3D打印生物陶瓷人工骨支架的研究进展

生物陶瓷骨支架是继金属骨支架之后,较为理想的人工骨缺损修复材料。由于骨缺损形状各异,增材制造技术与生物陶瓷的结合,为骨支架的制备提供了个性化、定制化、成型复杂型体的可能。目前,陶瓷人工骨的增材制造技术展现出了巨大应用前景,但仍面临着力学强度不高、生物性功能单一的问题。为此,本文从提高骨支架的力学性能、拓展其生物性功能的角度出发,归纳分析了浆料/粉体体系、脱脂烧结工艺、材料复合、结构设计对支架力学性能的影响,从药物释放、治疗肿瘤两个方面总结了多生物功能支架的研究进展,并介绍了增材制造陶瓷骨支架在生物体内的研究现状。最后,对增材制造生物陶瓷人工骨的发展进行了展望。

Status of urban vegetation in Guangzhou City

According to a survey for the urban vegetation of Guangzhou, urban vegetation has a significantly difference from natural vegetation because of intense human impacts. The research was conducted in a synthetic survey for soil, species di-versity, roadside trees and ecological function of urban vegetation in Guangzhou City. The results showed that: (1) soil densi-ties of urban roadside and park forests were higher than mean density of natural forest soil. The pH values of soil in urban roadside were higher too, and the content of organic matter and the concentration of nitrogen were lower. (2) Species diversity of urban vegetation was lower. The most number of species was only 16 species in tree layers of urban forest. (3) Tree growth was limited by narrow space in high-density urban area, where the trees with defects and disorders were common. (4) Com-paring with mature natural forests, the productivity of urban vegetation was lower. The effect of urban vegetation on balance of carbon and oxygen were influenced by the low primary production of urban vegetation. Therefore, the growth condition for urban vegetation should be improved. Biodiversity, primary production and ecological function should be increased for urban vegetation in order to improve urban eco-environment.

Screening of Preprocessing Method of Biolog for Soil Microbial Community Functional Diversity

As one of the main methods of microbial community functional diversity measurement, biolog method was favored by many researchers for its simple oper- ation, high sensitivity, strong resolution and rich data. But the preprocessing meth- ods reported in the literatures were not the same. In order to screen the best pre- processing method, this paper took three typical treatments to explore the effect of different preprocessing methods on soil microbial community functional diversity. The results showed that, method B＇s overall trend of AWCD values was better than A and C＇s. Method B＇s microbial utilization of six carbon sources was higher, and the result was relatively stable. The Simpson index, Shannon richness index and Car- bon source utilization richness index of the two treatments were B〉C〉A, while the Mclntosh index and Shannon evenness were not very stable, but the difference of variance analysis was not significant, and the method B was always with a smallest variance. Method B＇s principal component analysis was better than A and C＇s. In a word, the method using 250 r/min shaking for 30 minutes and cultivating at 28 ℃ was the best one, because it was simple, convenient, and with good repeatability.

The Influence of Plant Diversity and Functional Composition on Ecosystem Stability of Four Stipa Communities in the Inner Mongolia Plateau

The main purpose of this study was to examine the effects of plant species diversity and functional composition (the identity of the plant functional groups) on ecosystem stability of Stipa, communities in the Inner Mongolia Plateau. The research work was based on a 12-year study (from 1984 to 1995) of species abundance, diversity, and primary productivity of four Stipa communities, i.e. S. baicalensis Roshev., S. grandis P. Smirn., S, krylovii Roshev., and S. klemenzii Roshev. respectively. The Shnnon-Wiener index was used as a measurement of plant diversity, while functional composition was used to differentiate the functional groups that were included in the communities. The plant species of four Stipa communities were classified into functional groups based on the differences in life forms and ecological groups, which influence their performance in resource requirements, seasonality of growth, tolerance to water stress, and life history. Plant species were classified into five functional groups based on their differences in life form, shrubs and half shrubs, perennial bunch grasses, perennial rhizome grasses, forbs, annuals and biennials. Based on their differences in water requirement these species were classified into four functional groups: xerads, intermediate xerads, intermediate mesophytes, and mesophytes. The results showed: 1) Plant species diversity stabilized ecosystem processes. Shannon-Wiener index were 2.401 4, 2.172 0, 1.624 8, 0.354 3 from S. baicalensis community to S. grandis, S. krylovii and S. klemenzii community, respectively. The dynamics of the aboveground net primary productivity (ANPP) for a 12-year's period showed a reverse pattern, the coefficients of variation of the four communities were 21.94%, 20.63%, 29.21% and 39.72% respectively. 2) The Life form functional group component of diversity was a greater determinant of the ecosystem processes than the species component of diversity. The effects of perennial bunch grasses, perennial rhizome grasses and forbs on community stability were highly significant. 3) The ecological group component of diversity was also a great determinant of the ecosystem processes. The effects of xerads, intermediate xerads, and mesophytes on community stability were also very strong.

