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- Author or Editor: Meng Zhang x
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Late embryonic proteins (LEA) gene family was abundant mainly in higher plant embryos, which could protect the embryos from the damage caused by abiotic stress, especially drought and salt stresses. In the present study, GmLEA2-1 was cloned from soybean leaf tissue treated by 10% polyethylene glycol 6000 (PEG6000). The results of quantitative real-time PCR (qRT-PCR) revealed a variety of expression patterns of GmLEA2-1 in various tissues of soybean (root, stem, leaf, flower, pod, early embryo and late embryo). GmLEA2-1 gene shared a lower sequence similarity with other typical LEA genes of same group from different species, but similar functions. Overexpression of GmLEA2-1 in transgenic Arabidopsis thaliana conferred tolerance to drought and salt stresses. The fresh weight and dry weight of seedling, the primary root length and the lateral root density of transgenic Arabidopsis plants were higher than those of wild type Arabidopsis (WT) under drought and salt stresses. Cis-acting regulatory elements in the GmLEA2-1 promoter were also predicted. These data demonstrate that GmLEA2-1 protein play an important role in improving drought and salt tolerance in plants.
Abstract
On the basis of the theory of thermokinetics proposed in the literature, a novel thermokinetic method for determination of the reaction rate, the characteristic parameter method, is proposed in this paper. Mathematical models were established to determine the kinetic parameters and rate constants. In order to test the validity of this method, the saponifications of ethyl benzoate, ethyl acetate and ethyl propionate, and the formation of hexamethylenetetramine were studied with this method. The rate constants calculated with this method are in agreement with those in the literature, and the characteristic parameter method is therefore believed to be correct.In the light of the characteristic parameter method, we have developed further two thermo-kinetic methods, the thermoanalytical single and multi-curve methods, which are convenient for simultaneous determination of the reaction order and the rate constant. The reaction orders and rate constants of the saponifications of ethyl acetate and ethyl butyrate and the ring-opening reaction of epichlorohydrin with hydrobromic acid were determined with these methods, and their validity was verified by the experimental results.
Abstract
In this work, a simple and rapid high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method was developed and validated to carry out the simultaneous measurement of busulfan (BU) and phenytoin (PHT) in the plasma of children. In this method, plasma sample could be prepared by one-step protein precipitation using 1 mL of methanol/water (1:1, v/v). After centrifugation (14,500 rpm, 5 min, 4 °C), 10 μL of the supernatant was injected into a Hypersil Gold C18 column (150 × 2.1 mm, 5 μm, Thermo Fisher Scientific) for separation by gradient elution. Quantification was carried out using multiple reactions monitoring (MRM) under positive scan mode. In the method verification, the calibration curves of BU and PHT showed satisfactory linearity (r > 0.99) at the concentration ranging from 0.02 to 20 μg mL−1. The accuracy and precision were tested at four concentration levels (including the LLOQ level) with the relative error (RE) ranging from −0.80% to 11.45% and coefficient of variation (CV) between 0.93% and 7.74%. There was no pronounced matrix effect to interfere with the quantitative analysis. Compared to determine BU and PHT using two individual methods, less pre-treatment process, labor and blood sample volume are required in this proposed method. Finally, this method was successfully applied to the therapeutic drug monitoring of BU and PHT for children underwent hematological stem cell transplantation.
Abstract
Background and aims
Gambling disorder (GD) is a mental disorder with a relatively higher prevalence in university students compared to adolescents and adults. Its reciprocity with mental being indicators, such as psychological flourishing, would be expected, but prior to this study had not yet been empirically examined. In addition, the predictive value of purpose in life (PIL) on university students' GD and psychological flourishing also remained unknown. This 1-year longitudinal study was the first to test the potential bidirectional relationships among PIL, self-reported GD symptoms, and psychological flourishing.
Methods
In this study, a total of 283 university students (39.6% females; age = 18–27 years, M = 20.47, SD = 1.15) completed an anonymous questionnaire at both baseline and a year later in a follow-up study.
