Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 22
Filter
Add more filters










Publication year range
1.
Langmuir ; 2024 Jul 16.
Article in English | MEDLINE | ID: mdl-39014533

ABSTRACT

By combining molecular simulations and experimental measurements, the effect of the Nafion content on the performance of proton-exchange membrane fuel cells (PEMFCs) is explained from the perspective of the triple-phase boundary (TPB). The evaporation process of Nafion solvent is simulated on a triple-phase model to mimic the formation of the TPB, and the influence of the Nafion content on the TPB structure is investigated. When the Nafion content is 1.415 mg/m2, the coverages of Nafion on both Pt particles and the carbon carrier are saturated at 42.1% and 32.7%, respectively. With the increase of Nafion content, the amount of water molecules around Pt particles is increased, and the surrounding O2 content is decreased. The experimental PEMFC performance has confirmed such simulation results, which demonstrates a trend of enhancing first and then weakening with the increase of Nafion content and reaches a maximum with the Nafion content of 2.96 mg/m2. Therefore, the correlation between the structure of the TPB and the cell's efficiency has been established at a molecular level, enabling enhancements in the design of the TPB morphology and an increase in PEMFC efficiency.

2.
Foods ; 13(10)2024 May 10.
Article in English | MEDLINE | ID: mdl-38790784

ABSTRACT

Tartronic acid is known for its potential to inhibit sugar-to-lipid conversion in the human body, leading to weight loss and fat reduction. This compound is predominantly found in cucumbers and other cucurbit crops. Therefore, cultivating cucumbers with high tartronic acid content holds significant health implications. In this study, we assessed the tartronic acid content in 52 cucumber germplasms with favorable overall traits and identified 8 cucumber germplasms with elevated tartronic acid levels. Our investigation into factors influencing cucumber tartronic acid revealed a decrease in content with fruit development from the day of flowering. Furthermore, tartronic acid content was higher in early-harvested fruits compared to late-harvested ones, with the rear part of the fruit exhibiting significantly higher content than other parts. Foliar spraying of microbial agents increased tartronic acid content by 84.4%. This study provides valuable resources for breeding high tartronic acid cucumbers and offers practical insights for optimizing cucumber production practices.

3.
iScience ; 27(3): 109213, 2024 Mar 15.
Article in English | MEDLINE | ID: mdl-38439953

ABSTRACT

Patients with Graves' disease (GD) can develop Graves' ophthalmopathy (GO), but the underlying pathological mechanisms driving this development remain unclear. In our study, which included patients with GD and GO, we utilized single-cell RNA sequencing (scRNA-seq) and multiplatform analyses to investigate CD169+ classical monocytes, which secrete proinflammatory cytokines and are expanded through activated interferon signaling. We found that CD169+ clas_mono was clinically significant in predicting GO progression and prognosis, and differentiated into CD169+ macrophages that promote inflammation, adipogenesis, and fibrosis. Our murine model of early-stage GO showed that CD169+ classical monocytes accumulated in orbital tissue via the Cxcl12-Cxcr4 axis. Further studies are needed to investigate whether targeting circulating monocytes and the Cxcl12-Cxcr4 axis could alleviate GO progression.

4.
Int J Mol Sci ; 24(24)2023 Dec 06.
Article in English | MEDLINE | ID: mdl-38138999

ABSTRACT

Pre-harvest sprouting (PHS), the germination of seeds on the plant prior to harvest, poses significant challenges to agriculture. It not only reduces seed and grain yield, but also impairs the commodity quality of the fruit, ultimately affecting the success of the subsequent crop cycle. A deeper understanding of PHS is essential for guiding future breeding strategies, mitigating its impact on seed production rates and the commercial quality of fruits. PHS is a complex phenomenon influenced by genetic, physiological, and environmental factors. Many of these factors exert their influence on PHS through the intricate regulation of plant hormones responsible for seed germination. While numerous genes related to PHS have been identified in food crops, the study of PHS in vegetable crops is still in its early stages. This review delves into the regulatory elements, functional genes, and recent research developments related to PHS in vegetable crops. Meanwhile, this paper presents a novel understanding of PHS, aiming to serve as a reference for the study of this trait in vegetable crops.


