Towards Efficient Nonenzymatic DNA Ligation: Comparing Key Parameters for Maximizing Ligation Rates and Yields with Carbodiimide Activation**

Chemical ligation is an important tool for the generation of synthetic DNA structures, which are used for a wide range of applications. Surprisingly, reported chemical ligation yields can range from 30 to 95 % for the same chemical activating agent and comparable DNA structures. We report a systematic study of DNA ligation by using a well-defined bimolecular test system and a water-soluble carbodiimide (EDC) as a phosphate-activating agent. Our results emphasize the interplay between template-substrate complex stability and the rates of the chemical steps of ligation, with 3′ phosphate substrates providing yields near 100 % after 24 hours for particularly favorable reaction conditions. Ligation rates are also shown to be sensitive to the identity of the base pairs flanking a nick site, with as much as threefold variation. Finally, the observation that DNA substrates are modified by EDC at rates that can be comparable with ligation rates emphasizes the importance of considering side reactions when designing protocols to maximize ligation yields.     

Effect of microRNA-143-3p-mediated CTNND1 on the biological function of lung cancer cells

Lung cancer poses a serious threat to human life with high incidence and miRNA is an important biomarker in tumors. This study aimed to explore the effect of miR-143-3p on the biological function of lung cancer cells and the underlying mechanism. Eighty-seven samples of lung cancer tissues and 81 samples of tumor-adjacent tissues from patients undergoing radical lung cancer surgery in our hospital were collected. The lung cancer cells and lung fibroblast cells (HFL-1) were purchased, and then miR-143-3p-mimics, miR-NC, si-CTNND1, and NC were transfected into A549 and PC-9 cells to establish cell models. MiR-143-3p and CTNND1 expression levels were measured by the qRTPCR, Bax, Bcl-2, and CTNND1 expression levels by the Western Blot (WB), and cell proliferation, invasion, and apoptosis by the MTT assay, Transwell assay, and flow cytometry. Dual luciferase report assay was used to determine the relationship between miR-143-3p and CTNND1. In this study, miR-143-3p was lowly expressed in lung cancer and CTNND1 was highly expressed in lung cancer. The overexpression of miR-143-3p inhibited cell proliferation and invasion, promoted cell apoptosis, significantly increased Bax protein expression, and decreased Bcl-2 protein expression. The inhibition of CTNND1 led to opposite biological characteristic in cells. The dual luciferase reporter assay demonstrated that miR-143-3p was a target region of CTNND1. Such results suggest that miR-143-3p can inhibit the proliferation and invasion of lung cancer cells by regulating the expression of CTNND1 and promote the apoptosis of lung cancer cells, sott is expected to be a potential target for lung cancer.     

Proteome changes in lamb semimembranosus muscles associated with the inclusion of sunflower cake in their diet

A diet based on sunflower cake for lambs was assayed in order to reuse biodiesel industrial by-products with the aim of reducing livestock costs and evaluating their influence on meat quality. To achieve these goals, sixteen male lambs were fed diets containing different levels of sunflower cake (control, 5%, 10% and 15%). Afterwards, their semimembranosus muscles were analysed by two-dimensional electrophoresis coupled to mass spectrometry and their functional protein association was examined using STRING. Structural and metabolic proteins in the lambs’ proteomes changed significantly according to their diet. Fifteen proteins showed significant changes caused by the inclusion of sunflower cake, and the most differentially abundant structural proteins were detected in 2-DE gels from the lambs. Differentially abundant metabolic proteins such as ENO3 (enolase 3), MDH1 (malate dehydrogenase) and ALDH1A1 (retinal dehydrogenase) have been proposed as biomarkers of quality parameters in other species.     

