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1.
J Adv Nurs ; 2024 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-38332497

RESUMEN

AIMS: To explore women's and health professionals' views on the development of a midwifery-led mHealth app intervention in antenatal care and their demands for app functionality. DESIGN: Descriptive qualitative research was utilized. METHODS: In total, 15 pregnant or postpartum women were interviewed via in-depth interviews and 10 health professionals including obstetricians, midwives and obstetric nurses were invited to participate in a focus group discussion (FGD). All interviews and the FGD were analysed using qualitative content analysis. RESULTS: Four key themes emerged from the data, including (1) limitations of current maternity care services; (2) potential benefits for mHealth app-based midwifery care; (3) possible challenges for providing midwifery care through mHealth apps and (4) suggestions and needs for developing a midwifery-led mHealth app. Participants agreed on the potential need of developing a midwifery-led mHealth app in antenatal care to increase access to midwifery care services and to meet women's diverse needs. Participants preferred to develop professional, reliable, full-featured and interactive mobile applications. The main functions of midwifery-led mHealth apps included personalized assessment and health education, self-monitoring and feedback, data sharing and interactive functions. Women mentioned that online communication and consultation with midwives could help them receive continuous support outside facilities. Health professionals expressed it would be of great convenience and timeliness to send personalized messages to women and to inform them of healthy lifestyles during pregnancy. The challenges included a shortage of human resources, medico-legal risks associated with mHealth and data security risks. CONCLUSIONS: This study explores the individual views and functional needs of target users and healthcare providers for developing a midwifery-led mHealth app in antenatal care, which will serve as a reference for future application development. IMPACT: Our study has important and practical implications for guiding the development of future midwifery-led mHealth app interventions. PATIENT OR PUBLIC CONTRIBUTION: No patient or public contribution.

2.
Immunogenetics ; 75(4): 385-393, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37269334

RESUMEN

The recombination activating gene 1 (RAG1) is essential for V(D)J recombination during T- and B-cell development. In this study, we presented a case study of a 41-day-old female infant who exhibited symptoms of generalized erythroderma, lymphadenopathy, hepatosplenomegaly, and recurrent infections including suppurative meningitis and septicemia. The patient showed a T+B-NK+ immunophenotype. We observed an impaired thymic output, as indicated by reduced levels of naive T cells and sjTRECs, coupled with a restricted TCR repertoire. Additionally, T-cell CFSE proliferation was impaired, indicating a suboptimal T-cell response. Notably, our data further revealed that T cells were in an activated state. Genetic analysis revealed a previously reported compound heterozygous mutation (c. 1186C > T, p. R396C; c. 1210C > T, p. R404W) in the RAG1 gene. Structural analysis of RAG1 suggested that the R396C mutation might lead to the loss of hydrogen bonds with neighboring amino acids. These findings contribute to our understanding of RAG1 deficiency and may have implications for the development of novel therapies for patients with this condition.


Asunto(s)
Proteínas de Homeodominio , Inmunodeficiencia Combinada Grave , Femenino , Humanos , Lactante , Genes RAG-1 , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Mutación , Inmunodeficiencia Combinada Grave/genética , Linfocitos T
3.
BMC Pregnancy Childbirth ; 23(1): 868, 2023 Dec 16.
Artículo en Inglés | MEDLINE | ID: mdl-38104121

