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1.
Anal Bioanal Chem ; 416(5): 1293-1305, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38189918

RESUMEN

The rising crime rate associated with document forgery has a significant impact on public safety and social stability. In document fraud cases, determining the origin of a particular stamp-pad ink is the most important objective. In this study, a comprehensive analysis of the volatile compounds in quick-drying stamp-pad inks from six commonly used brands were performed for the first time, utilizing a combination of headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) and multivariate statistical analysis methods. Visual and comparative analysis of the differential volatile components among different stamp-pad ink samples was conducted using fingerprints and volcano plots. A total of 127 volatile compounds were accurately identified, with ketones, esters, alcohols, and aldehydes being the most abundant compounds in the stamp-pad inks. Hierarchical clustering analysis (HCA), including dendrograms and clustering heatmaps, was utilized to explore the correlations between these compounds and the samples. Additionally, the precise identification of positional isomers and functional group isomers of aliphatic compounds was achieved. To achieve accurate discrimination of various stamp-pad ink samples, a multivariate statistical analysis method was utilized to establish a classification model for them. Based on the results obtained from HS-GC-IMS, effective discrimination among different brands of stamp-pad ink samples was achieved through principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA). The model exhibited excellent performance, with the fit index of dependent variables (R2Y) and the predictive index of the model (Q2) values of 0.99 and 0.984, respectively. These results provided significant theoretical evidence for the application of HS-GC-IMS as an efficient technique in the analysis of volatile compounds, identification of positional isomers and functional group isomers, as well as tracing the origin of stamp-pad ink and analyzing the formation time of documents.

2.
Anal Chim Acta ; 1283: 341965, 2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-37977789

RESUMEN

The light induced hot-electron on plasmonic nanostructures has been recognized as a breakthrough discovery for photovoltaic and photocatalytic applications. With mass spectrometry, we demonstrate the dynamics of hot electron transfers of anaerobic oxidization reactions on Au decorated TiO2 plasmonic nanoparticles, which were coated on the inner surface of a flask. Those nanoparticles were covered by continuously renewed liquid droplets of solvent and reactants that were transported through a Venturi jet mixer with auto-spray. In addition to intensive mass transfer in such droplet-based nanoreactors, as well as strong adsorption of reactants and rapid desorption of products on materials surfaces, the localized surface plasmon resonance (LSPR) excitation upon visible light illumination, by which accumulated energies of plasmons are transferred to electrons in the conduction band of the material, attributes to the efficient photocatalytic transformation. Mass spectrometric detection of intermediate radical anions and negative ions with stable isotope labeling unambiguously identifies that highly energetic hot electrons can escape from the plasmonic nanostructures, be collected by adsorbed molecules, and initiate bond cleavages. It was demonstrated that losses of two H atoms result in the anaerobic oxidization of each benzyl alcohol molecule to a benzyl aldehyde molecule in the absence of molecular oxygen with more than 90 % yields. The well recyclable plasmonic nanoreactors implicate the injection of transferred electrons eventually back to electronically depleted Au+ positive ions. Bridged by adsorbed molecules, electrons were repeatedly circulated back and forth in plasmonic nanoreactors, where the collected light was eventually converted into chemical energy.