Research on Stoichiometry of Early-spring Herbs Functional Group in the Subtropical Artificial Wetland

[Objective]The aim was to carry out stoichiometry on the early-spring herbs functional group in subtropical artificial wetland.[Method]UV-Vis spectrophotometer was used for the determination of nitrate-nitrogen,ammonium nitrogen and phosphorus concentrations.Potassium persulfate absorptiometry was used for the measurement of total N content,while the flame photometer was used to detect the potassium and sodium concentration in plants.All the nutrient determination of plant samples were repeated for four times.[Result]The four nutrient concentrations in almost all samples were in the normal range of natural plant nutrition concentrations;in early-spring herbs functional groups,different species showed diversity on the nutrient concentrations;plant height had no significant effect on the nutrient concentrations in plants;the nutrient concentrations of non-grass group plants were higher than that of grass group plants;the nutrient concentrations of the annual herb were higher than that of perennial herbs.[Conclusion]The study had provided basis for the understanding of the effects of changes in nutritional conditions on species diversity,community structure and succession of the system.

Evaluation of Ecological Effectiveness of Protected Areas in Northwest China

Protected areas(PAs) have experienced explosive growth in Northwest China over the last three decades, but their effectiveness in representing regional ecological system diversity has not attracted considerable attention. Low effectiveness would exacerbate the conservation-development conflicts, particularly those that arise as a result of the Great Western Development Strategy(GWDS). Thus, an assessment of the effectiveness of the PA network has become quite important. We proposed natural vegetation communities to represent regional ecological system diversities, and proposed Global 200 Priority Ecoregions, Important Bird Areas, and ecosystem function regions to represent important conservation areas. To determine their effectiveness, we studied the extent to which ecological system diversities and important conservation areas are represented by the existing 96 PAs. Our results indicated that the total coverage of vegetation communities in PAs in Northwest China is not sufficiently comprehensive. As the PA system has expanded, the growth in the total area of the PAs has been greater than that of their vegetation community richness. While most of the important conservation areas are covered by PAs, some regions have not yet reached the 10% threshold; further, PAs are distributed unevenly and conservation gaps remain in the region. Therefore, these regions should receive more attention when planning new PAs. It is vital that more biodiversity datasets and assessment of ecosystem function regions are integrated in order to provide a basis for the government to formulate appropriate protection and development strategies.

Interfacial-interaction-induced fabrication of biomass-derived porous carbon with enhanced intrinsic active sites

Carbon catalysis is an attractive metal-free catalytic transformation,and its performance is significantly dependent on the number of accessible active sites.However,owing to the inherent stability of the C-C linkage,only limited active sites at the edge defects of the basal plane can be obtained even after a harsh oxidation treatment.In this study,the concept of interfacial interactions was adopted to propose an efficient strategy to develop highly active carbon catalysts.The alumina/carbon interface formed in situ acted as a cradle for the generation of oxygen-containing functional groups.In the absence of oxidation treatment,the concentration of oxygen-containing functional groups and the specific surface area can reach 1.27 mmol·g^(-1) and 2340 m^(2)·g^(-1),respectively,which are significantly higher than those of carbon prepared by traditional hard template methods.This active carbon shows a significant enhancement in catalytic performance in the oxidative coupling of amine to imine,about 22-fold higher than that of a well-known graphite oxide catalyst.Such interfacial interaction strategies are based on sustainable carbon sources and can effectively tune the porous structure of carbon in the micro-and meso-ranges.This conceptual finding offers new opportunities for the development of high-performance carbon-based metal-free catalysts.

