Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 79
Filtrar
1.
J Hazard Mater ; 474: 134808, 2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-38861903

RESUMO

The release of carbon disulfide can have adverse effects on our environment and human health. The stability of carbon disulfide and the slow kinetics of hydrolysis can make it challenging to achieve efficient and practical cleavage of the CS bonds. Herein, a calix[4]arene-based porous organic polymer (CPOP-1) is innovatively synthesized through an optimized polycondensation reaction using C-Methylcalix[4]resorcinarene and hexafluoro-hexaazatriphenylene as monomers. Subsequently, palladium-induced calix[4]arene-based porous organic polymer was also synthesized via strong Pd-N coordination bonds to construct the metal-induced porous catalyst (CPOP-2). The polymeric catalyst active center [Pd2+(N^N)(NO3-)2] demonstrated outstanding catalytic hydrolysis performance (11.14 µmol g-1 h-1) in 10.5 h which is significantly enhanced by ca.13.2 times as compared to reported mononuclear Bpy-Pd(NO3)2, and 7.07 times than model trinuclear complex catalyst HATN-Pd-1, respectively. The control experiments revealed that POP catalysts showcased robust stability, prolonged effectiveness, and feasible recyclability during the hydrolytic cleavage of carbon disulfide at room temperature in aqueous solutions. Furthermore, the coordination environment of [Pd2+(N^N)] was validated through XPS, EXAFS, and isotope labeling measurements, and the hydrolysis cleavage products were confirmed e. g. CO2, sulfide, and protons. More importantly, a reaction mechanism was formulated coupled with theoretical calculations, and simulations. The proposed mechanism involves sequential OH- nucleophilic attacks on the carbon atoms of insert-coordinated CS2 and COS, leading to the cleavage of double CS bonds and the formation of CO bonds. The concurrent dissociation of the C-S bond and liberation of CO2 result in an intermediate structure characterized by [(N^N)Pd2+](SH-)2. This intermediate motif serves as the source of the thermodynamic driving force for the reaction.

2.
Nat Commun ; 15(1): 3293, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38632239

RESUMO

DNA-based artificial motors have allowed the recapitulation of biological functions and the creation of new features. Here, we present a molecular robotic system that surveys molecular environments and reports spatial information in an autonomous and repeated manner. A group of molecular agents, termed 'crawlers', roam around and copy information from DNA-labeled targets, generating records that reflect their trajectories. Based on a mechanism that allows random crawling, we show that our system is capable of counting the number of subunits in example molecular complexes. Our system can also detect multivalent proximities by generating concatenated records from multiple local interactions. We demonstrate this capability by distinguishing colocalization patterns of three proteins inside fixed cells under different conditions. These mechanisms for examining molecular landscapes may serve as a basis towards creating large-scale detailed molecular interaction maps inside the cell with nanoscale resolution.


Assuntos
Procedimentos Cirúrgicos Robóticos , DNA , Proteínas , Fenômenos Biofísicos , Armazenamento e Recuperação da Informação
3.
Nat Neurosci ; 27(3): 536-546, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38272968

RESUMO

During goal-directed navigation, 'what' information, describing the experiences occurring in periods surrounding a reward, can be combined with spatial 'where' information to guide behavior and form episodic memories. This integrative process likely occurs in the hippocampus, which receives spatial information from the medial entorhinal cortex; however, the source of the 'what' information is largely unknown. Here, we show that mouse lateral entorhinal cortex (LEC) represents key experiential epochs during reward-based navigation tasks. We discover separate populations of neurons that signal goal approach and goal departure and a third population signaling reward consumption. When reward location is moved, these populations immediately shift their respective representations of each experiential epoch relative to reward, while optogenetic inhibition of LEC disrupts learning the new reward location. Therefore, the LEC contains a stable code of experiential epochs surrounding and including reward consumption, providing reward-centric information to contextualize the spatial information carried by the medial entorhinal cortex.