3.
BMC Pregnancy Childbirth ; 23(1): 134, 2023 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-36864417

RESUMEN

BACKGROUND: The outcome of in vitro fertilization-embryo transfer (IVF) is often determined according to follicle and estradiol levels following gonadotropin stimulation. In previous studies, although most of them analyzed the estrogen level from ovaries or the average estrogen level of a single follicle, there was no study on the ratio of estrogen increase, which was also correlated with pregnancy outcomes in the clinic. This study aimed to make timely adjustments to follow-up medication to improve clinical outcomes based on the potential value of estradiol growth rate. METHODS: We comprehensively analyzed estrogen growth during the entire ovarian stimulation period. Serum estradiol levels were measured on the day of gonadotropin treatment (Gn1), five days later (Gn5), eight days later (Gn8), and on the trigger day (HCG). This ratio was used to determine the increase in estradiol levels. According to the ratio of estradiol increase, the patients were divided into four groups: A1 (Gn5/Gn1 ≤ 6.44), A2 (6.44 < Gn5/Gn1 ≤ 10.62), A3 (10.62 < Gn5/Gn1 ≤ 21.33), and A4 (Gn5/Gn1 > 21.33); B1 (Gn8/Gn5 ≤ 2.39), B2 (2.39 < Gn8/Gn5 ≤ 3.03), B3 (3.03 < Gn8/Gn5 ≤ 3.84), and B4 (Gn8/Gn5 > 3.84). We analyzed and compared the relationship between data in each group and pregnancy outcomes. RESULTS: In the statistical analysis, the estradiol levels of Gn5 (P = 0.029, P = 0.042), Gn8 (P < 0.001, P = 0.001), and HCG (P < 0.001, P = 0.002), as well as Gn5/Gn1 (P = 0.004, P = 0.006), Gn8/Gn5 (P = 0.001, P = 0.002), and HCG/Gn1 (P < 0.001, P < 0.001) both had clinical guiding significance, and lower one significantly reduced the pregnancy rate. The outcomes were positively linked to groups A (P = 0.036, P = 0.043) and B (P = 0.014, P = 0.013), respectively. The logistical regression analysis revealed that group A1 (OR = 0.376 [0.182-0.779]; P = 0.008*, OR = 0.401 [0.188-0.857]; P = 0.018*) and B1 (OR = 0.363 [0.179-0.735]; P = 0.005*, OR = 0.389 [0.187-0.808]; P = 0.011*) had opposite influence on outcomes. CONCLUSION: Maintaining a serum estradiol increase ratio of at least 6.44 on Gn5/Gn1 and 2.39 on Gn8/Gn5 may result in a higher pregnancy rate, especially in young people.


Asunto(s)
Estradiol , Estrógenos , Femenino , Embarazo , Humanos , Adolescente , Estudios Retrospectivos , Transferencia de Embrión , Fertilización In Vitro
4.
Anal Chim Acta ; 1243: 340842, 2023 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-36697178

RESUMEN

Aroma components are one of the crucial factors in dynamic processes analysis, quality control, and origin traceability. Various categories of Huaguo Tea possessed different taste due to the generation of aroma. In this study, a comprehensive analysis of volatiles was conducted for five popular Huaguo Tea samples (Lemon Slices, Bitter Gourd Slices, Citri Reticulatae Pericarpium, Red Lycium Barbarum, and Black Lycium Barbarum) via gas chromatography-ion mobility spectrometry (GC-IMS) combining with multivariate statistical strategies. Comparison analysis was achieved with the properties of visually and intuitively by drawing of topography plots. A total of one hundred and eighty volatiles were distinguished. Aliphatic isomers were identified simultaneously by fingerprint spectra. Alcohols, aldehydes, esters, and ketones were the most abundant volatiles in Huaguo Tea samples. To characterize the Huaguo Tea precisely and establish an analysis model for their classification, multivariate statistical analysis was applied to distinguish different Huaguo Tea. Satisfied discrimination was obtained by principal component analysis (PCA) and orthogonal partial least squares discrimination analysis (OPLS-DA) based on the HS-GC-IMS results with the robustness parameter (R2Y) of 99.4%, and prediction ability parameter (Q2) of 98.6%, respectively. The results provide a theoretical basis for aroma discrimination, isomer identification, and categories analysis of Huaguo Tea.


Asunto(s)
Espectrometría de Movilidad Iónica , Compuestos Orgánicos Volátiles , Cromatografía de Gases y Espectrometría de Masas/métodos , Compuestos Orgánicos Volátiles/análisis , Análisis Multivariante , Odorantes/análisis , Té/química
5.
Leg Med (Tokyo) ; 59: 102132, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35952617

