Biomimetic mineralization of high-strength apatite structure essentially relies on mimicking the inorganic building blocks of naturally occurring bones. However, conventional routes still have ...substantial function gaps in providing precision control over the geometrical dimensions and crystalline morphology of biomineralized apatite. Herein, we conceived the concept of microwave-assisted biomineralization (MAB) to customize 1D hydroxyapatite nanowhiskers (HANWs) at graphene templates, rendering the formation of graphene-hydroxyapatite (Gr-HA) nanohybrids. The HANWs essentially resembled bone apatite in elemental composition (Ca/P = 1.74), diameter (~20 nm), crystallinity (63 %), and rodlike geometry (aspect ratio of ~6). The Gr-HA nanohybrids were uniformly incorporated into poly(lactic acid) (PLA) microfibers (~1 μm) by electrospinning, engendering fibrous membranes with a set of Gr-HA loadings (10, 20 and 30 wt%). Intimate interactions were generated between Gr-HA and PLA matrix, contributing to significant promotion of the mechanical properties for PLA composite membranes. For example, the yield strength and elastic modulus of the PLA composite membranes loaded with 30 wt% Gr-HA achieved 5.4 and 66.4 MPa, increasing nearly 182 % and over 94 % compared to those of pure PLA, respectively. Moreover, the bone-like HANWs endowed PLA membranes with excellent cytocompatibility and good bioactivity, as demonstrated by over 38 % increase in cell viability and rapid apatite formation in mineral solution. The impressive combination of mechanical properties and biological characteristics make the PLA/Gr-HA scaffolds promising for guided tissue/bone regeneration therapy.
The concept of microwave-assisted biomineralization was conceived to customize 20-nm-sized hydroxyapatite nanowhiskers with bone apatite-like structural features, conferring a combination of mechanical strength, osteogenesis and bioactivity for the poly(lactic acid) scaffolds. Display omitted
•A microwave-assisted biomineralization (MAB) approach was established.•MAB enabled rapid fabrication of hydroxyapatite nanowhiskers (HANWs) at graphene templates.•The HANWs (diameter of ~20 nm, crystallinity of 63 %) copied the structure of bone apatite.•The bone-like HANWs promoted the osteogenesis and bioactivity of poly(lactic acid) scaffolds.
Due to its unique crystal structure and nano-properties, hydroxyapatite (HA) has become an important inorganic material with broad development prospects in electrical materials, for fire resistance ...and insulation, and in bone repair. However, its application is limited to some extent because of its low strength, brittleness and other shortcomings. Graphene (G) and its derivative graphene oxide (GO) are well known for their excellent mechanical properties, and are widely used to modify HA by domestic and foreign scholars, who expect to achieve better reinforcement and toughening effects. However, the enhancement mechanism has not been made clear. Accordingly, in this study, G and GO were selected to modify HA using the first-principles calculation method to explore the theory of interfacial bonding of composites and explain the microscopic mechanism of interfacial bonding. First-principles calculation is a powerful tool used to solve experimental and theoretical problems and predict the structure and properties of new materials with precise control at the atomic level. Therefore, the bonding behaviors of hydroxyapatite (100), (110) and (111) crystal planes with G or GO were comprehensively and systematically studied using first-principles calculation; this included analyses of the density of states and differential charge density, and calculations of interfacial adhesion work and elastic moduli. Compared to HA (100) and (111) crystal planes, HA (110) had the best bonding performance with G and with GO, as revealed by the calculation results. The composite material systems of HA (110)/G and HA (110)/GO had the smallest density of states at the Fermi level, the largest charge transfers of Ca atoms, the largest interfacial adhesion work and the most outstanding elastic moduli. These results provide a theoretical basis for the modification of HA to a certain extent, and are beneficial to the expansion of the scope of its application.
Objective
: Long non-coding RNA KCNQ1OT1 has been associated with the development of different types of cancers. The present research investigated the role of KCNQ1OT1 in osteosarcoma.
Methods
: ...Expression level of KCNQ1OT1 in osteosarcoma and paired non-cancerous tissue specimens from 56 osteosarcoma patients and its association with patients' clinicopathological features was investigated. KCNQ1OT1 overexpression and knockdown in primary-cultured osteosarcoma cells was constructed by lentiviral transduction. Influence of KCNQ1OT1 overexpression or knockdown on osteosarcoma cell growth, apoptosis, migration, invasion, epithelial-to-mesenchymal transition and beta-catenin activation was investigated.
