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1.
J Phys Chem Lett ; 15(16): 4422-4429, 2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38626393

RESUMEN

Heterocycles with saturated N atoms (HetSNs) are widely used electron donors in organic light-emitting diode (OLED) materials. Their relatively low bond dissociation energy (BDE) of exocyclic C-N bonds has been closely related to material intrinsic stability and even device lifetime. Thus, it is imperative to realize fast prediction and precise regulation of those C-N BDEs, which demands a deep understanding of the relationship between the molecular structure and BDE. Herein, via machine learning (ML), we rapidly and accurately predicted C-N BDEs in various HetSNs and found that five-membered HetSNs (5-HetSNs) have much higher BDEs than almost all 6-HetSNs, except emerging boron-N blocks. Thorough analysis disclosed that high aromaticity is the foremost factor accounting for the high BDE of 5-HetSNs, and introducing intramolecular hydrogen-bond or electron-withdrawing moieties could also increase BDE. Importantly, the ML models performed well in various realistic OLED materials, showing great potential in characterizing material intrinsic stability for high-throughput virtual-screening and material design efforts.

2.
Small ; : e2308483, 2024 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-38329171

RESUMEN

Phosphates featuring a 3D framework offer a promising alternative to aqueous sodium-ion batteries, known for their safety, cost-effectiveness, scalability, high power density, and tolerance to mishandling. Nevertheless, they often suffer from poor reversible capacity stemming from limited redox couples. Herein, N-containing Na2 VTi(PO4 )3 is synthesized for aqueous sodium-ion storage through multi-electron redox reactions. It demonstrates a capacity of 155.2 mAh g-1 at 1 A g-1 (≈ 5.3 C) and delivers an ultrahigh specific energy of 55.9 Wh kg-1 in a symmetric aqueous sodium-ion battery. The results from in situ X-ray diffraction analysis, ex situ X-ray photoelectron spectroscopy analysis, and first-principle calculations provide insights into the local chemical environment of sodium ions, the mechanisms underlying capacity decay during cycling, and the dynamics of ion and electron transfer at various states of charge. This understanding will contribute to the advancement of electrode materials for aqueous sodium-ion batteries.

3.
J Colloid Interface Sci ; 657: 913-920, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38091914

RESUMEN

Chirality dynamic tuning plays fundamental roles in chemistry, material science and biological system. Herein, a pair of azobenzene-bridged bis-tryptophan enantiomers (Azo-di-d/l-Trp) were designed and synthesized via simple reactions. With the fuel of glucono-δ-lactone (GdL), releasing protons during its hydrolysis, the alkaline solution of Azo-di-d/l-Trp gradually self-assembled into contrast chiral helical structures and displayed magnitude and mirror image of circular dichroism (CD) signals. While the chiral helices converted to CD silent nanoparticles when the azobenzene moiety isomerized from trans- to cis-form under UV irradiation. More importantly, this chiroptical switch, displaying reversible interconversion between chiral amplification and silent, can be smartly controlled via photoirradiation at various wavelengths.

4.
Nat Commun ; 14(1): 3927, 2023 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-37400475

RESUMEN

The 3rd-Gen OLED materials employing thermally-activated delayed fluorescence (TADF) combine advantages of first two for high-efficiency and low-cost devices. Though urgently needed, blue TADF emitters have not met stability requirement for applications. It is essential to elucidate the degradation mechanism and identify the tailored descriptor for material stability and device lifetime. Here, via in-material chemistry, we demonstrate chemical degradation of TADF materials involves critical role of bond cleavage at triplet state rather than singlet, and disclose the difference between bond dissociation energy of fragile bonds and first triplet state energy (BDE-ET1) is linearly correlated with logarithm of reported device lifetime for various blue TADF emitters. This significant quantitative correlation strongly reveals the degradation mechanism of TADF materials have general characteristic in essence and BDE-ET1 could be the shared "longevity gene". Our findings provide a critical molecular descriptor for high-throughput-virtual-screening and rational design to unlock the full potential of TADF materials and devices.

