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1.
Food Chem X ; 21: 101192, 2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38389575

RESUMO

This study utilized a colorimeter to determine the color values of 23 beauty tea (BT) samples, the color and the taste characteristics were also quantitatively described through ultraviolet-visible (UV-Vis) spectroscopy and taste equivalent quantification. Furthermore, metabolomic analysis was conducted by using ultra-high-performance liquid chromatography-mass spectrometry (UPLC-MS). Correlation analysis was employed to preliminarily identify the compounds that contribute to the color and taste of BT infusion. Finally, the contributing compounds were further determined through verification experiment. The results showed that within a certain range, as the color of BT infusion deepened, the taste became stronger, more bitter and astringent, while on the contrary, it became sweeter and mellower. Theaflavins, kaempferol, astragalin, and 5-p-coumaroylquinic acid influenced both the color and taste of the BT infusion. Gallic acid was also determined as a contributor to the color. This study provides new insights into research on tea quality in infusion color and taste aspects.

2.
Dalton Trans ; 53(11): 5034-5042, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38374728

RESUMO

The construction and investigation of dual-functional coordination polymers (CPs) with proton conduction and luminescence sensing is of great significance in clean energy and agricultural monitoring fields. In this work, an Mn-based coordination polymer (Mn-CP), namely, [Mn0.5(HL)] (H2L = HOOCC6H4C6H4CH2PO(OH)OCH3), was hydrothermally synthesized. Mn-CP has a one-dimensional (1D) chain structure, in which uncoordinated -COOH groups can serve as potential sites for fluorescence sensing. Moreover, Mn-CP shows good water and pH stabilities, offering the feasibility for proton conduction and sensing applications. Mn-CP displays comparatively high proton conductivity of 1.07 × 10-4 S cm-1 at 368 K and 95% relative humidity (RH), which is promising for proton conduction materials. Moreover, it can serve as a repeatable, highly selective, and visualized fluorescence sensor for detecting oxytetracycline (OTC). More importantly, Mn-CP reveals an amazing quantitative sensing of OTC in actual samples such as seawater, aquaculture freshwater, soil infiltration solutions, and tap water. This work proves the excellent application potential of dual-functional CPs in the field of clean energy and environmental protection, especially for the fluorescence detection of antibiotics in aquaculture systems.

3.
bioRxiv ; 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-37986994

RESUMO

The SARS-CoV-2 viral infection transforms host cells and produces special organelles in many ways, and we focus on the replication organelle where the replication of viral genomic RNA (vgRNA) occurs. To date, the precise cellular localization of key RNA molecules and replication intermediates has been elusive in electron microscopy studies. We use super-resolution fluorescence microscopy and specific labeling to reveal the nanoscopic organization of replication organelles that contain vgRNA clusters along with viral double-stranded RNA (dsRNA) clusters and the replication enzyme, encapsulated by membranes derived from the host endoplasmic reticulum (ER). We show that the replication organelles are organized differently at early and late stages of infection. Surprisingly, vgRNA accumulates into distinct globular clusters in the cytoplasmic perinuclear region, which grow and accommodate more vgRNA molecules as infection time increases. The localization of ER labels and nsp3 (a component of the double-membrane vesicle, DMV) at the periphery of the vgRNA clusters suggests that replication organelles are enclosed by DMVs at early infection stages which then merge into vesicle packets as infection progresses. Precise co-imaging of the nanoscale cellular organization of vgRNA, dsRNA, and viral proteins in replication organelles of SARS-CoV-2 may inform therapeutic approaches that target viral replication and associated processes.

4.
J Agric Food Chem ; 71(43): 16233-16247, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37850863

RESUMO

The fresh leaves were processed into beauty tea from the Camellia sinensis "Jinxuan" cultivar, which were punctured by tea green leafhoppers to different extents. Low-puncturing dry tea (LPDT) exhibited a superior quality. Altogether, 101 and 129 differential metabolites, including tea polyphenols, lipids, and saccharides, were identified from the fresh leaves and dry beauty tea, respectively. Most metabolite levels increased in the fresh leaves punctured by leafhoppers, but the opposite was observed for the dry beauty tea. According to relative odor activity values (rOAVs) and partial least-squares discriminant analysis (PLS-DA), four characteristic volatiles, including linalool, geraniol, benzeneacetaldehyde, and dihydrolinalool, were selected. Mechanical injury to leaves caused by leafhoppers, watery saliva secreted by the leafhopper, and different water contents of the fresh leaves in different puncturing degrees are the possible reasons for the difference in the quality of the beauty tea with different levels of puncturing. Overall, this study identified a wide range of chemicals that are affected by the degrees of leafhopper puncturing.