Results
: Expression of KCNQ1OT1 in osteosarcoma tissue specimens was significantly increased in comparison to that in adjacent counterparts. High expression of KCNQ1OT1 significantly associated with osteosarcoma progression and patients' decreased survival. Overexpression of KCNQ1OT1 significantly increased osteosarcoma cell growth, proliferation, migration, invasion, epithelial-to-mesenchymal transition and beta-catenin activation while reducing cell apoptosis
in vitro
, and KCNQ1OT1 knockdown showed opposite effects. Inhibition of beta-catenin/TCF activity by ICG-001 treatment significantly attenuated the promoting effect of KCNQ1OT1 overexpression on osteosarcoma cell malignancy described above.
Conclusion
: KCNQ1OT1 might be a potential prognostic factor in osteosarcoma. High expression of KCNQ1OT1 might promote osteosarcoma development by increasing the activation of WNT/beta-catenin signaling pathway.
Long non-coding RNA KCNQ1OT1 has been associated with the development of different types of cancers.
: Long non-coding RNA KCNQ1OT1 has been associated with the development of different types of cancers. The present research investigated the role of KCNQ1OT1 in osteosarcoma.
: Expression level of ...KCNQ1OT1 in osteosarcoma and paired non-cancerous tissue specimens from 56 osteosarcoma patients and its association with patients' clinicopathological features was investigated. KCNQ1OT1 overexpression and knockdown in primary-cultured osteosarcoma cells was constructed by lentiviral transduction. Influence of KCNQ1OT1 overexpression or knockdown on osteosarcoma cell growth, apoptosis, migration, invasion, epithelial-to-mesenchymal transition and beta-catenin activation was investigated.
: Expression of KCNQ1OT1 in osteosarcoma tissue specimens was significantly increased in comparison to that in adjacent counterparts. High expression of KCNQ1OT1 significantly associated with osteosarcoma progression and patients' decreased survival. Overexpression of KCNQ1OT1 significantly increased osteosarcoma cell growth, proliferation, migration, invasion, epithelial-to-mesenchymal transition and beta-catenin activation while reducing cell apoptosis
, and KCNQ1OT1 knockdown showed opposite effects. Inhibition of beta-catenin/TCF activity by ICG-001 treatment significantly attenuated the promoting effect of KCNQ1OT1 overexpression on osteosarcoma cell malignancy described above.
: KCNQ1OT1 might be a potential prognostic factor in osteosarcoma. High expression of KCNQ1OT1 might promote osteosarcoma development by increasing the activation of WNT/beta-catenin signaling pathway.
The objective of this study was to evaluate the surgical effectiveness of posterior procedure with long segment stabilization for treating thoracolumbar pseudarthrosis associated with ankylosing ...spinal disorders (ASDs) without anterior fusion or osteotomy.
Twelve patients with thoracolumbar pseudarthrosis in ASD were enrolled. All patients underwent posterior long-segment stabilization procedures. In some patients, the percutaneous technique or the aid of a robot or O-arm navigation was utilized for pedicle screw implantation. The clinical results were evaluated by means of the visual analog scale and Oswestry Disability Index. Radiological outcomes were evaluated for bone fusion, anterior column defect, local kyphotic correction, and position of the pedicle screws.
All patients experienced effective bone fusion at the sites of pseudarthrosis. The mean operative time was 161.7 ± 57.1 minutes, and the average amount of blood loss was 305.8 ± 293.2 mL. For 6 patients who underwent surgery with the assistance of a robot or O-arm navigation, there was no statistically significant difference observed in terms of operative time and mean blood loss compared to those who used the freehand technique (P > 0.05). The visual analog scale score, Oswestry Disability Index value, and mean local kyphotic angle showed significant improvements at the final follow-up (P < 0.05). The accuracy of pedicle screw placement was 96%.
Posterior surgery with long-segment fixation, without anterior fusion or osteotomy, can achieve satisfactory outcomes in ASD patients with thoracolumbar pseudarthrosis. The application of percutaneous techniques, as well as the assistance of robots or navigation technique may be a good choice for the treatment of pseudarthrosis in ASD patients.