5.
Int J Ophthalmol ; 16(3): 453-464, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36935799

RESUMEN

AIM: To investigate changes of choroidal thickness (ChT) in children with myopia and the effect of current myopia control interventions on ChT. METHODS: Major literature databases were searched for studies relevant to myopia in children. All studies used swept-source optical coherence tomography (SS-OCT) or enhanced depth imaging optical coherence tomography (EDI-OCT) to measure the ChT value. The weighted mean difference (WMD) and 95% confidence interval (CI) were pooled to evaluate ChT in myopia children. RESULTS: A total of 11 eligible articles, including 1693 myopic and 1132 non-myopic eyes, were included in the first Meta-analysis. The sub-foveal choroidal thickness (SFCT; WMD=-40.06, 95%CI, -59.36 to -20.75, P<0.001) and ChT at other sectors were significantly thinner in myopic eyes compared with the non-myopic eyes. The Meta-analysis revealed that the ChT decreased horizontally from the temporal sector toward the nasal sector in the pediatric myopia population. Another 11 studies reporting the effect of myopia control interventions were included in the second Meta-analysis for the relationship between myopia control treatments and ChT. SFCT significantly increased after orthokeratology (OK) treatment and OK combined with 0.01% atropine (OKA) treatment (WMD=19.47, 95%CI, 15.96 to 22.98, P<0.001; WMD=21.81, 95%CI, 12.92 to 29.70, P<0.001, respectively). The forest plots showed that SFCT changed little in myopic children receiving 0.01% atropine (P=0.30). Furthermore, the Meta-analysis showed that OK treatment had a stronger effect on the value of SFCT in myopic children as compared with 0.01% atropine (WMD=9.86; 95%CI, -0.21 to 19.93, P=0.05). There is no difference between the treatment with OK and OKA treatment in ChT in myopic children (P=0.37). CONCLUSION: The ChT in myopic eyes is thinner than that in non-myopic eyes in pediatric population. Myopia control interventions including OK and OKA lead to ChT thickening, but other treatments such as 0.01% atropine did not show an increase in ChT.

6.
Front Immunol ; 13: 911859, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35663993

RESUMEN

Safe and effective vaccines and therapeutics based on the understanding of antiviral immunity are urgently needed to end the COVID-19 pandemic. However, the understanding of these immune responses, especially cellular immune responses to SARS-CoV-2 infection, is limited. Here, we conducted a cohort study of COVID-19 patients who were followed and had blood collected to characterize the longitudinal dynamics of their cellular immune responses. Compared with healthy controls, the percentage of activation of SARS-CoV-2 S/N-specific T cells in recovered patients was significantly higher. And the activation percentage of S/N-specific CD8+ T cells in recovered patients was significantly higher than that of CD4+ T cells. Notably, SARS-CoV-2 specific T-cell responses were strongly biased toward the expression of Th1 cytokines, included the cytokines IFNγ, TNFα and IL2. Moreover, the secreted IFNγ and IL2 level in severe patients was higher than that in mild patients. Additionally, the number of IFNγ-secreting S-specific T cells in recovered patients were higher than that of N-specific T cells. Overall, the SARS-CoV-2 S/N-specific T-cell responses in recovered patients were strong, and virus-specific immunity was present until 14-16 weeks after symptom onset. Our work provides a basis for understanding the immune responses and pathogenesis of COVID-19. It also has implications for vaccine development and optimization and speeding up the licensing of the next generation of COVID-19 vaccines.


Asunto(s)
COVID-19 , Linfocitos T CD8-positivos , Vacunas contra la COVID-19 , Estudios de Cohortes , Humanos , Inmunidad Celular , Interleucina-2 , Pandemias , SARS-CoV-2
7.
Zhen Ci Yan Jiu ; 46(5): 385-90, 2021 May 25.
Artículo en Chino | MEDLINE | ID: mdl-34085461