RESUMEN

Species identification of unknown biological samples is crucial for forensic applications, especially in cases of explosion, disaster accidents, and body mutilation after murdering, as well as poaching, illegal trade in endangered animals, and meat food fraud. In this study, we identified 60 volatile organic compounds (VOCs) in fresh skeletal muscle tissues of seven different animal species (cattle, sheep, pigs, rabbits, rats, chickens and carp) and a human dead body by headspace-gas-chromatography ion-mobility spectrometry (HS-GC-IMS), and compared their differences by retention time, drift time and molecular weight. The results showed that these VOCs formed different gallery plot fingerprints in the skeletal muscle tissues of the human dead body and seven animal species. Principal component analysis (PCA) showed significantly different fingerprints between these species, and these fingerprints maintained good stability between the species and within the same species. Some VOCs have high species specificity, while VOCs of human fresh muscle tissues from different individual sources have little difference, demonstrating that all tested muscle tissue samples could be distinguished based on different VOCs. HS-GC-IMS has proved to be a rapid, high-throughput, highly sensitive and specific species identification method, which can be used for forensic species identification in criminal cases and disaster accidents, as well as detection in the field of food safety, such as meat fraud and adulteration.


Asunto(s)
Compuestos Orgánicos Volátiles , Animales , Porcinos , Bovinos , Humanos , Ovinos , Conejos , Ratas , Compuestos Orgánicos Volátiles/análisis , Cromatografía de Gases y Espectrometría de Masas/métodos , Pollos , Espectrometría de Movilidad Iónica/métodos , Músculos
6.
Eur J Obstet Gynecol Reprod Biol ; 277: 32-41, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35987076

RESUMEN

OBJECTIVE: To explore the mechanism of intracavitary physiotherapy combined with acupuncture to improve the receptivity of thin endometrium. METHODS: From October 2020 to April 2021, 40 patients diagnosed with thin endometrium and preparing for hormone replacement cycle freeze-thaw embryo transfer in our centre for Reproduction were included, 40 patients were randomized to treatment group and control group. 20 patients with normal endometrium during the same period were selected as the normal group.All patients underwent freeze-thaw embryo transfer using hormone replacement cycles.The treatment group added endovascular physiotherapy combined with acupuncture. RESULTS: The endometrial receptivity of the patients with thin endometrium was significantly lower than that of the normal group(P < 0.01). Endovascular therapy combined with acupuncture can significantly increase endometrial thickness in patients with thin endometrium and the proportion of patients with type A endometrium, reduce bilateral Uterine arterial pulsatilityindex (PI), Uterine arterial resistance index (RI), and peaksystolicvelocity/diastolicvelocity (S/D), upregulate the expression of HOXA10 protein and mRNA in endometrium tissue, and improve the rate of embryo implantation and clinical pregnancy(P < 0.01).there was no significant difference between the treatment group and the normal group (P > 0.05). This may be related to the regulation of the AMPK/mTOR signalling pathway by intracavitary physiotherapy combined with acupuncture, downregulation of the expression of the AMPK gene and protein and upregulation of the expression of the mTOR gene and protein. CONCLUSIONS: 1. Abnormal energy metabolism is present in the endometrium of patients with thin endometrium, which affects the autophagy process and leads to a decrease in the receptivity of thin endometrium. 2. Intracavitary physiotherapy combined with acupuncture mediated the AMPK/mTOR pathway to improve energy metabolism, promote the autophagy process, improve endometrial morphology and ultrasonic indicators of patients, upregulate the expression of endometrial receptivity-related HOXA10 genes and proteins, and improve the embryo implantation rate and clinical pregnancy rate.


Asunto(s)
Proteínas Quinasas Activadas por AMP , Terapia por Acupuntura , Proteínas Quinasas Activadas por AMP/metabolismo , Implantación del Embrión/genética , Endometrio/metabolismo , Femenino , Proteínas Homeobox A10 , Hormonas , Humanos , Modalidades de Fisioterapia , Embarazo , ARN Mensajero/metabolismo , Serina-Treonina Quinasas TOR/metabolismo
7.
Anal Chem ; 94(21): 7466-7474, 2022 05 31.
Artículo en Inglés | MEDLINE | ID: mdl-35536683