Soil pH in liaoning tobacco planting area and its impact tobacco quality Du Jian, Shengyang Agricultural University, Shenyang(China), College of Land and Environment; Zhang Rui, Shengyang Agricultural University, Shenyang(China), College of Land and Environment; Zhang Hui, Shengyang Agricultural University, Shenyang(China), College of Land and Environment
Shenyang nong ye da xue xue bao,
20/Dec., Volume:
40, Issue:
6
Journal Article
以辽宁省7个植烟县为对象,采集了154个土壤和中部烟叶样品,在测定土壤pH值的基础上,测定烟叶中的烟碱含量、糖含量、总糖含量以及氮钾含量。通过数理统计的方法分析了土壤pH值与烟叶内在质量指标之间的关系,结果表明：辽宁烟区植烟土壤的pH值大多比较适合烟叶生长,但是仍有12%的植烟土壤pH值过高或过低,需要进行改良。土壤pH值与烟叶总氮含量、烟碱含量、钾含量两两之间均呈显著或极显著的曲线相关关系,即当土壤pH值从4.0变化到6.5时土壤pH值与烟碱含量之间为负效应关系,当土壤pH值从6.5变化到9.0时土壤pH值与烟碱含量之间为正效应关系,土壤pH值与总氮含量、钾含量、总糖含量之间为负效应关系。著者文摘
154 samples of soil and middle tobacco leaf collected in seven tobacco planting counties in Liaoning Province were examined in this experiment.Soil pH value,the contents of nicotine,reducing sugar,total sugar,potassium and total nitrogen in tobacco leaves were measured.The relationship between the soil pH value and the intrinsic quality of tobacco leaves were analysed through the method of mathematical statistics.The results showed that the soil pH value was mostly suitable for tobacco growing,about 12%of pH value high or low.Soil pH value had significant correlations with the contents of total nitrogen, nicotine,potassium in tobacco leaves.When the soil pH value changed from 4.0 to 6.5,the soil pH value and
研究了硝酸钙＋IAA处理对成熟期不同夜间低温下设施薄皮甜瓜果实品质的影响，以薄皮甜瓜（Cucumis melo L．）玉美人为试材，选择浓度为0．5％硝酸钙和20×10. ...6IAA喷施甜瓜植株。结果表明：硝酸钙＋IAA处理明显提高了12℃和9℃夜温下薄皮甜瓜果实中可溶性固形物、维生素C、果糖、葡萄糖、蔗糖和总糖的含量，喷施硝酸钙＋IAA处理的总糖含量在12℃和9℃低夜温处理后分别比未喷施硝酸钙＋IAA提高了12．63mg・g. 和9．877mg・g. ，蔗糖也分别提高了7．403mg・g. 和5．768mg・g. 。12℃低夜温处理喷施硝酸钙＋IAA比未喷施硝酸钙＋IAA的苹果酸和酒石酸含量降低了16．7％，9℃低夜温处理喷施硝酸钙＋IAA比未喷施处理降低了18．4％。硝酸钙＋IAA处理降低了果实中有机酸含量，改善了果实营养品质。著者文摘
Muskmelon ＂Yu mei ren＂ was taken as the experimental material and the mixture of calcium nitrate （0.5%） and IAA （20×10. ） was sprayed to melon plants in order to study the effect of calcium nitrate ＋ IAA treatment on the maturation of muskmelon fruit under low temperature stress at night. The results showed that calcium nitrate ＋ IAA treatment increased significantly soluble solids, vitamin C, fructose, glucose, sucrose and total sugar content in muskmelon fruit at the night temperatures of 12 ℃ and 9 ℃. Total sugar contents increased 12.63 mg・g. and 9.877mg・g. at the 9 ℃and 12 ℃, and the sucrose also raised 7.403 mg・g. and 5.768 mg・g. . T
Apolipoprotein C2 is an important member of the apolipoprotein C family, and is a potent activator of lipoprotein lipase. In the central nervous system, apolipoprotein C2 plays an important role in ...the catabolism of triglyceride-rich lipoproteins. Studies into the exact regulatory mechanism of mouse apolipoprotein C2 expression have not been reported. In this study, seven luciferase expression vectors, which contained potential mouse apolipoprotein C2 gene promoters, were constructed and co-transfected with pRL-TK into HEK293T cells to investigate apolipoprotein C2 promoter activity. Luciferase assays indicated that the apolipoprotein C2 promoter region was mainly located in the ＋104 bp to ＋470 bp region. The activity of the different lengths of apolipoprotein C2 promoter region varied. This staggered negative-positive-negative arrangement indicates the complex regulation of apolipoprotein C2 expression and provides important clues for elucidating the regulatory mechanism of apolipoprotein C2 gene transcription.
MoS2 presents a promising catalyst for the hydrogen evolution reaction (HER) in water splitting, but its worse catalytic performance in neutral and alkaline media than in acidic environment may be ...problematic for practical application. This is because the other half reaction of water splitting, i.e., oxygen evolution reaction, often needs to be implemented in alkaline environment. Here we demonstrate a universal strategy that may be used to significantly improve the HER catalysis of MoS2 in all kinds of environments from acidic to alkaline, proton intercalation. Protons may be enabled to intercalate between monolayer MoS2 and underlying substrates or in the interlayer space of thicker MoS2 by two processes: electrochemically polarizing MoS2 at negative potentials (vs RHE) in acidic media or immersing MoS2 into certain acid solutions like TFSI. The improvement in catalytic performance is due to the activity enhancement of the active sites in MoS2 by the intercalated protons, which might be related with the effect of the intercalated protons on electrical conductance and the adsorption energy of hydrogen atoms. The enhancement in catalytic activity by the intercalated proton is very stable even in neutral and alkaline electrolytes.
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