RESUMEN

BACKGROUND: Postnatal period is a critical transitional phase in the lives of mothers and newborn babies. In recent years the importance on promoting a positive experience of care following childbirth is increasingly emphasized. Yet published evidence of the methodological and psychometric quality of instruments to evaluate women's experience of comprehensive postnatal care is still lacking. OBJECTIVE: This study aimed to develop and validate a unique scale (the Chinese version of the Postnatal Care Experience Scale, PCES) to measure women's overall experience of care during postnatal periods. METHODS: The PCES instrument was developed and validated over three phases, including item development, scale development, and scale evaluation. The item pool of the PCES was generated through existing literature and in-depth semi-structured interviews, followed by assessment of content validity and rating of importance and feasibility of items through two-round Delphi surveys. Psychometric properties were examined in a convenience sample of 736 postpartum women. Both exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were conducted to assess the construct validity of the developed PCES. The relationship between the total PCES score and the global item construct was estimated using Pearson product-moment coefficient. Reliability was assessed using Cronbach's alpha and Spearman Brown coefficients. RESULTS: The content validity index of the Chinese version PCES was 0.867. Following item reduction analysis, this instrument consisted of 30 five-point Likert items. The Kaiser-Meyer-Olkin statistic was 0.964 and the chi-square value of the Bartlett spherical test was 11665.399 (P < .001). The scale explained 75.797% of the total variance and consisted of three subscales, including self-management, social support, and facility- and community-based care. The Pearson correlation coefficient between the total PCES score and the global item construct was 0.909. The CFA showed that the 3-factor model had suitable fitness for the data. Cronbach's alpha value and Spearman-Brown Split-half reliability for the total scale were 0.979 and 0.941, respectively. CONCLUSIONS: The newly developed 30-item PCES is a psychometrically reliable and valid instrument that assesses women's overall experience of postnatal care. Future research should aim to use the PCES in various populations to obtain further evidence for its validity and reliability.


Asunto(s)
Atención Posnatal , Periodo Posparto , Embarazo , Recién Nacido , Humanos , Femenino , Encuestas y Cuestionarios , Psicometría , Reproducibilidad de los Resultados
4.
World Wide Web ; : 1-16, 2023 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-37361139

RESUMEN

The COVID-19 is still spreading today, and it has caused great harm to human beings. The system at the entrance of public places such as shopping malls and stations should check whether pedestrians are wearing masks. However, pedestrians often pass the system inspection by wearing cotton masks, scarves, etc. Therefore, the detection system not only needs to check whether pedestrians are wearing masks, but also needs to detect the type of masks. Based on the lightweight network architecture MobilenetV3, this paper proposes a cascaded deep learning network based on transfer learning, and then designs a mask recognition system based on the cascaded deep learning network. By modifying the activation function of the MobilenetV3 output layer and the structure of the model, two MobilenetV3 networks suitable for cascading are obtained. By introducing transfer learning into the training process of two modified MobilenetV3 networks and a multi-task convolutional neural network, the ImagNet underlying parameters of the network models are obtained in advance, which reduces the computational load of the models. The cascaded deep learning network consists of a multi-task convolutional neural network cascaded with these two modified MobilenetV3 networks. A multi-task convolutional neural network is used to detect faces in images, and two modified MobilenetV3 networks are used as the backbone network to extract the features of masks. After comparing with the classification results of the modified MobilenetV3 neural network before cascading, the classification accuracy of the cascading learning network is improved by 7%, and the excellent performance of the cascading network can be seen.

5.
Small ; 18(27): e2201298, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35652504

RESUMEN

Cancer immunotherapy has great potential in tumor eradication and metastasis suppression. However, systemic administration of immune adjuvants and inadequate specificity in cancer treatment, lead to restricted therapeutic benefits and potential immune-related side effects in clinical settings. In this report, the synthesis of various lengths of heptamethine cyanine small molecules to act as multifunctional photosensitizers (PS) for tumor-specific accumulation, near-infrared (NIR) fluorescent imaging, and photodynamic/photothermal/immunotherapy is optimized. In particular, it is demonstrated that C8, which contains eight carbons on two N-alkyl side chains, efficiently self-assembles with albumin to form nanosized dye-albumin complexes. This feature facilitates C8 in vivo self-assembly to remarkably improve its water-solubility, NIR fluorescent emission, long-term blood circulation, as well as tumor-specific accumulation. More importantly, C8 not only exhibits a superior phototherapeutic effect on primary tumors, but also elicits secretion of damage associated molecular patterns, cytokine secretion, dendritic cell maturation, and cytotoxic T lymphocytes activation, ultimately triggering a sufficient antitumor immune response to suppress growths of distant and metastatic tumors. Hence, this multifunctional small molecular PS is characterized with excellent tumor-preferential accumulation, imaging-guided laser irradiation, and phototherapy-induced in situ antitumor immune response, providing a prospective future of its use in tumor-targeting immunotherapy.