RESUMEN

A substrate with n phosphorylated sites may have 2n phosphor-forms for temporal-spatial regulation of biological events. Because phosphates do not significantly change molecular masses but net charges of proteins, those isoforms cannot be separated by regular mass-based sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE). A tandem polymerized gel was developed to resolve phosphor-isoforms with different masses, charges, and posttranslational modifications. Without the usage of SDS, the electrophoresis was primarily performed on three adjacent acidic polyacrylamide gels. After being concentrated on a stacking gel, protonated proteins were then separated on the Zr4+ immobilized gel through the coordination of metal ions with phosphates followed by further charge and mass (z/m)-based electrophoretic separation on a TiO2 containing gel. The presence of TiO2 nanoparticles in the third gel is aimed for the initiation of the polymerization of acrylamide in acidic conditions upon ultraviolet irradiation. Distinct isoforms of α-S1-casein, α-S2-casein, ß-casein, and κ casein model proteins located on 11, 8, 8, and 7 different bands of the tandem gel were unambiguously identified, respectively. With the tandem polymerized gel electrophoresis, new phosphorylation events that may occur simultaneously or sequentially were discovered in not only model proteins but also complex biological samples including human saliva, chicken egg, and sprouting maize. This provides a new tool to dissect complex biological processes that are triggered by dynamic phosphorylation events.


Asunto(s)
Caseínas , Fosfoproteínas , Caseínas/análisis , Electroforesis en Gel de Poliacrilamida , Fosfatos , Fosfoproteínas/química , Polimerizacion
8.
Front Cell Dev Biol ; 10: 1079387, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36684431

RESUMEN

Extracellular vesicles (EVs) have become a research hotspot in recent years because they act as messengers between cells in the physiological and pathological processes of the human body. It can be produced by the follicle, prostate, embryo, uterus, and oviduct in the reproductive field and exists in the extracellular environment as follicular fluid, semen, uterine cavity fluid, and oviduct fluid. Because extracellular vesicles are more stable at transmitting information, it allows all cells involved in the physiological processes of embryo formation, development, and implantation to communicate with one another. Extracellular vesicles carried miRNAs and proteins as mail, and when the messenger delivers the mail to the recipient cell, the recipient cell undergoes a series of changes. Current research begins with intercepting and decoding the information carried by extracellular vesicles. This information may help us gain a better understanding of the secrets of reproduction, as well as assist reproductive technology as an emerging marker and treatment.

9.
Anal Chem ; 93(47): 15597-15606, 2021 11 30.
Artículo en Inglés | MEDLINE | ID: mdl-34762390

RESUMEN

Protonation/deprotonation is the well-recognized mass spectrometric mechanism in matrix-assisted laser desorption ionization of organic molecules but not for metal ions with different oxidation states. We describe herein a soft evaporation and ionization technique for metal ions based on iodination/de-iodination in metal-iodide cluster ionization (MICI). It is not only able to determine identities and oxidation states of metal ions but also reveal spatial distributions and isotope ratios in response to physiological or environmental changes. A long chain alcohol 1-tetradecanol with no functional groups that can absorb laser irradiation was used to cover and prevent samples from direct laser ablation. Upon the irradiation of the third harmonic Nd3+:YAG (355 nm, 3 ns), iohexol containing three covalently bonded iodine atoms instantly generates negative iodide ions that can quantitatively form clusters with at least 14 essential metal ions present in plants. The detection limits vary with different metal ions down to low fmol. MICI eliminates the atomization process that obscures metal charges in inductively coupled plasma mass spectrometry. Because only metal ions can be iodinated with iohexol, interferences from the abundant organic molecules of plants that are confronted by secondary ion mass spectrometry (SIMS) are also greatly decreased.