Assuntos
Córtex Entorrinal , Hipocampo , Camundongos , Animais , Córtex Entorrinal/fisiologia , Hipocampo/fisiologia , Comportamento Exploratório/fisiologia , Comportamento Espacial/fisiologia , Recompensa
4.
bioRxiv ; 2023 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-37873482

RESUMO

During goal-directed navigation, "what" information, which describes the experiences occurring in periods surrounding a reward, can be combined with spatial "where" information to guide behavior and form episodic memories1,2. This integrative process is thought to occur in the hippocampus3, which receives spatial information from the medial entorhinal cortex (MEC)4; however, the source of the "what" information and how it is represented is largely unknown. Here, by establishing a novel imaging method, we show that the lateral entorhinal cortex (LEC) of mice represents key experiential epochs during a reward-based navigation task. We discover a population of neurons that signals goal approach and a separate population of neurons that signals goal departure. A third population of neurons signals reward consumption. When reward location is moved, these populations immediately shift their respective representations of each experiential epoch relative to reward, while optogenetic inhibition of LEC disrupts learning of the new reward location. Together, these results indicate the LEC provides a stable code of experiential epochs surrounding and including reward consumption, providing reward-centric information to contextualize the spatial information carried by the MEC. Such parallel representations are well-suited for generating episodic memories of rewarding experiences and guiding flexible and efficient goal-directed navigation5-7.

5.
Inorg Chem ; 62(38): 15403-15411, 2023 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-37703056

RESUMO

The rational design and controlling synthesis of an anionic cuprous iodide supramolecular cluster with high nuclearity through noncovalent interactions remains a significant challenge. Herein, a cationic organic ligand (L1)3+ was driven by anion-cation ion-pair electrostatic interaction to induce free cuprous iodide to aggregate into an anionic supramolecular cluster, [(Cu5I8)3-(L1)3+] (C1). Moreover, five copper(I) atoms bind with eight iodides through multiply bridged Cu-I bonds associated with intramolecular cuprophilic interactions in this butterfly-shaped cluster core. Supramolecular cluster C1 exhibited a solid-state emission at 380 nm and an emission at 405 nm in acetonitrile at room temperature, respectively. Interestingly, this unprecedented cuprous iodide cluster demonstrated a good catalytic performance for azide-alkyne cycloaddition reaction (CuAAC) and the catalytic yield can be up to 80% for eight different substrates at 80 °C. Furthermore, the density functional theory (DFT) calculation revealed that the thermodynamic-dependent cycloaddition reaction underwent a four-step pathway with an overall energy barrier of -43.6 kcal mol-1 on the basis of intermediates monitored by mass spectrum.

6.
Am J Cancer Res ; 13(1): 227-235, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36777518

RESUMO

Oral squamous cell carcinoma (OSCC) is common worldwide. In this study, the interaction of microRNA-141 (miR-141) with long non-coding RNA (lncRNA) PSMG3 Antisense RNA 1 (PSMG3-AS1) in OSCC was explored. RT-qPCR was used to analyze the expression of PSMG3-AS1 and miR-141 (both mature and premature) in OSCC. Nuclear fractionation assay was applied to detect PSMG3-AS1 in subcellular locations. RNA pull-down assay was performed to evaluate the binding of miR-141 to PSMG3-AS1. Overexpression assay followed by RT-qPCR was performed to explore the role of PSMG3-AS1 in maturation of miR-141. The function of PSMG3-AS1 and miR-141 in regulating OSCC cell proliferation was assessed by BrdU assay. The results showed that PSMG3-AS1 was highly upregulated in OSCC and miR-141 was downregulated in OSCC. However, no alteration in the expression of premature miR-141 was observed in OSCC. Premature miR-141 was found to directly bind to PSMG3-AS1. Overexpression of PSMG3-AS1 suppressed the maturation of miR-141. PSMG3-AS1 increased OSCC cell proliferation and tumor growth and suppressed the inhibitory role of miR-141 in cell proliferation and tumor growth. Therefore, PSMG3-AS1 may inhibit the maturation of miR-141 to promote OSCC cell proliferation.