RESUMEN

OBJECTIVE: To investigate the effect of joint administration of electroacupuncture (EA) and bone marrow mesenchymal stem cells (BMMSC) on the expression of estrogen receptor (ER) and progesterone receptor (PR) in thin endometrium rats, so as to explore its mechanisms underlying improvement of conception rate. METHODS: Forty female SD rats were divided into control, model, BMMSC and EA+BMMSC groups. The thin endometrium model was established by intrauterine infusion of 95% ethanol and saline. EA (1 mA, 2 Hz/15 Hz) was applied to "Guanyuan"(CV4), unilateral "Zigong" (EX-CA1) and unila-teral "Sanyinjiao" (SP6) for 15 min, once daily for 10 d. Rats of the BMMSC and EA+BMMSC groups received injection of BMMSC suspension through caudal vein on the day of modeling, the 3rd day after surgery, and the 2nd and the 3rd estrus phases, respectively. Changes of body weight and estrus phase were continuously recorded. After three estrus cycles, uterine specimens were taken and the uterine coefficient was calculated. The immunoactivity of KI67(an antigen for cell proliferation) was detected by immunohistochemistry, and the expression of ER and PR was detected by Western blot. RESULTS: Compared with the control group, the uterine coefficient, and expression of endometrium ER and PR proteins were significantly decreased in the model group (P<0.001, P<0.01). In Comparison with the model group, the uterine coefficient, immunoactivity of KI67, and expression of ER and PR proteins were significantly increased in both BMMSC and EA+BMMSC groups (P<0.000 1,P<0.001, P<0.01). The expression level of PR in the EA+BMMSC group was notably higher than that in the BMMSC group (P<0.05), but no significant difference was found between the BMMSC and EA+BMMSC groups in the levels of uterine coefficient and ER expression (P>0.05). CONCLUSION: EA combined with BMMSC injection has a positive effect in promoting the proliferation of endometrium cells in rats with thin endometrium, which may be related to its effect in up-regulating the expression of ER and PR proteins.


Asunto(s)
Electroacupuntura , Células Madre Mesenquimatosas , Puntos de Acupuntura , Animales , Endometrio , Femenino , Ratas , Ratas Sprague-Dawley , Receptores de Estrógenos/genética , Receptores de Progesterona/genética
8.
Zhen Ci Yan Jiu ; 45(3): 243-50, 2020 Mar 25.
Artículo en Chino | MEDLINE | ID: mdl-32202718

RESUMEN

OBJECTIVE: To evaluate the clinical effect of acupuncture combined with Chinese medicine in the treatment of oligozoospermia/asthenozoospermia. METHODS: Randomized controlled trials (RCTs) of acupuncture combined with traditional Chinese medicine (TCM) in the treatment of oligozoospermia/asthenozoospermia published up to February 15, 2019 were searched from databases of CNKI, CBM, Wanfang Data, VIP, PubMed, Embase, and The Cochrane Library. Two reviewers independently performed quality assessment and data extraction of the studies, and RevMan5.3 was used to perform the meta-analysis. RESULTS: A total of 13 articles with 12 RCTs were included, with a total of 1 183 patients. The meta-analysis showed that acupuncture combined with TCM achieved a significantly higher pregnancy rate than TCM alone in the treatment of oligozoospermia/asthenozoospermia(risk ratio [RR] =1.46, 95% confidence interval [CI]: 1.13-1.90,P=0.004). The patients treated with acupuncture combined with TCM had a significantly higher effective rate than those treated with TCM alone (RR=1.17, 95% CI:1.10-1.24, P<0.000 01). Compared with TCM alone, acupuncture combined with TCM achieved significantly better improvements in sperm survival rate (mean difference [MD]=8.28, 95% CI: 6.48-10.08, P<0.000 01), sperm motility (MD=17.01, 95%CI:11.06-22.96, P<0.000 01), sperm concentration (MD=8.71, 95%CI:5.92-11.50, P<0.000 01), and number of grade A sperms (MD=6.39, 95%CI:5.27-7.50, P<0.000 01). CONCLUSION: Acupuncture combined with TCM has a better clinical effect than TCM alone in the treatment of oligozoospermia/asthenozoospermia. Due to the low methodological quality of the studies included in this analysis, acupuncture combined with TCM in the treatment of oligozoospermia/asthenozoospermia should be used based on patients' conditions in clinical practice.