Asunto(s)
Yoduros , Metales , Iones , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Espectrometría de Masa de Ion Secundario
10.
Front Biosci (Landmark Ed) ; 26(9): 485-495, 2021 09 30.
Artículo en Inglés | MEDLINE | ID: mdl-34590461

RESUMEN

Background: Dysregulated migration and invasion of endometrial stromal cells is implicated in the pathogenesis of endometriosis. Hypoxia functions as critical microenvironmental factor that results in promotion of endometrial stromal cells migration and invasion through up-regulation of autophagy. Paeonol functioned as a tumor suppressor in human ovarian cancer and promoted cytoprotective autophagy. However, the role of paeonol in hypoxia-induced autophagy in endometriosis remains unknown. Methods: Stromal cells were isolated from endometriotic patients by enzymatic digestion of ectopic endometrial tissues, and then characterized by immunohistochemical analysis of cytoskeleton 19 (CK19) and vimentin. Cellular morphology was evaluated under microscope. Cell viability, proliferation and apoptosis of stromal cells were assessed by Cell Counting Kit-8, EdU labeling and flow cytometry, respectively. Wound healing and transwell assays were performed to detect metastasis of the stromal cells. Hypoxia-induced autophagy was evaluated through immunohistochemistry and western blot. Results: Paeonol treatment dosage dependently decreased cell proliferation and metastasis of the ectopic endometrial stromal cells (ecESCs), while promoted the cell apoptosis. Hypoxia-induced autophagy in the ecESCs was repressed by paeonol through down-regulation of LC3-II/LC3-I and Beclin-1, while up-regulation of p62. Hypoxia-inducible factor-1α (HIF-1α) was reduced post paeonol treatment, and paeonol-induced increase of p62 and decrease of LC3-II/LC3-I and Beclin-1 were reversed by over-expression of HIF-1α. Over-expression of HIF-1α also attenuated the suppressive effect of paeonol on cell growth of ecESCs. Conclusions: Paeonol attenuated HIF-1α-induced promotion of ecESCs migration and invasion through reducing autophagy, and reduced HIF-1α-induced endometriotic lesion in rats, providing potential therapeutic strategy for the treatment of endometriosis.


Asunto(s)
Endometriosis , Acetofenonas , Animales , Autofagia , Endometriosis/tratamiento farmacológico , Endometriosis/genética , Endometrio , Femenino , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Ratas , Células del Estroma
11.
J Am Soc Mass Spectrom ; 32(1): 322-329, 2021 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-33200938

RESUMEN

A protonation/deprotonation mechanism has been established for the interpretation of ions in MALDI. We show herein that negative ions can be generated in different ways. Molecules with different electron affinities have been spotted on surfaces of TiO2, ZnO, and a stainless steel plate for the investigation of electron capture dissociation in comparison with photo- or thermal-induced deprotonation upon irradiation of the third harmonic of Nd3+:YAG (355 nm) laser pulses. Detection of C60•- and Fe (II) (porph•-) radical anions unambiguously demonstrates the electron-transfer process and the exothermic capture of electrons. Radical anions of fatty acids were difficult to observe because of electron-directed ultrafast homolytic cleavage of O-H bonds unless there is a conjugated system as that in C60 and porphyrin for the delocalization and stabilization of acquired changes. The surface basicity of substrate materials was found to determine the competition of the electron-capture dissociation with deprotonation processes. Multiple electron transfers to pyrrole, -COOH, and Fe2+ of the heme were observed on TiO2 and the stainless steel plate but not on ZnO. When the heme was deprotonated by proton sponge 1,8-bis(dimethylamino)naphthalene, the occurrence of electron transfer on TiO2 was also not observed. It is proposed that negative charges of deprotonated ions prevent electron transfer due to the repulsive force. When both deprotonation and electron transfer are inhibited, adsorbed fatty acids on TiO2 undergo dehydration reactions to form titanium esters. In contrast, ZnO generates gaseous micelles composed of positive metal ions and negative fatty acid ions through either deprotonation or electron-capture dissociation.

