Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Exp Ther Med ; 27(2): 57, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38234620

RESUMEN

The present study reports the case of a superficial limbal dermoid surgically treated without suture by using a new technique of lamellar keratoplasty with allogenic lenticule from small incision lenticule extraction. The limbal lesion area was circumscribed by a trephine marker and lamellae were peeled off the anterior corneal stroma and sclera. After excision of the dermoid, the liquid on the bed was dried as much as possible and an appropriate stromal lenticule was attached to the implant bed without fibrin glue or suture. A bandage contact lens was applied to fix the graft. During postoperative follow-ups, the anterior segment optical coherence tomography, corneal refractive power, corneal topography and best-corrected visual acuity were examined to evaluate the surgical results. On the first day after the operation, the patient reported tearing and pain at the site. At one week after the operation, the patient reported no discomfort and conjunctival sutures were removed. At one month after the operation, the thickness of the lesion area was similar to that of the adjacent cornea, and the corneal curvature and refractive power of the lesion area were higher than that of the adjacent cornea. At three months after the operation, the patient was satisfied with the cosmetic outcome and no sign of corneal neovascularization, graft rejection or pseudo-pterygium formation was observed. The astigmatic error remained at 2.50 D. The present case provides insights into a potential treatment option for patients who need lamellar keratoplasty and may provide its benefit in contrast to conventional lamellar keratoplasty.

2.
J Plant Dis Prot (2006) ; 130(2): 371-382, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-35965943

RESUMEN

This study was designed to investigate the insecticidal activity of the essential oils (EOs) and extracts from Rhododendron rufum and Rhododendron przewalskii. The EOs were extracted from the leaves of R. Rufum and R. przewalskii by hydro-distillation and their chemical components were analyzed by gas chromatography-mass spectrometry (GC-MS). The repellency, contact toxicity and antifeedant activity of the EOs and extracts were evaluated against Sitophilus oryzae and Tribolium castaneum along with those of their main components. A total of nine compounds were identified from the EO of R. Rufum, and the most abundant component was myristicin (79.72%). The EO of R. Rufum exhibited repellent activities at different levels and its main compound myristicin showed contact toxicity and repellent effects against S. oryzae and T. castaneum. Meanwhile, by bioassay-guided fractionation, four compounds with strong antifeedant activities against T. castaneum, 24-methylenecycloartanyl-2'E, 4'Z-tetradecadienoate (1), methyl thyrsiflorin B acetate (2), friedelin (3) and Excoecarin R1 methyl ester (4) were separated and identified from the ethanol extract of R. przewalskii for the first time. Considering the significant anti-insect activities, the EOs and extracts of R. Rufum and R. przewalskii might be used in integrated pest strategies, establishing a good perspective for the comprehensive use of natural plant resources of Rhododendron genus.

3.
Chem Biodivers ; 19(12): e202200740, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36310430

RESUMEN

In order to assess the repellent, contact, and fumigant properties of three essential oils (EOs) from Rhododendron species in China against adults of Tribolium castaneum, Lasioderma serricorne, Sitophilus oryzae, this study analyzed their chemical components. The three EOs were extracted by hydrodistillation from leaves of Rhododendron species, including R. davidsonianum, R. heliolepis and R. strigillosum. Sesquiterpenoids and monoterpenes were the main components of the three EOs that were detected by GC/MS and GC-FID. α-Pinene, ß-Caryophyllene, α-Humulene, Kaura-16-ene and Sandaracopimaradiene was among the comparatively high components. In this study, the EOs of three Rhododendron species demonstrated repellent activities against T. castaneum and L. serricorne in 2 h and 4 h exposure, but the repellent activity to S. oryzae was not obvious. The three EOs from R. davidsonianum, R. heliolepis and R. strigillosum also had contact activities and fumigant activities against the Tribolium castaneum (LC50 =13.453 mg/L air, 4.728 mg/L air, 4.529 mg/L air and LD50 =15.027 µg/adult, 15.017 µg/adult, 10.994 µg/adult, respectively), Lasioderma serricorne (LC50 =8.584 mg/L air, 6.044 mg/L air, 6.355 mg/L air and LD50 =4.566 µg/adult, 7.067 µg/adult, 3.652 µg/adult, respectively) and Sitophilus oryzae (LC50 =3.304 mg/L air, 6.795 mg/L air, 7.130 mg/L air and LD50 =10.200 µg/adult, 15.021 µg/adult, 9.178 µg/adult, respectively) adults. The above results not only opened a potential prospect for applications of Rhododendrons in the prevention and control of insects in stored products, but also provide a basis for the comprehensive utilization of the rich natural Rhododendron plant resources.


