Involvement of a catalase gene in lignin catalysis and immune defense against pathogenic fungus in Coptotermes formosanus: a potential new target for termite control.

BACKGROUND: Detoxifying enzymes are likely involved in lignin feeding and immune defense mechanisms within termites, rendering them potential targets for biological control. However, investigations into the dual functionality of termite detoxification enzymes in vivo have not been documented. RESULTS: In this study, the complete cDNA of the catalase gene (Cfcat) derived from Coptotermes formosanus Shiraki was amplified. CFCAT comprises an open reading frame spanning 1527 bp, encoding a 508-amino acid sequence. The highest expression was observed in the epidermal tissues (including the fat body and hemolymph) followed by the foregut/salivary gland. Furthermore, we confirmed the catalase activity of the recombinant Cfcat protein. Using RNA interference (RNAi) technology, the importance of Cfcat in the lignin-feeding of C. formosanus was demonstrated, and the role of Cfcat in innate immunity was investigated. Survival assays showed that Cfcat RNAi significantly increased the susceptibility of C. formosanus to Metarhizium anisopliae. Irrespective of the infection status, Cfcat inhibition had a significant impact on multiple factors of humoral and intestinal immunity in C. formosanus. Notably, Cfcat RNAi exhibited a more pronounced immunosuppressive effect on humoral immunity than on intestinal immunity. CONCLUSION: Cfcat plays an important role in the regulation of innate immunity and lignin feeding in C. formosanus. Cfcat RNAi can weaken the immune response of termites against M. anisopliae, which may aid the biocontrol efficiency of M. anisopliae against C. formosanus. This study provides a theoretical basis and technical reference for the development of a novel biocontrol strategy targeting detoxifying enzymes of termites. © 2024 Society of Chemical Industry.

A 20-year shift in China's sewage sludge heavy metals and its feasibility of nutrient recovery in land use.

Recycling resources from wastewater is even more important for developing a more sustainable society. Disposing sewage sludge, which accumulates most pollutants and resources in sewage, is the main challenge in wastewater pollution control and resource utilization. Heavy metals (HMs) are the greatest constraint limiting the application of sewage sludge to land as a sustainable use of this material. We conducted a meta-analysis of the concentrations of HMs in Chinese sewage sludge by combining data from studies published from 2000 to 2019 (N = 8477). Over this period, the reported concentrations of HMs in sewage sludge declined in three stages (a fluctuating stage, a slight decrease stage, and a rapid and stable decrease stage). The results revealed that economic development and environmental policy implementation were the main factors mitigating HM pollution in sewage sludge in China. Moreover, if environmental regulations were strengthened and HM pollution-mitigation strategies were made consistent, such that the proportion of sewage sludge applied to land in China could be increased from 18.6% to 48.0% (the proportion applied to land in the United States), the ecosystem services analysis showed that huge ecological-economic benefits could be realized (3.1 billion Chinese Yuan) and the use of fertilizers could be substantially reduced (the use of nitrogen fertilizers by 8.5% and the use of phosphate fertilizers by 18.1%). This review shows that China should formulate a unified policy and interdepartmental committee for sustainable application of sewage sludge to land and wastewater resource recycling management.

Content categorization for memory retrieval: A method for evaluating design performance.

Designers search for memories and retrieve appropriate mental information during design brainstorming. The specific contents of retrieved memories can serve as stimuli for new ideas, or act as barriers to innovation. These contents can be divided into different categories, which are reflected in designers' creativities, and derived from individual lives and design experiences. Appropriate categorization of retrieved memory exemplars remains a fundamental research issue. This study tentatively divided retrieved memory exemplars into eight categories from brainstorming on the topic of library desk and chair design. A verification questionnaire was performed and validated the accuracy of categorization. The categorization result could be applied to design education in terms of understanding students' design performances and capabilities.

Genome-wide identification of Coptotermes formosanus immune genes and their potential roles in termite control.

