Alkali etching zinc and manganese silicates derived from natural green algaes for supercapacitors with enhanced electrochemical properties.

A facile novel method of alkali etching was proposed to enhance the application of metal-silicates in supercapacitors. First, 3D N, S, P-doped C-zinc-silicate (C-ZnSi), and C-manganese-silicate (C-MnSi) were derived from calcined green algaes (GAs) in a N2 atmosphere. Second, the synthesized products were soaked in a 3.0 M NaOH aqueous solution for alkali etching (soaked for 6, 12 and 24 h) to obtain the etching metal silicates (e-C-ZnSi and e-C-MnSi). This method can yield a higher specific surface area and more pores, and this in turn can improve the electrochemical performance. In the three-electrode system, e-C-ZnSi and e-C-MnSi, which were soaked in NaOH solution for 12 h, exhibited the highest specific capacitances and cycling performance. Solid-state hybrid supercapacitor (HSC) devices were manufactured using C-MSi, e-C-MSi (M = Zn and Mn), and activated carbon (AC) (denoted as C-MSi//AC and e-C-MSi//AC). In the two-electrode system, the e-C-MSi//AC HSC devices exhibited higher areal specific capacitances and energy densities and better cycle performance than those of C-MSi//AC, especially e-C-MSi//AC-12 h HSC devices, which exhibited the best electrochemical properties. This study demonstrated that the naturally polluted GAs can be used as a reusable silica source for the synthesis of supercapacitors. Furthermore, alkali etching can enhance the electrochemical performance of metal silicates and can be used to prepare electrode materials applied for high-performance supercapacitors.

Assessment of the Ecological Compensation Standards for Cross-Basin Water Diversion Projects from the Perspective of Main Headwater and Receiver Areas.

This paper aims to explore how to develop reasonable ecological compensation standards to improve the effectiveness of water diversion projects. Watershed ecological compensation is an important means to coordinate watershed protection and development and, additionally, compensation standard accounting is the core issue of ecological compensation. The previous literature has mainly calculated watershed ecological compensation standards from a single perspective, such as the main headwater or receiver areas, meaning the interests of another under-appreciated area would inevitably be ignored. The calculation results of different perspectives and methods vary greatly, directly affecting the implementation of watershed ecological compensation mechanisms. In this paper, the world's largest water diversion project, the Middle Route of the South-to-North Water Diversion Project, was selected as the study area. The total cost correction model was selected from the perspective of the main headwater areas. The water resources input-output model was selected from the perspective of the receiver areas to evaluate the ecological compensation criteria and compare the differences between the two models. The results show that the ecological compensation standards based on the perspective of water source areas are mainly influenced by the ecological construction expenditures and industrial opportunity cost losses in the watershed, with higher compensation costs in the early period but a more moderate growth trend in the later period. The ecological compensation standards based on the perspective of the receiver areas increase with the annual increase in project water diversion, with a low compensation cost in the early period, but a faster growth trend in the later period. The ecological compensation standards calculated by different perspectives and methods differ significantly; the main contribution of this paper is to enrich the ecological compensation research on cross-basin water diversion projects from multiple perspectives.

Rice-like and rose-like zinc silicates anchored on amorphous carbon derived from natural reed leaves for high-performance supercapacitors.

3D N, S, P-doped rice-like C-Zn4Si2O7(OH)2·H2O (C-ZnSi-N2) and rose-like C-Zn2SiO4 (C-ZnSi-CO2) are derived from reed leaves and used for application in supercapacitors. The as-prepared C-ZnSi architectures with a large number of hierarchical pores and high specific surface area from reed leaves have outstanding electrochemical performance. The obtained C-ZnSi-N2 shows 341 F g-1 at the current density of 0.5 A g-1, while the C-ZnSi-CO2 exhibits 498 F g-1, and both of the C-ZnSi materials significantly retain above 99% of their capacitance after 10 000 cycles. Furthermore, the flexible solid-state asymmetric supercapacitors (ASCs) synthesized from C-ZnSi and activated carbon (denoted as C-ZnSi-N2//AC and C-ZnSi-CO2//AC) achieve a high capacitance (405 and 194 mF cm-2 at the current density of 2 mA cm-2, respectively). Besides, the ASC devices show good cycling stability for 7300 cycles with 73% and 77% capacitance retention. The results presented in this study indicate that the N, S, P-doped C-ZnSi architectures from natural reed leaves are promising and efficient materials for manufacturing high performance supercapacitors.

Compression Characteristics and Microscopic Mechanism of Coastal Soil Modified with Cement and Fly Ash.