7.
Chin Med ; 18(1): 9, 2023 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-36709303

RESUMO

BACKGROUND: Elderly rheumatoid arthritis (ERA) population faces multiple treatment dilemma. Here we aim to investigate if Gancao Nourishing-Yin decoction (GCNY) added to methotrexate (MTX) exhibit better effects in an ERA mice model. METHODS: ERA mice model was established by adding D-galactose (Dgal) to collagen-induced arthritis (CIA) mice. The model was then assigned into control group (CIA + Dgal), MTX treatment group (MTX), GCNY treatment group (GCNY), and integrative treatment group (MTX + GCNY). Pathological scoring was performed to evaluate the severity between the groups. Proteomic analysis was applied to investigate the secretory phenotype of the ERA mouse model and the underlying mechanism of GCNY, MTX and their combination. Representative cytokines related to proteomic results were further validated by ELISAs. RESULTS: CIA + Dgal mice showed more aggressive joints damage than the CIA mice. Besides changes in the inflammatory pathway such as Pi3k-Akt signaling pathway in both model, differential expressed proteins (DEPs) indicated metabolism-related pathways were more obvious in CIA + Dgal mice. Low-dose MTX failed to show pathological improvement in CIA + Dgal mice, while GCNY improved joints damage significantly. Besides down-regulated inflammation-related targets, GCNY-regulated DEPs (such as Apoc1 ~ 3, Grk2 and Creb3l3) were broadly enriched in metabolism-related pathways. MTX + GCNY showed the best therapeutic effect, and the DEPs enriched in a variety of inflammatory,metabolism and osteoclast differentiation signaling pathway. Notably, MTX + GCNY treatment up-regulated Dhfr, Cbr1, Shmt1 involved in folic acid biosynthesis and anti-folate resistance pathways indicated a coincidence synergic action. ELISAs confirmed CPR and Akt that elevated in CIA + Dgal mice were significantly ameliorated by treatments, and adding on GCNY elevated folic acid levels and its regulator Dhfr. CONCLUSION: Aging aggravated joints damage in CIA, which probably due to metabolic changes rather than more severe inflammation. GCNY showed significant effects in the ERA mice model especially when integrated with MTX to obtain a synergic action.

8.
Inorg Chem ; 62(6): 2652-2662, 2023 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-36719869

RESUMO

Coordination polymers (CPs) have recently emerged as promising candidates for heterogeneous photocatalysis due to their structural designability and tunable properties. Herein, we developed two novel Ag(I)-calix[4]arene coordination polymers with the formula {[Ag2(µ-NO3)L1]}n (CP 1) and {[AgL1]·PF6}n (CP 2) (L1 = 2-mercapto-5-methyl-1,3,4-thiadiazole resorcinol calix[4]arene). Crystallography revealed that anion coordination and self-inclusion behavior induced the cavitand and silver ions to self-assemble into well-defined CPs 1 and 2 with different topological coordination frameworks, respectively. Furthermore, CPs 1 and 2 display high photocatalytic activity for the photodegradation of rhodamine B (RhB) and methyl orange (MO) in an aqueous solution under mild conditions (WLED and UV irradiation). The comparison results demonstrate that CP 1 exhibited better photocatalytic performance than CP 2, which correlated well with the differences in their molecular structure and HOMO-LUMO energy gaps. The photocatalysis products and possible intermediates were successfully monitored and determined using mass spectrum, gas chromatography, and electron paramagnetic resonance measurements. The rational photocatalysis mechanism was further investigated and proposed.

9.
Inorg Chem ; 61(36): 14267-14274, 2022 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-36047770

RESUMO

The self-assembly of mechanoluminochromic polynuclear gold(I) complexes has attracted more and more attention in the field of supramolecular gold(I) chemistry. In this work, we adopted a stepwise self-assembly strategy to precisely synthesize two polynuclear gold(I) supramolecular clusters. Through cooperative AuI···AuI and Au-N interactions, the gold(I) clusters 1+•BF4- and 24+•4BF4- with Au4 and Au16 cores, respectively, were successfully constructed. In these supramolecular clusters, (dppm)Au2Cl2 coordination motifs and trithiocyanuric linkers were stepwise assembled via sequential thiolate-chloride/phosphine coordination substitution and Au-S/Au-N coordination bond rearrangement. Two well-defined gold(I) supramolecular clusters displayed intense emission both in the solid state and in solution. Furthermore, the ladder-shaped cluster 24+•4BF4- exhibited reversible mechanochromic luminescence behavior in the solid state as well as aggregation-caused redshifted emission in solution. Upon mechanical grinding, the emission of the cluster 24+•4BF4- changed from yellow at 582 nm to red at 612 nm. The initial emission could be fully recovered by treatment with acetonitrile.