In recent years, the use of microbes to control termites has attracted increasing attention. It was found that pathogenic bacteria, nematodes, and fungi effectively control termites under laboratory conditions. However, their effects have not been replicated in the field, and one reason for this is the complex immune defense mechanisms of termites, which are mainly regulated by immune genes. Therefore, altering the expression of immune genes may have a positive influence on the biocontrol efficacy of termites. Coptotermes formosanus Shiraki is one of the most economically important termite pests worldwide. Currently, the large-scale identification of immune genes in C. formosanus is primarily based on cDNA library or transcriptome data rather than at the genomic level. In this study, we identified the immune genes of C. formosanus according to genome-wide analysis. In addition, our transcriptome analysis showed that immune genes were significantly downregulated when C. formosanus was exposed to the fungus Metarhizium anisopliae or nematodes. Finally, we found that injecting dsRNA to inhibit three immune genes (CfPGRP-SC1, CfSCRB3, and CfHemocytin), which recognize infectious microbes, significantly increased the lethal effect of M. anisopliae on termites. These immune genes show great potential for C. formosanus management based on RNAi. These results also increase the number of known immune genes in C. formosanus which will provide a more comprehensive insight into the molecular basis of immunity in termites.

Empowering Quasi-solid Electrolyte with Smart Thermoresistance and Damage Repairability to Realize Safer Lithium Metal Batteries.

Thermal runaway, a complex chemical/electrochemical heat breakout process caused by complex abuse conditions, remains a big issue to significantly hinder further practical application of lithium batteries. Here we design and fabricate a smart thermoregulatory and self-healing gel electrolyte (TRSHGE) by cross-linking phase-transition chains to polymer networks through reversibly dynamic interactions while maintaining the desirable electrochemical performance. Impressively, on the one hand, the phase-transition chains with endothermic effects can efficiently accommodate the heat accumulation, enabling lithium batteries to work safely and normally even up to 80 °C. On the other hand, the dynamic covalent boronic eater bonds and hydrogen bonds endow the TRSHGE damage repairability upon mechanical shock even at the nail penetration test. Such smart electrolyte with thermoresistance and damage repairability indicates significant technological advancement toward the safe commercial application of lithium batteries, even great potential to develop other functional batteries beyond the lithium-based systems discussed herein.

Active Indoor Soundscape Design: A Case Study of Ceramic Passive Amplifiers.

Indoor soundscape research has developed rapidly in recent years, with the aim of improving the single indoor noise reduction method and people's acoustic comfort. However, practical solutions to promote the generation of positive indoor soundscapes are still insufficient. The purpose of this study was to explore the improvement effect of ceramic passive amplifiers on the indoor soundscape and the relationship between the improvement effect and different amplifier shapes. Objective sound pressure level (SPL) values and subjective soundscape perception were measured for 10 ceramic passive amplifiers based on the soundscape, mainly using a comparative method. Ten sample amplifiers were compared with the acoustic data of the original open-plan studio environment, and then with an electronic sound amplifier. The results show that ceramic passive amplifiers can improve the quality of the indoor soundscape by creating sound scenes with appropriate loudness. Regarding non-acoustic aspects, the shape and materials of ceramic passive amplifiers play a positive role in emotional guidance.

Differences in thinking flexibility between novices and experts based on eye tracking.

The influence of thinking flexibility on design is often underestimated by researchers in the field of design education. In this study, morphological analysis was used as a tool to develop design proposals and eye tracking technology was applied to track the attention. The feature of thinking activities in problem-solving between two groups (novice and expert) was analyzed by Heat map and Gaze plot in qualitative, and measured by indicators such as fixation and saccade in quantitative. Findings suggested that, i) Experts showed more fixation duration and fixation numbers in thinking activities, and the attention containing more AOIs was positively related to the rationality of the scheme. ii) Saccades with greater amplitude were more beneficial to the novelty of scheme. iii) Experts considered the information of each block in a balanced way, while novices tended to ignore unimportant blocks. These results will have a far-reaching impact on the development of designers' thinking and help novices to exercise creative thinking and produce high-quality designs.