Asunto(s)
Escarabajos , Repelentes de Insectos , Insecticidas , Aceites Volátiles , Rhododendron , Tribolium , Animales , Aceites Volátiles/farmacología , Aceites Volátiles/química , Insecticidas/farmacología , Insecticidas/química , Repelentes de Insectos/farmacología , Repelentes de Insectos/química
4.
Nat Prod Res ; 36(17): 4452-4456, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34629001

RESUMEN

The objective of this work was to investigate the chemical compositions of the essential oil (EO) extracted from Senecio scandens by hydrodistillation and their insecticidal activities against Tribolium castaneum, Lasioderma serricorne and Liposceis bostrychophila. The chemical profile of the EO were analyzed by gas chromatography-mass spectrometry (GC-MS), and 20 compounds were identified which accounted for 88.03% of the total EO. Five major compounds identified in the EO were assayed against the three stored product insects. The EO showed strong contact toxicity to T. castaneum (LD50 = 18.01 µg/adult), L. serricorne (LD50 = 20.11 µg/adult) and L. bostrychophila (LD50 = 72.14 µg/cm2). Among all compounds, geraniol showed the contact toxicity against L. serricorne and L. bostrychophila with LD50 values of 15.82 µg/adult and 26.64 µg/cm2. The EO and its five chemical compounds also exhibited different level of potential repellence to the three stored product insects.


Asunto(s)
Repelentes de Insectos , Insecticidas , Aceites Volátiles , Senecio , Tribolium , Animales , Repelentes de Insectos/química , Repelentes de Insectos/farmacología , Insectos , Insecticidas/química , Aceites Volátiles/química
5.
Molecules ; 26(21)2021 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-34770847

RESUMEN

The objective of this study was to establish the chromatographic fingerprints of the essential oil (EO) from Stellera chamaejasme flowers collected from various natural sites by gas chromatography (GC) combined with chemometric methods. The EO was obtained by hydrodistillation, and its chemical composition was analyzed by gas chromatography-mass spectrometry (GC-MS). Most components were identified as ketones and the relatively high-content components were fitone (38.973%), n-hentriacontane (5.807%), myristic acid (4.944%) and phytol (3.988%). In addition, the repellent activities of the EO from S. chamaejasme flowers and its four main chemical compounds were evaluated against three stored product pests (Tribolium castaneum, Lasioderma serricorne, Liposcelis bostrychophila) for the first time. In this work, the EO and the four chemical compounds showed a repellent effect against three storage pests after 2 and 4 h exposure. The experimental method and repellent activity of S. chamaejasme flower EO could provide a basis for the development of botanical pesticide and the utilization of the rich plant resources of S. chamaejasme in the future.


Asunto(s)
Cromatografía de Gases , Flores/química , Repelentes de Insectos/química , Repelentes de Insectos/farmacología , Malvales/química , Aceites Volátiles/química , Aceites Volátiles/farmacología , Relación Dosis-Respuesta a Droga , Cromatografía de Gases y Espectrometría de Masas , Repelentes de Insectos/análisis , Aceites Volátiles/análisis , Fitoquímicos/análisis , Fitoquímicos/química , Extractos Vegetales/análisis , Extractos Vegetales/química , Extractos Vegetales/farmacología
6.
World J Clin Cases ; 8(7): 1326-1336, 2020 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-32337210

