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- Author or Editor: Min Zhang x
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Abstract
Nanoscience and technology (NST) is a young scientific and technological field that has generated great worldwide interest in the past two decades. Previous bibliometric analyses have unmistakably demonstrated the remarkable growth of the global NST literature. While almost all published research articles in NST are in English, increasingly a larger share of NST publications is published in the Chinese language. Perplexingly, Chinese is the only language — apart from English — that displays an ascendant trend in the NST literature. In this brief note, we explore and evaluate three arguments that could explain this phenomenon: coverage bias, language preference, and community formation.
Abstract
A conjugate of 6-hydrazinopyridine-3-carboxylic acid (HYNIC) with the amino analogue of metronidazole (MN) was synthesized through a multiple-step reaction. HYNIC-MN could be labeled easily and efficiently with 99mTc using N-(2-hydroxy-1,1-bis(hydroxymethyl)ethyl)glycine (tricine) and ethylenediamine -N,N′-diacetic acid (EDDA) as coligands to form the 99mTc–HYNIC–MN complex in high yield (>95%). Its partition coefficient indicated that it was a good hydrophilic complex. The tumor cell experiment showed that the 99mTc–HYNIC–MN complex had a certain hypoxic selectivity. The biodistribution studies of 99mTc–HYNIC–MN in Kunming mice bearing S180 tumor showed a favorable tissue distribution profile with high tumor uptake, and low or negligible accumulation in non-target organs, suggesting 99mTc–HYNIC–MN would be a novel potential tumor hypoxia imaging agent.
Abstract
A cataract in the lenses of Wistar rats was induced by injecting Na2SeO3 into their bodies; they exhibited various kinds of cataract between 8 and 28 days. Samples were prepared using the method of low temperature ashing. The trace-element analyses of samples of different kinds of lenses were carried out by PIXE method. From the results obtained we have studied the ratio of their concentrations relative to the control values in relation to the formation time of cataract. It was found that the metabolites, of most trace-elements in the control lenses are stable, but in various kinds of cataractous lenses they display certain changes. Elements are clearly divided into two types. Elements of the first type are S, Cl, Ca, Fe and Zn. They appear to accumulate relative to the controls, while the second type, P, K and Rb, shows deficiency. The functions of trace-element metabolism during the formation of cataract are also discussed.
Abstract
Differential elastic scattering cross sections for backscattering of 0.96–2.74 MeV protons incident on an aluminum layer covered by a gold layer deposited on a graphite crystal have been measured. The lowest proton energy in the experiment is in the Rutherford backscattering energy region. The measured cross sections are compared with the previous data and presented in graphical and tabular forms.
Abstract
The thermal curves and the enthalpy changes of the interaction between some oral sustained release preparations (Contac, Fenbid and Benza sustained release capsules) and physiological saline have been measured at 298.15 K with a MS-80 standard Calvet microcalorimeter. The curves that recorded the changes of heat effect with time have clearly shown the sustained release action and process of the above preparations. A method for examining the sustained release action of sustained release preparations can be developed from the above experiments. The principle of application and the experimental procedure of this method have been expounded, and some results of the above experiments have also been discussed.
Abstract
A conjugate of 6-hydrazinopyridine-3-carboxylic acid (HYNIC) with aminomethylenediphosphonic acid (AMDP) was synthesized through a multiple-step reaction. HYNIC–AMDP could be labeled easily and efficiently with 99mTc using N-(2-hydroxy-1,1-bis(hydroxymethyl)ethyl)glycine (tricine) as coligand to form the 99mTc–HYNIC–AMDP complex in high yield (> 95%). Its partition coefficient indicated that it was a good hydrophilic complex. The biodistribution studies of 99mTc–HYNIC–AMDP in normal ICR mice showed that this complex had high bone uptake and low or negligible accumulation in non-target organs. As compared with 99mTc–MDP, 99mTc–HYNIC–AMDP had a higher bone uptake and the ratios of bone/blood and bone/muscle at early time after injection, suggesting that it could be potentially useful for bone imaging at an earlier time after injection according to further investigations of the biological behavior of this complex.
