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1.
Small ; : e2402651, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38747046

RESUMEN

SnTe, as a potential medium-temperature thermoelectric material, reaches a maximum power factor (PF) usually above 750 K, which is not conducive to continuous high-power output in practical applications. In this study, PF is maintained at high values between 18.5 and 25 µW cm-1 K-2 for Sn0.99In0.01Te-x wt% tourmaline samples within the temperature range of 323 to 873 K, driving the highest PFeng of 1.2 W m-1 K-1 and PFave of 22.5 µW cm-1 K-2, over 2.5 times that of pristine SnTe. Such an extraordinary PF is attributed to the synergy of resonant levels and Sn vacancy suppression. Specifically, the Seebeck coefficient increases dramatically, reaching 88 µV K-1 at room temperature. Meanwhile, by Sn vacancy suppression, carrier concentration, and mobility are optimized to ≈1019 cm-3 and 740 cm2 V-1 s-1, respectively. With the tourmaline compositing, Sn vacancies are further suppressed and the thermal conductivity simultaneously decreases, with the minimum lattice thermal conductivity of 0.9 W m-1 K-1. Finally, the zT value ≈0.8 is obtained in the Sn0.99In0.01Te sample. The peak of the power output density reaches 0.89 W cm-2 at a temperature difference of 600 K. Such SnTe alloys with high and "temperature-independent" PF will offer an option for realizing high output power in thermoelectric devices.

2.
Int J Mol Sci ; 24(13)2023 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-37445824

RESUMEN

Genetic transformation is an important strategy for enhancing plant biomass or resistance in response to adverse environments and population growth by imparting desirable genetic characteristics. Research on plant genetic transformation technology can promote the functional analysis of plant genes, the utilization of excellent traits, and precise breeding. Various technologies of genetic transformation have been continuously discovered and developed for convenient manipulation and high efficiency, mainly involving the delivery of exogenous genes and regeneration of transformed plants. Here, currently developed genetic transformation technologies were expounded and compared. Agrobacterium-mediated gene delivery methods are commonly used as direct genetic transformation, as well as external force-mediated ways such as particle bombardment, electroporation, silicon carbide whiskers, and pollen tubes as indirect ones. The regeneration of transformed plants usually involves the de novo organogenesis or somatic embryogenesis pathway of the explants. Ectopic expression of morphogenetic transcription factors (Bbm, Wus2, and GRF-GIF) can significantly improve plant regeneration efficiency and enable the transformation of some hard-to-transform plant genotypes. Meanwhile, some limitations in these gene transfer methods were compared including genotype dependence, low transformation efficiency, and plant tissue damage, and recently developed flexible approaches for plant genotype transformation are discussed regarding how gene delivery and regeneration strategies can be optimized to overcome species and genotype dependence. This review summarizes the principles of various techniques for plant genetic transformation and discusses their application scope and limiting factors, which can provide a reference for plant transgenic breeding.


Asunto(s)
Técnicas de Transferencia de Gen , Fitomejoramiento , Plantas Modificadas Genéticamente/genética , Transformación Genética , Agrobacterium/genética
3.
Inorg Chem ; 60(5): 3452-3459, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33591740

RESUMEN

The quaternary chalcogenide composites Cu2ZnSn1-xAgxSe4 (0 ≤ x ≤ 0.075) have been successfully synthesized by high-temperature melting and annealing followed by hot-pressing. The phase structure of the bulk sample has been analyzed by powder X-ray diffraction and Rietveld refinement combined with Raman spectroscopy to confirm Cu2ZnSnSe4 as the main phase with ZnSe and Cu5Zn8 secondary phases. The thermoelectric properties of all specimens have been investigated in the temperature range of 300-700 K. The replacement of Sn by Ag significantly enhances the electrical transport properties by providing extra charge carriers. The tremendous reduction in electrical resistivity enhances the power factor, and a maximum power factor of 804 µW K-2 m-1 is achieved at 673 K for the specimen with 5% Ag content. Furthermore, increased point defects increase phonon scattering, resulting in reduced thermal conductivity. The combined effect of improved power factor and suppressed thermal conductivity provides a good boost to the dimensionless figure of merit. The maximum figure of merit of zT = 0.25 has been achieved at 673 K for Cu2ZnSn0.95Ag0.05Se4, which is 2.5 times the value of the parent sample.