10.
Bioresour Technol ; 354: 127161, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35429596

RESUMO

In order to further obtain sustainable wastewater treatment technology, in-depth analysis based on algal-bacterial symbiosis, quorum sensing signal molecules and algal-bacterial relationship will lay the foundation for the synergistic algal-bacterial wastewater treatment process. The methods of enhancing algae and bacteria wastewater treatment technology were systematically explored, including promoting symbiosis, reducing algicidal behavior, eliminating the interference of quorum sensing inhibitor, and developing algae and bacteria granular sludge. These findings can provide guidance for sustainable economic and environmental development, and facilitate carbon emissions reduction by using algae and bacteria synergistic wastewater treatment technology in further attempts. The future work should be carried out in the following four aspects: (1) Screening of dominant microalgae and bacteria; (2) Coordination of stable (emerging) contaminants removal; (3) Utilization of algae to produce fertilizers and feed (additives), and (4) Constructing recombinant algae and bacteria for reducing carbon emissions and obtaining high value-added products.


Assuntos
Microalgas , Purificação da Água , Bactérias , Carbono , Percepção de Quorum , Águas Residuárias
12.
J Am Acad Dermatol ; 86(6): e257-e258, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-32652191
13.
BMC Med Genomics ; 14(1): 175, 2021 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-34193122

RESUMO

BACKGROUND: Mucopolysaccharidosis type II (MPS II) is an X-linked multisystem disorder caused by mutations in the gene encoding iduronate 2-sulfatase (IDS). The clinical manifestations of MPS II include skeletal deformities, airway obstruction, cardiomyopathy, and neurologic deterioration. MPS II has high genetic heterogeneity disorder, and ~ 658 variants of IDS have been reported. METHODS: We undertook a detailed pedigree analysis of four patients within the same family by targeted next-generation sequencing and Sanger sequencing. RESULTS: We identified a novel heterozygous frameshift variant, c.1224delC(p.Pro408ProfsTer31), of IDS in three patients. We defined c.1224delC as a pathogenic variant according to the 2015 guidelines set by the American College of Medical Genetics and Genomics. CONCLUSION: We reported the second Chinese female MPS II patient. We helped to ensure that these two families had healthy babies. Our findings have enlarged the mutational spectrum of IDS, and these findings could be useful for genetic counseling and the prenatal diagnosis of MPS II.


Assuntos
Mucopolissacaridose II
14.
Nat Commun ; 11(1): 5318, 2020 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-33087709

RESUMO

Synaptic vesicles (SVs) can be pooled across multiple synapses, prompting questions about their dynamic allocation for neurotransmission and plasticity. We find that the axonal traffic of recycling vesicles is not supported by ubiquitous microtubule-based motility but relies on actin instead. Vesicles freed from synaptic clusters undergo ~1 µm bouts of active transport, initiated by nearby elongation of actin filaments. Long distance translocation arises when successive bouts of active transport were linked by periods of free diffusion. The availability of SVs for active transport can be promptly increased by protein kinase A, a key player in neuromodulation. Vesicle motion is in turn impeded by shutting off axonal actin polymerization, mediated by nitric oxide-cyclic GMP signaling leading to inhibition of RhoA. These findings provide a potential framework for coordinating post-and pre-synaptic strength, using retrograde regulation of axonal actin dynamics to mobilize and recruit presynaptic SV resources.


Assuntos
Citoesqueleto de Actina/fisiologia , Proteínas Quinases Dependentes de AMP Cíclico/fisiologia , Óxido Nítrico/fisiologia , Vesículas Sinápticas/fisiologia , Animais , Transporte Axonal/fisiologia , Transporte Biológico Ativo , Células Cultivadas , GMP Cíclico/fisiologia , Feminino , Hipocampo/citologia , Hipocampo/fisiologia , Proteínas Luminescentes/metabolismo , Masculino , Neurônios/fisiologia , Nocodazol/farmacologia , Ratos , Ratos Sprague-Dawley , Transmissão Sináptica/fisiologia , Vesículas Sinápticas/efeitos dos fármacos
15.
J Clin Lab Anal ; 34(9): e23407, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32666542

RESUMO

BACKGROUND: Silver-Russell syndrome (SRS) is a heterogeneous imprinting disorder featuring severe intrauterine and postnatal growth retardation and dysmorphic features. Pendred syndrome (PDS) is an autosomal recessive disorder caused by mutations in the SLC26A4 gene characterized by sensorineural hearing loss. METHODS: Karyotyping analysis was performed to investigate any chromosomal abnormalities. Whole-genome copy number variation and loss of heterozygosity were analyzed using an Affymetrix CytoScan 750 K Microarray. Variant screening was performed by targeted next-generation sequencing on all known deafness-causing genes. RESULTS: The proband was a patient with SRS caused by maternal uniparental disomy 7. The PDS of the proband was caused by homozygous variant c.919-2A > G of SLC26A4; both mutated alleles were inherited from his mother. CONCLUSION: This is the first report of uniparental disomy 7 leading to SRS and Pendred syndrome. Patients with intrauterine growth retardation or those born small for gestational age and exhibiting postnatal growth failure should undergo molecular testing to reach a clinical diagnosis.