RESUMEN

BACKGROUND: Apatinib is a small-molecule multitargeted tyrosine kinase inhibitor. Apatinib has demonstrated encouraging antitumor activities. This study aimed to observe the efficacy and safety of apatinib for the treatment of multiple brain micrometastases. CASE SUMMARY: We report two patients with multiple brain micrometastases after failure of second-line treatment. Both patients had extracerebral metastases. When the patients took 250 mg/d apatinib orally, the intracerebral lesions disappeared. The extracerebral lesions were partially alleviated. Both patients had a progression-free survival of more than 12 mo and were still stable. The safety was good. The main adverse events (AEs) were mild hypertension and proteinuria, which could be controlled. CONCLUSION: Apatinib has clear efficacy and good tolerance in patients with multiple brain micrometastases after failure of second-line treatment.

7.
Mikrochim Acta ; 185(4): 215, 2018 03 12.
Artículo en Inglés | MEDLINE | ID: mdl-29594743

RESUMEN

A nafion film containing cerium phosphate nanotubes was pasted onto a glassy carbon electrode (GCE) to obtain a sensor for hydroquinone (HQ). The morphologies and components of the coating were characterized by transmission electron microscopy, scanning electron microscopy and energy-dispersive spectroscopy. Cyclic voltammetry and differential pulse voltammetry (DPV) showed the specific surface of the electrode to be significantly increased and the electron transfer rate to be accelerated. The modified GCE was applied to the determination of hydroquinone (HQ) via DPV. The oxidation current increases linearly in the 0.23 µM to 16 mM HQ concentration range which is as wide as five orders of magnitude. The limit of detection is 0.12 µM (based on a signal-to-noise ratio of 3), and the sensitivity is 1.41 µA·µM-1 cm-2. The method was further applied to the simultaneous determination of HQ, catechol and resorcinol. The potentials for the three species are well separated (20, 134, and 572 mV vs SCE). Average recoveries from (spiked) real water samples are between 95.2 and 107.0%, with relative standard deviations of 0.9~2.7% (for n = 3) at three spiking levels. The method was validated by independent assays using HPLC. Graphical abstract ᅟ.

8.
Nanoscale ; 9(2): 899-906, 2017 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-28000832

RESUMEN

Herein, an autocatalytic route to fabricate dual metal ion-equipped organic/inorganic hybrid silica, an ideal precursor for multifunctional silica-based composites integrated with well-dispersed Ag and Co3O4 nanoparticles was demonstrated. Significantly, by rational selection of reactants, such dual metal ion-equipped organic/inorganic hybrid silica can be synthesized through successive spontaneous reactions under near neutral conditions without an additional catalyst. Both the Ag+ and Co2+ ions are introduced into silica by chemical bonds, which favor the formation of small-sized and well-dispersed Ag and Co3O4 nanoparticles without aggregation in the entire silica matrix. After calcination, multifunctional silica composites equipped with well-dispersed Ag and Co3O4 nanoparticles were obtained. The as-obtained silica composites, as indicated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), have a spherical morphology and smooth surface. TEM tests also reveal the well dispersed fashion of Ag and Co3O4 nanoparticles. In addition, the obtained Ag-Co3O4@SiO2 composites exhibit good catalytic performance in the reduction of methylene blue (MB) with NaBH4 as a reducing agent, and can be readily recycled by an external magnetic field due to their superparamagnetic properties.

9.
Talanta ; 151: 114-118, 2016 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-26946017

RESUMEN

In this work, the direct determination of creatinine was achieved using a poly(ethyleneimine)/phosphotungstic acid multilayer modified electrode with the assistance of Copper(II) ions by cyclic voltammetry. The quantity of creatinine were determined by measuring the redox peak current of Cu(II)-creatinine complex/Cu(I)-creatinine complex. Factors affecting the response current of creatinine at the modified electrode were optimized. A linear relationship between the response current and the concentration of creatinine ranging from 0.125 to 62.5µM was obtained with a detection limit of 0.06µM. The proposed method was applied to determine creatinine in human urine, and satisfied results were gotten which was validated in accordance with high performance liquid chromatography. The proposed electrode provided a promising alternative in routine sensing for creatinine without enzymatic assistance.