Let N be a sufficiently large integer. In this paper, it is proved that, with at most O(N
119/270+
s
) exceptions, all even positive integers up to N can be represented in the form
where p 1 , p 2 , p 3 , p 4 , p 5 , p 6 are prime numbers.
Abstract
Polyaniline/NiO (PANI/NiO) composites were synthesized by in situ polymerization at the presence of HCl (as dopant). FTIR, TEM and XRD were used to characterize the composites. Thermogravimetry (TG)–mass spectrometer (MS) and temperature modulated differential scanning calorimetry (TMDSC) were used to study the thermal stability, decomposition and glass transition temperature (T g) of the composites, respectively. FTIR and XRD results showed that NiO nanoparticles connected with PANI chains in the PANI/NiO composites. TEM results exhibited that the morphologies of PANI/NiO composites were mostly spherical, which were different from the wirelike PANI. TG–MS curves indicated that the products for oxidative degradation of both PANI and PANI/NiO composite were H2O, CO2, NO and NO2. TG curves showed that with NiO contents increased in PANI/NiO composites, thermal stability of PANI/NiO composites increased firstly and then decreased when the NiO content was higher than 66.2 wt%. T g of PANI/NiO composites also increased from 163.19 to 252.36 °C with NiO content increasing from 0 to 50 wt%, and then decreased with NiO content increasing continuously.
Abstract
Bao-Yuan Decoction (BYD), a widely used traditional Chinese medicine formula, is worth developing into modern dosage forms. To assess the quality of traditional decoction, the commonly used ultra-performance liquid chromatography coupled with diode array and evaporative light scattering detection (UPLC-DAD/ELSD) method was initially applied to develop the analytical methods for the qualitative fingerprints and simultaneous quantitation of multiple marker compounds in BYD. Based on 16 batches of BYD prepared from multiple batches of qualified crude herbs combined randomly, the characteristic fingerprints were generated, with 41 and 19 common peaks detected by DAD and ELSD, respectively. Furthermore, ginsenosides Re, Rg1 and Rb1, calycosin-7-glucoside, calycosin, liquiritin, isoliquiritin apioside, isoliquiritin, glycyrrhizic acid and cinnamic acid were qualified as marker compounds to represent the herbs composing the formula. The characteristic fingerprints and the content ranges of multiple batches of the decoction were obtained, thus providing guidance for the quality control of modern dosage forms. The combination of these qualitative and quantitative methods will be an effective operational measure by which to evaluate and control the quality of BYD from traditional decoction to modern dosage forms.
Background and aims
Although studies have suggested that individuals with Internet gaming disorder (IGD) may have impairments in cognitive functioning, the nature of the relationship is unclear given that the information is typically derived from cross-sectional studies.
Methods
Individuals with active IGD (n = 154) and those individuals no longer meeting criteria (n = 29) after 1 year were examined longitudinally using functional magnetic resonance imaging during performance of cue-craving tasks. Subjective responses and neural correlates were contrasted at study onset and at 1 year.
Results
Subjects’ craving responses to gaming cues decreased significantly at 1 year relative to study onset. Decreased brain responses in the anterior cingulate cortex (ACC) and lentiform nucleus were observed at 1 year relative to onset. Significant positive correlations were observed between changes in brain activities in the lentiform nucleus and changes in self-reported cravings. Dynamic causal modeling analysis showed increased ACC–lentiform connectivity at 1 year relative to study onset.
Conclusions
After recovery from IGD, individuals appear less sensitive to gaming cues. This recovery may involve increased ACC-related control over lentiform-related motivations in the control over cravings. The extent to which cortical control over subcortical motivations may be targeted in treatments for IGD should be examined further.