Subject(s)
Plant Breeding , Vegetables , Vegetables/genetics , Germination/genetics , Phenotype , Seeds/genetics
5.
Int J Mol Sci ; 24(7)2023 Mar 29.
Article in English | MEDLINE | ID: mdl-37047408

ABSTRACT

Glandular trichomes (GTs), specialized structures formed by the differentiation of plant epidermal cells, are known to play important roles in the resistance of plants to external biotic and abiotic stresses. These structures are capable of storing and secreting secondary metabolites, which often have important agricultural and medicinal values. In order to better understand the molecular developmental mechanisms of GTs, studies have been conducted in a variety of crops, including tomato (Solanum lycopersicum), sweetworm (Artemisia annua), and cotton (Gossypium hirsutum). The MYC transcription factor of the basic helix-loop-helix (bHLH) transcription factor family has been found to play an important role in GT development. In this study, a total of 13 cucumber MYC transcription factors were identified in the cucumber (Cucumis sativus L.) genome. After performing phylogenetic analyses and conserved motifs on the 13 CsMYCs in comparison to previously reported MYC transcription factors that regulate trichome development, seven candidate MYC transcription factors were selected. Through virus-induced gene silencing (VIGS), CsMYC2 is found to negatively regulate GT formation while CsMYC4, CsMYC5, CsMYC6, CsMYC7, and CsMYC8 are found to positively regulate GT formation. Furthermore, the two master effector genes, CsMYC2 and CsMYC7, are observed to have similar expression patterns indicating that they co-regulate the balance of GT development in an antagonistic way.


Subject(s)
Cucumis sativus , Trichomes , Trichomes/genetics , Trichomes/metabolism , Cucumis sativus/metabolism , Phylogeny , Plant Proteins/genetics , Plant Proteins/metabolism , Basic Helix-Loop-Helix Transcription Factors/genetics , Basic Helix-Loop-Helix Transcription Factors/metabolism , Gossypium/genetics , Gene Expression Regulation, Plant
6.
Plant Physiol ; 192(4): 2723-2736, 2023 08 03.
Article in English | MEDLINE | ID: mdl-37099480

ABSTRACT

Glandular trichomes (GTs) are outgrowths of plant epidermal cells that secrete and store specialized secondary metabolites that protect plants against biotic and abiotic stresses and have economic importance for human use. While extensive work has been done to understand the molecular mechanisms of trichome organogenesis in Arabidopsis (Arabidopsis thaliana), which forms unicellular, nonglandular trichomes (NGTs), little is known about the mechanisms of GT development or regulation of secondary metabolites in plants with multicellular GTs. Here, we identified and functionally characterized genes associated with GT organogenesis and secondary metabolism in GTs of cucumber (Cucumis sativus). We developed a method for effective separation and isolation of cucumber GTs and NGTs. Transcriptomic and metabolomic analyses showed that flavonoid accumulation in cucumber GTs is positively associated with increased expression of related biosynthesis genes. We identified 67 GT development-related genes, the functions of 7 of which were validated by virus-induced gene silencing. We further validated the role of cucumber ECERIFERUM1 (CsCER1) in GT organogenesis by overexpression and RNA interference transgenic approaches. We further show that the transcription factor TINY BRANCHED HAIR (CsTBH) serves as a central regulator of flavonoid biosynthesis in cucumber GTs. Work from this study provides insight into the development of secondary metabolite biosynthesis in multicellular GTs.


Subject(s)
Arabidopsis , Cucumis sativus , Humans , Cucumis sativus/metabolism , Trichomes/metabolism , Gene Expression Profiling , Plants/genetics , Arabidopsis/genetics , Flavonoids/genetics , Flavonoids/metabolism , Gene Expression Regulation, Plant
7.
Sci Total Environ ; 828: 154390, 2022 Jul 01.
Article in English | MEDLINE | ID: mdl-35271931