Asunto(s)
Terapia por Acupuntura , Astenozoospermia , Oligospermia , Astenozoospermia/terapia , Humanos , Masculino , Medicina Tradicional China , Oligospermia/terapia , Motilidad Espermática
9.
Int J Ophthalmol ; 12(7): 1146-1150, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31341806

RESUMEN

AIM: To explore the process of retinal vascularization and risk factors for retinopathy of prematurity (ROP) treated with intravitreal ranibizumab (IVR) as monotherapy. METHODS: Infants with type 1 ROP who received IVR as primary treatment from August 2014 to October 2016 at Peking University People's Hospital's Ophthalmology Department were included in the study. All eyes received 0.25 mg ranibizumab at initial treatment. Retinal vascularization was evaluated clinically. Potential risk factors were also recorded and examined. RESULTS: Retinal vascularization was completed in 126 eyes (62.7%), and retinal vascularization terminated in zone II and zone III with 16 eyes (7.9%) and 44 eyes (21.9%), respectively, after more than 1-year follow-up. In multivariate regression analysis, lower birth weight (BW), severity of ROP and repeated injections were found to be risk factors for peripheral avascular area (P<0.05). CONCLUSION: In our retrospective study, 29.8% of the ROP eyes treated with ranibizumab have peripheral avascular area at the last follow-up. Lighter BW and the severity of ROP are risk factors. Furthermore, repeated injections also increase the risk of retinal peripheral avascular area remaining in ROP patients.

10.
Environ Sci Technol ; 49(24): 14184-94, 2015 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-26561729

RESUMEN

Air pollution health studies of fine particulate matter (diameter ≤2.5 µm, PM2.5) often use outdoor concentrations as exposure surrogates. Failure to account for variability of indoor infiltration of ambient PM2.5 and time indoors can induce exposure errors. We developed and evaluated an exposure model for individuals (EMI), which predicts five tiers of individual-level exposure metrics for ambient PM2.5 using outdoor concentrations, questionnaires, weather, and time-location information. We linked a mechanistic air exchange rate (AER) model to a mass-balance PM2.5 infiltration model to predict residential AER (Tier 1), infiltration factors (Tier 2), indoor concentrations (Tier 3), personal exposure factors (Tier 4), and personal exposures (Tier 5) for ambient PM2.5. Using cross-validation, individual predictions were compared to 591 daily measurements from 31 homes (Tiers 1-3) and participants (Tiers 4-5) in central North Carolina. Median absolute differences were 39% (0.17 h(-1)) for Tier 1, 18% (0.10) for Tier 2, 20% (2.0 µg/m(3)) for Tier 3, 18% (0.10) for Tier 4, and 20% (1.8 µg/m(3)) for Tier 5. The capability of EMI could help reduce the uncertainty of ambient PM2.5 exposure metrics used in health studies.


Asunto(s)
Contaminación del Aire Interior/análisis , Exposición a Riesgos Ambientales/análisis , Modelos Teóricos , Adulto , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Contaminación del Aire Interior/efectos adversos , Monitoreo del Ambiente/métodos , Femenino , Vivienda , Humanos , Masculino , North Carolina , Material Particulado/efectos adversos , Material Particulado/análisis , Reproducibilidad de los Resultados , Encuestas y Cuestionarios , Factores de Tiempo , Tiempo (Meteorología)
11.
J Expo Sci Environ Epidemiol ; 24(6): 555-63, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23715084

RESUMEN

A critical aspect of air pollution exposure assessments is estimation of the air exchange rate (AER) for various buildings where people spend their time. The AER, which is the rate of exchange of indoor air with outdoor air, is an important determinant for entry of outdoor air pollutants and for removal of indoor-emitted air pollutants. This paper presents an overview and critical analysis of the scientific literature on empirical and physically based AER models for residential and commercial buildings; the models highlighted here are feasible for exposure assessments as extensive inputs are not required. Models are included for the three types of airflows that can occur across building envelopes: leakage, natural ventilation, and mechanical ventilation. Guidance is provided to select the preferable AER model based on available data, desired temporal resolution, types of airflows, and types of buildings included in the exposure assessment. For exposure assessments with some limited building leakage or AER measurements, strategies are described to reduce AER model uncertainty. This review will facilitate the selection of AER models in support of air pollution exposure assessments.