Assuntos
Camellia sinensis , Hemípteros , Animais , Camellia sinensis/química , Análise Discriminante , Folhas de Planta/química , Chá/química
5.
Inorg Chem ; 62(32): 12730-12740, 2023 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-37529894

RESUMO

The construction of attractive dual-functional lanthanide-based metal-organic frameworks (Ln-MOFs) with ratiometric fluorescent detection and proton conductivity is significant and challenging. Herein, a three-dimensional (3D) Eu-MOF, namely, [Eu4(HL)2(SBA)4(H2O)6]·9H2O, has been hydrothermally synthesized with a dual-ligand strategy, using (4-carboxypiperidyl)-N-methylenephosphonic acid (H3L = H2O3PCH2-NC5H9-COOH) and 4-sulfobenzoic acid monopotassium salt (KHSBA = KO3SC6H4COOH) as organic linkers. Eu-MOF showed ratiometric fluorescent broad-spectrum sensing of benzophenone-like ultraviolet filters (BP-like UVFs) with satisfactory sensitivity, selectivity, and low limits of detection in water/ethanol (1:1, v/v) solutions and real urine systems. A portable test paper was prepared for the convenience of actual detection. The potential sensing mechanisms were thoroughly analyzed by diversified experiments. The synergistic effect of the forbidden energy transfer from the ligand to Eu3+, the internal filtration effect (IFE), the formation of a complex, and weak interactions between the KHSBA ligand and BP-like UVFs is responsible for the ratiometric sensing effect. Meanwhile, Eu-MOF displayed relatively high proton conductivity of 2.60 × 10-4 S cm-1 at 368 K and 95% relative humidity (RH), making it a potential material for proton conduction. This work provides valuable guidance for the facile and effective design and construction of multifunctional Ln-MOFs with promising performance.

6.
Dalton Trans ; 52(25): 8558-8566, 2023 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-37288585

RESUMO

By selecting a bisphosphonic ligand H4L (H4L = 4-F-C6H4CH2N(CH2PO3H2)2) and a coligand oxalate (H2C2O4), three isostructural lanthanide metal-organic frameworks (Ln-MOFs) with a 2D layer structure, [Ln(H3L)(C2O4)]·2H2O (Ln = Eu (1), Gd (2), or Tb (3)), were hydrothermally prepared. By tuning the molar ratio of Eu3+, Gd3+, and Tb3+ in the above reactions, six bimetallic or trimetallic doped Ln-MOFs (EuxTb1-x (x = 0.02 (4), 0.04 (5), and 0.06 (6)), Gd0.94Eu0.06 (7), Gd0.96Tb0.04 (8) and Gd0.95Tb0.03Eu0.02 (9)) were obtained. The powder X-ray diffraction (PXRD) patterns of doped Ln-MOFs 4-9 show that they are isomorphous with 1-3. The bimetallic doped Ln-MOFs show a gradual variation of luminous colors between yellow-green, yellow, orange, pink, and light blue. Meanwhile, the trimetallic doped Gd0.95Tb0.03Eu0.02 Ln-MOF (9) displays near white-light emission with a quantum yield of 11.39%. Interestingly, the luminous inks of 1-9 are invisible and color tunable, which makes it possible to promote their anti-counterfeiting applications. Additionally, 3 displays good thermal, water, and pH stabilities, which provides the feasibility for its sensing application. The luminescence sensing experiments show that 3 can serve as a highly selective, reusable, and ratiometric luminescent sensor of sulfamethazine (SMZ). Moreover, 3 shows an excellent SMZ detection performance in real samples, such as mariculture water and real urine. Owing to the visible variation of the response signal under a UV lamp, portable SMZ test paper was prepared.