ABSTRACT

Printing and dyeing wastewater generally has high pH, high turbidity, poor biodegradability, complex composition, and high chroma, which make it one of the most difficult industrial wastewaters to treat. Herein, heterogeneous ozone oxidation technology is applied to oxidize and degrade printing and dyeing wastewater. A metal oxide catalyst supported on activated carbon (γ-MnO2/AC) was prepared by hydrothermal synthetic method and shown to enable synergistic catalysis involving MnO2 metal sites and N/C sites. A simulated methyl orange solution was used to determine the effects of various preparation and operation parameters. The results confirmed that the γ-MnO2/AC catalyst exhibited good chemical oxygen demand (COD) removal and reusability. Additionally, γ-MnO2/AC demonstrated excellent degradation of the secondary biochemical effluent of printing and dyeing wastewater (COD removal = 72.45% within 120 min). The γ-MnO2/AC catalyst was fully characterized, and the mechanism governing its catalytic ozone oxidation process was investigated experimentally.


Subject(s)
Ozone , Water Pollutants, Chemical , Catalysis , Coloring Agents , Manganese/chemistry , Manganese Compounds/chemistry , Oxides/chemistry , Ozone/chemistry , Wastewater/chemistry , Water Pollutants, Chemical/analysis
8.
ACS Appl Mater Interfaces ; 13(8): 9436-9444, 2021 Mar 03.
Article in English | MEDLINE | ID: mdl-33306339

ABSTRACT

High levels of heat shock protein 70 (HSP70) in tumors are commonly associated with poor prognosis, enhanced doxorubicin (DOX)-induced cardiotoxicity, and even drug resistance in DOX-related cancer chemotherapy. Several peptides possess remarkable protein inhibition and chemosensitization effects, which are attributed to their specific targeting ability against HSP70. However, the inherent poor cell penetration capacity considerably restricts the biomedical applications of these peptides. We herein describe the design and development of anti-MUC1 aptamer-peptide conjugates (ApPCs) as targeted chemosensitizers to overcome the above-mentioned issues. Moreover, DOX could be loaded on the ApPC to deliver the DOX-enclosed agent ApPC-DOX, which simultaneously acts as a targeted chemosensitizer and anticancer agent for combating drug resistance in breast cancer therapy. This innovative, engineered biocompatible conjugate not only enhances the sensitivity of DOX-resistant cells but also alleviates cardiotoxicity of DOX in vivo, highlighting the success of this targeted chemosensitizer strategy.


Subject(s)
Antineoplastic Agents/therapeutic use , Aptamers, Nucleotide/therapeutic use , Breast Neoplasms/drug therapy , Doxorubicin/therapeutic use , Drug Carriers/therapeutic use , Peptides/therapeutic use , Animals , Antineoplastic Agents/toxicity , Apoptosis/drug effects , Aptamers, Nucleotide/metabolism , Breast Neoplasms/metabolism , Cardiotoxicity/prevention & control , DNA/metabolism , DNA/therapeutic use , Doxorubicin/toxicity , Drug Carriers/metabolism , Drug Resistance, Neoplasm/drug effects , Endocytosis/drug effects , HSP70 Heat-Shock Proteins/antagonists & inhibitors , Humans , MCF-7 Cells , Mice, Inbred BALB C , Mucin-1/metabolism , Myocardium/pathology , Peptides/metabolism , Xenograft Model Antitumor Assays
9.
J Colloid Interface Sci ; 580: 256-263, 2020 Nov 15.
Article in English | MEDLINE | ID: mdl-32683122

ABSTRACT

Antibiotic residues in wastewater have attracted great attention for their potential toxicity to environment. In this work, a zirconium-based metal-organic framework (PCN-777) was synthesized as adsorbent to remove cephalexin from water. Attributed to synergistic effect of the electrostatic interaction and coordination interaction between MOF framework and cephalexin, PCN-777 exhibits a high adsorption capacity of 442.48 mg·g-1, which is higher than those of reported adsorbents. The adsorption behavior follows Langmuir model and pseudo-second-order model. Besides, this MOF can be reused via a simple method. Therefore, PCN-777 may have a promising potential application for purification of waste water containing trace antibiotics.