Asunto(s)
Contaminantes Atmosféricos/análisis , Contaminación del Aire Interior/análisis , Monitoreo del Ambiente/métodos , Ventilación , Arquitectura y Construcción de Instituciones de Salud , Humanos , Análisis de Regresión , Medición de Riesgo/métodos , Tiempo (Meteorología)
13.
Guang Pu Xue Yu Guang Pu Fen Xi ; 31(12): 3218-22, 2011 Dec.
Artículo en Chino | MEDLINE | ID: mdl-22295763

RESUMEN

In the present paper, a novel nanophosphor, Y10W2O21:Eu was synthesized through a simple and low-cost method: co-precipitation. The results of XRD show that resultant samples are Orthorhombic phase and primitive lattice. The average crystallographic sizes could be confirmed to be approximately 80 nm by means of the Scherrer formula, which are in good agreement with the particles sizes exhibited by SEM. In the excitation spectra of Y10W2O21:Eu nanophosphor, by monitoring 610 nm, the charge transfer bands (CTB) of O--Eu and O--W, centering at around 270 and 307 nm, can be observed, respectively. The spectral lines shape and locations of excitation peak corresponding to 4f-->4f transitions are similar in all samples. But the relative intensity ratios between O--Eu and O--W CTB excitation peak increase with the Eu3+ doping concentration increasing. The characteristic red emission at around 610 nm of Eu3+ was also observed, ascribed to the (5)D0--(7)>F2 transition of Eu3+, and the optimal doping concentration is 20 mol%. Finally, the transition intensity parameters omega(lamda = 2,4) and the quantum efficiencies of (5)D0 level of Eu3+ were calculated according to Judd-Ofelt theory. The results indicate that Eu(3+5)D0-->(7)F2 610 nm red luminescence can be effectively excited by 394 nm near-UV light and 464 nm blue light in Y10W2O21 host, which is similar to the familiar Eu3+ doped tungstate (e.g., Gd2(WO4)3, CaWO4). Therefore, the Y10W2O21:Eu red nanophosphors may have a potential application for white LED.

14.
Guang Pu Xue Yu Guang Pu Fen Xi ; 30(5): 1224-8, 2010 May.
Artículo en Chino | MEDLINE | ID: mdl-20672606

RESUMEN

Y0.96 Er0.02 Yb0.02)O3 nanocrystals of 10 and 40 nm average particle size were prepared by combustion method. And bulk materials of the same components were obtained by annealing at 1 200 degrees C. X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectra, transmission electron microscope (TEM), and scanning electron microscopy (SEM) were used to characterize the crystal structure and morphology of the samples. The upconversion emission spectra and NIR (near-infrared) emission spectra were measured, under 980 nm excitation. The research result indicates that as the particle size decreases, the upconversion red emission and NIR emission components increase in the emission spectra. This phenomenon is attributed to the large ratio of surface area to volume in nanocrystals. This characteristic makes the nanocrystals absorb more OH-, whose vibrational energy is 3 200-3 800 cm(-1). The increase in the OH- number enhances the rate of nonradiative relaxation from Er3+ 4I11/2 to 4I13/2 energy level (energy gap is 3 600 cm(-1)). This nonradiative relaxation process depopulates the 4I11/2 level and makes the green emission weaker. Meanwhile, this process populates the 4I3/2 level and makes the red and NIR emissions stronger. The intensity of 1.5 microm main peak is 1.6 times that of bulk materials. This result has great significance in actual applications of nanophosphors.

15.
Guang Pu Xue Yu Guang Pu Fen Xi ; 29(1): 151-5, 2009 Jan.
Artículo en Chino | MEDLINE | ID: mdl-19385227

RESUMEN

Nano-powders Y2O3 with various particle sizes and different doping concentrations of Ln (Ln = Tb, Tm, Eu) were prepared by using a combustion technique. The bulky powders doped with concentrations corresponding to nano-powders were obtained by annealing the nano-powders at high temperature. The emission spectra, XRD spectra and TEM were used in the present study. The concentration quenching of luminescent centers and energy transfer between luminescent centers in Y2O3 : Ln nanocrystal powders were investigated. It was found that the behaviors of luminescence concentration quenching for 5D4 --> 7F5 : Tb3+ and 5D0 --> 7F2 : Eu3+ in nano-powders are similar to that in bulky powders. On the contrary, the quenching concentrations for 5D3 --> 7F5 : Tb3+ and 1D2 --> 3H4 : Tm3+ are distinctly higher than that in bulk powders. This owes to the size confinement effect: the interface of nanocrystal particles can stop a portion of the energy transfer, which happens in the bulk ones, between luminescent centers. The size confinement effect can bring different influences to the different types of energy transfer. For instance, it will restrain the energy transfer (governed by electric dipole-dipole interaction) between the ions in long distances, and will hardly affect the energy transfer (governed by exchange interaction) between the ions locating at near intervals.