7.
Foods ; 12(9)2023 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-37174277

RESUMO

Beauty tea with special flavor can be affected by the degree of leafhopper puncturing. The present research adopted widely targeted metabolomics to analyze the characteristic metabolites of fresh tea leaves and beauty tea with different degrees of leafhopper puncturing. Low-puncturing beauty tea (LPBT) exhibited a superior quality. Altogether, 95 and 65 differential metabolites, including tea polyphenols, saccharides, and lipids, were identified from fresh leaves and beauty tea, respectively. The partial least squares regression (PLSR) analysis results showed that isomaltulose, theaflavic acid, and ellagic acid, may be the characteristic metabolites that form the different taste outlines of beauty tea. Based on odor activity values (OAVs) and partial least squares discriminant analysis (PLS-DA), dihydrolinalool and cis-linalool oxide were identified as characteristic volatile components, which may be essential for the formation of the different aroma characteristic of beauty tea. The results provide a theoretical basis for selecting raw materials, performing quality research, and developing beauty tea industrially.

8.
Dalton Trans ; 52(16): 5202-5211, 2023 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-36970992

RESUMO

Developing high-accuracy luminescent sensors for detecting emerging environmental pollutants is of great importance and is still a challenge. Utilizing a 4-carboxyphenylphosphonic acid (H3pbc) ligand, a novel one-dimensional (1D) Zn-based coordination polymer with the formula [Zn2(Hpbc)2(2,2'-bipy)(H2O)]·H2O (Zn-CP, H3pbc = 4-HOOCC6H4PO3H2, 2,2'-bipy = 2,2'-bipyridine) has been hydrothermally synthesized. Each of the 1D chains was linked via π-π stacking interactions and formed a supramolecular framework. Furthermore, due to the existence of uncoordinated -COOH groups, the terbium-functionalized hybrid (Tb3+@Zn-CP) was prepared by introducing Tb3+ ions into the structure through coordinated postsynthetic modification (PSM). Tb3+@Zn-CP shows the characteristic emission of Tb3+ ions due to the "antenna effect" of the H3pbc ligand. Based on the excellent luminescence properties and structural stabilities of Zn-CP and Tb3+@Zn-CP, they can be used as highly sensitive and selective luminescent probes of the UV filter BP (benzophenone) depending on multiquenching effects. In addition, their obvious color change can be easily distinguished by the naked eye under ultraviolet light, which was successfully used in the preparation of portable BP test paper. More importantly, Tb3+@Zn-CP is the first example of CPs as a ratiometric luminescent sensor for BP. This work provides a novel strategy for the construction of ratiometric luminescent probes of BP-type UVFs through coordinated postsynthetic modification.

9.
Eur Spine J ; 32(3): 1068-1076, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36717400

RESUMO

PURPOSE: To investigate the imaging characteristics of thoracic ossification of ligamentum flavum (OLF) combined with dural ossification (DO) and the clinical efficacy of zoning laminectomy. METHOD: The clinical data of 48 patients with thoracic OLF combined with DO who underwent zoning laminectomy between June 2016 and May 2020 were retrospectively analyzed. The modified Japanese Orthopedic Association (mJOA) score was used to evaluate neurological function before and after surgery, and the clinical efficacy was evaluated according to the improvement rate. RESULTS: The symptoms of all patients significantly improved after the operation, and the average follow-up time was 27.8 (10-47) months. In addition, the average mJOA score had increased from 5.0 (2-8) preoperatively to 8.7 (6-11) postoperatively (t = 18.880, P < 0.05). The average improvement rate was 62.6% (25-100%), with 16 patients graded as excellent, 21 as good, and 11 as fair. Cerebrospinal fluid leakage occurred in 12 cases (25.0%), and all of them healed well after treatment. No postoperative aggravation of neurological dysfunction, wound infection or hematoma occurred. At the last follow-up, there was no recurrence of symptoms and kyphosis. CONCLUSION: The Zoning laminectomy described here is both safe and effective.


Assuntos
Ligamento Amarelo , Ossificação Heterotópica , Humanos , Descompressão Cirúrgica/métodos , Osteogênese , Ligamento Amarelo/diagnóstico por imagem , Ligamento Amarelo/cirurgia , Estudos Retrospectivos , Ossificação Heterotópica/diagnóstico por imagem , Ossificação Heterotópica/cirurgia , Ossificação Heterotópica/complicações , Vértebras Torácicas/diagnóstico por imagem , Vértebras Torácicas/cirurgia
10.
Asian J Surg ; 46(2): 723-729, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35803890