Functional genomic approach to the study of biodiversitywithin Trichoderma

Trichoderma is a fungal genus of great and demonstrable biotechnological value, but its genome is poorly surveyed compared with other model microorganisms. Due to their ubiquity and rapid substrate colonization, Trichoderma species have been widely used as biocontrol organisms for agriculture, and their enzyme systems are widely used in industry. Therefore, there is a clear interest to explore beyond the phenotype to exploit the underlying genetic systems using functional genomics tools. The great diversity of species within the Trichoderma genus, the absence of optimized systems for its exploration, and the great variety of genes expressed under a wide range of ambient conditions are the main challenges to consider when starting a comprehensive functional genomics study. An initial project started by three Spanish groups has been extended into the project TRICHOEST, funded by the EU (FP5, QLRT-2001-02032) to target the transcriptome analysis of selected Trichoderma strains with biocontrol potential, in conditions related to antagonism, nutrient stress and plant interactions. Once specific conditions were defined, cDNA libraries were produced and used for EST sequencing. Nine strains from seven Trichoderma species have been considered in this study and an important amount of gene sequence data has been generated, analyzed and used to compare the gene expression in different strains. In parallel to sequencing, genomic expression studies were carried out by means of macro-arrays to identify genes expressed in specific conditions. In silico analysis of DNA sequencing data together with macro-array expression results have lead to a selection based on the potential use of the gene sequences. The selected clone sequences were completed and cloned in appropriate vectors to initiate functional analysis by means of expression studies in homologous and heterologous systems.

Recent Advances in Colloidal Lubricant Detergents

Overbased lubricant detergents are important components in lubricating oil. Recently, a lot of papers about the synthesis mechanism, colloidal structure, acid neutralization and antifrictiorL properties of overbased detergents have been published with the development of experimental techniques, which can help us better understand the process of preparation and application of overbased detergents and propound new strategies for improving various performances of overbased detergents. In the future, the synthesis of environmentally friendly and multi-functional lubricant detergent using biodegradable vegetable oil instead of mineral oil as raw materials will be a primary objective for the colloidal lubricant detergent industry.This paper mainly presents the latest advances in the investigation of colloidal lubricant detergents.

Comprehensive Study on Degradation and Management of Baiyangdian Lake in North China

Baiyangdian lake as the kidney of north China plays a huge ecological function, bringing about environmental and economic benefits as well as aesthetics value. It takes the role of adjusting climate, slowing flood, storing water, alleviating drought, maintaining the water body＇s purifying capacity, protecting biodiversity as well as vegetating fish and reed, developing eco-tourism etc.. Now it is degenerating under the pressure from both physical and human society. This paper studied the process, condition and root causes of the lake shrinking, pollution, biodiversity losing and disasters. Adaptation and integrative management strategies are also put forward for maintaining the ecological function and sustainable development.

The Study of Diversities of Marine Microbes in China

The oceans account for 71% of the Earth’s surface and are rich in the most advantageous and characteristic resources of marine microbes. The research on diversity is the key point for exploring and exploiting marine microbial resources. Giving attention to species diversity and genetic diversity of marine microbes, discovering novel metabolites with multiple functions, revealing key secondary metabolic process and the main regulation mechanisms in marine microbes, and developing a new technology of biosynthesis, are the important foundation for discovering innovative drugs and developing functional products with characteristics. The present paper has reviewed the recent advances in the four research areas of marine microbial species diversity, genetic diversity, chemical diversity and metabolic diversity in China.