Asunto(s)
Nanopartículas , Neoplasias , Albúminas , Línea Celular Tumoral , Colorantes , Humanos , Inmunoterapia , Nanopartículas/química , Neoplasias/diagnóstico por imagen , Neoplasias/terapia , Fármacos Fotosensibilizantes/uso terapéutico , Fototerapia/métodos , Estudios Prospectivos
6.
J Cardiovasc Pharmacol ; 79(4): 558-567, 2022 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-34983912

RESUMEN

ABSTRACT: As a highly efficient anticancer agent, doxorubicin (DOX) is used for treatment of various cancers, but DOX-induced oxidative damages contribute to a degenerative irreversible cardiac toxicity. Saikosaponin D (SSD), which is a triterpenoid saponin with many biological activities including anti-inflammatory effects and antioxidant properties, provides protection against pathologic cardiac remodeling and fibrosis. In the present study, we investigated the work of SSD for DOX-induced cardiotoxicity and the involved mechanisms. We observed that DOX injection induced cardiac injury and malfunction and decreased survival rate. Besides, DOX treatment increased lactate dehydrogenase leakage, cardiomyocyte apoptosis, and myocardium fibrosis and decreased the size of cardiomyocytes. Meanwhile, all the effects were notably attenuated by SSD treatment. In vitro, we found that 1 µM SSD could enhance the proliferation of H9c2 cells and inhibit DOX-induced apoptosis. It was found that the levels of malondialdehyde (MDA) and reactive oxygen species were significantly reduced by improving the activities of the endogenous antioxidative enzymes including catalase and glutathione peroxidase. Furthermore, SSD treatment could downregulate the DOX-induced p38 phosphorylation. Our results suggested that SSD efficiently protected the cardiomyocytes from DOX-induced cardiotoxicity by inhibiting the excessive oxidative stress via p38-MAPK (mitogen-activated protein kinase, MAPK) signaling pathway.


Asunto(s)
Cardiotoxicidad , Saponinas , Antioxidantes/metabolismo , Antioxidantes/farmacología , Apoptosis , Doxorrubicina/toxicidad , Fibrosis , Humanos , Miocitos Cardíacos , Ácido Oleanólico/análogos & derivados , Estrés Oxidativo , Especies Reactivas de Oxígeno/metabolismo , Saponinas/farmacología
7.
Molecules ; 27(14)2022 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-35889531

RESUMEN

68Ga-prostate specific membrane antigen (PSMA)-11 PET/CT has been widely used in the diagnosis of prostate cancer (PCa); however, the urine lead shielding resulting from the urinary metabolism of tracers may obstruct the detection of surrounding metastasis. In this research, the additive value of super early scanning in diagnosing primary lesions and metastasis in the pelvic cavity was evaluated. Firstly, the differentiation efficiency of 68Ga-PSMA-11 PET scanned at 3 min post-injection (min P.I.) was measured in PSMA-positive (22rv1 cells) and PSMA-negative (PC3 cells) model mice. Secondly, 106 patients were scanned at 3 min P.I. for the pelvic cavity and then scanned as a standard protocol at 45 min P.I. In the results, the differential diagnosis of PSMA expression was completely reflected as early as 3 min P.I. for mice models. For patients, when correlated with the Gleason score, the quantitative results of the super early scan displayed a comparable correlation coefficient with the routine scan. The target to bladder ratios increased from 1.44 ± 2.40 at 45 min to 10.10 ± 19.10 at 3 min (p < 0.001) for the primary lesions, and it increased from 0.99 ± 1.88 to 9.27 ± 23.03 for metastasis. Meanwhile, the target to background ratios increased from 2.21 ± 2.44 at 3 min to 19.13 ± 23.93 at 45 min (p < 0.001) for the primary lesions, and it increased from 1.68 ± 2.71 to 12.04 ± 18.73 (p < 0.001) for metastasis. In conclusion, super early scanning of 68Ga-PSMA-11 PET/CT added referable information for metastasis detection in order to avoid disturbing tracer activity in the urinary system.


Asunto(s)
Tomografía Computarizada por Tomografía de Emisión de Positrones , Neoplasias de la Próstata , Animales , Ácido Edético , Isótopos de Galio , Radioisótopos de Galio , Humanos , Masculino , Ratones , Oligopéptidos , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Neoplasias de la Próstata/patología
8.
BMC Pregnancy Childbirth ; 20(1): 423, 2020 07 27.
Artículo en Inglés | MEDLINE | ID: mdl-32718307

RESUMEN

An amendment to this paper has been published and can be accessed via the original article.