RESUMO

OBJECTIVE: Spinal cord injury is a common occurrence during spinal surgery. In this study, we proposed a zoning laminectomy, which could reduce the incidence of nerve injury. We also discussed the safety and clinical efficacy of the zoning laminectomy for thoracic ossification of the ligamentum flavum (TOLF). METHODS: Forty-five patients with TOLF who underwent zoning laminectomy from October 2016 to February 2020 were included in the retrospective analysis. The Japan Orthopedic Association (JOA) score was used to evaluate clinical outcomes. Meanwhile, the occurrence of complications was recorded. RESULTS: All 45 patients underwent the operation successfully, and the mean follow-up period was 25.3 months, the mean operation time was 160.2 min, the average blood loss was 474.2 ml, and the average hospital time was 8.0 days. At the final evaluation, the JOA score was significantly higher than the preoperative JOA score (P < 0.001) and the overall recovery rate of the JOA score averaged 69.6%. Seventeen patients were graded as excellent, twenty-six as good, and two as fair. The complications included dural tears in nine patients (20.0%), cerebrospinal fluid leakage in seven patients (15.6%), deep infection in one patient (2.2%), and epidural hematoma in one patient (2.2%). All patients recovered well after treatment. Besides, there was no neurological deterioration and thoracic kyphosis occurred. CONCLUSIONS: Zoning laminectomy adopts a phased resection from "safe zone" to "danger zone" and defines the safe removal range of the lamina, which reduces the risks of spinal cord injury caused by instrument manipulation. Therefore, it is a safe and effective surgical option.


Assuntos
Ligamento Amarelo , Ossificação Heterotópica , Traumatismos da Medula Espinal , Humanos , Laminectomia , Osteogênese , Descompressão Cirúrgica , Ligamento Amarelo/cirurgia , Estudos Retrospectivos , Ossificação Heterotópica/cirurgia , Ossificação Heterotópica/complicações , Vértebras Torácicas/cirurgia , Resultado do Tratamento , Traumatismos da Medula Espinal/complicações , Traumatismos da Medula Espinal/cirurgia
11.
Inorg Chem ; 61(49): 20111-20122, 2022 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-36424127

RESUMO

Construction and investigation of dual-functional metal-organic frameworks (MOFs) with luminescent sensing and proton conduction provide widespread applications in clean energy and environmental monitoring fields. By selecting a phosphonic acid ligand 4-pyridyl-CH2N(CH2PO3H2)2 (H4L) and coligand 2,2'-biimidazole (H2biim), two cadmium-based MOFs [Cd1.5(HL)(H2biim)0.5] (1) and (H4biim)0.5·[Cd2(L)(H2biim)Cl] (2) with different structures and properties have been hydrothermally synthesized by controlling reaction temperature. Based on the excellent thermal and chemical stabilities, and good luminescent stabilities in water solution, 1 and 2 can serve as luminescent sensors of chloramphenicol (CAP) with different quenching constant (KSV) values and detection limits (LODs) in water, simulated environmental system, and real fish water system. Meanwhile, different sensing effects and possible sensing mechanisms are analyzed in detail. Moreover, 1 and 2 can also serve as good proton-conducting materials. The proton conductivities can reach up to 1.41 × 10-4 S cm-1 for 1 and 1.02 × 10-3 S cm-1 for 2 at 368 K and 95% relative humidity (RH). Among them, 2 shows better luminescent sensing and proton conduction performance than 1, which indicates that different crystal structures have a great impact on the properties of MOFs. Through the discussion of the relationship between structures and properties in detail, the possible reasons for the differences in properties are obtained, which can provide theoretical guidance for the rational design of this kind of dual-functional MOFs in the future.


Assuntos
Estruturas Metalorgânicas , Animais , Prótons , Antibacterianos , Cádmio , Água
12.
Int J Mol Sci ; 23(18)2022 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-36142822