Using the response-effect trait framework to disentangle the effects of environmental change on the ecosystem services

Functional traits play a vital role in mediating the responses of ecosystem services to environmental changes and in predicting the functioning of the ecosystem.However,the connection between functional traits and ecosystem services has become increasingly intricate due to climate change and human activities for degraded ecosystems.To investigate this relationship,we selected 27 sampling sites in the Yanhe River Basin of the Chinese Loess Plateau,each containing two types of vegetation ecosystems:natural vegetation and artificial vegetation ecosystems.At each sampling site,we measured ecosystem services and calculated the composition index of community traits.We established a response–effect trait framework that included environmental factors such as climate,elevation and human activities.Our results showed that leaf tissue density(LTD)was the overlapping response and effect trait when responding to climate change.LTD is positively correlated with mean annual temperature and negatively correlated with supporting services.Under the influence of human activities,leaf nitrogen content and leaf dry matter content were carriers of environmental change.Comparing the two vegetation ecosystems,the relationship between functional traits and ecosystem services showed divergent patterns,indicating that human activities increased the uncertainty of the relationship between functional traits and ecosystem services.Trait-based ecology holds promise for enhancing predictions of ecosystem services responses to environmental changes.However,the predictive ability is influenced by the complexity of environmental changes.In conclusion,our study highlights the importance of understanding the complex connection between functional traits and ecosystem services in response to climate changes and human activities.

Riparian plant community structure and assembly processes differed by variations in riverbank curvatures:implications for restoring habitats along the Three Gorges Reservoir

A meandering riverbank plays a vital role in maintaining natural river ecosystems,providing habitats for riparian vegetation.However,dams have significantly altered riverbank shapes.To restore the riparian ecosystems,it is imperative to understand how different riverbank curvatures influence them.This study aims to uncover the ecological impacts of riverbank curvature on the structure and assembly process of plant communities in the riparian zone of the Yangtze River,regulated by the Three Gorges Dam(TGD)in China.We categorized the riparian zones into four types:cove,lobe,wavy and linear shapes.We documented the composition and diversity of riparian plant communities.Our findings revealed that wavy and cove riverbanks exhibited greater species diversity(with Shannon–Wiener diversity index values 1.5×higher)compared to communities along linear riverbanks.Furthermore,the analysis of functional traits indicated that wavy riverbanks promoted the differentiation of plant functional traits,thus enhancing ecosystem functions,with functional dispersion index(FDis)values 1.3 times higher than those of linear riverbanks.Significant variations in the assembly of riparian communities were also observed among different riverbanks,with standardized effect size(SES)values indicating a higher degree of niche differentiation in cove riverbanks(SES=0.4)compared to linear riverbanks(SES=–0.6).These results highlight the ecological importance of diverse riverbank curvatures in influencing the diversity,structure and assembly of riparian communities along the waterway.In summary,this study underscores the necessity of maintaining or restoring various natural morphological curvatures when rehabilitating riparian communities along rivers impacted by human activities.

A National Key R&D Program: Technologies and Guidelines for Monitoring Ecological Quality of Terrestrial Ecosystems in China

Ecological quality is defined as the stability, adaptability and resilience of an ecosystem. Monitoring and assessing ecological quality are important bases for China’s ecological civilization construction. The national key research and development program "Technologies and guidelines for monitoring ecological quality of terrestrial ecosystems in China", launched in July 2017, includes plans to study the observation technologies and provide guidelines on the ecological in-situ observation, the regional biodiversity and ecosystem function monitoring and its applications, all of which contribute to national ecological quality assessment. A year after its implementation,some important progress has been achieved, such as building the indicator system for comprehensive monitoring of ecological quality and improvement of the methods, mass data transmission, infrared camera-based monitoring of biodiversity, multi-angle automatic spectral observation systems, and unmanned aerial vehicle(UAV) based desert monitoring. We have organized this special issue and attempted to introduce the monitoring techniques and assessment methods on ecological quality from different perspectives in order to further promote the development of ecology and its observation methods.