Subject(s)
Metal-Organic Frameworks , Water Pollutants, Chemical , Adsorption , Cephalexin , Kinetics , Static Electricity , Water , Water Pollutants, Chemical/analysis , Zirconium
10.
Bioconjug Chem ; 31(7): 1766-1774, 2020 07 15.
Article in English | MEDLINE | ID: mdl-32463664

ABSTRACT

Although the extensive clinical use of the ADC trastuzumab-DM1(T-DM1) for human epidermal growth factor receptor 2 (HER2) targeted cancer therapy, many patients who initially respond to T-DM1 treatment eventually met the insufficient efficacy issue, which is partly attributed to the decreased amount of surface HER2 caused by HER2 degradation in target cells. In our study, we have engineered a HER2 targeted DNA aptamer-DM1 conjugate (HApDC) that can maintain the homeostasis of surface HER2 on the target cancer cell. These conclusions are supported by determining the efficient internalization of HApDC into HER2 overexpressed BT474 and SKBR3 cancer cell lines and by identifying the membranal HER2 level on HApDC-treated BT474 cells. Consistent with the impressive in vitro properties of our newly developed anticancer agent, DM1 could precisely be delivered to the tumor tissue in BT474 xenografted mouse models, because of the specific recognition of aptamer. Noteworthy, HApDC exhibited excellent in vivo tumor inhibition function with much lower healthy organ toxicity, compared with the free drug, which might be explained by the persistently targeted DM1 delivery, which is attributed to the remaining HER2 levels on cells.


Subject(s)
Antineoplastic Agents, Phytogenic/administration & dosage , Aptamers, Nucleotide/pharmacology , Homeostasis/drug effects , Maytansine/administration & dosage , Receptor, ErbB-2/metabolism , Animals , Antineoplastic Agents, Phytogenic/therapeutic use , Aptamers, Nucleotide/chemistry , Cell Line, Tumor , Humans , Maytansine/therapeutic use , Mice , Xenograft Model Antitumor Assays
11.
Int J Clin Exp Pathol ; 13(2): 172-178, 2020.
Article in English | MEDLINE | ID: mdl-32211097

ABSTRACT

The present study aimed to investigate the effect of arsenic trioxide (ATO) on the proliferation of retinal pigment epithelium (RPE) and its mechanism. RPE cells were cultivated with 0.5-11 µmol/L ATO for 24, 48, and 72 h and their survival and growth were measured by MTT assay. The expression of p27 and proliferating cell nuclear antigen (PCNA) in RPE cells was detected using cell immunofluorescence and western blotting. Dose-dependency was evident in both the experimental and control groups. The 50% inhibitory concentration was obtained at a concentration of 6 mol/L with cells treated for 3 days. The optimum concentration of ATO was 6 µmol/L based on the result of MTT. After the third day of ATO treatment, the number of cells was significantly lower in the experimental group compared with the control group. The expression of extracellular matrix (ECM) components decreased relative to the control group. The expression of p27 and PCNA declined gradually in cells treated for 72 h at 6 µmol/L ATO compared with the control group. The difference between the experimental and control groups was significant (P=0.005). ATO has the ability to inhibit the growth and proliferation of RPE cells by regulating the expression of the ECM components' p27 and PCNA, in a time- and dose-dependent manner. Thus, ATO may lead to an innovative method for the treatment of proliferative retinopathy.

12.
Int J Mol Sci ; 20(19)2019 Sep 29.
Article in English | MEDLINE | ID: mdl-31569563

ABSTRACT

Both the presence of, and the important contribution to growth and development made by TCP transcription factors, have been established in various plant species. Here, a TCP4 homolog isolated from Chrysanthemum nankingense was shown to be more strongly transcribed in the diploid than in the autotetraploid form of the species. CnTCP4 was shown to encode a member of the class II TCP family and to be transcribed most strongly in the leaf and ligulate flowers. Its transcription was found to be substantially inhibited by spraying the plant with the synthetic cytokinin 6-benzylaminopurine. The transient expression of CnTCP4 in onion epidermal cells showed that its product localized to the nucleus, and a yeast one hybrid assay suggested that its product had transcriptional activation ability. The constitutive expression of CnTCP4 in fission yeast suppressed cell proliferation, inducing the formation of longer and a higher frequency of multinuclated cells. Its constitutive expression in Arabidopsis thaliana reduced the size of the leaves. The presence of the transgene altered the transcription of a number of cell division-related genes. A yeast one hybrid assay identified a second TCP gene (CnTCP2) able to interact with the CnTCP4 promoter. A transient expression experiment in Nicotiana benthamiana leaves showed that CnTCP2 was able to activate the CnTCP4 promoter. Like CnTCP4, CnTCP2 was shown to encode a member of the class II TCP family, to be transcribed most strongly in the leaf and ligulate flowers, and to be suppressed by exogenous 6-benzylaminopurine treatment. The CnTCP2 protein also localized to the nucleus, but had no transcriptional activation ability. Its constitutive expression in A. thaliana had similar phenotypic consequences to those induced by CnTCP4.