Asunto(s)
Europio/química , Indio/química , Terbio/química , Itrio/química , Cristalización , Luz , Luminiscencia , Mediciones Luminiscentes , Nanopartículas/química , Tamaño de la Partícula
16.
Atmos Environ (1994) ; 43(36): 5750-5758, 2009 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20339526

RESUMEN

Effects of physical/environmental factors on fine particle (PM(2.5)) exposure, outdoor-to-indoor transport and air exchange rate (AER) were examined. The fraction of ambient PM(2.5) found indoors (F(INF)) and the fraction to which people are exposed (alpha) modify personal exposure to ambient PM(2.5). Because F(INF), alpha, and AER are infrequently measured, some have used air conditioning (AC) as a modifier of ambient PM(2.5) exposure. We found no single variable that was a good predictor of AER. About 50% and 40% of the variation in F(INF) and alpha, respectively, was explained by AER and other activity variables. AER alone explained 36% and 24% of the variations in F(INF) and alpha, respectively. Each other predictor, including Central AC Operation, accounted for less than 4% of the variation. This highlights the importance of AER measurements to predict F(INF) and alpha. Evidence presented suggests that outdoor temperature and home ventilation features affect particle losses as well as AER, and the effects differ.Total personal exposures to PM(2.5) mass/species were reconstructed using personal activity and microenvironmental methods, and compared to direct personal measurement. Outdoor concentration was the dominant predictor of (partial R(2) = 30-70%) and the largest contributor to (20-90%) indoor and personal exposures for PM(2.5) mass and most species. Several activities had a dramatic impact on personal PM(2.5) mass/species exposures for the few study participants exposed to or engaged in them, including smoking and woodworking. Incorporating personal activities (in addition to outdoor PM(2.5)) improved the predictive power of the personal activity model for PM(2.5) mass/species; more detailed information about personal activities and indoor sources is needed for further improvement (especially for Ca, K, OC). Adequate accounting for particle penetration and persistence indoors and for exposure to non-ambient sources could potentially increase the power of epidemiological analyses linking health effects to particulate exposures.

17.
Zhongguo Zhong Yao Za Zhi ; 33(15): 1890-4, 2008 Aug.
Artículo en Chino | MEDLINE | ID: mdl-19007024

RESUMEN

OBJECTIVE: To study absorption kinetics of scopoletin in rat stomachs and intestines. METHOD: Rats was cannulated for in situ recirculation. UV and HPLC methods were used to determine the concentrations of phenolsulfonphthalein and scopoletin, respectively. RESULT: The absorption rates in rat stomachs at 2 h after administration was 76.31%; The absorption rates at colon, duodenum, ileum and jejunum were 46.25%, 40.54%, 38.21%, 32.77%, respectively. The absorption rate constant (Ka) at concentrations of 10.0144, 20.0288-40.0576 mg x L(-1) in intestine were 0.6434, 0.6137, 0.5970 h(-1), respectively. The Ka of scopoletin at pH of 6.0, 6.8 and 7.4 in intestine were 0.6217, 0.6033, 0.6137 h(-1), respectively. CONCLUSION: The concentrations and pH values of scopoletin solution had no distinctive effect on the absorption kinetics. The absorption of scopoletin was a first-order process with passive diffusion mechanism. Scopoletin was well absorbed at stomachs and intestines in rats. Colon was the best absorption site of scopoletin, which suggest that a sustained-release preparation should be suitable for this compound.


Asunto(s)
Mucosa Gástrica/metabolismo , Mucosa Intestinal/metabolismo , Escopoletina/farmacocinética , Absorción , Animales , Cromatografía Líquida de Alta Presión , Femenino , Concentración de Iones de Hidrógeno , Absorción Intestinal , Masculino , Ratas , Ratas Sprague-Dawley , Espectrofotometría Ultravioleta
18.
Zhong Yao Cai ; 31(3): 397-9, 2008 Mar.
Artículo en Chino | MEDLINE | ID: mdl-18619246

RESUMEN

OBJECTIVE: To investigate the mechanisms of treating 2-DM by Rehmannia glutinosa Libosch water extraction (RGLE). METHODS: The mRNA level of proinsulin in rats panreas tissue was examined by semi-quatitativa RT-PCR,and the protein was measured by SDS-PAGE. RESULTS: The mRNA and protein expressions of proinsulin in RGLE group were higher than those of diabetic model group (P<0.01). The levels of FPG decreased. FINS,IS, HbetaCI increased (P<0.01). CONCLUSION: It may be the mechanism how the RGLE to decline high FPG and cure the 2-DM.