Variation in the methods leads to variation in the interpretation of biodiversity-ecosystem multifunctionality relationships

Aims Biodiversity is often positively related to the capacity of an ecosystem to provide multiple functions simultaneously(i.e.multifunctionality).However,there is some controversy over whether biodiversity–multifunctionality relationships depend on the number of functions considered.Particularly,investigators have documented contrasting findings that the effects of biodiversity on ecosystem multifunctionality do not change or increase with the number of ecosystem functions.Here,we provide some clarity on this issue by examining the statistical underpinnings of different multifunctionality metrics.Methods We used simulations and data from a variety of empirical studies conducted across spatial scales(from local to global)and biomes(temperate and alpine grasslands,forests and drylands).We revisited three methods to quantify multifunctionality including the averaging approach,summing approach and threshold-based approach.Important Findings Biodiversity–multifunctionality relationships either did not change or increased as more functions were considered.These results were best explained by the statistical underpinnings of the averaging and summing multifunctionality metrics.Specifically,by averaging the individual ecosystem functions,the biodiversity–multifunctionality relationships equal the population mean of biodiversity-single function relationships,and thus will not change with the number of functions.Likewise,by summing the individual ecosystem functions,the strength of biodiversity–multifunctionality relationships increases as the number of functions increased.We proposed a scaling standardization method by converting the averaging or summing metrics into a scaling metric,which would make comparisons among different biodiversity studies.In addition,we showed that the range-relevant standardization can be applied to the threshold-based approach by solving for the mathematical artefact of the approach(i.e.the effects of biodiversity may artificially increase with the number of functions considered).Our study highlights different approaches yield different results and that it is essential to develop an understanding of the statistical underpinnings of different approaches.The standardization methods provide a prospective way of comparing biodiversity–multifunctionality relationships across studies.

Multi-biomarker strategy for prediction of myocardial dysfunction and mortality in sepsis

Objective:The present study was to evaluate the feasibility of using the multi-biomarker strategy for the prediction of sepsis-induced myocardial dysfunction(SIMD)and mortality in septic patients.Methods:Brain natriuretic peptide(BNP),cardiac troponin I(cTnI),and heart-type fatty acid-binding protein(h-FABP)in 147 septic patients were assayed within 6 h after admission.We also determined the plasma levels of myeloperoxidase(MPO)and pregnancyassociated plasma protein-A(PAPP-A).The receiver operating characteristic(ROC)curve was used to assess the best cutoff values of various single-biomarkers for the diagnosis of SIMD and the prediction of mortality.Also,the ROC curve,net reclassification improvement(NRI),and integrated discrimination improvement(IDI)indices were used to evaluate the feasibility of using multi-biomarkers to predict SIMD and mortality.Results:Our statistics revealed that only h-FABP independently predicted SIMD(P<0.05).The addition of MPO and cTnI to h-FABP for SIMD prediction provided an NRI of 18.7%(P=0.025)and IDI of 3.3%(P=0.033).However,the addition of MPO or cTnI to h-FABP did not significantly improve the predictive ability of h-FABP to SIMD,as evidenced by the area under the curve(AUC),NRI,and IDI(all P>0.05).A history of shock and MPO were independent predictors of mortality in septic patients(both P<0.05).The addition of PAPP-A and h-FABP to MPO resulted in a mortality prediction with NRI of 25.5%(P=0.013)and IDI of 2.9%(P=0.045).However,this study revealed that the addition of h-FABP or PAPP-A to MPO did not significantly improve the ability to predict mortality,as evidenced by the AUC,NRI,and IDI(all P>0.05).Conclusions:The findings of this study indicate that a sensitive and specific strategy for early diagnosis of SIMD and mortality prediction in sepsis should incorporate three biomarkers.

A buried Neolithic paddy soil reveals loss of microbial functional diversity after modern rice cultivation

It has been documented that human activities are causing the rapid loss of taxonomic, phylogenetic, genetic and functional diversity in soils. However, it remains unclear how modern intensive rice cultivation impacts the soil microbiome and its functionality. Here we examined the microbial composition and function differences between a buried Neolithic paddy soil and an adjacent, currently-cultivated paddy soil using high throughput metagenomics technologies. Our results showed that the currently cultivated soil contained about 10-fold more microbial biomass than the buried one. Analyses based on both 16S rRNA genes and functional gene array showed that the currently cultivated soil had significantly higher phylogenetic diversity, but less functional diversity than the buried Neolithic one. The community structures were significantly different between modern and ancient soils, with functional structure shifting towards accelerated organic carbon （C） degradation and nitrogen （N） transfor- mation in the modem soils. This study implies that, modern intensive rice cultivation has substantially altered soil microbial functional structure, leading to functional homogenization and the promotion of soil ecological functions related to the acceleration of nutrient cycling which is necessary for high crop yields.

