Three-dimensional porous carbon derived from different organic acid salts for application in electrochemical sensing

Three-dimensional porous carbon materials were synthesized by the one-step pyrolysis of organic salts with different numbers of hydroxyl groups on the side chain (sodium tartrate, sodium malate and sodium succinate). Further, the formation of these porous carbon materials was explored. And then, three kinds of carbon materials were used for constructing electrochemical sensors for nitrite detection, respectively. Porous carbon derived from sodium tartrate (PC_ST) showed the highest electrocatalytic ability for nitrite oxidation among all three materials. The PC_ST-based sensors allow for rapid detection of nitrite in a wide linear range of 0.1–100 μM with a low detection limit of 0.043 μM. The sensor was applied to detect nitrite in meat samples and the results tested by the developed sensor were consistent with the results obtained by HPLC. We envision that PC_ST-based electrochemical sensor is promising as an alternative choice for the development of electrochemical analysis.

Three-dimensional porous carbon materials were synthesized by the one-step pyrolysis of organic salts with different numbers of hydroxyl groups on the side chain (sodium tartrate, sodium malate and sodium succinate).     

Photoluminescence,thermal and surface properties of triarylimidazole-containing polyimide nanocomposite films

In this work, a triarylimidazole-containing diamine 2-(4-methylphenyl)-4,5-bis(4-(4-amino-2-trifluoromethylphenoxy)phenyl)imidazole (MPBAI) was firstly synthesized and polymerized with 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA) to prepare transparent polyimide (PI) films by means of thermal imidization. Then, inorganic nanoparticles including silica (SiO₂), alumina (Al₂O₃) and silicon nitride (Si₃N₄) were separately introduced into the PI(MPBAI-CBDA) with different mass fractions of 0.02%, 0.10%, 0.50% and 2.50% to obtain three series of PI nanocomposite films. All these films were close to colorless and transparent, although the light transmittance showed a downward trend due to the introduction of nanoparticles. Moreover, as the content of inorganic nanoparticles increased, the fluorescence intensities of these films were increased. Comparatively, the improvement effect of nano-SiO₂ was the most obvious. When the content of SiO₂ was 2.50%, the maximum intensity of the fluorescence absorption peak was increased by 9.6 times, and the absolute fluorescence quantum yield reached 17.2%, about 5.2 times that of the original PI film. Moreover, the maximum absorption peak produced a red shift of 85 nm due to the addition of 2.50% Si₃N₄, which was probably caused by the weakening of fluorescence quenching effect and high permittivity. The nanocomposites exhibited high glass transition temperatures of around 300 °C and excellent thermal stabilities. The surface hydrophobicity was changed by adjusting the mass and type of nanoparticles. Thus, this work provided a simple way to improve the photoluminescence effect by introducing the nanoparticles. The functional films will be expected to be applied in some optical applications.

Three series of triarylimidazole-containing polyimide nanocomposite films were prepared via thermal imidization. Due to the introduction of inorganic nanoparticles including SiO₂, Al₂O₃ and Si₃N₄, the fluorescence intensities of these composite films were clearly increased.     

Investigation on the upconversion luminescence and ratiometric thermal sensing of SrWO4:Yb3+/RE3+ (RE = Ho/Er) phosphors

SrWO₄ phosphors doped with Ho³⁺(Er³⁺)/Yb³⁺ are successfully prepared by a high temperature solid-state reaction method. The upconversion (UC) luminescence properties of all the samples have been investigated under 980 nm excitation. Strong green emissions are obtained in the SrWO₄:Yb³⁺/Ho³⁺ and SrWO₄:Yb³⁺/Er³⁺ samples with the naked eyes. In a temperature range going from 303 K to 573 K, the UC emission spectra of the phosphors have been measured. Then the temperature sensing properties also have been discussed via fluorescence intensity ratio (FIR) technology. For the SrWO₄:Yb³⁺/Ho³⁺ phosphor, the FIR technologies based on thermal coupling levels (TCLs)(⁵F₄,⁵F₅) and non-thermal coupling levels (non-TCLs)(⁵S₂, ⁵F₄/⁵F₅) are used for investigating the sensitivity. The results show that the maximum absolute sensitivity reaches 0.0158 K⁻¹ with non-TCLs. As for Yb³⁺/Er³⁺ codoped SrWO₄ phosphor, the maximum absolute sensitivity reaches 0.013 K⁻¹ with TCLs (²H_11/2,⁴S_5/2) at a temperature of 513 K. These significant results demonstrate that the SrWO₄:Ho³⁺(Er³⁺)/Yb³⁺ phosphors are robust for optical temperature sensors.