3D thermo-electro-chemo-mechanical coupled modeling of solid oxide fuel cell with double-sided cathodes

A solid oxide fuel cell based on double-sided cathodes is developed in our group, showing special properties and many advantages under some harsh conditions. To optimize the cell further, a thermo-electro-chemo-mechanical coupled 3D model is developed to simulate the distributions of temperature, current density, fuel gas and thermal stress under different voltages. The numerical results indicate that the temperature distribution, current, fuel gases and thermal stress is non-uniform in the cell at different voltages. The distribution of thermal stress in the electrolyte is also non-uniform because of the un-even electrochemical reaction and convective heat transfer. Furthermore, the result shows that about 47%~54% of maximum 1st principal stress in SOFC is caused by the mismatch of coefficients of thermal expansion (CTEs) among materials, while the other part of the maximum 1st principal stress is mainly caused by temperature gradient.     

早冠丝瓜406新品种的选育

早冠丝瓜406是以S4为母本、X06为父本配制而成的一代杂种.极早熟,植株主蔓分枝性强,生长性强盛;雌花节位低,首朵雌花着生于主蔓第5节~7节,采收期为播种后58 d^60 d开始;嫩瓜呈长棒形,果端较圆,果皮深绿色,单果重0.5 kg^0.9 kg,果实纵径42 cm^50 cm,横径3.7 cm^4.2 cm,前期产量为16772.0 kg/hm^2,总产量可达47447.5 kg/hm^2.适合长江流域、云贵高原及湖南地区早春设施和露地栽培.     

Oval cuboid TiO2 particles with mesoporous structure fabricated by using fluorinated block copolymers as templates with photocatalytic performance

In this work, a poly(ethylene glycol)-b-poly(1H,1H,7H-dodecafluoroheptyl methacrylate) (PEG-b-PDFMA) block copolymer was first synthesized by the reversible addition−fragmentation chain transfer (RAFT) polymerization. Then a novel facile approach was developed to fabricate oval cuboid TiO₂ particles with mesoporous structure by using the PEG-b-PDFMA block copolymer as a template and titanium tetrabutoxide (TBOT) as a precursor, followed by evaporation-induced self-assembly (EISA) process and calcination process. The results show that the PEG-b-PDFMA block copolymer can control the oriented assembly of nanoparticles and act as templates for the formation of a mesopore. It is found that the mass ratio of TBOT/PEG-b-PDFMA and water content in the solution have a significant influence on the morphology of TiO₂ particles. When the mass ratio of TBOT/PEG-b-PDFMA is 0.25/1, oval cuboid TiO₂ particles with mesopores are obtained, which exhibits a high photocatalytic activity for the degradation of methylene blue (MB) dye under UV light irradiation.     

回火工艺对1Cr17Ni2不锈钢锻后回火硬度的影响

采用正交试验等研究了回火温度、回火时间、回火次数及冷却方式对1Cr17Ni2不锈钢锻后回火硬度的影响。结果表明,本试验中在回火温度630~730 ℃,回火时间120~360 min,回火1~3次以及冷却方式分别为空冷、堆冷、砂冷的条件下,对1Cr17Ni2钢锻后回火硬度影响因素的主次排序为:回火次数＞回火温度＞回火时间＞冷却方式,其中随着回火次数增加,硬度逐步下降,其余参数在试验参数范围内与硬度无明显正相关关系。在保温时间为240 min时,将回火温度升高至720 ℃,或在680 ℃下,将保温时间延长至720 min,进行一次回火,回火后空冷,硬度均高于3.5 HBS。在加热温度为680 ℃、回火时间为180~210 min,回火后空冷,回火3次可将硬度降低至3.6 HBS以下。     

Effect of Acute Sprint Exercise on Myokines and Food Intake Hormones in Young Healthy Men