9.
BMC Pregnancy Childbirth ; 20(1): 386, 2020 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-32616073

RESUMEN

BACKGROUND: There is an increasing global trend towards the widespread over-medicalisation of labour and childbirth. The present study aimed to investigate pregnant women's clinical characteristics, intrapartum interventions, duration of labour and its associated factors; and to compare the differences of these variables between nulliparas and multiparas in China. METHODS: A multi-center cross-sectional study was carried out in three tertiary hospitals of Fudan University in Shanghai, China. A total of 1523 participants were approched and assessed for eligibility. Data on women's sociodemographic characteristics, intrapartum interventions, and duration of labour were measured and collected. Kaplan-Meier survival analysis was performed to present the curves of total duration of labour by parity. After z-transformation of labour duration, multivariable linear regression was used to control for confounding and to identify independent associations between potential associated factors and the primary outcome of labour duration. RESULTS: Overall, 1209 eligible women agreed to participate and were investigated. Rates of different intrapartum interventions were 27.4% in use of amniotomy, 37.9% in use of oxytocin, 53.0% in continuous electronic fetal monitoring, and 52.9% in epidural use, respectively. The curve of total duration of labour was significantly different between nulliparas and multiparas (P < .001). Of the 1209 participants, 983 (81.3%) women eventually achieved successful vaginal birth while 226 (18.7%) women ended in intrapartum caesarean section. The median duration of total stage of labour was significantly longer in the nulliparous group [9.38 (6.33,14.10) hours] than that in the multiparous group [5.08 (3.00,7.83) hours] (P < .001). The following factors were independently associated with longer duration of total stage of labour: epidural analgesia (P < .001), primiparity (P < .001), continuous electronic fetal monitoring (P = .035), and increased birth weight (P = .005). CONCLUSIONS: Intrapartum medical interventions become common obstetric practices in urban China. Multifactorial variables independently associated with longer duration of labour were identified, including epidural analgesia, primiparity, continuous electronic fetal monitoring, and increased birth weight. Further research is required to validate these variables and to determine the modifiable factors for labour management. And models of care with lower intervention rates such as midwife-led models of care should be developed and implemented in China.


Asunto(s)
Parto Obstétrico/estadística & datos numéricos , Trabajo de Parto , Adulto , Analgesia Epidural/estadística & datos numéricos , Peso al Nacer , Índice de Masa Corporal , Cardiotocografía , Cesárea/estadística & datos numéricos , China , Estudios Transversales , Femenino , Ganancia de Peso Gestacional , Humanos , Primer Periodo del Trabajo de Parto , Segundo Periodo del Trabajo de Parto , Tercer Periodo del Trabajo de Parto , Persona de Mediana Edad , Oxitocina/uso terapéutico , Paridad , Parto , Embarazo , Adulto Joven
10.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 37(2): 340-348, 2020 Apr 25.
Artículo en Zh | MEDLINE | ID: mdl-32329288

RESUMEN

This study aimed to explore the role of miR-130a-3p in cardiomyocyte hypertrophy and its underlying mechanisms. Pressure-overload induced myocardial hypertrophy mice model was constructed by thoracic aortic constriction (TAC). In vitro, norepinephrine (NE) was used to stimulate neonatal rat cardiomyocytes (NRCMs) and H9c2 rat cardiomyocytes to induce hypertrophic phenotypes. The expression of miR-130a-3p was detected in mice hypertrophic myocardium, hypertrophic NRCMs and H9c2 cells. The mimics and inhibitors of miR-130a-3p were transfected into H9c2 cells to observe the role of miR-130a-3p on the hypertrophic phenotype change of cardiomyocytes separately. Furthermore, whether miR-130a-3p regulated hypertrophic related signaling pathways was explored. The results showed that the expression of miR-130a-3p was significantly decreased in hypertrophic myocardium, hypertrophic NRCMs and H9c2 cells. After transfection of miR-130a-3p mimics, the expression of hypertrophic marker genes, atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and ß-myosin heavy chain (ß-MHC), and the cell surface area were notably down-regulated compared with the control group (mimics N.C. + NE group). But after transfection of miR-130a-3p inhibitor, the expression of ANP, BNP and ß-MHC in H9c2 cells increased significantly, and the cell area increased further. By Western blot, it was found that the protein phosphorylation level of Akt and mTOR were down-regulated after over-expression of miR-130a-3p. These results suggest that miR-130a-3p mimics may alleviate the degree of cardiomyocyte hypertrophy, meanwhile its inhibitor can further aggravate cardiomyocyte hypertrophy. Over-expression of miR-130a-3p may attenuate cardiomyocytes hypertrophy by affecting the Akt pathway.