SrWO₄ phosphors doped with Ho³⁺(Er³⁺)/Yb³⁺ are successfully prepared by a high temperature solid-state reaction method.     

Advances in the application of Let-7 microRNAs in the diagnosis,treatment and prognosis of leukemia

The lethal-7 (Let-7) family of microRNAs (miRNAs) controls the process of development and differentiation, but is also related to the occurrence of tumors and a poor prognosis of patients with tumors. Thus, a more comprehensive exploration of its functions will provide further insights into these processes, and may promote the diagnosis and treatment of tumors. Leukemia is a type of progressive malignant disease, and its pathogenesis involves a variety of epigenetic factors. Amongst the several related epigenetic factors, the Let-7 miRNAs are an important family of molecules that play a crucial role in maintaining a variety of critical biological processes, including development, differentiation and proliferation. In the present study, the role of Let-7 as a tumor suppressor gene and oncogene is reviewed, and the complex regulatory functions of several Let-7 family members in different subtypes of leukemia are described. The current body of knowledge thus far indicates that Let-7 is not only a potential diagnostic and prognostic marker of leukemia, but also a potential therapeutic target for the treatment of affected patients, with particular potential when targeted by adjuvant treatments alongside traditional treatment to improve their survival rate.     

先天性肛门直肠畸形术后合并便秘患儿排便功能评定及病因探讨

目的便秘是先天性肛门直肠畸形(anorectal malformation,ARM)术后常见的并发症,其病理改变复杂,病因尚不清楚。本研究利用多种客观检查方法对ARM术后便秘患儿肛门直肠功能和神经功能进行评定,并对其病因进行探讨。方法利用同位素排便造影、直肠肛管测压、肌电图和肛门括约肌神经电生理等方法对49例ARM患儿和31例正常儿童的排便功能进行全面、系统和动态的评价,49例ARM患儿根据畸形位置分为中低位组和高位组,每组再根据是否发生便秘分出两个亚组,并对上述测量指标进行统计分析。结果同位素排便造影结果显示,ARM术后便秘组半排时间[中低位:(13.45±8.35)s;高位:(20.59±4.26)s]与术后无便秘组[中低位:(4.69±6.86)s;高位:(7.66±6.38)s]相比明显延长,ARM术后便秘组排空率[中低位:(29.35±14.84)s;高位:(33.00±9.04)s]与术后无便秘组[中低位:(61.70±23.01)s;高位:(60.31±30.38)s]相比明显降低,差异具有统计学意义(P<0.05)。直肠肛管测压检测结果显示,直肠感觉阈在所有ARM组中均明显高于正常组(P<0.05),ARM便秘组[中低位:(53.57±9.45)mL;高位:(57.50±9.14)mL]高于ARM无便秘组[中低位:(46.32±14.61)mL;高位:(47.27±8.76)mL]。ARM便秘组感觉收缩时间[中低位:(2.79±0.39)s;高位:(3.51±1.93)s]明显长于ARM无便秘组[中低位:(1.97±0.67)s;高位:(2.11±0.43)s],差异具有统计学意义(P<0.05)。肌电图结果显示,反映排便动力的痉挛指数在术后合并便秘组均明显高于未合并便秘组。神经电生理结果显示会阴-肛门反射潜伏期在ARM患儿组均明显延长,其中ARM合并便秘组[中低位:(66.04±16.20)ms;高位:(70.41±17.91)ms]延长更加明显,与ARM无便秘组[中低位:(38.51±16.92)ms;高位:(49.91±9.45)ms]相比存在统计学差异(P<0.05)。结论ARM术后便秘患儿直肠感觉功能和排便动力存在明显异常,其严重程度与支配盆底肌肉的神经功能异常有关。治疗前应进行详细、系统的肛门直肠和神经功能的客观检查,明确排便功能障碍的具体病因和病理改变。     

Correction to: Limb Remote Ischemic Preconditioning Reduces Repeated Ketamine Exposure-Induced Adverse Effects in the Developing Brain of Rats

Journal of Molecular Neuroscience - The original version of this article unfortunately contained mistakes in Fig.&nbsp;2c, d and Funding section.     

Cortico-thalamic dysconnection in early-stage schizophrenia: a functional connectivity magnetic resonance imaging study

European Archives of Psychiatry and Clinical Neuroscience - Studies have indicated thalamus-related network dysfunction in schizophrenia and psychotic disorders. However, whether thalamus-related...