Ultravioleta/efeitos adversos , Proliferação de Células/genética , Reparo do DNA , Dano ao DNA
15.
Cell Death Dis ; 14(9): 624, 2023 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-37737256

RESUMO

Bromodomain-containing protein 4 (BRD4), the major component of bromodomain and extra-terminal domain (BET) protein family, has important functions in early embryonic development and cancer development. However, the posttranslational modification of BRD4 is not well understood. Multiple approaches were used to explore the mechanism of PRMT1-mediated BRD4 methylation and to determine the biological functions of BRD4 and PRMT1 in ovarian cancer. Here we report that BRD4 is asymmetrically methylated at R179/181/183 by PRMT1, which is antagonized by the Jumonji-family demethylase, JMJD6. PRMT1 is overexpressed in ovarian cancer tissue and is a potential marker for poor prognosis in ovarian cancer patients. Silencing of PRMT1 inhibited ovarian cancer proliferation, migration, and invasion in vivo and in vitro. PRMT1-mediated BRD4 methylation was found to promote BRD4 phosphorylation. Compared to BRD4 wild-type (WT) cells, BRD4 R179/181/183K mutant-expressing cells showed reduced ovarian cancer metastasis. BRD4 arginine methylation is also associated with TGF-ß signaling. Our results indicate that arginine methylation of BRD4 by PRMT1 is involved in ovarian cancer tumorigenesis. Targeting PRMT1-mediated arginine methylation may provide a novel diagnostic target and an effective therapeutic strategy for ovarian cancer treatment.


Assuntos
Proteínas Nucleares , Neoplasias Ovarianas , Gravidez , Humanos , Feminino , Fosforilação , Metilação , Proteínas Nucleares/genética , Neoplasias Ovarianas/genética , Fatores de Transcrição/genética , Processamento de Proteína Pós-Traducional , Metiltransferases , Arginina , Proteína-Arginina N-Metiltransferases/genética , Proteínas Repressoras , Histona Desmetilases com o Domínio Jumonji , Proteínas de Ciclo Celular
16.
Global Spine J ; 13(3): 630-635, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33896208

RESUMO

STUDY DESIGN: Retrospective study. OBJECTIVE: Lumbar magnetic resonance imaging (MRI) findings are believed to be associated with low back pain (LBP). This study sought to develop a new predictive classification system for low back pain. METHOD: Normal subjects with repeated lumbar MRI scans were retrospectively enrolled. A new classification system, based on the radiological features on MRI, was developed using an unsupervised clustering method. RESULTS: One hundred and fifty-nine subjects were included. Three distinguishable clusters were identified with unsupervised clustering that were significantly correlated with LBP (P = .017). The incidence of LBP was highest in cluster 3 (57.14%), nearly twice the incidence in cluster 1 (30.11%). There were obvious differences in the sagittal parameters among the 3 clusters. Cluster 3 had the smallest intervertebral height. Based on follow-up findings, 27% of subjects changed clusters. More subjects changed from cluster 1 to clusters 2 or 3 (14.5%) than changed from cluster 2 or cluster 3 to cluster 1 (5%). Participation in sport was more frequent in subjects who changed from cluster 3 to cluster 1. CONCLUSION: Using an unsupervised clustering method, we developed a new classification system comprising 3 clusters, which were significantly correlated with LBP. The prediction of LBP is independent of age and better than that based on individual sagittal parameters derived from MRI. A change in cluster during follow-up may partially predict lumbar degeneration. This study provides a new system for the prediction of LBP that should be useful for its diagnosis and treatment.

17.
J Mater Chem B ; 11(33): 7950-7960, 2023 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-37491975

RESUMO

Membrane fouling induces catastrophic loss of separation performance and seriously restricts the applications of reverse osmosis (RO) membranes. Inspired by the mussel structure, polydopamine (PDA) and cystamine molecules (CA) with excellent anti-fouling properties were used to prepare accessible, biocompatible, and redox-responsive coatings for RO membranes. The PDA/CA-coated RO membranes exhibit a superior water flux of 65 L m-2 h-1 with a favourable NaCl rejection exceeding 99%. The water permeability through the PDA/CA-coated membrane is much higher than that of most membranes with similar rejection rates. Due to the formed protective hydration layers by PDA/CA coatings, anti-fouling properties against proteins, polysaccharides and surfactants were evaluated separately, and ultralow fouling properties were demonstrated. Moreover, the disulfide linkages in CA molecules can cleave in a reducing environment, yielding the degradation of PDA/CA coatings, thereby removing the foulants deposited on the coatings. The degradation endows the coated membranes with satisfying longtime anti-fouling properties, where the flux recovery reaches up to 90%. The construction of redox-responsive smart coatings not only provided a promising route to alleviate membrane fouling but can also be upscaled for use in numerous practical applications like sensors, medical devices, and drug delivery.