Advancements in three-dimensional titanium alloy mesh scaffolds fabricated by electron beam melting for biomedical devices: mechanical and biological aspects

We elucidate here the process-structure-property relationships in three-dimensional（3 D） implantable titanium alloy biomaterials processed by electron beam melting（EBM） that is based on the principle of additive manufacturing. The conventional methods for processing of biomedical devices including freeze casting and sintering are limited because of the difficulties in adaptation at the host site and difference in the micro/macrostructure, mechanical, and physical properties with the host tissue. In this regard, EBM has a unique advantage of processing patient-specific complex designs, which can be either obtained from the computed tomography（CT） scan of the defect site or through a computeraided design（CAD） program. This review introduces and summarizes the evolution and underlying reasons that have motivated 3 D printing of scaffolds for tissue regeneration.The overview comprises of two parts for obtaining ultimate functionalities. The first part focuses on obtaining the ultimate functionalities in terms of mechanical properties of 3 D titanium alloy scaffolds fabricated by EBM with different characteristics based on design, unit cell, processing parameters, scan speed, porosity, and heat treatment. The second part focuses on the advancement of enhancing biological responses of these 3 D scaffolds and the influence of surface modification on cell-material interactions. The overview concludes with a discussion on the clinical trials of these 3 D porous scaffolds illustrating their potential in meeting the current needs of the biomedical industry.

Applications and challenges for single-bacteria analysis by flow cytometry

Flow cytometry(FCM)is a powerful technique for single-bacteria analysis via simultaneous light-scattering and fluorescence measurements.By offering high-throughput,quantitative,and multiparameter analysis at the single-cell level,FCM has gained an increased popularity in microbiological research,food safety monitoring,water quality control,and clinical diagnosis.Here we will review the recent applications of flow cytometry in areas such as(1)total bacterial cell count,(2)bacterial viability analysis,(3)specific bacterial detection and identification,(4)characterization of physiological changes under environmental perturbations,and(5)biological function studies.Nevertheless,despite these widespread applications,challenges still remain for the detection of small sizes of bacteria and biochemical features that cannot be brightly stained via fluorescence.Recent improvement in FCM instrumentation will be discussed,and particularly the development of high sensitivity flow cytometry for advanced analysis of single bacterial cells will be highlighted.

Oligonucleotide delivery by chitosan-functionalized porous silicon nanoparticles

Porous silicon nanoparficles （pSiNPs） are a promising nanocarrier system for drug delivery owing to their biocompatibility, biodegradability, and non-inflammatory nature. Here, we investigate the fabrication and characterization of thermally hydrocarbonized pSiNPs （THCpSiNPs） and chitosan-coated THCpSiNPs for therapeutic oligonucleotide delivery. Chitosan coating after oligonucleotide loading significantly improves sustained oligonucleotide release and suppresses burst release effects. Moreover, cellular uptake, endocytosis, and cytotoxicity of oligonucleotide-loaded THCpSiNPs have been evaluated in vitro. Standard cell viability assays demonstrate that cells incubated with the NPs at a concentration of 0.1 mg/mL are 95% viable. In addition, chitosan coating significantly enhances the uptake of oligonucleotide-loaded THCpSiNPs across the cell membrane. Moreover, histopathological analysis of liver, kidney, spleen, and skin tissue collected from mice receiving NPs further demonstrates the biocompatible and non-inflammatory properties of the NPs as a gene delivery vehicle for intravenous and subcutaneous administration in vivo. Taken together, these results suggest that THCpSiNPs provide a versatile platform that could be used as efficient vehicles for the intracellular delivery of oligonucleotides for gene therapy.