Asunto(s)
MicroARNs/genética , Miocardio/patología , Miocitos Cardíacos/patología , Animales , Factor Natriurético Atrial , Cardiomegalia , Ratones , Cadenas Pesadas de Miosina , Péptido Natriurético Encefálico , Miosina Tipo IIB no Muscular , Proteínas Proto-Oncogénicas c-akt , Ratas
11.
Org Biomol Chem ; 16(17): 3109-3113, 2018 05 02.
Artículo en Inglés | MEDLINE | ID: mdl-29667683

RESUMEN

An iron-catalysed intermolecular vicinal aminoazidation of alkenes, using N-fluorobenzenesulfonimide (NFSI) and trimethylsilyl azide (TMSN3) as the imidating and azidating reagents, respectively, is described, which could potentially provide a valuable route toward diverse vicinal diamine derivatives of great significance in medicinal chemistry and organic synthesis. Such iron-catalysed aminative bisfunctionalization of alkenes with NFSI has not been reported yet. Comparing to previously employed copper or palladium catalysts, the iron catalyst, FeCl2, was demonstrated to be a good alternative for its comparable efficiency and broad alkene scope. Preliminary mechanistic study suggested that this iron-catalysed reaction is realized through radical processes.

12.
J Bioenerg Biomembr ; 49(5): 347-355, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28643238

RESUMEN

Regulator of the H+-ATPase of the vacuolar and endosomal membranes (RAVE) is essential for the reversible assembly of H+-ATPase. RAVE primarily consists of three subunits: Rav1p, Rav2p and Skp1p. To characterize these subunits, in this study, four strains derived from Saccharomyces cerevisiae BY4742 were constructed with a FLAG tag on the Rav1p and Rav2p subunits. Then, the corresponding RAVE containing complex was isolated by affinity purification. Western blot and MALDI-TOF mass spectrometry analyses showed that the RAVE complex contains not only the known V1-ATPase subunits (Vma1p and Vma2p) but also a newly found Leu1p that interacts with the RAVE subunit. Furthermore, we constructed rav1-/rav2-/vma2-/leu1-deficient recombinants by fusion PCR and homologous recombination and demonstrated that leu1 is indispensable in adjusting the microbial cell to adverse environments and that the function is similar to that of rav1/rav2 but significantly differs from that of vma2. Leu1p probably plays an important role in RAVE regulation of V-ATPase activity in conjunction with RAVE.


Asunto(s)
Endosomas/ultraestructura , Membranas Intracelulares/enzimología , ATPasas de Translocación de Protón Vacuolares/metabolismo , Vacuolas/ultraestructura , Endosomas/enzimología , Subunidades de Proteína , Proteínas de Saccharomyces cerevisiae/fisiología , Vacuolas/enzimología
13.
J Pineal Res ; 63(1)2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28247536

RESUMEN

Cellular senescence is an important tumor-suppressive mechanism. However, acquisition of a senescence-associated secretory phenotype (SASP) in senescent cells has deleterious effects on the tissue microenvironment and, paradoxically, promotes tumor progression. In a drug screen, we identified melatonin as a novel SASP suppressor in human cells. Strikingly, melatonin blunts global SASP gene expression upon oncogene-induced senescence (OIS). Moreover, poly(ADP-ribose) polymerase-1 (PARP-1), a sensor of DNA damage, was identified as a new melatonin-dependent regulator of SASP gene induction upon OIS. Here, we report two different but potentially coherent epigenetic strategies for melatonin regulation of SASP. The interaction between the telomeric repeat-containing RNA (TERRA) and PARP-1 stimulates the SASP, which was attenuated by 67.9% (illustrated by the case of IL8) by treatment with melatonin. Through binding to macroH2A1.1, PARP-1 recruits CREB-binding protein (CBP) to mediate acetylation of H2BK120, which positively regulates the expression of target SASP genes, and this process is interrupted by melatonin. Consequently, the findings provide novel insight into melatonin's epigenetic role via modulating PARP-1 in suppression of SASP gene expression in OIS-induced senescent cells. Our studies identify melatonin as a novel anti-SASP molecule, define PARP-1 as a new target by which melatonin regulates SASP, and establish a new epigenetic paradigm for a pharmacological mechanism by which melatonin interrupts PARP-1 interaction with the telomeric long noncoding RNA(lncRNA) or chromatin.