4.
Prep Biochem Biotechnol ; 50(5): 477-485, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31900079

RESUMEN

Heparinase I (Hep I) specifically degrades heparin to oligosaccharide or unsaturated disaccharide and has been widely used in preparation of low molecular weight heparin (LMWH). In this work, a novel Hep I from Bacteroides eggerthii VPI T5-42B-1 was cloned and overexpressed in Escherichia coli BL21 (DE3). The enzyme has specific activity of 480 IU·mg-1 at the optimal temperature and pH of 30 °C and pH 7.5, and the Km and Vmax were 3.6 mg·mL-1 and 647.93 U·mg-1, respectively. The Hep I has good stability with t1/2 values of 350 and 60 min at 30 and 37 °C, respectively. And it showed a residual relative activity of 70.8% after 21 days incubation at 4 °C. Substrate docking study revealed that Lys99, Arg101, Gln241, Lys270, Asn275, and Lys292 were mainly involved in the substrate binding of Hep I. The shorter hydrogen bonds formed between heparin and these residues suggested the higher specific activity of BeHep I. And the minimum conformational entropy value of 756 J·K-1 provides an evidence for the improved stability of this enzyme. This Hep I could be of interest in the industrial preparation of LMWH for its high specific activity and good stability.


Asunto(s)
Proteínas Bacterianas/química , Bacteroides/enzimología , Liasa de Heparina/química , Secuencia de Aminoácidos , Proteínas Bacterianas/genética , Proteínas Bacterianas/aislamiento & purificación , Proteínas Bacterianas/metabolismo , Clonación Molecular , Pruebas de Enzimas , Escherichia coli/genética , Expresión Génica , Heparina/química , Heparina/metabolismo , Liasa de Heparina/genética , Liasa de Heparina/aislamiento & purificación , Liasa de Heparina/metabolismo , Simulación del Acoplamiento Molecular , Pedobacter/enzimología , Unión Proteica , Alineación de Secuencia
5.
Entropy (Basel) ; 21(2)2019 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-33266917

RESUMEN

The continuous casting process is a continuous, complex phase transition process. The noise components of the continuous casting process are complex, the model is difficult to establish, and it is difficult to separate the noise and clear signals effectively. Owing to these demerits, a hybrid algorithm combining Variational Mode Decomposition (VMD) and Wavelet Threshold denoising (WTD) is proposed, which involves multiscale resolution and adaptive features. First of all, the original signal is decomposed into several Intrinsic Mode Functions (IMFs) by Empirical Mode Decomposition (EMD), and the model parameter K of the VMD is obtained by analyzing the EMD results. Then, the original signal is decomposed by VMD based on the number of IMFs K, and the Mutual Information Entropy (MIE) between IMFs is calculated to identify the noise dominant component and the information dominant component. Next, the noise dominant component is denoised by WTD. Finally, the denoised noise dominant component and all information dominant components are reconstructed to obtain the denoised signal. In this paper, a comprehensive comparative analysis of EMD, Ensemble Empirical Mode Decomposition (EEMD), Complementary Empirical Mode Decomposition (CEEMD), EMD-WTD, Empirical Wavelet Transform (EWT), WTD, VMD, and VMD-WTD is carried out, and the denoising performance of the various methods is evaluated from four perspectives. The experimental results show that the hybrid algorithm proposed in this paper has a better denoising effect than traditional methods and can effectively separate noise and clear signals. The proposed denoising algorithm is shown to be able to effectively recognize different cast speeds.

6.
Inorg Chem ; 57(15): 9133-9141, 2018 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-30009606

RESUMEN

Perovskite manganite Ca0.9R0.1MnO3-δ (R = Dy, Yb) ceramics have been synthesized by a traditional solid-state reaction with multicalcination processes. A heterogeneous microstructure including large and small micrometer-sized grains, coherent interfaces, and oxygen defects has been formed with optimized calcination time. The carrier concentration of the third-calcined samples is enhanced approximately 3 times compared with those synthesized through conventional methods. Thus, the electrical resistivity of the third-calcined Ca0.9R0.1MnO3-δ (R = Dy, Yb) ceramic samples obviously decreases, leading to a higher power factor. Additionally, the thermal conductivity is also reduced by multiscale scattering of the heterogeneous structure. The lowest lattice thermal conductivities of Dy- or Yb-doped samples are 1.24 and 1.22 W m-1 K-1, respectively. Thus, the high thermoelectric performance for Ca0.9R0.1MnO3-δ (R = Dy, Yb) has been achieved by the multicalcination process. The highest figure of merit is almost 30% higher than that of the first-calcined samples. Therefore, a heterogeneous microstructure formed by optimized multicalcination can effectively optimize the thermoelectric performance of oxides.