Asunto(s)
Diabetes Mellitus Tipo 2/tratamiento farmacológico , Medicamentos Herbarios Chinos/farmacología , Proinsulina/genética , Rehmannia/química , Animales , Glucemia/metabolismo , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/genética , Medicamentos Herbarios Chinos/administración & dosificación , Medicamentos Herbarios Chinos/uso terapéutico , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Hipoglucemiantes/farmacología , Hipoglucemiantes/uso terapéutico , Insulina/biosíntesis , Células Secretoras de Insulina/efectos de los fármacos , Células Secretoras de Insulina/metabolismo , Masculino , Páncreas/efectos de los fármacos , Páncreas/metabolismo , Plantas Medicinales/química , Proinsulina/biosíntesis , ARN Mensajero/biosíntesis , ARN Mensajero/genética , Distribución Aleatoria , Ratas , Ratas Wistar , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
19.
Environ Sci Technol ; 41(21): 7315-21, 2007 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-18044505

RESUMEN

The indoor environment is an important venue for exposure to fine particulate matter (PM2.5) of ambient (outdoor) origin. In this work, paired indoor and outdoor PM2.5 species concentrations from three geographically distinct cities (Houston, TX, Los Angeles County, CA, and Elizabeth, NJ) were analyzed using positive matrix factorization (PMF) and demonstrate that the composition and source contributions of ambient PM2.5 are substantially modified by outdoor-to-indoor transport. Our results suggest that predictions of "indoor PM2.5 of ambient origin" are improved when ambient PM2.5 is treated as a combination of four distinct particle types with differing infiltration behavior (primary combustion, secondary sulfate and organics, secondary nitrate, and mechanically generated PM) rather than as a "single internally mixed entity". Study-wide average infiltration factors (i.e., fraction of ambient PM2.5 found indoors) for Relationship of Indoor, Outdoor, and Personal Air (RIOPA) study homes were 0.51, 0.78, and 0.04 (consistent with P = 0.6, 0.9, and 0.09; k = 0.2, 0.1, and 0.6 h(-1)) for PM2.5 associated with primary combustion, secondary formation (excluding nitrate), and mechanical generation, respectively. Modification of the composition, properties, and source contributions of ambient PM2.5 in indoor environments has important implications for exposure mitigation strategies, development of health hypotheses, and evaluation of exposure error in epidemiological studies that use ambient central-site PM2.5 as a surrogate for PM2.5 exposure.


Asunto(s)
Contaminantes Atmosféricos/análisis , Contaminación del Aire Interior/análisis , Material Particulado/análisis , Carbono/análisis , Monitoreo del Ambiente , Vivienda , Los Angeles , Metales/análisis , New Jersey , Tamaño de la Partícula , Agua de Mar , Silicio/análisis , Suelo , Texas
20.
Guang Pu Xue Yu Guang Pu Fen Xi ; 27(4): 629-33, 2007 Apr.
Artículo en Chino | MEDLINE | ID: mdl-17608161

RESUMEN

A novel red phosphor alpha-Gd2 (MoO4)3: Eu was synthesized by conventional solid state reaction method with the starting materials: Gd2O3, MoO3 and Eu2O3. The effects of flux and Eu concentration on the crystal structure, morphology and luminescent properties of the phosphors were investigated. The results showed that non-agglomeration phosphors with regular morphology and fine size were produced after the mixture being calcined at 800 degrees C for 4h with 3% NH4F as flux. The main emission peak of the samples is at 613 nm. The excitation spectrum showed that this phosphor can be effectively excited by ultraviolet (UV) (395 nm) and blue (465 nm) light, nicely fitting in with the widely applied output wavelengths of ultraviolet or blue LED chips. The alpha-Gd2 (MoO4)3 phosphor may be a good candidate phosphor for solid state lighting application.

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