RESUMO

The soybean pod borer (Leguminivora glycinivorella) (SPB) is a major cause of soybean (Glycine max L.) yield losses in northeast Asia, thus it is desirable to elucidate the resistance mechanisms involved in soybean response to the SPB. However, few studies have mapped SPB-resistant quantitative trait loci (QTLs) and deciphered the response mechanism in soybean. Here, we selected two soybean varieties, JY93 (SPB-resistant) and K6 (SPB-sensitive), to construct F2 and F2:3 populations for QTL mapping and collected pod shells before and after SPB larvae chewed on the two parents to perform RNA-Seq, which can identify stable QTLs and explore the response mechanism of soybean to the SPB. The results show that four QTLs underlying SPB damage to seeds were detected on chromosomes 4, 9, 13, and 15. Among them, qESP-9-1 was scanned in all environments, hence it can be considered a stable QTL. All QTLs explained 0.79 to 6.09% of the phenotypic variation. Meanwhile, 2298 and 3509 DEGs were identified for JY93 and K6, respectively, after the SPB attack, and most of these genes were upregulated. Gene Ontology enrichment results indicated that the SPB-induced and differently expressed genes in both parents are involved in biological processes such as wound response, signal transduction, immune response, and phytohormone pathways. Interestingly, secondary metabolic processes such as flavonoid synthesis were only significantly enriched in the upregulated genes of JY93 after SPB chewing compared with K6. Finally, we identified 18 candidate genes related to soybean pod borer resistance through the integration of QTL mapping and RNA-Seq analysis. Seven of these genes had similar expression patterns to the mapping parents in four additional soybean germplasm after feeding by the SPB. These results provide additional knowledge of the early response and induced defense mechanisms against the SPB in soybean, which could help in breeding SPB-resistant soybean accessions.


Assuntos
Mariposas , Locos de Características Quantitativas , Animais , Mapeamento Cromossômico/métodos , Flavonoides/metabolismo , Mariposas/genética , Fenótipo , Melhoramento Vegetal , Reguladores de Crescimento de Plantas/metabolismo , RNA-Seq , Sementes/genética , Glycine max/genética , Glycine max/metabolismo
13.
Cancers (Basel) ; 14(15)2022 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-35954330

RESUMO

PTEN is the second most highly mutated tumor suppressor in cancer, following only p53. The PTEN protein functions as a phosphatase with lipid- and protein-phosphatase activity. PTEN-lipid-phosphatase activity dephosphorylates PIP3 to form PIP2, and it then antagonizes PI3K and blocks the activation of AKT, while its protein-phosphatase activity dephosphorylates different protein substrates and plays various roles in tumorigenesis. Here, we review the PTEN mutations and protein-phosphatase substrates in tumorigenesis and metastasis. Our purpose is to clarify how PTEN protein phosphatase contributes to its tumor-suppressive functions through PI3K-independent activities.

14.
Science ; 377(6610): 1077-1085, 2022 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-35951677

RESUMO

Mammalian genomes have multiple enhancers spanning an ultralong distance (>megabases) to modulate important genes, but it is unclear how these enhancers coordinate to achieve this task. We combine multiplexed CRISPRi screening with machine learning to define quantitative enhancer-enhancer interactions. We find that the ultralong distance enhancer network has a nested multilayer architecture that confers functional robustness of gene expression. Experimental characterization reveals that enhancer epistasis is maintained by three-dimensional chromosomal interactions and BRD4 condensation. Machine learning prediction of synergistic enhancers provides an effective strategy to identify noncoding variant pairs associated with pathogenic genes in diseases beyond genome-wide association studies analysis. Our work unveils nested epistasis enhancer networks, which can better explain enhancer functions within cells and in diseases.


Assuntos
Doença , Elementos Facilitadores Genéticos , Epistasia Genética , Aprendizado de Máquina , Proteínas de Ciclo Celular , Doença/genética , Estudo de Associação Genômica Ampla , Humanos , Células K562 , Proteínas Nucleares/genética , Fatores de Transcrição/genética
15.
Plants (Basel) ; 11(9)2022 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-35567137

RESUMO

Heterosis is an important biological phenomenon and is widely applied to increase agricultural productivity. However, the underlying molecular mechanisms of heterosis are still unclear. Here we constructed three combinations of reciprocal hybrids of soybean, and subsequently used MethylRAD-seq to detect CCGG and CCWGG (W = A or T) methylation in the whole genome of these hybrids and their parents at the middle development period of contemporary seed. We were able to prove that changes in DNA methylation patterns occurred in immature hybrid seeds and the parental variation was to some degree responsible for differential expression between the reciprocal hybrids. Non-additive differential methylation sites (DMSs) were also identified in large numbers in hybrids. Interestingly, most of these DMSs were hyper-methylated and were more concentrated in gene regions than the natural distribution of the methylated sites. Further analysis of the non-additive DMSs located in gene regions exhibited their participation in various biological processes, especially those related to transcriptional regulation and hormonal function. These results revealed DNA methylation reprogramming pattern in the hybrid soybean, which is associated with phenotypic variation and heterosis initiation.