Asunto(s)
Senescencia Celular/efectos de los fármacos , Fibroblastos/efectos de los fármacos , Melatonina/farmacología , Poli(ADP-Ribosa) Polimerasa-1/metabolismo , Línea Celular , Células Cultivadas , Senescencia Celular/genética , Fibroblastos/metabolismo , Humanos , Pulmón/citología , Poli(ADP-Ribosa) Polimerasa-1/genética
14.
Org Biomol Chem ; 15(29): 6084-6088, 2017 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-28686259

RESUMEN

A novel and concise C5-alkylation of oxazoles using alkylboronic acids as alkyl donors via Pd(ii)-catalysed C-H bond activation has been achieved in moderate to good yields with satisfactory functional group tolerance. Instead of commonly used BQ as a key promoter, DDQ was discovered to be a better additive that significantly promoted this alkylation. This efficient and advanced method represents the first C(sp2)-C(sp3) cross-coupling reaction at the C5-position of oxazoles, which is particularly attractive due to its potential applications in the late-stage functionalization of oxazole-containing bioactive molecules.

15.
Anal Bioanal Chem ; 408(20): 5567-76, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27255103

RESUMEN

An electrochemical sensor of acetaminophen based on poly(diallyldimethylammonium chloride) (PDDA)-functionalized reduced graphene-loaded Al2O3-Au nanoparticles coated onto glassy carbon electrode (Al2O3-Au/PDDA/reduced graphene oxide (rGO)/glass carbon electrode (GCE)) were prepared by layer self-assembly technique. The as-prepared electrode-modified materials were characterized by scanning electron microscopy, X-ray powder diffraction, and Fourier transform infrared spectroscopy. The electrocatalytic performances of Al2O3-Au/PDDA/rGO-modified glassy carbon electrode toward the acetaminophen were investigated by cyclic voltammetry and differential pulse voltammetry. The modified electrodes of graphene oxide (GO)/GCE, PDDA/rGO/GCE, and Al2O3-Au/PDDA/rGO/GCE were constructed for comparison and learning the catalytic mechanism. The research showed Al2O3-Au/PDDA/rGO/GCE having good electrochemical performance, attributing to the synergetic effect that comes from the special nanocomposite structure and physicochemical properties of Al2O3-Au nanoparticles and graphene. A low detection limit of 6 nM (S/N = 3) and a wide linear detection range from 0.02 to 200 µM (R (2) = 0.9970) was obtained. The preparation of sensor was successfully applied for the detection of acetaminophen in commercial pharmaceutical pills. Graphical abstract Schematic diagram of synthesis of Al2O3-Au/PDDA/rGO/GCE.


Asunto(s)
Acetaminofén/análisis , Técnicas Biosensibles/instrumentación , Conductometría/instrumentación , Grafito/química , Nanopartículas del Metal/química , Polietilenos/química , Compuestos de Amonio Cuaternario/química , Acetaminofén/química , Óxido de Aluminio/química , Electrodos , Diseño de Equipo , Análisis de Falla de Equipo , Oro/química , Nanopartículas del Metal/ultraestructura , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
16.
J Sep Sci ; 38(9): 1584-90, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25726925

RESUMEN

A novel palladium solid-phase microextraction coating was fabricated on a stainless-steel wire by a simple in situ oxidation-reduction process. The palladium coating exhibited a rough microscaled surface and its thickness was about 2 µm. Preparation conditions (reaction time and concentration of palladium chloride and hydrochloric acid) were optimized in detail to achieve sufficient extraction efficiency. Extraction properties of the fiber were investigated by direct immersion solid-phase microextraction of several polycyclic aromatic hydrocarbons and phthalate esters in aqueous samples. The extracted analytes were transferred into a gas chromatography system by thermal desorption. The effect of extraction and desorption conditions on extraction efficiency were investigated. Under the optimum conditions, good linearity was obtained and correlation coefficients between 0.9908 and 0.9990 were obtained. Limits of detection were 0.05-0.10 µg/L for polycyclic aromatic hydrocarbons and 0.3 µg/L for phthalate esters. Their recoveries for real aqueous samples were in the range from 97.1 to 121% and from 89.1 to 108%, respectively. The intra- and interday tests were also investigated with three different addition levels, and satisfactory results were also obtained.