12.
Anal Chim Acta ; 1130: 10-19, 2020 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-32892928

RESUMEN

Development of analytical techniques that can monitor the adsorption, transfer and in-situ distribution of environmental pollutants in agricultural products is essential to ensure the implementation of stringent food safety standards for consumer protection. A mass spectrometric imaging approach is described herein to investigate the dynamic changes and spatial distributions of 4, 4'-DDT (dichlorodiphenyltrichloroethane) in soybean seeds and sprouts during the growth. Soy beans seeds incubated in DDT containing water were sliced in every 20 µm and directly blotted on the surface of a compressed thin film of (Bi2O3)0.07(CoO)0.03(ZnO)0.9 nanoparticles. Endogenous molecules and exogenous DDT compounds in soy bean seeds were ionized and dissociated by photoelectrons that are generated on surfaces of semiconductor nanoparticles upon the irradiation of the 3rd harmonic (355 nm) of Nd3+:YAG laser. Structural identification is achieved by the interpretation of fragment ions resulting from electron-initiated specific bond cleavages or hole oxidization. Mass spectrometric images reveal increased quantities of DDT residues in soy bean seeds and sprouts during the growth. It provides an in situ way without extensive sample preparation to monitor the transfer and distribution of exogenous pollutants as well as the possible impacts on plant growth.


Asunto(s)
Glycine max , Semillas , Adsorción , Electrones , Espectrometría de Masas
13.
Anal Chim Acta ; 1054: 104-113, 2019 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-30712580

RESUMEN

Organochlorines are highly persistent and toxic contaminants that are widely distributed and accumulated in various aquatic or soil environments as well as food chains. Heterogeneous photocatalytic degradation of such pollutants by using semiconductor nanoparticles has been recognized as one of the effective purification ways. Understanding of degradation mechanisms and designing of highly efficient semiconductor nanoparticles require structural identification of various degradation intermediates that are difficult to achieve with current spectroscopic techniques. Herein a mass spectrometric approach was developed to tackle interfacial photoelectron transfer and hydroxyl radical abstraction on different semiconductor nanoparticles. Chlorobenzenes (including hexachlorobenzene and chlorothalonil) adsorbed on the surfaces of nanoparticles were found to instantly undergo dechlorination and ring dissociation through photoelectron capture dissociation and abstraction of a chlorine atom from aromatic C-Cl bond by hydroxyl radicals. Different intermediates have been unambiguously identified with experimental evidences provided by a Q-TOF mass spectrometer. It has been demonstrated that both electron density around atoms and steric effects of side chains contribute to the site selectivity for photoelectron capture and hydroxyl radical abstraction. But the energies needed for chemical bond cleavages and the stabilization of acquired charges play important roles in degradation efficiency. By using mass spectrometric imaging, photocatalytic differences of different semiconductor nanoparticles have been revealed.

14.
ACS Chem Neurosci ; 10(1): 757-767, 2019 01 16.
Artículo en Inglés | MEDLINE | ID: mdl-30576595

RESUMEN

Dysfunctional glutamate receptors (GluRs) have been implicated in neurological disorders and injuries. Hetero-tetrameric assemblies of different GluR subunits or splicing variants have distinct spatiotemporal expression patterns and pharmacological properties. Mass spectrometric imaging of GluRs-targeted small molecules is important for determining the regional preferences of these compounds. We report herein the development of a mass tag covalently bonded with glutamate or N-methyl-d-aspartate that functions as both an electron acceptor to generate mass spectrometric signals on irradiated (Bi2O3)0.07(CoO)0.03(ZnO)0.9 nanoparticles with the third harmonic (355 nm) of Nd3+:YAG laser and as the core component to target bilobed clamshell-like structures of GluRs. In this approach, different molecules produce the same tag ion. It provides a new avenue for quantitative assessment of spatial densities of different compounds, which cannot be achieved with well-established stable isotope labeling technique due to different ionization efficiency of different compounds. Various coexisting endogenous molecules are also simultaneously detected for investigation of overall physiological changes induced by these compounds. Because semiconductors do not generate background peaks, this method eliminates interferences from organic matrix materials that are used in regular MALDI (matrix assisted laser desorption ionization). The localized ionization provides high spatial resolution that can be down to sub-micrometers.