7.
Phys Chem Chem Phys ; 20(31): 20571-20574, 2018 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-30058658

RESUMEN

The electron localization in Nb-doped CaMnO3 is analyzed in terms of the space and energy distribution of electronic states employing first-principles calculations. The energy difference of Mn 3d states and Nb 4d states makes NbO6 octahedra impede electrical conduction, so the random distribution of Nb in lattices leads to the localization of electrons near the bottom of the conduction bands. Therefore, although more carriers are introduced when Nb-doping content increases, both the electrical conductivity and absolute thermopower decrease in Nb heavy doped CaMnO3. The calculated transport properties agree well with the experimental data, supporting the analysis of localization.

8.
Med Sci Monit ; 24: 736-742, 2018 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-29401205

RESUMEN

BACKGROUND The mammalian cyclic guanosine monophosphate (cGMP)-dependent protein kinases type II (PKG II) plays critical physiological or pathological functions in different tissues. However, the biological effects of PKG II are dependent on cGMP. Published data indicated that L-arginine (L-Arg) promoted NO production, NO can activate soluble guanylate cyclase (sGC), and catalyzes guanosine triphosphate (GTP) into cGMP, which suggested L-Arg could activate PKG II. Therefore, the present work was performed to address: (i) whether L-Arg could be a potential alternative in PKG II activation, and (ii) whether L-Arg also contributes to PKG II against cancer. MATERIAL AND METHODS Nude BALB/c mice were inoculated with human MCF-7, HepG2, and SW480 cell lines via subcutaneous (s.c.) injecting. After 7 days of inoculation, Ad-PKG II was injected into the cancer tissues every 4 days, and the next day 10 µmol/mouse L-Arg was administered. Western blotting and immunohistochemistry were used to assess protein expression. RESULTS Our results demonstrated that L-Arg significantly activated PKG II and effectively ameliorated xenograft tumor development through inhibiting cancer growth, angiogenesis, and metastasis, which was partially dependent on blocking of epidermal growth factor receptor (EGFR) activity, as well as downstream signaling pathways such as Erk1/2. CONCLUSIONS Our results provide an exciting new insight: L-Arg is a potential alternative to PKG II activation.


Asunto(s)
Arginina/farmacología , Carcinogénesis/metabolismo , Carcinogénesis/patología , Proteínas Quinasas Dependientes de GMP Cíclico/metabolismo , Ensayos Antitumor por Modelo de Xenoinjerto , Animales , Carcinogénesis/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Activación Enzimática/efectos de los fármacos , Factor de Crecimiento Epidérmico/metabolismo , Receptores ErbB/metabolismo , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Femenino , Humanos , Ratones Endogámicos BALB C , Ratones Desnudos , Metástasis de la Neoplasia , Neovascularización Patológica/enzimología , Neovascularización Patológica/patología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal/efectos de los fármacos , Carga Tumoral/efectos de los fármacos
9.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 42(1): 88-97, 2017 Jan 28.
Artículo en Zh | MEDLINE | ID: mdl-28216504