Assuntos
Aberrações Cromossômicas , Cromossomos Humanos Par 7/genética , Bócio Nodular/patologia , Perda Auditiva Neurossensorial/patologia , Herança Materna , Síndrome de Silver-Russell/patologia , Dissomia Uniparental/genética , Pré-Escolar , Feminino , Bócio Nodular/etiologia , Perda Auditiva Neurossensorial/etiologia , Humanos , Cariotipagem , Masculino , Fenótipo , Síndrome de Silver-Russell/etiologia
16.
Artigo em Inglês | MEDLINE | ID: mdl-31704622

RESUMO

Puerariae Radix (PR) serves as food and medicinal plant for thousands of years with explicit efficacy for heart diseases, while biological target specifically binding-oriented screening of the active components in PR remains a preliminary stage. Cell membrane chromatography (CMC) is newly developed approach where interactions between active components and certain biological targets can be effectively studied, Human umbilical vein endothelial cell (HUVEC) membrane, with its abundant receptors such as ß and AT1, is most eligible for constructing CMC. In this study, an HUVEC/CMC-LC-MS2 system was developed for screening active components in PR, 11 compounds were screened out and four of them were identified. Besides puerarin, the rest identified are daidzin, pueroside D and 3'-hydroxypuerarin. The study provides more reference for CMC applications and PR exploitation.


Assuntos
Membrana Celular/metabolismo , Cromatografia de Afinidade/métodos , Medicamentos de Ervas Chinesas/análise , Isoflavonas/análise , Espectrometria de Massas/métodos , Linhagem Celular , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/metabolismo , Células Endoteliais da Veia Umbilical Humana , Humanos , Isoflavonas/química , Isoflavonas/isolamento & purificação , Isoflavonas/metabolismo , Pueraria , Reprodutibilidade dos Testes
17.
Onco Targets Ther ; 12: 1395-1400, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30863106

RESUMO

Merkel cell carcinoma (MCC) is a rare, aggressive skin malignancy that has a propensity for local recurrence and metastasis to the lymph nodes. In this case report, we discuss a 54-year-old female with rheumatoid arthritis (RA) who had received treatment with prednisone (15 mg/day) for symptom relief and management. The patient visited our hospital with complaints of a nodule in right preauricular area. Computed tomography (CT) scans revealed no distant metastasis. The patient underwent surgical resection and histopathological evaluation of the nodule led to the diagnosis of MCC. The patients received post-surgical treatment with 6 MeV electronic wire radiotherapy. Six months later, CT of the head, neck, abdomen and chest demonstrated a right cervical lymph node mass at the C2 level. The patient then underwent cervical lymph node biopsy and pathological diagnosis confirmed metastatic MCC. One month after the lymph node biopsy, the patients received postoperative intensity modulated radiation therapy in the biopsied area. The patient did not experience any adverse effects to the therapy. In conclusion, the MCC patients with RA can tolerate radiation therapy. As MCC is a highly malignant neoplasia, considering the immune checkpoint inhibitors can lead to immune-related adverse events, detection of MCC at earlier stages is associated with better survival. The treatment decisions of MCC patients with RA continues is still challenging.