16.
Nat Commun ; 13(1): 2766, 2022 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-35589813

RESUMO

A major challenge in coronavirus vaccination and treatment is to counteract rapid viral evolution and mutations. Here we demonstrate that CRISPR-Cas13d offers a broad-spectrum antiviral (BSA) to inhibit many SARS-CoV-2 variants and diverse human coronavirus strains with >99% reduction of the viral titer. We show that Cas13d-mediated coronavirus inhibition is dependent on the crRNA cellular spatial colocalization with Cas13d and target viral RNA. Cas13d can significantly enhance the therapeutic effects of diverse small molecule drugs against coronaviruses for prophylaxis or treatment purposes, and the best combination reduced viral titer by over four orders of magnitude. Using lipid nanoparticle-mediated RNA delivery, we demonstrate that the Cas13d system can effectively treat infection from multiple variants of coronavirus, including Omicron SARS-CoV-2, in human primary airway epithelium air-liquid interface (ALI) cultures. Our study establishes CRISPR-Cas13 as a BSA which is highly complementary to existing vaccination and antiviral treatment strategies.


Assuntos
Tratamento Farmacológico da COVID-19 , SARS-CoV-2 , Antivirais/farmacologia , Humanos , Lipossomos , Nanopartículas , SARS-CoV-2/genética
17.
Int J Mol Sci ; 23(4)2022 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-35216173

RESUMO

(1) Antimicrobial peptides (AMPs) are a promising alternative to conventional antibiotics. Among AMPs, the disulfide-rich ß-defensin AvBD103b, whose antibacterial activities are not inhibited by salts contrary to most other ß-defensins, is particularly appealing. Information about the mechanisms of action is mandatory for the development and approval of new drugs. However, data for non-membrane-disruptive AMPs such as ß-defensins are scarce, thus they still remain poorly understood. (2) We used single-cell fluorescence imaging to monitor the effects of a ß-defensin (namely AvBD103b) in real time, on living E. coli, and at the physiological concentration of salts. (3) We obtained key parameters to dissect the mechanism of action. The cascade of events, inferred from our precise timing of membrane permeabilization effects, associated with the timing of bacterial growth arrest, differs significantly from the other antimicrobial compounds that we previously studied in the same physiological conditions. Moreover, the AvBD103b mechanism does not involve significant stereo-selective interaction with any chiral partner, at any step of the process. (4) The results are consistent with the suggestion that after penetrating the outer membrane and the cytoplasmic membrane, AvBD103b interacts non-specifically with a variety of polyanionic targets, leading indirectly to cell death.


Assuntos
Antibacterianos/farmacologia , beta-Defensinas/farmacologia , Antibacterianos/química , Escherichia coli/efeitos dos fármacos , beta-Defensinas/química
18.
Biophys J ; 120(23): 5243-5254, 2021 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-34757079

RESUMO

Synthetic, cationic random nylon-3 polymers (ß-peptides) show promise as inexpensive antimicrobial agents less susceptible to proteolysis than normal peptides. We have used superresolution, single-cell, time-lapse fluorescence microscopy to compare the effects on live Escherichia coli cells of four such polymers and the natural antimicrobial peptides LL-37 and cecropin A. The longer, densely charged monomethyl-cyclohexyl (MM-CH) copolymer and MM homopolymer rapidly traverse the outer membrane and the cytoplasmic membrane. Over the next ∼5 min, they locally rigidify the chromosomal DNA and slow the diffusive motion of ribosomal species to a degree comparable to LL-37. The shorter dimethyl-dimethylcyclopentyl (DM-DMCP) and dimethyl-dimethylcyclohexyl (DM-DMCH) copolymers, and cecropin A are significantly less effective at rigidifying DNA. Diffusion of the DNA-binding protein HU and of ribosomal species is hindered as well. The results suggest that charge density and contour length are important parameters governing these antimicrobial effects. The data corroborate a model in which agents having sufficient cationic charge distributed across molecular contour lengths comparable to local DNA-DNA interstrand spacings (∼6 nm) form a dense network of multivalent, electrostatic "pseudo-cross-links" that cause the local rigidification. In addition, at times longer than ∼30 min, we observe that the MM-CH copolymer and the MM homopolymer (but not the other four agents) cause gradual coalescence of the two nucleoid lobes into a single dense lobe localized at one end of the cell. We speculate that this process involves coacervation of the DNA by the cationic polymer, and may be related to the liquid droplet coacervates observed in eukaryotic cells.