RESUMEN

OBJECTIVE: To evaluate the safety, feasibility and effectiveness of laparoscopic-assisted resection of colorectal cancer without incision at abdomen vs the traditional laparoscopic resection.
 Methods: We retrieved literature published from August, 2005 to August, 2015 to compare laparoscopic-assisted resection for colorectal cancer without incision at abdomen with the traditional laparoscopic resection. The clinical indicators were extracted from literature met inclusion criteria. The RevMan 5.3 software with a Meta-analysis was used.
 Results: Seven literature with a total of 621 patients, including 262 in laparoscopic-assisted resection of colorectal cancer without auxiliary incision at abdomen group (NOSE group) and 359 in conventional laparoscopic colorectal resection group (LAP group), were enrolled. The Meta-analysis showed that the total complication rate in the NOSE group was significantly less than that in the LAP group (OR=0.31, 95% CI 0.18 to 0.53, P<0.05). Complications of incision in the NOSE group were less than those in the LAP group (OR= 0.15, 95% CI 0.05 to 0.40, P=0.0002). Postoperative bleeding (OR=1.52, 95% CI 0.38 to 6.18, P=0.55), intestinal obstruction (OR= 0.30, 95% CI 0.09 to 0.98, P=0.05), anastomotic complications (OR=0.92, 95% CI 0.28 to 3.07, P=0.89), and other related complications (OR=0.63, 95% CI 0.23 to 1.66, P=0.35) showed no significant difference between the 2 groups (P>0.05). Hospitalization (MD=-0.66, 95% CI -1.33 to 0.01, P=0.05), duration of surgery (MD=14.78, 95% CI -1.75 to 31.31, P=0.08), bleeding amount (MD=-12.81, 95% CI -40.36 to 14.74, P=0.36), the tumor size (SMD=-0.40, 95% CI -0.87 to 0.08, P=0.10), the number of lymph node dissection (MD=-0.49, 95% CI 1.80 to 0.82, P=0.46), and the recurrence of 2-year follow-up (OR=1.15, 95% CI 0.38 to 3.50, P=0.81) were not statistically significant between the 2 groups. Time of gas passage (SMD=-0.62, 95% CI -0.82 to -0.42, P<0.001) and time of regular diet after surgery (SMD=-0.60, 95% CI -1.15 to 0.05, P=0.03) in the NOSE group were earlier than those in the LAP group. The postoperative pain score (MD=-1.49, 95% CI -1.97 to -1.01, P<0.001) in the NOSE group was significantly lower than that in the LAP group. Cosmetic surgery in the NOSE group had a higher index (MD=1.37, 95% CI 0.59 to 2.14, P=0.0005) compared with that in the LAP group.
 Conclusion: Laparoscopic-assisted resection for colorectal cancer without auxiliary incision at abdomen can obviously reduce the incidence of incision complications, and the patients can recover early and incision is showed more cosmetic. The method is safe, feasible, and effective.


Asunto(s)
Neoplasias Colorrectales/cirugía , Laparoscopía/efectos adversos , Laparoscopía/métodos , Complicaciones Posoperatorias/epidemiología , Herida Quirúrgica/complicaciones , Colon/cirugía , Humanos , Laparoscopía/rehabilitación , Escisión del Ganglio Linfático , Recurrencia Local de Neoplasia/epidemiología , Dolor Postoperatorio/epidemiología , Recuperación de la Función , Recto/cirugía , Resultado del Tratamiento
10.
Water Sci Technol ; 66(12): 2695-701, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23109588

RESUMEN

A central composite factorial design methodology was employed to optimize the degradation of naproxen (NPX) by the combination of Fenton reagent and ultrasound (US) irradiation. In this study, the variables considered for the process optimization were the hydrogen peroxide, ferrous ion and NPX initial concentrations, while ultrasonic power amplitude was adjusted at 90% and initial pH was 3. An appropriate quadratic model was developed in order to plot the response surface and contour curves. Optimum dosage of Fenton reagent for NPX removal was found to be hydrogen peroxide concentration = 9.98 mmol L⁻¹, ferrous ion concentration = 4.83 mg L⁻¹ while NPX concentration was equal to 20 mg L⁻¹. A degradation efficiency of 100% was achieved within 10 min under US.


Asunto(s)
Peróxido de Hidrógeno/química , Hierro/química , Naproxeno/química , Ultrasonido , Purificación del Agua/métodos , Análisis de Varianza , Concentración de Iones de Hidrógeno , Espectrometría de Fluorescencia
11.
Polymers (Basel) ; 14(9)2022 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-35566938

RESUMEN

Enzymatic preparation of low-molecular-weight chondroitin sulfate (LMWCS) has received increasing attention. In this work, a chondroitin sulfate lyase ABC (Chon-ABC) was successfully cloned, expressed, and characterized. The Km and Vmax of the Chon-ABC were 0.54 mM and 541.3 U mg-1, respectively. The maximal activity was assayed as 500.4 U mg-1 at 37 °C in pH 8.0 phosphate buffer saline. The half-lives of the Chon-ABC were 133 d and 127 min at 4 °C and 37 °C, respectively. Enzymatic preparation of LMWCS was performed at room temperature for 30 min. The changes between the substrate and product were analyzed with mass spectrometry (MS), high-performance liquid chromatography (HPLC), gel permeation chromatography (GPC), and nuclear magnetic resonance (NMR). Overall, the Chon-ABC from Bacteroides thetaiotaomicron is competitive in large-scale enzymatic preparation of LMWCS for its high activity, stability, and substrate specificity.