Results
The results of our cross-lagged analysis did not show the hypothesized reciprocity between GD symptoms and psychological flourishing (P > 0.05). However, PIL significantly predicted fewer GD symptoms (β = −0.23, P < 0.001) and higher levels of psychological flourishing (β = 0.30, P < 0.001) in the follow-up study. Moreover, psychological flourishing predicted PIL a year later.
Conclusion
The findings demonstrate the potential efficacy of purpose/meaning oriented interventions in gambling prevention and in well-being promotion programs.
Abstract
Background and aims
Internet gaming disorder (IGD) has been recognized as a mental illness. Cognitive and emotional illness representations affect coping and health outcomes. Very little is known about such perceptions related to IGD, in both general and diseased populations. This study examined the psychometric properties of the Revised Illness Perception Questionnaire (IPQ-R) for IGD in a general population that included mostly non-cases while a small proportion of the sample was IGD cases.
Methods
An anonymous cross-sectional telephone survey was conducted in a random sample of 1,501 Chinese community-dwelling adults (41.3% male; mean age = 40.42, SD = 16.85) in Macao, China.
Results
The confirmatory factor analysis identified a modified 6-factor model (i.e., timeline cyclical, consequences, personal control, treatment control, illness coherence, and emotional representations) of 26 items that showed satisfactory model fit and internal consistency. Criterion-related validity was supported by the constructs' significant correlations with stigma (positive correlations: timeline cyclical, consequence, emotional representations; negative correlations: illness coherence). Ever-gamers, compared to never-gamers, reported higher mean scores in the subscales of personal control and illness coherence, and lower mean scores in time cyclical, consequence, and emotional representations. Among the sampled gamers, probable IGD cases were more likely than non-IGD cases to perceive IGD as cyclical and involved more negative emotions.
Conclusions
This study shows that the revised 26-item version of IPQ-R is a valid instrument for assessing illness representation regarding IGD in a general population of Chinese adults. It can be used in future research that examines factors of incidence and prevention related to IGD.
Mycoplasma pneumoniae (M. pneumoniae) is one of the most important pathogens that cause respiratory tract infection in children and adults. In this study, we describe a rapid and sensitive colorimetric loop mediated isothermal amplification (LAMP) method to detect M. pneumoniae. The specificity and sensitivity of this assay were detected with 21 common respiratory pathogens and 39 M. pneumoniae DNA. The sensitivity of LAMP was 100% among 39 M. pneumoniae isolates and the specificity was 100% among 9 members of other Mycoplasma and 12 common respiratory pathogens. The lowest detectable limit (LDL) of this assay was 102 copies, which detected by a series of standard M. pneumoniae DNA. To evaluate the clinical applicability of the LAMP assay, a total of 80 clinical samples were examined by conventional PCR, real-time PCR and the LAMP assays, respectively. The positive rates were 15.0%, 32.5% and 26.3%, respectively. This colorimetric LAMP assay demonstrated a high level of sensitivity comparable with that of conventional PCR for the detection of M. pneumoniae. It is a valuable method for simple, cost-effective and rapid detection of M. pneumoniae in the rural areas and basic clinical of China.