Subject(s)
Arabidopsis/genetics , Cell Division/genetics , Chrysanthemum/genetics , Gene Expression , Transcription Factors/genetics , Yeasts/genetics , Amino Acid Sequence , Arabidopsis/classification , Arabidopsis/metabolism , Gene Expression Profiling , Phenotype , Phylogeny , Promoter Regions, Genetic , Transcriptome , Yeasts/classification , Yeasts/metabolism
13.
Org Lett ; 21(13): 5111-5115, 2019 07 05.
Article in English | MEDLINE | ID: mdl-31199659

ABSTRACT

A mild amination protocol of N-heteroaryl alkyl ethers with various amines is described. This transformation is achieved by utilizing simple and readily available base as promoter via C-O bond cleavage, offering a new amination strategy to access several anticancer-active compounds. This work is highlighted by the excellent functional group compatibility, scalability, wide substrate scope, and easy derivatization of a variety of drugs.


Subject(s)
Amines/chemistry , Amines/chemical synthesis , Antineoplastic Agents/chemistry , Antineoplastic Agents/chemical synthesis , Ethers/chemistry , Alkylation , Amination , Chemistry Techniques, Synthetic
14.
Plant Physiol Biochem ; 115: 239-248, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28395169

ABSTRACT

TCP transcription factors are important for plant growth and development, but their activity in chrysanthemum (Chrysanthemum morifolium) has not been thoroughly explored. Here, a chrysanthemum TCP-P sequence, which encodes a protein harboring the conserved basic helix-loop-helix (bHLH) motif, was shown to be related phylogenetically to the Arabidopsis thaliana gene AtTCP14. A yeast-one hybrid assay showed that the encoding protein had no transcriptional activation ability, and a localization experiment indicated that it was localized in the nucleus. Transcription profiling established that the gene was most active in the stem and leaf. Its heterologous expression in A. thaliana down-regulated certain cell cycle-related genes, reduced the size of various organs and increased the chlorophyll and carotenoid contents of the leaf which led to delayed senescence and a prolonged flowering period. Moreover, by screening the cDNA library of chrysanthemum, we found that the CmTCP14 can interact with CmFTL2 and some CmDELLAs.


Subject(s)
Arabidopsis/metabolism , Chrysanthemum/genetics , Plant Proteins/metabolism , Transcription Factors/metabolism , Arabidopsis/genetics , Arabidopsis/physiology , Gene Expression Regulation, Developmental/genetics , Gene Expression Regulation, Developmental/physiology , Gene Expression Regulation, Plant/genetics , Gene Expression Regulation, Plant/physiology , Organ Size/genetics , Organ Size/physiology , Plant Leaves/genetics , Plant Leaves/metabolism , Plant Proteins/genetics , Plants, Genetically Modified/genetics , Plants, Genetically Modified/metabolism , Plants, Genetically Modified/physiology , Transcription Factors/genetics , Transcriptional Activation/genetics , Transcriptional Activation/physiology
16.
Int J Ophthalmol ; 9(12): 1725-1731, 2016.
Article in English | MEDLINE | ID: mdl-28003970