12.
N Biotechnol ; 62: 18-25, 2021 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-33460816

RESUMEN

L-Tagatose, a promising building block in the production of many value-added chemicals, is generally produced by chemical routes with a low yield, which may not meet the increasing demands. Synthesis of l-tagatose by enzymatic oxidation of d-galactitol has not been applied on an industrial scale because of the high cofactor costs and the lack of efficient cofactor regeneration methods. In this work, an efficient and environmentally friendly enzymatic method containing a galactitol dehydrogenase for d-galactitol oxidation and a water-forming NADH oxidase for regeneration of NAD+ was first designed and used for l-tagatose production. Supplied with only 3 mM NAD+, subsequent reaction optimization facilitated the efficient transformation of 100 mM of d-galactitol into l-tagatose with a yield of 90.2 % after 12 h (obtained productivity: 7.61 mM.h-1). Compared with the current chemical and biocatalytic methods, the strategy developed avoids by-product formation and achieves the highest yield of l-tagatose with low costs. It is expected to become a cleaner and more promising route for industrial biosynthesis of l-tagatose.


Asunto(s)
Hexosas/biosíntesis , Complejos Multienzimáticos/metabolismo , NADH NADPH Oxidorreductasas/metabolismo , Deshidrogenasas del Alcohol de Azúcar/metabolismo , Hexosas/química , Concentración de Iones de Hidrógeno , Modelos Moleculares , Conformación Molecular , Temperatura
13.
Dalton Trans ; 47(44): 15957-15966, 2018 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-30378635

RESUMEN

High figures of merit of n-type Pb1-xBixTe alloys have been achieved by rapid synthesis at low temperature. The effects of Bi dopant and microwave hydrothermal technology on microstructure and thermoelectric performance have been studied. The solid solubility limit of Bi in PbTe is between x = 0.02 and 0.03. Homogenous nanopowders of about 70 nm have been synthesized by the microwave hydrothermal method. When followed by hot pressing, sub-microscale grain sizes are also formed for Pb1-xBixTe alloys. With increase in Bi, the carrier concentration is improved within the solubility limit. This leads to low electrical resistivity and higher power factor at high temperature. A higher power factor of 8.5 µW cm-1 K-2 is obtained for x = 0.02 sample at 623 K. In addition, the introduction of Bi effectively prohibits the p-n transition and bipolar thermal conductivity of pristine PbTe. Thus, a low lattice thermal conductivity of 0.68 W m-1 K-1 is achieved at 673 K, combining scattering of alloys, grain boundaries, dislocations and defects. As a result, the highest peak figure of merit, i.e., zT = 0.62 at 673 K is achieved for Pb0.98Bi0.02Te sample, which is comparable with that of Bi-doped PbTe alloys synthesized by the conventional melting method. Thus, the right synthesis conditions of the microwave hydrothermal method can rapidly result in thermoelectric materials with comparable figures of merit.

14.
Sci Rep ; 8(1): 16628, 2018 11 09.
Artículo en Inglés | MEDLINE | ID: mdl-30413778

RESUMEN

Heat shock protein 70 (Hsp70) family members play important roles in protecting plants against abiotic stresses, including salt, drought, heat, and cold. In this study, 20 putative StHsp70 genes were identified in potato (Solanum tuberosum L.) through the integration of the gene structures, chromosome locations, phylogenetic relationships, and expression profiles. These StHsp70 genes were classified into five sub-families based on phylogenetic analysis. Chromosome mapping revealed that they were unevenly and unequally distributed on 10 of the 12 chromosomes. Furthermore, segmental and tandem duplication events contributed to the expansion of the StHsp70 genes. Phylogenetic tree of the HSP70 genes from potato and other plant species revealed multiple sub-families. These findings indicated a common ancestor which had generated diverse sub-families prior to a mono-dicot split. In addition, expression analysis using RNA-seq revealed that the majority of these genes were expressed in at least one of the tested tissue, and were induced by Phytophthora infestans. Then, based on qRT-PCR analysis, the results showed that the transcript levels of some of the StHsp70 genes could be remarkably induced by such abiotic and hormone stresses, which indicated their potential roles in mediating the responses of potato plants to both abiotic and biotic stress conditions.