Summary
A selective and sensitive liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS) method was developed and validated for analysis of xanthotoxol (1), xanthotoxin (2), isoimpinellin (3), bergapten (4), oxypeucedanin (5), imperatorin (6), cnidilin (7), and isoimperatorin (8) in rat bile and urine using pimpinellin as an internal standard (IS). An Agilent 1200 liquid chromatography system (Agilent Technologies, USA) equipped with a quaternary pump, an autosampler, and a column compartment was used for all analyses. Chromatographic separations were performed on a Sapphire C18 column (150 mm × 4.6 mm, 5 μm), and the column temperature was maintained at 30°C; the sample injection volume was 10 μL. The specificity, linearity, accuracy, precision, recovery, matrix effect, and several stabilities were validated for all analytes in the rat bile and urine samples. The method was successfully applied in monitoring the concentrations of eight coumarins in rat bile and urine after a single oral administration of Radix Angelicae Dahuricae extract with a dosage of 8.0 mL/kg. In the bile samples, the eight coumarins excreted completely in twenty-four hours. The average percentages of coumarins (1–8) excreted were 0.045%, 0.019%, 0.177%, 0.105%, 0.337%, 0.023%, 0.024%, 0.021%. In the urine samples, the eight coumarins excreted completely in seventy-two hours. The average percentages of coumarins (1–8) excreted were 1.78%, 0.095%, 0.130%, 0.292%, 0.082%, 0.008%, 0.005%, 0.004%. The method is robust and specific and it can successfully complete the requirements of the excretion study of the eight coumarins in Radix Angelicae Dahuricae.
Abstract
A sensitive and rapid method using HPLC-MS/MS was developed for the determination of eight glucocorticoids residues in chicken muscle simultaneously by Turbo Flow. The eight glucocorticoids were prednisone, prednisolone, hydrocortisone, methylprednisolone, dexamethasone, betamethasone, beclomethasone and fludrocortisones. Samples were extracted with ethyl acetate and on-line cleaned up through a Turbo Flow solid-phase extraction column without time-consuming pretreatment before HPLC-MS/MS analysis. Sample pretreatment conditions, Turbo Flow conditions and mass spectral parameters were optimized and obtained eight glucocorticoids calibration curves. These curves showed good linearity over the concentration from 0.2 μg/kg to 50 μg/kg with an average recovery from 71.63% to 117.36%. This method could be applied on real samples and provided simple, rapid, sensitive and highly selective analysis, which made it feasible to be adopted in food inspection organizations or carry out quantitative analysis for other banned substance.
Abstract
Two sensitive and effective methods were developed for the detection of catecholamines and related biogenic amines (dopamine, epinephrine, norepinephrine, serotonin, levodopa and tyramine) using high performance liquid chromatography with fluorescence detection and capillary electrophoresis with laser-induced fluorescence detection. A BODIPY fluorescent dye, 1, 3, 5, 7-tetramethyl-8-(N-hydroxysuccinimidyl propionic ester)-difluoroboradiaza- s-indacene was used as pre-column derivatization reagent. The separation and derivatization conditions were optimized in detail. In high performance liquid chromatography with fluorescence detection method, the derivatization reaction was completed at 35 °C for 20 min. At the wavelength of λ ex/λ em = 493 nm/513 nm, dopamine, epinephrine, norepinephrine, and levodopa derivatives achieved baseline separation within 15 min. The limits of detection (S/N = 3) were 1.0, 2.0, 5.0, and 0.5 nmol/L, respectively. In capillary electrophoresis with laser-induced fluorescence detection method, the derivatization reaction was completed at 25 °C for 20 min. Serotonin, tyramine and dopamine derivatives reached baseline separation within 10 min at the wavelength of λ ex = 473 nm. The limits of detection (S/N = 3) for serotonin, tyramine, and dopamine were 0.3, 0.02, and 0.2 nmol/L, respectively. The amino compounds in human serum and urine samples were detected successfully, and the recoveries were 93.3%–106.7% and 91.0%–103.1%, respectively.
Abstract
Recently, it was reported that the toxicity of copper particles increases with the decrease of the particle size on a mass basis. To understand this phenomenon, inductively coupled plasma mass spectrometry (ICP-MS) techniques and in vitro chemical studies were carried out to explore how they produce toxicity in vivo. The results suggest that when the sizes of particles become small and down to a nanoscale, copper becomes extremely reactive in a simulative intracorporeal environment. The nanosized copper particles consume the hydrogen ions in stomach more quickly than micron ones. These processes further convert the copper nanoparticles into cupric ions whose toxicity is very high in vivo.