Asunto(s)
Encéfalo/patología , Electrones , Nanopartículas , Receptores de Glutamato/metabolismo , Animales , Encéfalo/metabolismo , Marcaje Isotópico/métodos , Ratones , Nanopartículas/química , Neuroimagen/métodos , Semiconductores , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos
15.
Anal Chim Acta ; 1044: 1-11, 2018 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-30442389

RESUMEN

Structural identification is challenging in mass spectrometric imaging because of inadequate sample quantities and limited sampling time in each pixel for tandem mass spectrometry (MS/MS) experiments, which are usually used for the generation of fragment ions. We report herein the observation of a cascade of highly specific chemical bond cleavages via a low-energy photoelectron activated radical relays and a competed hole oxidization on surfaces of (Bi2O3)0.07(CoO)0.03(ZnO)0.9 semiconductor nanoparticles irradiated with the 3rd harmonic (355 nm) of the Nd3+: YAG laser. Distinguished from high energy electron impact (EI), this approach generates gaseous radical anions through the exothermic capture of low-energy tunneling electrons that are not able to cause extensive vibrational excitations. It was found not only original radical center but also secondary or even tertiary radical centers cause specific bond cleavages exclusively on α positions. The original radical center directly activates the cleavages of α-positioned chemical bonds that cause the formation of secondary radical centers. Ion fragmentations proceed along the newly formed radical centers that further activate the cleavages of their α-positioned chemical bonds. Using 8 compounds, we have demonstrated various radical reactions involved in desulfonation, cyclization, and ring contraction reactions as well as competed hole oxidization-generated hydroxyl radical substitution reactions. The interpretable fragment ions provide unambiguous experimental evidences for structural elucidation of drug residues and metabolites in mass spectrometric imaging of tissue slices without tandem mass spectrometry (MS/MS).


Asunto(s)
Electrones , Espectrometría de Masas , Nanopartículas/química , Semiconductores , Sulfaquinoxalina/análisis , Animales , Radicales Libres/química , Hígado/química , Hígado/metabolismo , Masculino , Oxidación-Reducción , Tamaño de la Partícula , Procesos Fotoquímicos , Porosidad , Ratas , Sulfaquinoxalina/metabolismo , Propiedades de Superficie
16.
Org Lett ; 17(6): 1381-4, 2015 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-25738835

RESUMEN

A general and efficient Pd/sulfoxide-phosphine complex-catalyzed direct asymmetric N-allylic alkylation of indoles has been developed to allow for the preparation of various N-allylated indoles in generally good yields with excellent enantioselectivities. This catalytic system could also be extended to other N-containing heterocycles with good results.

17.
Zhongguo Zhong Xi Yi Jie He Za Zhi ; 31(7): 892-5, 2011 Jul.
Artículo en Chino | MEDLINE | ID: mdl-21866656

RESUMEN

OBJECTIVE: To study the clinical efficacy of the laparoscopic surgery in combination of Quyu Jiedu Recipe (QYJDR) on endometriosis (EMs)-related infertility patients. METHODS: 130 EMs-related infertility patients of blood stasis and toxin accumulation syndrome diagnosed and treated by laparoscopic surgery were randomly assigned to two groups, i.e., the test group (75 cases) and the control group (55 cases). All patients received routine progesterone treatment after laparoscopic surgery. QYJDR was given to patients in the test group after laparoscopic surgery, lasting for twelve months. The pregnancy rate within one year after laparoscopic surgery were compared between the two groups. The Chinese medicine syndrome integrals, serum endometrium antibody (EMAb) and cancer antigen 125 (CA125) levels were compared between before drug therapy and three months after drug therapy. RESULTS: The pregnancy rate within one year after laparoscopic surgery was higher in the test group than in the control group [61.33% (46/75) vs 45.45% (25/55)], showing significant difference (P<0.05). The Chinese medicine syndrome integral was (16.07 +/- 6.77) score and (7.25 +/- 3.27) score before and 3 months after drug therapy in the test group, while it was (15.92 +/- 7.51) score and (12.73 +/- 6.12) score in the control group. The Chinese medicine syndrome integral after drug therapy was lower than that before drug therapy in the same group. Besides, the integral difference between before and after drug therapy was higher in the test group than in the control group [(9.12 +/- 6.16) score vs (3.48 +/- 2.06) score)], showing statistical difference (P<0.05). After three-month drug therapy, the serum EMAb negative conversion rate was obviously higher in the test group than in the control group (44.44% vs 15.62%), showing statistical difference (P<0.05). The serum CA125 level was (31.88 +/- 15.78) U/mL before drug therapy and (18.82 +/- 10.08) U/mL three months after drug therapy in the test group, while it was (30.63 +/- 19.28) U/mL and (18.05 +/- 11.20) U/mL respectively in the control group. It was lowered after drug therapy in the two groups with statistical difference (P<0.05). There was no statistical difference between the two groups after drug therapy (P>0.05). CONCLUSIONS: The laparoscopic surgery in combination of QYJDR could effectively improve clinical symptoms of EMs patients of blood stasis and toxin accumulation syndrome, promote negative conversion of EMAb, lower serum CA125 levels, and elevate the clinical pregnancy rate. QYJDR is an effective formula in treatment of EMs-related infertility.