It is of great significance to study the consolidation characteristics of modified coastal cement-soil. A one-dimensional consolidation test and microscopic test were carried out. In the tests, the cement content was 20%, fly ash content was 0%, 5%, 10%, 20%, and 30%, and the water content was 80%. The consolidation test results showed that: (1) Compared with coastal cement soil, the deformation of coastal cement soil modified with a 20% fly ash content was reduced from 4.31 to 2.70 mm, and the vertical compression deformation was reduced by 1.61 mm. (2) During consolidation and compression, the e-p curve (pore ratio-pressure curve) of fly ash-modified coastal cement soil was slower than that of coastal cement soil and the rate of change of pore ratio. (3) The compression coefficient of fly ash-modified coastal cement soil was reduced from 0.780 to 0.598 MPa-1 compared with that of coastal cement soil. The microscopic test results indicate that after adding the proper amount of fly ash, a skeleton was formed between the microscopic particles of the sample, which improved its resistance to compression and deformation. The results of this study indicate that it is feasible to modify coastal cement soil with an appropriate amount of fly ash to improve its compression resistance.

An injectable supramolecular self-healing bio-hydrogel with high stretchability, extensibility and ductility, and a high swelling ratio.

Reversible networks are a key factor for designing self-healing hydrogels with high stretching properties. To achieve that, it is often necessary to modify or graft functional groups to the main chains for inducing the formation of reversible covalent-bond-based chemical cross-linking or hydrogen-bond-based physical cross-linking, thus leading to a complicated chemical process and high cost. Here, we proposed a dynamic sliding physical crosslinking mechanism of chains to design and synthesize hydrogels with both good self-healing ability and extensibility by introducing interstitial phases of small organic molecules into the hydrogel networks to enhance hydrogen bonds, which has been proved to be a quite facile and practical approach to achieve stretchable and self-healing properties. Our work might greatly promote our ability to understand the role of hydrogen bonds that are often overlooked in the design of materials. The as-synthesized hydrogels displayed extraordinary swelling properties with a swelling ratio of 2750% in PBS and of nearly 10 000% in stilled water, respectively, and they also showed excellent performance after many stress cycles under 95% compressive deformation. The use of 10% diethylene glycol could allow the elongation to be increased from 238% to 2705%. Our cell and animal experimental studies indicated that the as-synthesized supramolecular hydrogels have good biocompatibility and bioactivity and show potential for clinical application.

Hybrid use of combined and sequential delivery of growth factors and ultrasound stimulation in porous multilayer composite scaffolds to promote both vascularization and bone formation in bone tissue engineering.

In this study, a multilayer coating technology would be adopted to prepare a porous composite scaffold and the growth factor release and ultrasound techniques were introduced into bone tissue engineering to finally solve the problems of vascularization and bone formation in the scaffold whilst the designed multilayer composite with gradient degradation characteristics in the space was used to match the new bone growth process better. The results of animal experiments showed that the use of low intensity pulsed ultrasound (LIPUS) combined with growth factors demonstrated excellent capabilities and advantages in both vascularization and new bone formation in bone tissue engineering. The degradation of the used scaffold materials could match new bone formation very well. The results also showed that only RGD-promoted cell adhesion was insufficient to satisfy the needs of new bone formation while growth factors and LIPUS stimulation were the key factors in new bone formation.

Porous nanoapatite scaffolds synthesized using an approach of interfacial mineralization reaction and their bioactivity.

There is a growing interest in the use of calcium phosphate, used to fabricate porous scaffolds for bone tissue regeneration and repair. However, it is difficult to obtain interconnected pores with very high porosity and to engineer the topography of the pore walls for calcium phosphate ceramic scaffolds. In this study, a novelty method interfacial mineralization reaction was used to fabricate porous nano-calcium phosphate ceramic scaffolds with three-dimensional surface topography of walls, which was tuned using different surfactants; using this method, porous scaffolds with different shapes were obtained, which demonstrates that interfacial mineralization reaction is not only a good method to prepare porous ceramic scaffolds of calcium phosphate but also an efficient approach to engineer the topography of the pore walls. The as-prepared porous ceramic scaffolds have also been proved to have good biocompatibility, bioactivity, and biodegradability, which are necessary for the clinical application. In vivo experimental results revealed that not only osteoconduction but also osteoinduction was responsible for the bone formation in our scaffolds, which accelerated the formation of new bone, and that the degradation process of our porous scaffolds could match osteoinduction, mineralization of matrix and bone, and reconstruction of new bone very well, and porous scaffolds could be completely substituted by the new bone.