Physical exercise is known to influence hormonal mediators of appetite, but the effect of short-term maximal intensity exercise on plasma levels of appetite hormones and cytokines has been little studied. We investigated the effect of a 30 s Wingate Test, followed by a postprandial period, on appetite sensations, food intake, and appetite hormones. Twenty-six physically active young males rated their subjective feelings of hunger, prospective food consumption, and fatigue on visual analogue scales at baseline, after exercise was completed, and during the postprandial period. Blood samples were obtained for the measurement of nesfatin-1, ghrelin, leptin, insulin, pancreatic polypeptide (PP), human growth factor (hGH) and cytokine interleukin-6 (IL-6), irisin and plasma lactate concentrations, at 30 min before exercise, immediately (210 s) after exercise, and 30 min following a meal and at corresponding times in control sedentary males without ad libitum meal intake, respectively. Appetite perceptions and food intake were decreased in response to exercise. Plasma levels of irisin, IL-6, lactate, nesfatin-1 and ghrelin was increased after exercise and then it was returned to postprandial/control period in both groups. A significant rise in plasma insulin, hGH and PP levels after exercise was observed while meal intake potentiated this response. In conclusion, an acute short-term fatiguing exercise can transiently suppress hunger sensations and food intake in humans. We postulate that this physiological response involves exercise-induced alterations in plasma hormones and the release of myokines such as irisin and IL-6, and supports the notion of existence of the skeletal muscle–brain–gut axis. Nevertheless, the detailed relationship between acute exercise releasing myokines, appetite sensations and impairment of this axis leading to several diseases should be further examined.     

Effects of Synthesis Conditions on the Formation of Si-Substituted Alpha Tricalcium Phosphates

Powders of α-TCP containing various amounts of silicon were synthesized by two different methods: Wet chemical precipitation and solid-state synthesis. The obtained powders were then physico–chemically studied using different methods: Scanning and transmission electron microscopy (TEM and SEM), energy-dispersive X-ray spectroscopy (EDS), powder X-ray diffractometry (PXRD), infrared and Raman spectroscopies (FT-IR and R), and solid-state nuclear magnetic resonance (ssNMR). The study showed that the method of synthesis affects the morphology of the obtained particles, the homogeneity of crystalline phase and the efficiency of Si substitution. Solid-state synthesis leads to particles with a low tendency to agglomerate compared to the precipitation method. However, the powders obtained by the solid-state method are less homogeneous and contain a significant amount of other crystalline phase, silicocarnotite (up to 7.33%). Moreover, the microcrystals from this method are more disordered. This might be caused by more efficient substitution of silicate ions: The silicon content of the samples obtained by the solid-state method is almost equal to the nominal values.     

Effects of Ga and Sn on the electrochemical behavior of Mg–6Al–1Zn as anode materials

The microstructure and electrochemical behavior of Mg–6Al–1Zn, Mg–6Al–1Zn–1Ga, Mg–6Al–1Zn–1Sn, and Mg–6Al–1Zn–0.5Sn–0.5Ga as anode materials in a 3.5 wt% NaCl solution are compared systematically. The results show that Sn alloying refines the second-phases of Mg–6Zn–1Al by promoting tiny granular Mg₁₇Al₁₂ phases containing Sn, and inspires their disperse distribution. However, the Ga results in the formation of semicontinuous reticular Ga containing Mg₁₇Al₁₂ phases. The comparison of discharge tests indicates that Mg–6Al–1Zn–1Sn has the highest discharge activity, and Mg–6Al–1Zn–1Ga displays the largest hydrogen evolution corrosion resistance in 3.5 wt% NaCl solution at 298 K. The synergy of Ga and Sn can shorten discharge activation time and promote low discharge potential. In addition, the utilization efficiencies of the alloys decrease as follows: Mg–6Al–1Zn–1Ga > Mg–6Al–1Zn–0.5Sn–0.5Ga > Mg–6Al–1Zn–1Sn > Mg–6Zn–1Al. This study illustrates that the Mg–6Al–1Zn–0.5Sn–0.5Ga alloy has acceptable utilization efficiency and desirable electrochemical activity, which implies that doping Ga and Sn obtains a balance between discharge activity and utilization efficiencies.