Asunto(s)
Medicamentos Herbarios Chinos/uso terapéutico , Endometriosis/terapia , Infertilidad Femenina/terapia , Fitoterapia , Adulto , Endometriosis/complicaciones , Femenino , Humanos , Infertilidad Femenina/etiología , Medicina Integrativa , Laparoscopía , Resultado del Tratamiento
18.
Appl Opt ; 45(28): 7480-7, 2006 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-16983437

RESUMEN

A series of novel cross-linkable bromo-fluorinated poly(arylene ether ketone)s have been synthesized and used to fabricate photonic devices. The polymers, prepared by polycondensation reactions of decafluorobenzophenone with mixtures of bisphenols in different ratios, exhibit excellent solubility in common organic solvents and can be easily cast into optical-quality thin films by spin coating. The materials are thermally stable with decomposition temperatures (Td, 5% weight loss) over 450 degrees C and have high glass transition temperatures (Tg) in the range of 164 degrees C-178 degrees C. By controlling the bromine content of the polymers, the refractive index can be precisely controlled over a range as wide as 0.07. The material has excellent design flexibility, low optical loss (0.4-0.6 dB/cm at 1550 nm), a low birefringence (2-3 x 10(-3)), and is suitable for use in wavelength sensitive photonic devices based on arrayed waveguide gratings.

20.
J Bone Miner Res ; 17(7): 1256-63, 2002 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12096839

RESUMEN

To investigate the role of osteoprotegerin (OPG) on alcohol (ethanol)-mediated osteoporosis, we measured a variety of bone remodeling parameters in mice that were either on a control diet, an ethanol (5%) diet, or an ethanol (5%) diet plus OPG administration. OPG diminished the ethanol-induced (1) decrease in bone mineral density (BMD) as determined by dual-energy densitometry, (2) decrease in cancellous bone volume and trabecular width and the increase of osteoclast surface as determined by histomorphometry of the femur, (3) increase in urinary deoxypyridinolines (Dpd's) as determined by ELISA, and (4) increase in colony-forming unit-granulocyte macrophage (CFU-GM) formation and osteoclastogenesis as determined by ex vivo bone marrow cell cultures. Additionally, OPG diminished the ethanol-induced decrease of several osteoblastic parameters including osteoblast formation and osteoblast culture calcium retention. These findings were supported by histomorphometric indices in the distal femur. Taken together, these data show that OPG diminishes ethanol-induced bone loss. Furthermore, they suggest that OPG achieves this through its ability to abrogate ethanol-induced promotion of osteoclastogenesis and promote osteoblast proliferation.


Asunto(s)
Etanol/efectos adversos , Glicoproteínas/uso terapéutico , Osteoporosis/tratamiento farmacológico , Receptores Citoplasmáticos y Nucleares/uso terapéutico , Animales , Densidad Ósea/efectos de los fármacos , Calcio/metabolismo , Fémur/efectos de los fármacos , Fémur/fisiopatología , Masculino , Ratones , Ratones Endogámicos C57BL , Osteoclastos/efectos de los fármacos , Osteoporosis/fisiopatología , Osteoprotegerina , Receptores del Factor de Necrosis Tumoral
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