[Bio-mechanical evaluation of extreme lateral transforaminal lumbar interbody fusion].

OBJECTIVE: To evaluate the feasibility and post-operation stability of extreme lateral transforaminal lumbar interbody fusion (E-TLIF) and other traditional surgical approach via bio-mechanical test. METHODS: There were 24 normal lumbar spine segment of swine were divided into the following four groups: control group, standard group (internal fixed with pedicle screws only), transforaminal lumbar interbody fusion (TLIF) group and E-TLIF group. The specimen in anteflect, hypsokinesis, lateral flexion and rotate movements were tested respectively with bio-mechanical devices to study on the load-straining changes and biomechanics index. RESULTS: After TLIF or E-TLIF, specimen turned out more steady than normal control group (t = 4.17 - 4.53, P < 0.01). Compared with TLIF group [linear displacement (3.98 ± 0.22) mm, angular displacement 3.03° ± 0.18°], specimen after E-TLIF [linear displacement (3.40 ± 0.09) mm, angular displacement 2.57° ± 0.12°] were more stable in biomechanics index on lateral flection movement (t = 2.61, P < 0.05), but no difference on axial or rotational movements (P > 0.05). CONCLUSION: E-TLIF is a safe and more efficient operation approach.

Astragalus Improved Cardiac Function of Adriamycin-Injured Rat Hearts by Upregulation of SERCA2a Expression.

The traditional Chinese medical herb Astragalus, the dried root of Astragalus membranaceus (Fisch.) Bge., has been widely applied to treat patients with cardiovascular disease in China and has profound cardioprotective effects. This study investigated the effect of Astragalus on hemodynamic changes in adriamycin (ADR)-injured rat hearts and its underlying molecular mechanism. Sprague-Dawley rats were divided into four groups: control, ADR only, ADR + low dose of Astragalus and ADR + high dose of Astragalus. Rats were injected intraperitoneally with 6 equal doses of ADR (cumulative dose, 12 mg/kg) over a period of 2 weeks. Treatment of Astragalus began 1 day before the onset of ADR injection and was given orally once a day for 50 days (3.3 or 10 g/kg/day). Five weeks after the final injection of ADR, rats treated with ADR only showed a significant inhibition of cardiac diastolic function accompanied by the presence of ascites, a remarkable reduction in body weight and heart weight as well as survival rate compared to the controls. Moreover, SERCA2a mRNA and protein expressions in hearts were obviously downregulated by ADR. However, this impaired cardiac function was significantly improved in both doses of Astragalus feeding groups. The amount of ascites was also reduced in a similar extent in these 2 groups. Only the high dose treatment of Astragalus significantly attenuated the changes of SERCA2a expression in injured hearts and improved survival. These results indicated that Astragalus could improve cardiac function of ADR-injured rat hearts, which was partly mediated by upregulation of SERCA2a expression.

[Effects of Astragalus membranaccus on cardiac function and SERCA2a gene expression in myocardial tissues of rats with chronic heart failure].

OBJECTIVE: To investigate the effects of Astragalus membranaccus (As) on cardiac function and SERCA2a gene expression in left ventricular tissues of rats with chronic heart failure. METHODS: Heart failure was induced by clipping the abdominal aorta 60 male SD rats were divided into four groups: sham-operated (Sham), aortic stenosis (Model), Model + As (20 g/kg) and Model + Captopril (0.05 g/kg). The drugs were administered orally from the 13th week after surgery. Rats were examined after 12 weeks' treatment with drugs. The parameters of hemodynamics including LVSP, LVEDP, and +/- LVdp/dt(max) were measured. SERCA2a mRNA and protein expressions in left ventricular tissues were determined by half-quantitative RT-PCR and Western blot normalized to abundance of GAPDH mRNA and portein, respectively. RESULTS: LVSP and LVEDP were obviously enhanced (P < 0.01 or P < 0.001) in model rats in vivo. Both Captopril and As prevented the increase of LVSP (P < 0.05 or P < 0.01) and LVEDP (P < 0.05 or P < 0.01). RT-PCR and Western blot results demonstrated that SERCA2a gene expression was downregulated (P < 0.05) significantly in model group compared with sham group. As upregulated SERCA2a gene expression (P < 0.05), whereas Captopril had no effect on that. CONCLUSION: As can ameliorate abnormity of cardiac function, especially diastoilc function in rats with pressure overload-induced heart failure, and that may be partly related to its up-regulation of SERCA2a gene expressions in left ventricular tissues.