Assuntos
Nylons , Polímeros , Peptídeos Antimicrobianos , DNA/genética , Escherichia coli/genética
19.
Inorg Chem ; 60(22): 17303-17314, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34699193

RESUMO

It remains a challenge to exploit dual-functional metal-organic frameworks (MOFs) for applications, including luminescence detection and proton conduction. With the deliberate selection of the bifunctional organic ligand 5-sulfoisophthalic acid monosodium salt (NaH2bts), and the phosphonic acid ligand N,N'-piperazine (bismethylenephosphonic acid; H4L), a robust three-dimensional (3D) noninterpenetrating dual-functional MOF, [Tb(H2L)(H2bts)(H2O)]·H2O (1), has been synthesized hydrothermally. On the basis of the excellent thermal and chemical as well as superior luminescence stabilities in water and solutions with different pHs, 1 can serve as the simple, rapid, and highly selective and sensitive luminescence detection of the carcinoid biomarkers 5-hydroxytryptamine (HT) and its metabolite 5-hydroxyindole-3-acetic acid (HIAA) with detection limits of nanomolar magnitude in water and in simulated blood plasma and urine systems. Due to the change in the signals that could be readily differentiated by the naked eye under a UV lamp, a portable test paper has been developed. The probable quenching mechanisms are discussed in detail. In addition, a great number of hydrogen-bonding networks are formed among the uncoordinated carboxylic oxygen atoms, sulfonate oxygen atoms, protonated nitrogen atoms, and water molecules, which provide potential proton-hopping sites for proton conduction, leading to a maximum proton conductivity of 2.3 × 10-4 S cm-1 at 368 K and 95% relative humidity. The above results suggest that rationally designed dual-functional MOFs can open an avenue for the development of occupational diagnostic tools and alternative energy technology.


Assuntos
Tumor Carcinoide/química , Luminescência , Estruturas Metalorgânicas/química , Prótons , Biomarcadores/análise , Estruturas Metalorgânicas/síntese química , Modelos Moleculares
20.
J Exp Zool B Mol Dev Evol ; 336(5): 431-442, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34101984

RESUMO

Vasa, one of the best-studied germ cell markers plays a critical role in germ cell development and differentiation in animals. Vasa deficiency would lead to male-specific sterility in most vertebrates, but female sterility in the fly. However, the role of the vasa gene involved in germ cell differentiation is largely elusive. Here, we first characterized the expression profile of vasa products in the Asian yellow pond turtle by quantitative reverse-transcription polymerase chain reaction and fluorescence immunostaining. The results showed that vasa messenger RNA (mRNA) is initially detected in embryos at stage 16, and then dramatically increased in embryos at stage 19. In particular, like the sex-related genes, vasa mRNA exhibited differential expression in embryos between the male-producing temperature (MPT, 25°C) and the female-producing temperature (FPT, 33°C), whereas there was no difference in methylation levels of vasa promoter detected between FPT and MPT. In contrast, in the adult Asian yellow pond, the level of vasa mRNA was much higher in the testis than ovary. Moreover, the immunostaining on testicular sections and cells showed that Vasa protein was exclusively expressed in germ cells: Weak but detectable in spermatogonia, highest in spermatocytes, moderate and concentrated in chromatid bodies in spermatids and spermatozoa, and bare in somatic cells. The expression profile of Vasa protein is similar in turtle species studied so far but distinct from those in fish species in this study. The findings of this study would provide new insights into our understanding of the conservation and divergence of the vasa gene, even other germ cell genes across phyla.


Assuntos
RNA Helicases DEAD-box/metabolismo , Regulação Enzimológica da Expressão Gênica/fisiologia , Diferenciação Sexual/fisiologia , Tartarugas/fisiologia , Animais , RNA Helicases DEAD-box/genética , DNA Complementar , Embrião não Mamífero/metabolismo , Feminino , Peixes/genética , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Marcadores Genéticos , Masculino , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Espermatozoides , Transcriptoma , Tartarugas/embriologia , Tartarugas/genética
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