Asunto(s)
Cromosomas de las Plantas/genética , Regulación de la Expresión Génica de las Plantas , Genoma de Planta , Proteínas HSP70 de Choque Térmico/metabolismo , Proteínas de Plantas/metabolismo , Solanum tuberosum/metabolismo , Perfilación de la Expresión Génica , Proteínas HSP70 de Choque Térmico/genética , Familia de Multigenes , Filogenia , Proteínas de Plantas/genética , Solanum tuberosum/genética , Solanum tuberosum/crecimiento & desarrollo , Estrés Fisiológico
15.
Ther Adv Med Oncol ; 10: 1758834017751635, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29434677

RESUMEN

Type II cyclic guanosine monophosphate (cGMP)-dependent protein kinase (PKG II) is a membrane-anchored enzyme expressed mainly in the intestinal mucosa and the brain, and is associated with various physiological or pathological processes. Upregulation of PKG II is known to induce apoptosis and inhibit proliferation and metastasis of cancer cells. The inhibitory effect of PKG II has been shown to be dependent on the inhibition of the activation of epidermal growth factor receptor (EGFR) and blockade of EGFR downstream signal transduction in vitro. However, it remains unclear whether similar phenomena/mechanisms exist in vivo and whether these effects are independent of cGMP or cGMP analogues. In the present work, nude mice with transplanted orthotopic tumours were infected with adenovirus encoding cDNA of constitutively active PKG II mutant (Ad-a-PKG II) and the effect of constitutively active PKG II (a-PKG II) on tumour development was detected. The results showed that a-PKG II effectively ameliorated gastric tumour development through delaying the growth, inducing the apoptosis, and inhibiting the metastasis and angiogenesis. The effect was related to blockade of EGFR activation and abrogation of the downstream signalling cascades. These findings provide novel insight which will benefit the development of new cancer therapies.

16.
Rev Sci Instrum ; 87(6): 064701, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27370476

RESUMEN

In this work, it was investigated how to measure Seebeck coefficient accurately. The offset voltages, between the specimen and measurement wires, might influence the results measured significantly and should be eliminated during measuring process. They do not depend on temperature difference but on temperature and include two parts: the intrinsic component related to the materials and the random one related to the contact. The inversion method could eliminate the offset voltages more accurately than the traditional differential methods, and thus measure Seebeck coefficient more accurately. The accuracy of Seebeck coefficient measurement could be further improved by performing a proper temperature difference, optimizing temperature control, and using an electromagnetic screen. The most accurate results were obtained with a standard deviation of 0.06 µV/K, measured under temperature difference of 1 K, temperature variation of 0.002 K, and with an iron electromagnetic screen.

17.
Guang Pu Xue Yu Guang Pu Fen Xi ; 24(3): 270-3, 2004 Mar.
Artículo en Zh | MEDLINE | ID: mdl-15759972

RESUMEN

The principle and application in the environmental analysis of Solid Phase Extraction (SPE) combined with Room Temperature Phosphorescence (RTP) analysis were reviewed. The principle, device, separation modes, operation procedures and application of SPE were commented. The merits and shortages in the operation procedure and quantitative analysis of classic RTP were also summarized. The potential application in the trace sample analysis and the advantage of coupling technique of SPE and RTP were indicated. The sensitivity and selectivity of the coupling technique could be greatly increased because of the strong enrichment ability of the SPE materials and the high selectivity of RTP. So far the technique has been successfully used in the analysis of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and polychlorinated dibenzofurans (PClDBFs) in the environmental samples according to their phosphorescence emission after preconcentration on the Whatman 1PS filter paper and C18 or C8 SPE membranes.