Asunto(s)
Creatinina/orina , Técnicas Electroquímicas/métodos , Ácido Fosfotúngstico/química , Polietileneimina/química , Técnicas Biosensibles/instrumentación , Técnicas Biosensibles/métodos , Cromatografía Líquida de Alta Presión , Cobre/química , Creatinina/química , Conductividad Eléctrica , Técnicas Electroquímicas/instrumentación , Electrodos , Electrólitos/química , Humanos , Concentración de Iones de Hidrógeno , Oxidación-Reducción , Reproducibilidad de los Resultados , Soluciones/química
10.
Phys Chem Chem Phys ; 16(6): 2641-6, 2014 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-24382520

RESUMEN

Using the CCSD(T) method with relativistic correlation consistent basis sets up to cc-pVQZ-PP, the entrance complex, transition state, and exit complex for the endothermic reaction I + H2O → HI + OH have been studied. The vibrational frequencies and the zero-point vibrational energies of the five stationary points for the title reaction are reported and compared with the limited available experimental results. Opposite to the valence isoelectronic F + H2O system, but similar to the Cl + H2O and Br + H2O reactions, the I + H2O reaction is endothermic, in this case by 46 kcal mol(-1). After the zero-point vibrational energy and spin-orbit coupling corrections, the endothermic reaction energy is predicted to be 48 kcal mol(-1), which agrees well with experimental values. For the reverse reaction HI + OH → I + H2O the transition state lies below the reactants, consistent with the experimental negative temperature dependence for the rate constants.


Asunto(s)
Yodo/química , Agua/química , Modelos Moleculares , Teoría Cuántica , Termodinámica
11.
Zhongguo Zhong Yao Za Zhi ; 36(4): 465-7, 2011 Feb.
Artículo en Chino | MEDLINE | ID: mdl-21598543

RESUMEN

OBJECTIVE: To investigate the chemical constituents from Lamiophlomis rotata and the bioactivities of 8-epideoxyloganic acid. METHOD: The constituents were isolated by using a combination of various chromatographic techniques including column chromatography over ployamide, silica gel and Sephadex LH-20. Structures of the isolates were identified by spectroscopic data analysis. Bioactivities were screened by using models in vivo. RESULT: Five constituents were isolated. 8-epideoxyloganic acid was isolated for the first time in L. rotata and also in lamioplomis genus. 8-epideoxyloganic acid could significantly inhibit aectic acid-induced twisting times and slower the time of homeostatsis, also inhibit xylene-induced ear edema in mice. CONCLUSION: 8-epideoxyloganic acid possesses bioactivities of analgesia, homeostasis and anti-inflammatory.


Asunto(s)
Lamiaceae/química , Piranos/farmacología , Analgésicos/farmacología , Animales , Antiinflamatorios/farmacología , Femenino , Masculino , Ratones , Piranos/aislamiento & purificación
12.
J Phys Condens Matter ; 20(23): 235230, 2008 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-21694321

RESUMEN

Using the projector augmented wave (PAW) within the Perdew-Burke-Ernzerhof (PBE) form of the generalized gradient approximation (GGA), we investigate the effect of hydrostatic pressure on the structures of zirconium metal at zero temperature. We obtain the [Formula: see text] transition at around 26.8 GPa, which is in excellent agreement with the experimental values. We also find that the ω phase is most stable at 0 K and 0 GPa. This conclusion is supported by first-principles calculations of Schell et al and Jona et al. The elastic constants of ω-Zr under high pressures are calculated for the first time. We find that the compressional and shear wave velocities increase monotonically with increasing pressure and the results are in good agreement with the available experimental data. The pressure dependences of three anisotropies of elastic waves are also presented.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...