17.
J Sep Sci ; 37(24): 3691-8, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25283136

RESUMEN

Graphene oxide was bonded onto a silver-coated stainless-steel wire using an ionic liquid as the crosslinking agent by a layer-by-layer strategy. The novel solid-phase microextraction fiber was characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy and Raman microscopy. A multilayer graphene oxide layer was closely coated onto the supporting substrate. The thickness of the coating was about 4 µm. Coupled with gas chromatography, the fiber was evaluated using five polycyclic aromatic hydrocarbons (fluorene, anthracene, fluoranthene, 1,2-benzophenanthrene, and benzo(a)pyrene) as model analytes in direct-immersion mode. The main conditions (extraction time, extraction temperature, ionic strength, and desorption time) were optimized by a factor-by-factor optimization. The as-established method exhibited a wide linearity range (0.5-200 µg/L) and low limits of determination (0.05-0.10 µg/L). It was applied to analyze environmental water samples of rain and river water. Three kinds of the model analytes were quantified and the recoveries of samples spiked at 10 µg/L were in the range of 92.3-120 and 93.8-115%, respectively. The obtained results indicated the fiber was efficient for solid-phase microextraction analysis.

18.
J Sep Sci ; 37(16): 2153-9, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24865572

RESUMEN

A dicationic imidazolium ionic liquid modified silica stationary phase was prepared and evaluated by reversed-phase/anion-exchange mixed-mode chromatography. Model compounds (polycyclic aromatic hydrocarbons and anilines) were separated well on the column by reversed-phase chromatography; inorganic anions (bromate, bromide, nitrate, iodide, and thiocyanate), and organic anions (p-aminobenzoic acid, p-anilinesulfonic acid, sodium benzoate, pathalic acid, and salicylic acid) were also separated individually by anion-exchange chromatography. Based on the multiple sites of the stationary phase, the column could separate 14 solutes containing the above series of analytes in one run. The dicationic imidazolium ionic liquid modified silica can interact with hydrophobic analytes by the hydrophobic C6 chain; it can enhance selectivity to aromatic compounds by imidazolium groups; and it also provided anion-exchange and electrostatic interactions with ionic solutes. Compared with a monocationic ionic liquid functionalized stationary phase, the new stationary phase represented enhanced selectivity owing to more interaction sites.

19.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 45(6): 928-32, 2014 Nov.
Artículo en Zh | MEDLINE | ID: mdl-25571717

RESUMEN

OBJECTIVE: To study whether there is apoptosis in brainstem neurons while aging by oberving the distribution of Caspase-3 positive apoptotic cells in in brainstem of young and old SD rats. METHODS: Healthy male SD rats were divided into 2 groups (3 and 18 month-old respectively), 3 rats each group. Brainstem specimens were treated followed the brainstem's common paraffin embedding, sectioning and HE staining procedures (sections were 6 µm in thickness). The sections were also determined by Caspase-3 immunostaining and TUNEL. The Caspase-3 positive cells on the rat stereotaxic atlas were drew, then composed the sections into a 3D model. RESULTS: Compared to 3 month-old rats, there were more Caspase-3 positive neurons in the brainstem and the positive neurons were distributed more extensively in 18 month-old rats spectially in nucleus of solitary tract and pontine reticular nuclei. CONCLUSION: More neurons suffer apoptotic changes in the brainstem while aging.


Asunto(s)
Envejecimiento , Apoptosis , Tronco Encefálico/citología , Caspasa 3/metabolismo , Neuronas/citología , Animales , Masculino , Ratas , Ratas Sprague-Dawley
20.
Heliyon ; 10(1): e22498, 2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-38332877

RESUMEN

[This corrects the article DOI: 10.1016/j.heliyon.2022.e11190.].

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