ABSTRACT

AIM: To explore whether resveratrol (Res) can inhibit human retinal pigment epithelial cell (ARPE-19 cell) proliferation and migration, and to research the molecular mechanisms. METHODS: ARPE-19 cells were pretreated with various concentrations at 0, 50, 100, 150, 200 and 300 µmol/L of Res, and with 0 µmol/L Res as the control for 24, 48 and 72h. The cell proliferation, apoptosis and migration were measured with cell counting kit-8 (CCK-8), flow cytometry, and wound-healing and Transwell assays, respectively. The expression of proliferating cell nuclear antigen (PCNA), P21 and P27, as well as matrix metalloproteinase-9 (MMP-9) and p38 mitogen-activated protein kinases (p38MAPK) was identified by Western blot. RESULTS: Cell proliferation was effectively inhibited by Res (P<0.05). When pretreated with Res, cells arrested in S-phase increased remarkably (P<0.05), but the apoptosis ratios showed no significant difference between the treatment and control groups (P>0.05). Cell migration was suppressed by Res both in wound-healing assay and Transwell migration assay (P<0.05). Decreases of PCNA, MMP-9 and p38MAPK, as well as increases of P21 and P27 were detected by Western blot (P<0.05). CONCLUSION: Res can inhibit APRE-19 cell proliferation and migration in a concentration-dependent manner with up-regulation of the expression of P21 and P27, and down-regulation of PCNA, MMP-9 and p38MAPK.

17.
Elife ; 52016 11 18.
Article in English | MEDLINE | ID: mdl-27855782

ABSTRACT

Neuromodulators shape neural circuit dynamics. Combining electron microscopy, genetics, transcriptome profiling, calcium imaging, and optogenetics, we discovered a peptidergic neuron that modulates C. elegans motor circuit dynamics. The Six/SO-family homeobox transcription factor UNC-39 governs lineage-specific neurogenesis to give rise to a neuron RID. RID bears the anatomic hallmarks of a specialized endocrine neuron: it harbors near-exclusive dense core vesicles that cluster periodically along the axon, and expresses multiple neuropeptides, including the FMRF-amide-related FLP-14. RID activity increases during forward movement. Ablating RID reduces the sustainability of forward movement, a phenotype partially recapitulated by removing FLP-14. Optogenetic depolarization of RID prolongs forward movement, an effect reduced in the absence of FLP-14. Together, these results establish the role of a neuroendocrine cell RID in sustaining a specific behavioral state in C. elegans.


Subject(s)
Caenorhabditis elegans/physiology , Neural Pathways/drug effects , Neurons/physiology , Neuropeptides/metabolism , Neurosecretory Systems/physiology , Neurotransmitter Agents/metabolism , Animals , Behavior, Animal , Locomotion , Neurons/metabolism
18.
Int J Ophthalmol ; 8(1): 138-47, 2015.
Article in English | MEDLINE | ID: mdl-25709924

ABSTRACT

AIM: To systematically compare the efficacy and safety of off-label bevacizumab versus licensed ranibizumab intravitreal injections as well as monthly regimen versus pro re nata [PRN (as needed)] regimen in the treatment of neovascular age-related macular degeneration (nAMD). METHODS: Relevant publications were identified through automatically retrieve of database and manually retrieving. The methodological quality of studies included was assessed using the Jadad score and the risk-of-bias assessment. The efficacy estimates were measured by the weight mean difference (WMD) for the improvement of best-corrected visual acuity (BCVA) and central retinal thickness (CRT) reduction. The safety estimates were measured by odds ratios (OR) for adverse events rates. Statistical analysis was conducted by Revman 5.2.7. RESULTS: Seven studies were included in the Meta-analysis. There were no statistically significant differences between bevacizumab and ranibizumab in BCVA at 1 and 2y (P=0.37, P=0.18, respectively), However, both drugs has better BCVA given monthly than given as needed at 1 and 2y (P<0.05). The results demonstrated the mean decrease in CRT was less in bevacizumab group than ranibizumab group at 1y (P<0.05), while the difference was not significant at 2y (P=0.24). Treatment monthly gained much more decrease in CRT at 1 and 2y (P<0.005). There were no differences between drugs in the rates of death, arterial thrombotic events and venous thrombotic events (P=0.41, P=0.55, P=0.10, respectively), while the rates of medical dictionary for regulatory activities (MedDAR) system organ class events and ≥1 systemic serious adverse events were higher in bevacizumab group than ranibizumab group (P<0.05). But the incidences of death, arterial thrombotic events, venous thrombotic events, MedDAR system organ class events as well as ≥1 systemic serious adverse events were not statistically different between both treatment regimens of monthly and as needed (P=0.14, P=0.76, P=0.73, P=0.12, P=0.11, respectively). CONCLUSION: Bevacizumab was equivalent to ranibizumab for BCVA, however bevacizumab tended to gain less decrease in CRT and had higher rates of serious adverse events. Compared with treatment as needed, treatment monthly showed superior efficacy in BCVA improvement and CRT reduction, while the rates of adverse events were similar in the two dosing regimens.

19.
Analyst ; 138(2): 659-65, 2013 Jan 21.
Article in English | MEDLINE | ID: mdl-23181258

ABSTRACT

The electrospray ionization (ESI) is a complex process and there has been a long debate regarding the gas-phase effect on ion generation in the process. In this paper we investigated the effect of liquid chromatographic mobile phase additives (formic acid, aqueous ammonia and their combination) on the ESI signal intensities for a wide variety of compounds. The addition of a trace amount of aqueous ammonia to the common formic acid-methanol mobile phase significantly enhances the ESI signals of protonated molecules and suppresses the formation of sodium adduct ions. This effect is well observed for the compounds containing the -N-C=O group but not for those without N or O atoms. The ESI signal intensity of deprotonated molecules increases with increase in pH of the mobile phase for neutral compounds, such as substituted urea, whereas this trend is not observed for acidic compounds such as phenoxy acids. The mechanistic analysis regarding liquid- and gas-phase protonation and deprotonation is discussed.


Subject(s)
Quaternary Ammonium Compounds/chemistry , Spectrometry, Mass, Electrospray Ionization/methods , Aldicarb/analysis , Aldicarb/chemistry , Atrazine/analysis , Atrazine/chemistry , Carbon/chemistry , Formates/chemistry , Hydrogen-Ion Concentration , Methanol/chemistry , Nitrogen/chemistry , Oxygen/chemistry , Simazine/analysis , Simazine/chemistry
20.
Mol Vis ; 18: 601-5, 2012.
Article in English | MEDLINE | ID: mdl-22419853

ABSTRACT

PURPOSE: To investigate whether transfection with Krüppel-like factor 6 splice variant 1 (KLF6SV1) siRNA can inhibit proliferation of human lens epithelial cell (HLEC). METHODS: Plasmid containing KLF6SV1 siRNA was used to decrease the level of KLF6SV1 protein in HLEC. The expression of protein27 kinase inhibition protein 1 (p27(kip1)) and proliferation cell nuclear antigen (PCNA) was tested with western blot. Cell proliferation was assayed by 3-(4,5-dimethylthiazolyl-2-)-2,5-diphenyltetrazoliumbromide (MTT) assay and bromodeoxyuridine (BrdU) incorporation. RESULTS: KLF6SV1 siRNA can decrease KLF6SV1 expression which leads to increased levels of p27(kip1) and decreased expression of PCNA in HLEC. Cells transfected with pKLF6SV1 siRNA showed less viability compared with the control group in vitro. CONCLUSIONS: KLF6SV1 siRNA can effectively inhibit HLEC proliferation. It can be regarded as a novel target to treat posterior capsular opacity (PCO).


Subject(s)
Epithelial Cells/cytology , Kruppel-Like Transcription Factors/metabolism , Lens, Crystalline/cytology , Proto-Oncogene Proteins/metabolism , RNA, Small Interfering/metabolism , Cell Proliferation , Cell Survival/genetics , Cells, Cultured , Cyclin-Dependent Kinase Inhibitor p27/genetics , Cyclin-Dependent Kinase Inhibitor p27/metabolism , Epithelial Cells/metabolism , Gene Expression , Humans , Kruppel-Like Factor 6 , Kruppel-Like Transcription Factors/genetics , Lens, Crystalline/metabolism , Plasmids , Proliferating Cell Nuclear Antigen/genetics , Proliferating Cell Nuclear Antigen/metabolism , Proto-Oncogene Proteins/genetics , RNA, Small Interfering/genetics , Signal Transduction , Transfection
SELECTION OF CITATIONS
SEARCH DETAIL
...