Assuntos
Biomimética , Filtração , Osmose , Água/química , Oxirredução
18.
Nat Commun ; 14(1): 501, 2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36720860

RESUMO

Electrocatalytic reduction of carbon monoxide into fuels or chemicals with two or more carbons is very attractive due to their high energy density and economic value. Herein we demonstrate the synthesis of a hydrophobic Cu/Cu2O sheet catalyst with hydrophobic n-butylamine layer and its application in CO electroreduction. The CO reduction on this catalyst produces two or more carbon products with a Faradaic efficiency of 93.5% and partial current density of 151 mA cm-2 at the potential of -0.70 V versus a reversible hydrogen electrode. A Faradaic efficiency of 68.8% and partial current density of 111 mA cm-2 for ethanol were reached, which is very high in comparison to all previous reports of CO2/CO electroreduction with a total current density higher than 10 mA cm-2. The as-prepared catalyst also showed impressive stability that the activity and selectivity for two or more carbon products could remain even after 100 operating hours. This work opens a way for efficient electrocatalytic conversion of CO2/CO to liquid fuels.

19.
Eur J Med Chem ; 254: 115348, 2023 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-37060755

RESUMO

The increase in antibiotic resistance has made it particularly urgent to develop new antibiotics with novel antibacterial mechanisms. Inhibition of bacterial cell division by disrupting filamentous temperature-sensitive mutant Z (FtsZ) function is an effective and promising approach. A series of novel fascaplysin derivatives with tunable hydrophobicity were designed and synthesized here. The in vitro bioactivity assessment revealed that these compounds could inhibit the tested Gram-positive bacteria including methicillin-resistant S. aureus (MRSA) (MIC = 0.049-25 µg/mL), B. subtilis (MIC = 0.024-12.5 µg/mL) and S. pneumoniae (MIC = 0.049-50 µg/mL). Among them, compounds B3 (MIC = 0.098 µg/mL), B6 (MIC = 0.098 µg/mL), B8 (MIC = 0.049 µg/mL) and B16 (MIC = 0.098 µg/mL) showed the best bactericidal activities against MRSA and no significant tendency to trigger bacterial resistance as well as rapid bactericidal properties. The cell surface integrity of bacteria was significantly disrupted by hydrophobic tails of fascaplysin derivatives. Further studies revealed that these highly active amphiphilic compounds showed low hemolytic activity and cytotoxicity to mammalian cells. Preliminary mechanistic exploration suggests that B3, B6, B8 and B16 are potent FtsZ inhibitors to promote FtsZ polymerization and inhibit GTPase activity of FtsZ, leading to the death of bacterial cells by inhibiting bacterial division. Molecular docking simulations and structure-activity relationship (SAR) study reveal that appropriate increase in the hydrophobicity of fascaplysin derivatives and the addition of additional hydrogen bonds facilitated their binding to FtsZ proteins. These amphiphilic fascaplysin derivatives could serve as a novel class of FtsZ inhibitors, which not only gives new prospects for the application of compounds containing this skeleton but also provides new ideas for the discovery of new antibiotics.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Animais , Estrutura Molecular , Simulação de Acoplamento Molecular , Testes de Sensibilidade Microbiana , Antibacterianos/química , Proteínas de Bactérias , Mamíferos
20.
Front Genet ; 13: 844684, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35795205

RESUMO

Background: Uterine leiomyomas (ULs) is the most common gynecological benign tumor in women. Our previous study showed that the phenomenon of vitamin D deficiency existed in patients with ULs. However, the association of vitamin D anabolism-related gene polymorphisms and susceptibility to ULs was unclear. Methods: Vitamin D anabolism-related gene polymorphisms in 110 patients with ULs and 110 healthy controls were detected by sequencing and the differences of the 92 SNPs were analyzed in the two groups via chi-square test. To verify the association between the significantly different SNPs and the risk of ULs, the SNPs were genotyped in another 340 patients and 340 healthy controls. Additionally, an unconditional logistic regression model was conducted to calculate the odds ratio (OR) of ULs occurrence and the 95% confidence interval (CI), adjusting for age and BMI. Findings: In sequencing samples, there were differences in DHCR7 rs1044482 C > T (p = 0.008) and NADSYN1 rs2276360 G > C (p = 0.025) between patients with ULs and healthy controls. DHCR7 rs1044482 was related to the susceptibility to ULs in validation samples (heterogeneous: adjusted OR = 1.967, p = 0.002; homogenous: adjusted OR = 2.494, p = 0.002; additive: adjusted OR = 1.485, p < 0.041; and dominant: adjusted OR = 2.084, p < 0.001). Stratified analysis further showed that the DHCR7 rs1044482 polymorphisms were associated with ULs risks in women over 40 and with 18.5-25.0 BMI. In contrast to the wild-type CG haplotype vectors, individuals with TC haplotypes had a higher risk of developing ULs. Interpretation: The vitamin D anabolism-related gene DHCR7 rs1044482 C > T polymorphism was a risk factor of ULs, especially in patients over 40 with 18.5-25.0 BMI, while the relationship between NADSYN1 rs2276360 and ULs risk was not clear.

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