Asunto(s)
Benzofuranos/análisis , Mediciones Luminiscentes/métodos , Bifenilos Policlorados/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Extracción en Fase Sólida/métodos , Adsorción , Benzofuranos/química , Bifenilos Policlorados/química , Hidrocarburos Policíclicos Aromáticos/química , Sensibilidad y Especificidad , Temperatura
18.
ACS Nano ; 5(8): 6233-43, 2011 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-21749108

RESUMEN

Concomitant development of [6,6]-phenyl-C(61)-butyric acid methyl ester (PCBM) aggregation and poly(3-hexylthiophene) (P3HT) crystallization in bulk heterojunction (BHJ) thin-film (ca. 85 nm) solar cells has been revealed using simultaneous grazing-incidence small-/wide-angle X-ray scattering (GISAXS/GIWAXS). With enhanced time and spatial resolutions (5 s/frame; minimum q ≈ 0.004 Å(-1)), synchrotron GISAXS has captured in detail the fast growth in size of PCBM aggregates from 7 to 18 nm within 100 s of annealing at 150 °C. Simultaneously observed is the enhanced crystallization of P3HT into lamellae oriented mainly perpendicular but also parallel to the substrate. An Avrami analysis of the observed structural evolution indicates that the faster PCBM aggregation follows a diffusion-controlled growth process (confined by P3HT segmental motion), whereas the slower development of crystalline P3HT nanograins is characterized by constant nucleation rate (determined by the degree of supercooling and PCBM demixing). These two competing kinetics result in local phase separation with space-filling PCBM and P3HT nanodomains less than 20 nm in size when annealing temperature is kept below 180 °C. Accompanying the morphological development is the synchronized increase in electron and hole mobilities of the BHJ thin-film solar cells, revealing the sensitivity of the carrier transport of the device on the structural features of PCBM and P3HT nanodomains. Optimized structural parameters, including the aggregate size and mean spacing of the PCBM aggregates, are quantitatively correlated to the device performance; a comprehensive network structure of the optimized BHJ thin film is presented.

19.
Zhonghua Liu Xing Bing Xue Za Zhi ; 32(8): 808-15, 2011 Aug.
Artículo en Zh | MEDLINE | ID: mdl-22093474

RESUMEN

OBJECTIVE: The aim of this study was to demonstrate the immunogenicity and safety of diphtheria, tetanus, pertussis (acellular, component), poliomyelitis (inactivated) vaccine (adsorbed) and Haemophilus influenzae type b conjugate vaccine (DTaP-IPV//PRP-T) combined vaccine compared with commercially available DTaP (diphtheria, tetanus and pertussis), Haemophilus influenzae type b (Hib), tetanus conjugate and IPV monovalent vaccine. METHODS: Subjects were randomly divided into three groups, Group A and Group B were DTaP-IPV//PRP-T combined vaccine (PENTAXIM(TM)) vaccinated at 2, 3, 4 months of age or 3, 4, 5 months of age respectively; Group C was commercially available DTaP. Hib tetanus conjugate (Act-HIB(TM)) and IPV (IMOVAX PolioTM(TM)) vaccines vaccinated at 3, 4, 5 months of age. All groups received booster dose at 18 to 20 months of age, with antibody titers tested. Non-inferiority analysis was demonstrated in terms of seroprotection/seroconversion rates between Group A, Group B respectively and Group C. Safety information was collected after each vaccination to assess the safety of investigational vaccines. RESULTS: The non-inferiority of DTaP-IPV//PRP-T combined vaccine vaccinated at 2, 3, 4 or 3, 4, 5 months of age versus DTaP, Hib tetanus conjugate and IPV vaccine was demonstrated for all vaccine antigens in both primary and booster phases in terms of seroprotection/seroconversion rates. DTaP-IPV//PRP-T combined vaccine was well tolerated. The rate of solicited/unsolicited severe adverse reactions was very low and similar to the control vaccines. CONCLUSION: DTaP-IPV//PRP-T combined vaccine was highly immunogenic with good safety profile in Chinese infants, which was comparable to the commercially available control vaccines.


Asunto(s)
Vacunas contra Difteria, Tétanos y Tos Ferina Acelular , Vacunas contra Haemophilus , Vacuna Antipolio de Virus Inactivados , Vacunas Conjugadas , Vacunas contra Difteria, Tétanos y Tos Ferina Acelular/inmunología , Femenino , Vacunas contra Haemophilus/efectos adversos , Vacunas contra Haemophilus/inmunología , Humanos , Inmunización Secundaria , Lactante , Masculino , Vacuna Antipolio de Virus Inactivados/efectos adversos , Vacuna Antipolio de Virus Inactivados/inmunología , Vacunas Conjugadas/efectos adversos , Vacunas Conjugadas/inmunología
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