18.
Chin Med J (Engl) ; 131(23): 2800-2807, 2018 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-30511682

RESUMO

BACKGROUND: Neural respiratory drive (NRD) using diaphragm electromyography through an invasive transesophageal multi-electrode catheter can be used as a feasible clinical physiological parameter in patients with chronic obstructive pulmonary disease (COPD) to provide useful information on the treatment response. However, it remains unknown whether the surface diaphragm electromyogram (EMGdi) could be used to identify the deterioration of clinical symptoms and to predict the necessity of hospitalization in acute exacerbation of COPD (AECOPD) patients. METHODS: COPD patients visiting the outpatient department due to acute exacerbation were enrolled in this study. All patients who were subjected to EMGdi and classical parameters such as spirometry parameters, arterial blood gas analysis, COPD assessment test (CAT) score, and the modified early warning score (MEWS) in outpatient department, would be treated effectively in the outpatient or inpatient settings according to the Global Initiative for Chronic Obstructive Lung Disease guideline. When the acute exacerbation of the patients was managed, all the examination above would be repeated. RESULTS: We compared the relationships of admission-to-discharge changes (Δ) in the normalized value of the EMGdi, including the change of the percentage of maximal EMGdi (ΔEMGdi%max) and the change of the ratio of minute ventilation to the percentage of maximal EMGdi (ΔVE/EMGdi%max) with the changes of classical parameters. There was a significant positive association between ΔEMGdi%max and ΔCAT, ΔPaCO2, and ΔpH. The change (Δ) of EMGdi%max was negatively correlated with ΔPaO2/FiO2in the course of the treatment of AECOPD. Compared with the classical parameters including forced expiratory volume in 1 s, MEWS, PaO2/FiO2, the EMGdi%max (odds ratio 1.143, 95% confidence interval 1.004-1.300) has a higher sensitivity when detecting the early exacerbation and enables to predict the admission of hospital in the whole cohort. CONCLUSIONS: The changes of surface EMGdi parameters had a direct correlation with classical measures in the whole cohort of AECOPD. The measurement of NRD by surface EMGdi represents a practical physiological biomarker, which may be helpful in detecting patients who should be hospitalized timely.


Assuntos
Eletromiografia/métodos , Doença Pulmonar Obstrutiva Crônica/metabolismo , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Diafragma/fisiopatologia , Volume Expiratório Forçado/fisiologia , Hospitalização , Humanos , Espirometria , Capacidade Vital/fisiologia
19.
Nat Chem ; 10(2): 155-164, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29359755

RESUMO

DNA performs diverse functional roles in biology, nanotechnology and biotechnology, but current methods for autonomously synthesizing arbitrary single-stranded DNA are limited. Here, we introduce the concept of primer exchange reaction (PER) cascades, which grow nascent single-stranded DNA with user-specified sequences following prescribed reaction pathways. PER synthesis happens in a programmable, autonomous, in situ and environmentally responsive fashion, providing a platform for engineering molecular circuits and devices with a wide range of sensing, monitoring, recording, signal-processing and actuation capabilities. We experimentally demonstrate a nanodevice that transduces the detection of a trigger RNA into the production of a DNAzyme that degrades an independent RNA substrate, a signal amplifier that conditionally synthesizes long fluorescent strands only in the presence of a particular RNA signal, molecular computing circuits that evaluate logic (AND, OR, NOT) combinations of RNA inputs, and a temporal molecular event recorder that records in the PER transcript the order in which distinct RNA inputs are sequentially detected.


Assuntos
DNA Catalítico/metabolismo , DNA de Cadeia Simples/biossíntese , DNA Catalítico/química , DNA de Cadeia Simples/química
20.
J Food Drug Anal ; 25(2): 327-332, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28911674

RESUMO

Essential oils from the seed, pulp, and leaf of sea buckthorn were obtained with hydrodistillation, and their phytochemical composition was analyzed through gas chromatography-mass spectrometry. Furthermore, the antibacterial activity of the oils was tested on five food-borne bacteria by spectrometry and evaluated in terms of minimum inhibitory concentration. The results indicate that the composition of all essential oils is dominated by free fatty acids, esters, and alkanes. Minimum inhibitory concentration values on each bacterium were obtained for oils from different parts. The oils from different parts exhibited nearly equal inhibitory effect on Staphylococcus aureus. The pulp oil was found to be the most effective for the rest of bacteria tested except Escherichia coli, on which seed oil shows twice the inhibitory effect to that of leaf or pulp oil. Three natural inhibitory examples were found comparable with or even better than the positive control: pulp oil on Bacillus subtilis, and pulp oil and leaf oil on Bacillus coagulans.


Assuntos
Hippophae , Antibacterianos , Bactérias , Cromatografia Gasosa-Espectrometria de Massas , Testes de Sensibilidade Microbiana , Óleos Voláteis , Compostos Fitoquímicos , Sementes , Staphylococcus aureus
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA