RESUMO
Objective To develop a method for the quantification of amino acids and organic acids in trace urine by high performance liquid chromatography-tandem mass spectrometry.Methods Random urine samples(10 µl each)were precipitated by acetonitrile and underwent derivatization with 3 mol/L HCl in n-butanol.The analytes were separated by ACE Excel 2 AQ column(50×2.1 mm,2 µm).Electrospray ionization in positive ion mode was carried out and the analytes were detected in multiple reaction monitoring mode.According to existing guidelines,the method was systematically evaluated in terms of sensitivity,specificity,accuracy,precision,recovery,matrix effect,and stability.Then,the established method was employed to detect 19 target compounds in urine samples from 70 healthy children,27 children with suspected vitamin B12 deficiency,and 3 children with cblC type methylmalonic acidemia.Results The lower limit of quantification of the method for the 19 compounds ranged from 0.01 µmol/L to 1.00 µmol/L,and the calibration curves were linear,R2>0.990.The method showed good accuracy with relative error less than ±15% and the intra-day and intra-day precision less than 15%.The run time was 8 min.No obvious matrix effect was detected except for arginine,and the recovery ranged from 80.20% to 114.97%.The samples were stable after 8 h at room temperature and 3 freeze-thaw cycles.The measured values of the compounds in the urine of healthy children were within the children's reference intervals published by Labcorp.The levels of methylmalonic acid(P=0.030)and homocysteine(P<0.001)in the urine samples of children with suspected vitamin B12 deficiency were higher than those in healthy children.The levels of methylmalonic acid,methylcitric acid,and homocysteine in the urine samples of children with cblC type methylmalonic acidemia were 5.14-76.52 times higher than the median levels of healthy children. Conclusions The method established in this study has small sample demand and short run time,which can accurately quantify the levels of amino acids and metabolites in the urine of children.Moreover,it can provide data support for related studies about the metabolic characteristics of urine amino acids and their metabolites in children with vitamin B12 deficiency.
Assuntos
Aminoácidos , Deficiência de Vitamina B 12 , Criança , Humanos , Aminoácidos/química , Aminoácidos/urina , Espectrometria de Massas em Tandem/métodos , Estado Nutricional , Vitamina B 12 , Ácido Metilmalônico , Limite de Detecção , Cromatografia Líquida de Alta Pressão/métodosRESUMO
Dibutyl phthalate (DBP) is used worldwide in solvents and plasticizers. The cytotoxicity and potential tumorigenic effect of DBP have been reported. DBP has also been shown to impact reproductive function. In this study, to further evaluate the effects of DBP on granulosa cells (GCs), we treated rat GCs in vitro with DBP before evaluation of the biological alterations of these GCs. We found that DBP did not induce significant GC death at the tested concentrations. However, follicle-stimulating hormone (FSH)-induced KIT ligand (KITLG) expression in GCs was significantly reduced at both mRNA and protein levels by DBP treatment in a dose-dependent manner. The down-regulation of KITLG was due to the down-regulation of expression of FSH receptor (FSHR) in GCs. Down-regulation of FSHR impaired FSH-induced intracellular signaling in GCs, demonstrated by decreased phosphorylation of AKT and mechanistic target of rapamycin (mTOR). Furthermore, DBP treatment also reduced FSH-induced expression of hypoxia-inducible factor 1-alpha (HIF1A), which is an important signaling component for KITLG expression. Other FSH-induced biological effects, such as production of estradiol and progesterone, as well as GC proliferation, were also suppressed by DBP. Therefore, our study discovered a unique mechanism underlying the toxicity of DBP on GCs. These findings may initiate the development of novel therapeutic interventions for DBP-induced damage to GCs.
Assuntos
Dibutilftalato/toxicidade , Hormônio Foliculoestimulante/metabolismo , Células da Granulosa/efeitos dos fármacos , Plastificantes/toxicidade , Receptores do FSH/metabolismo , Animais , Células Cultivadas , Regulação para Baixo , Feminino , Células da Granulosa/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Ratos Sprague-Dawley , Fator de Células-Tronco/metabolismoRESUMO
This article explores the intricate interplay between inorganic nanoparticles and Earth's biochemical history, with a focus on their electron transfer properties. It reveals how iron oxide and sulfide nanoparticles, as examples of inorganic nanoparticles, exhibit oxidoreductase activity similar to proteins. Termed "life fossil oxidoreductases," these inorganic enzymes influence redox reactions, detoxification processes, and nutrient cycling in early Earth environments. By emphasizing the structural configuration of nanoparticles and their electron conformation, including oxygen defects and metal vacancies, especially electron hopping, the article provides a foundation for understanding inorganic enzyme mechanisms. This approach, rooted in physics, underscores that life's origin and evolution are governed by electron transfer principles within the framework of chemical equilibrium. Today, these nanoparticles serve as vital biocatalysts in natural ecosystems, participating in critical reactions for ecosystem health. The research highlights their enduring impact on Earth's history, shaping ecosystems and interacting with protein metal centers through shared electron transfer dynamics, offering insights into early life processes and adaptations.
RESUMO
Oxidoreductases play crucial roles in electron transfer during biological redox reactions. These reactions are not exclusive to protein-based biocatalysts; nano-size (<100 nm), fine-grained inorganic colloids, such as iron oxides and sulfides, also participate. These nanocolloids exhibit intrinsic redox activity and possess direct electron transfer capacities comparable to their biological counterparts. The unique metal ion architecture of these nanocolloids, including electron configurations, coordination environment, electron conductivity, and the ability to promote spontaneous electron hopping, contributes to their transfer capabilities. Nano-size inorganic colloids are believed to be among the earliest 'oxidoreductases' to have 'evolved' on early Earth, playing critical roles in biological systems. Representing a distinct type of biocatalysts alongside metalloproteins, these nanoparticles offer an early alternative to protein-based oxidoreductase activity. While the roles of inorganic nano-sized catalysts in current Earth ecosystems are intuitively significant, they remain poorly understood and underestimated. Their contribution to chemical reactions and biogeochemical cycles likely helped shape and maintain the balance of our planet's ecosystems. However, their potential applications in biomedical, agricultural, and environmental protection sectors have not been fully explored or exploited. This review examines the structure, properties, and mechanisms of such catalysts from a material's evolutionary standpoint, aiming to raise awareness of their potential to provide innovative solutions to some of Earth's sustainability challenges.
RESUMO
ABSTRACT: Platelet-rich plasma (PRP) shows promise as a regenerative modality for mild-to-moderate erectile dysfunction (ED). However, its efficacy in treating severe ED remains unknown. Blood samples from 8-week-old male rats were used to prepare PRP through a two-step centrifugation procedure, followed by chitosan activation and freeze thaw cycle. A hyperhomocysteinemia (HHcy)-related ED model was established using a methionine-enriched diet, and an apomorphine (APO) test was conducted during the 4 th week. APO-negative rats were divided into two groups and were injected with PRP or saline every 2 weeks. Erectile function and histological analyses of the corpus cavernosum were performed during the 16 th week. The results revealed that erectile function was significantly impaired in rats with HHcy-related ED compared to that in age-matched rats but was improved by repeated PRP injections. Immunofluorescence staining revealed a reduction in reactive oxygen species and additional benefits on the recovery of structures within the corpus cavernosum in rats that received PRP treatment compared to those in the saline-injected control group. Therefore, PRP could enhance functional and structural recovery in a severe HHcy-related ED model. A notable strength of the present study lies in the use of a repeated intracavernous injection method, mirroring protocols used in human studies, which offers more reliable results for translating the findings to humans.
Assuntos
Modelos Animais de Doenças , Disfunção Erétil , Hiper-Homocisteinemia , Pênis , Plasma Rico em Plaquetas , Ratos Sprague-Dawley , Animais , Masculino , Hiper-Homocisteinemia/terapia , Hiper-Homocisteinemia/complicações , Disfunção Erétil/terapia , Disfunção Erétil/etiologia , Ratos , Espécies Reativas de Oxigênio/metabolismo , Ereção Peniana/fisiologia , Apomorfina/administração & dosagemRESUMO
BACKGROUND: The midpoint transverse process to pleura (MTP) block, a novel technique for thoracic paravertebral block (TPVB), was first employed in laparoscopic renal cyst decortication. CASE SUMMARY: Thoracic paravertebral nerve block is frequently employed for perioperative analgesia during laparoscopic cyst decortication. To address safety concerns associated with TPVBs, we administered MTP blocks in two patients prior to administering general anesthesia for laparoscopic cyst decortication. The MTP block was performed at the T9 level under ultrasound guidance, with 20 mL of 0.5% ropivacaine injected. Reduced sensation to cold and pinprick was observed from the T8 to T11 dermatome levels. Immediately postoperative Numeric Pain Rating Scale scores were 0/10 at rest and on movement, with none exceeding a mean 24 h numeric rating scale > 3. CONCLUSION: MTP block was effective technique for providing postoperative analgesia for patients undergoing laparoscopic renal cyst decortication.
RESUMO
Epithelial ovarian cancer is the most lethal gynecological malignant tumor. Although debulking surgery, chemotherapy, and PARP inhibitors have greatly improved survival, the prognosis for patients with advanced EOC without HRD is still poor. LLGL2, as a cell polarity factor, is involved in maintaining cell polarity and asymmetric cell division. In the study of zebrafish development, LLGL2 regulated the proliferation and migration of epidermal cells and the formation of cortical F-actin. However, the role of LLGL2 in ovarian cancer has not been described. Our study found, through bioinformatics analysis, that low expression of LLGL2 was significantly associated with a more advanced stage and a higher grade of EOC and a poorer survival of patients. Functional experiments that involved LLGL2 overexpression and knockdown showed that LLGL2 inhibited the migration and invasion abilities of ovarian cancer cells in vitro, without affecting their proliferation. LLGL2-overexpressing mice had fewer metastatic implant foci than the controls in vivo. Mechanistically, immunoprecipitation combined with mass spectrometry analysis suggested that LLGL2 regulated cytoskeletal remodeling by interacting with ACTN1. LLGL2 altered the intracellular localization and function of ACTN1 without changing its protein and mRNA levels. Collectively, we uncovered that LLGL2 impaired actin filament aggregation into bundles by interacting with ACTN1, which led to cytoskeleton remodeling and inhibition of the invasion and metastasis of ovarian cancer cells.
RESUMO
BACKGROUND: Endothelial-mesenchymal transition (EndoMT) is an emerging adaptive process that modulates lymphatic endothelial function to drive aberrant lymphatic vascularization in the tumour microenvironment (TME); however, the molecular determinants that govern the functional role of EndoMT remain unclear. Here, we show that cancer-associated fibroblast (CAF)-derived PAI-1 promoted the EndoMT of lymphatic endothelial cells (LECs) in cervical squamous cell carcinoma (CSCC). METHODS: Immunofluorescent staining of α-SMA, LYVE-1 and DAPI were examined in primary tumour samples obtained from 57 CSCC patients. Assessment of cytokines secreted by CAFs and normal fibroblasts (NFs) was performed using human cytokine antibody arrays. The phenotype of EndoMT in lymphatic endothelial cells (LECs), gene expression levels, protein secretion and activity of signaling pathways were measured by real-time RT-PCR, ELISA or western blotting. The function of lymphatic endothelial monolayers was examined by transwell, tube formation assay, transendothelial migration assay in vitro. Lymphatic metastasis was measured using popliteal lymph node metastasis model. Furthermore, association between PAI-1 expression and EndoMT in CSCC was analyzed by immunohistochemistry. The Cancer Genome Atlas (TCGA) databases was used to assess the association of PAI-1 with survival rate in CSCC. RESULTS: CAF-derived PAI-1 promoted the EndoMT of LECs in CSCC. LECs undergoing EndoMT could initiate tumour neolymphangiogenesis that facilitated cancer cell intravasation/extravasation, which in turn promoted lymphatic metastasis in CSCC. Mechanistically, PAI-1 activated the AKT/ERK1/2 pathways by directly interacting with low-density lipoprotein receptor-related protein (LRP1), thereby leading to elevated EndoMT activity in LECs. Blockade of PAI-1 or inhibition of LRP1/AKT/ERK1/2 abrogated EndoMT and consequently attenuated CAF-induced tumour neolymphangiogenesis. Furthermore, clinical data revealed that increased PAI-1 levels positively correlated with EndoMT activity and poor prognosis in CSCC patients. CONCLUSION: Our data indicate that CAF-derived PAI-1 acts as an important neolymphangiogenesis-initiating molecular during CSCC progression through modulating the EndoMT of LECs, resulting in promotion of metastasis ability in primary site. PAI-1 could serve as an effective prognostic biomarker and therapeutic target for CSCC metastasis.
Assuntos
Fibroblastos Associados a Câncer , Células Endoteliais , Feminino , Humanos , Movimento Celular/genética , Células Endoteliais/metabolismo , Metástase Linfática , Inibidor 1 de Ativador de Plasminogênio/genética , Inibidor 1 de Ativador de Plasminogênio/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Microambiente TumoralRESUMO
OBJECTIVE: To identify the chemical components and their relative content in seeds oil from Croton tiglium. METHODS: The oil obtained by extracting of the seeds of Croton tiglium with petroleum ether was subjected to methyl-esterification or dilution with ethylether. GC-MS were used to identify the components in croton oil,peak area normalization method was used to determine the relative content of these substances in the sample. RESULTS: Seventeen fat acid components were identified from croton oil. The main components were linoleic acid, oleic acid, and eicosenoic acid in methyl-esterified sample, whose quantities accouted for 77.33%. In addition, five aromatic compounds were also found in the sample diluted with ethylether, such as isoborneol, fenchyl alcohol, etc. Phorbol esters, having carcinogenesis and anti-HIV-1 effects, were not been identified. CONCLUSION: There are abundant of linoleic acid, oleic acid and eicosenoic acid in the seeds oil extracted from Chinese Croton tiglium. In contrast, the active component with carcinogenesis and anti-HIV-1 might be very rare in the samples and difficult to be obtained by ordinary separating and extracting methods.
Assuntos
Óleo de Cróton/química , Croton/química , Ácidos Graxos/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Sementes/química , Óleo de Cróton/isolamento & purificação , Ácidos Graxos/química , Ácido Linoleico/análise , Ácido Linoleico/química , Estrutura Molecular , Norbornanos/análise , Norbornanos/química , Ácido Oleico/análise , Ácido Oleico/químicaRESUMO
Pogostemon cablin Benth (PCB) is a well-known traditional Chinese medicine that has been used for treatment of many ailments for several centuries. In presently, the chemical profiling and quality control study of PCB has mainly concentrated on the volatile fractions. However, the non-volatile chemical profile of PCB was still unclear. In this study, 73 non-volatile constituents (i.e., 33 flavonoids, 21 organic acids, 9 phenylpropanoids, 4 sesquiterpenes, 3 alkaloids, and 3 other types of compounds) were identified and characterized in PCB using high performance liquid chromatography coupled with quadruple time-of-flight tandem mass spectrometry (HPLC-Q-TOF-MS). Meanwhile, to assess PCB samples, an established HPLC-Q-TOF-MS fingerprint was combined with multivariate statistical analysis that included similarity analysis (SA), hierarchical cluster analysis (HCA), principal component analysis (PCA), and orthogonal partial least squares-discriminant analysis (OPLS-DA). The PCB samples could be classified into two groups (herbal decoction pieces and processed medicinal materials), and acteoside, isoacteoside, 4',6-Dihydroxy-5,7-dimethoxyflavone, pachypodol and pogostone were screened as the potential chemical markers that attributed classification. In addition, nine representative components (pachypodol, vicenin-2, apigenin, rhamnocitrin, acteoside, isoacteoside, chlorogenic acid, azelaic acid and pogostone) in PCB were simultaneously determined by using an ultra-high-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry (UPLC-QQQ-MS/MS). This study is the first to describe the chemical profile of PCB using liquid chromatography tandem mass spectrometry, which would improve our understanding of the substance basis of PCB and is helpful to the PCB further quality evaluation.
Assuntos
Medicamentos de Ervas Chinesas , Pogostemon , Cromatografia Líquida de Alta Pressão , Medicamentos de Ervas Chinesas/análise , Pogostemon/química , Espectrometria de Massas em TandemRESUMO
Myeloperoxidase is an important inflammatory factor in the myeloid system, primarily expressed in neutrophils and microglia. Myeloperoxidase and its active products participate in the occurrence and development of hemorrhagic and ischemic stroke, including damage to the blood-brain barrier and brain. As a specific inflammatory marker, myeloperoxidase can be used in the evaluation of vascular disease occurrence and development in stroke, and a large amount of experimental and clinical data has indicated that the inhibition or lack of myeloperoxidase has positive impacts on stroke prognosis. Many studies have also shown that there is a correlation between the overexpression of myeloperoxidase and the risk of stroke. The occurrence of stroke not only refers to the first occurrence but also includes recurrence. Therefore, myeloperoxidase is significant for the clinical evaluation and prognosis of stroke. This paper reviews the potential role played by myeloperoxidase in the development of vascular injury and secondary brain injury after stroke and explores the effects of inhibiting myeloperoxidase on stroke prognosis. This paper also analyzes the significance of myeloperoxidase etiology in the occurrence and development of stroke and discusses whether myeloperoxidase can be used as a target for the treatment and prediction of stroke.
RESUMO
Our previous studies on the phosphate sorption on sediments in Florida Bay at 25 °C in salinity 36 seawater revealed that the sorption capacity varies considerably within the bay but can be attributed to the content of sedimentary P and Fe. It is known that both temperature and salinity influence the sorption process and their natural variations are the greatest in estuaries. To provide useful sorption parameters for modeling phosphate cycle in Florida Bay, a systematic study was carried out to quantify the effects of salinity and temperature on phosphate sorption on sediments. For a given sample, the zero equilibrium phosphate concentration and the distribution coefficient were measured over a range of salinity (2-72) and temperature (15-35 °C) conditions. Such a suite of experiments with combinations of different temperature and salinity were performed for 14 selected stations that cover a range of sediment characteristics and geographic locations of the bay. Phosphate sorption was found to increase with increasing temperature or decreasing salinity and their effects depended upon sediment's exchangeable P content. This study provided the first estimate of the phosphate sorption parameters as a function of salinity and temperature in marine sediments. Incorporation of these parameters in water quality models will enable them to predict the effect of increasing freshwater input, as proposed by the Comprehensive Everglades Restoration Plan, on the seasonal cycle of phosphate in Florida Bay.
Assuntos
Baías/química , Sedimentos Geológicos/química , Fosfatos/química , Salinidade , Temperatura , Adsorção , Florida , Geografia , Estações do AnoRESUMO
Dissolved organic phosphorus (DOP) has been recognized as dominant components in total dissolved phosphorus (TDP) pools in many coastal waters, and its exchange between sediment and water is an important process in biogeochemical cycle of phosphorus. Adenosine monophosphate (AMP) was employed as a model DOP compound to simulate phosphorus exchange across sediment-water interface in Florida Bay. The sorption data from 40 stations were fitted to a modified Freundlich equation and provided a detailed spatial distribution both of the sediment's zero equilibrium phosphorus concentration (EPC(0-T)) and of the distribution coefficient (K(d-T)) with respect to TDP. The K(d-T) was found to be a function of the index of phosphorus saturation (IPS), a molar ratio of the surface reactive phosphorus to the surface reactive iron oxide content in the sediment, across the entire bay. However, the EPC(0-T) was found to correlate to the contents of phosphorus in the eastern bay only. Sediment in the western bay might act as a source of the phosphorus in the exchange process due to their high EPC(0-T) and low K(d-T), whereas sediments in the eastern bay might act as a sink because of their low EPC(0-T) and high K(d-T). These results strongly support the hypothesis that both phosphorus and iron species in calcareous marine sediments play a critical role in governing the sediment-water exchange of both phosphate and DOP in the coastal and estuarine ecosystems.
Assuntos
Monofosfato de Adenosina/química , Sedimentos Geológicos/química , Água do Mar/química , Florida , TermodinâmicaRESUMO
The growth of uniform nanostructures requires simple and reproducible ways to control the size. It is found that Co atoms can form two-dimensional structural islands on â3 x â3-Ag/Ge(111) surfaces. Temperature and Co coverage are two factors to modulate the island size. By using scanning tunneling microscopy, the surface structures and morphology for different annealing temperatures and variable Co coverage have been investigated. For 100 degrees C annealing temperature, Co atoms are difficult to condense into structural islands at 0.35 ML whereas several structural Co islands are found at 1.4 ML. This difference is due to the quantity of Co atoms per unit area for forming structural islands. As the temperature increases, Co atoms get more energy to diffuse. Therefore, the average island size increases with rising temperatures until the coverage of 3.5 ML. Yet, the island size stops growing above the coverage of 3.5 ML because of the limitation for the Co covered area. Therefore the Co islands increase their height rather than their size. In addition, the shape of Co islands can also be controlled. It transforms from random shapes to the hexagonal shape with increasing temperature.
RESUMO
It has been challenging to develop deep blue organic molecular fluorescent emitters with CIE y (yâ¯≤â¯0.08) based on triplet-triplet annihilation (TTA). Here, we report facilely available dianthracenylphenylene-based emitters, which have a 3,5-di(4-t-butylphenyl)phenyl moiety at the one end and 4-cyanophenyl or 3-pyridyl at the other end, respectively. Both fluorophores show a high glass transition temperature of over 220⯰C with a thermal decomposition temperature of over 430⯰C at an initial weight loss of 1%. The preliminary characterizations of the organic light-emitting diodes (OLEDs) that utilized these nondoped emitters provided high EQEs of 4.6%-5.9% with CIE coordinates (0.15, 0.07-0.08). The analysis of the EL transient decay revealed that TTA contributed to the observed performance. The results show that the new emitters are attractive as a potential TTA-based host to afford stable deep blue fluorescent OLEDs.
RESUMO
Three chemicals-ferrous sulfate (FeSul), calcium oxide (CaO), and aluminum sulfate (alum)-were applied at different rates to stabilize P in fresh, anaerobically digested biosolids (FBS) obtained from an activated sewage treatment plant. A modified Hedley fractionation procedure was used to assess P forms in these sludge-borne materials and in a biosolids compost (BSC) prepared from the same FBS. Each biosolids material exhibited a unique pattern of P distribution among fractions. The most available P forms, namely: (i) water-soluble P (WSP); (ii) membrane-P; and (iii) NaHCO(3)-P, were stabilized by small rates of each of the chemicals; but the P transformation into more stable forms depended on the type of chemical added. The stabilized P forms were enhanced by high rates of CaO and FeSul, but were reduced by high rates of alum. The organic P (P(o)) in the first three fractions of the FeSul- and alum-stabilized biosolids was enhanced by the chemical addition, and P(o) transformation from NaOH-P(o) into NaHCO(3)-P(o) was found in calcium-stabilized biosolids. A positive relationship was found between NaHCO(3)-P(o) and the NaHCO(3)-extracted organic C in all chemically stabilized biosolids. One-step extraction by NaHCO(3) or NaOH underestimated P extraction compared to the stepwise extraction. The reported results are consistent with solid-state P speciation reported earlier and contribute important information for optimizing biosolids stabilization to reduce P loss after incorporation in soils and for maximizing soil capacity to safely store pre-stabilized biosolids.
Assuntos
Fósforo/química , Esgotos/química , Compostos de Alúmen/química , Compostos de Cálcio/química , Carbono/química , Compostos Ferrosos/química , Óxidos/química , SoloRESUMO
Phosphorus ester hydrolysis is one of the key chemical processes in biological systems, including signaling, free-energy transaction, protein synthesis, and maintaining the integrity of genetic material. Hydrolysis of this otherwise kinetically stable phosphoester and/or phosphoanhydride bond is induced by enzymes such as purple acid phosphatase. Here, I report that, as in previously reported aged inorganic iron ion solutions, the iron oxide nanoparticles in the solution, which are trapped in a dialysis membrane tube filled with the various iron oxides, significantly promote the hydrolysis of the various phosphate esters, including the inorganic polyphosphates, with enzyme-like kinetics. This observation, along with those of recent studies of iron oxide, vanadium pentoxide, and molybdenum trioxide nanoparticles that behave as mimics of peroxidase, bromoperoxidase, and sulfite oxidase, respectively, indicates that the oxo-metal bond in the oxide nanoparticles is critical for the function of these corresponding natural metalloproteins. These inorganic biocatalysts challenge the traditional concept of replicator-first scenarios and support the metabolism-first hypothesis. As biocatalysts, these inorganic nanoparticles with enzyme-like activity may work in natural terrestrial environments and likely were at work in early Earth environments as well. They may have played an important role in the C, H, O, S, and P metabolic pathway with regard to the emergence and early evolution of life. Key Words: Enzyme-Hydrolysis-Iron oxide-Nanoparticles-Origin of life-Phosphate ester. Astrobiology 18, 294-310.
Assuntos
Biocatálise , Ésteres/química , Compostos Férricos/química , Nanopartículas/química , Trifosfato de Adenosina/química , Concentração de Íons de Hidrogênio , Hidrólise , Cinética , Fosfatos/química , Soluções , TemperaturaRESUMO
There has been an increasing demand for high-performance and cost-effective organic electron-transport materials for organic light-emitting diodes (OLEDs). In this contribution, we present a simple compound 3-(3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)-1,10-phenanthroline through the facile Pd-catalyzed coupling of a triphenyltriazine boronic ester with 3-bromo-1,10-phenanthroline. It shows a high Tg of 112⯰C. The ultraviolet photoelectron spectroscopy measurements reveal a deep HOMO level of -6.5â¯eV. The LUMO level is derived as -3.0â¯eV, based on the optical bandgap. The low-temperature solid-state phosphorescent spectrum gives a triplet energy of â¼2.36â¯eV. n-Doping with 8-hydroxyquinolatolithium (Liq, 1:1) leads to considerably improved electron mobility of 5.2â¯×â¯10-6-5.8â¯×â¯10-5â¯cm2â¯V-1â¯s-1 at Eâ¯=â¯(2-5)â¯×â¯105â¯Vâ¯cm-1, in contrast with the triarylphosphine oxide-phenantroline molecular conjugate we reported previously. It has been shown that through optimizing the device structure and hence suppressing polaron-exciton annihilation, introducing this single Liq-doped electron-transport layer could offer high-efficiency and stable phosphorescent OLEDs.
RESUMO
Stabilization of phosphorus (P) in sewage sludge (biosolids) to reduce water-soluble P concentrations is essential for minimizing P loss from amended soils and maximizing the capacity of the soil to safely serve as an outlet for this waste material. The chemical form at which P is retained in biosolids stabilized by Al(2)(SO(4))(3) x 18H(2)O (alum) or FeSO(4) x 7H(2)O (FeSul) was investigated by scanning electron microscopy (SEM) equipped with energy-dispersive X-ray elemental spectrometry (EDXS) and by X-ray diffraction (XRD). Both treatments resulted in the formation of a Ca-P phase, probably brushite. Phosphorus was further retained in the alum-treated biosolids by precipitation of an Al-P phase with an Al/P molar ratio of about 1:1, while in the FeSul-treated biosolids, P was retained by both precipitation with Fe/P molar ratios of 1:1 or 1.5:1, and by adsorption onto newly formed Fe hydroxides exhibiting an Fe/P molar ratio of up to 11:1. All of these mechanisms efficiently reduced P solubility and are crucial in biosolids environmentally safe agronomic beneficial use for this waste product; however, each P phase formed may react differently in the amended soil, depending on soil properties. Thus, the proper P stabilization method would depend on the target soil.
Assuntos
Compostos de Alúmen/química , Compostos Ferrosos/química , Fósforo/química , Esgotos/química , Alumínio/química , Cálcio/química , Ferro/química , Enxofre/química , Eliminação de Resíduos Líquidos/métodosRESUMO
OBJECTIVE: To establish the fingerprint chromatogram of Amomun kravak Pierre ex Gagnep. METHODS: The composition of the essential oil was isolated by PR solvent and determined by GC-MS. Forty-two species of compounds were identified, of which the relative contents were calculated using square peaks to normalization, among which the character components were 1,8-cineole, beta-pinene, alpha-pinene, p-cymene, etc. EMIC software was used and EMIC fingerprint chromatogram was established by selecting the character ion of those 10 compounds. Different extraction methods were also compared. RESULTS: The GC-MS fingerprint chromatogram can provide qualitative information confirming compounds of the corresponding chromatographic peaks. EMIC was first used to reason the quality control of the medicine quality and it can establish the foundation for safe and effective quality control of the medicine and its product. PR solvent can easily extract the essential oil from the medicine. CONCLUSION: This method has the advantage of high efficiency and low cost, and the GC-MS fingerprint chromatogram provided the ascription and quality of the medicine and will play an important role in promoting the modernization of Chinese traditional medicine.