Aging Behaviors of Phenol-Formaldehyde Resin Modified by Bio-Oil under Five Aging Conditions.

The bio-oil phenol-formaldehyde (BPF) resin, prepared by using bio-oil as a substitute for phenol, has similar bonding strength but lower price to phenol-formaldehyde (PF) resin. As a common adhesive for outdoor wood, the aging performance of BPF resin is particularly important. The variations in mass, bonding strength, microstructure, atomic composition, and chemical structure of BPF resin under five aging conditions (heat treatment, water immersion, UV exposure, hydrothermal treatment, and weatherometer treatment) were characterized by scanning electron microscope, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy, respectively. Compared under five aging conditions, after aging 960 h, the mass loss of plywood and film was largest under hydrothermal treatment; the bonding strength of plywood, the surface roughness, and O/C ratio of the resin film changed most obviously under weatherometer treatment. FT-IR analysis showed that the decreased degree of peak intensity on CH2 and C-O-C characteristic peaks of BPF resin were weaker under water immersion, hydrothermal treatment, and weatherometer treatment than those of PF resin. The comparison of data between BPF and PF resins after aging 960 h showed that adding bio-oil could obviously weaken the aging effect of water but slightly enhance that of heat. The results could provide a basis for the aging resistance modification of BPF resin.

A High Soldier Proportion Encouraged the Greater Antifungal Immunity in a Subterranean Termite.

Termites possess a mighty social immune system, serving as one of the key obstacles to controlling them biologically. However, the dynamic mechanism coordinating the social immunologic defense and caste distribution of the termites remains elusive. This study used the Coptotermes formosanus Shiraki and an entomopathogenic fungus as a host-pathogen system and experimentally manipulated a series of groups with different caste compositions of workers and soldiers. Then, the impact of demography on the behavior and innate immunity of termites was explored by analyzing the fungus susceptibility of the respective caste, efficiencies, and caste preferences of sanitary care, as well as the expression of the immune genes and phenoloxidase activity. Overall, to ensure the general health and survival of a group, the infected workers were found to sacrifice their survivorship for maintaining the soldier proportion of the group. If soldier proportion was limited within a threshold, both the survivorship of the workers and soldiers were not significantly affected by the infection. Correspondingly, the infected group with a higher proportion of soldiers stimulated the higher efficiency of a non-caste-biased sanitary care of the workers to the nestmate workers and soldiers. Moreover, the innate immunities of the infected workers were found to be more intensely upregulated in the group with higher soldier proportions. This suggested that the adjustable non-caste-biased sanitary care and innate immunity of the workers would contribute to the flexibility of the worker-soldier caste ratio in C. formosanus. This study, therefore, enhanced our understanding of the functional adaptation mechanism between pathogen-driven social immunity and the demography of the termites.

Citrinadin C, a new cytotoxic pentacyclic alkaloid from marine-derived fungus Penicillium citrinum.

A new cytotoxic pentacyclic alkaloid, citrinadin C (1), together with four known compounds (2-5), were isolated from deep-sea-derived fungus Penicillium citrinum. The structure of new compound 1 was elucidated by extensive 1D and 2D NMR and Mass spectroscopic data, and its absolute configuration was determined by CD spectrum. All the compounds were evaluated for their cytotoxic and antibacterial activities. Compound 1 showed cytotoxic activities against human liver cancer cell line MHCC97H, with IC50 value of 16.7 µM. Compound 4 displayed significant antibacterial activity against phytopathogen Xanthomonas campestris, with MIC value of 25 µM.

The trade-off between design fixation and quality: Physical objects or multiperspective pictures?

Physical objects and their pictures are two main kinds of design stimuli of creative activity, which can improve design quality but may induce design fixation. Previous studies are focused on the case where participants face a single picture, and their design stimulus may be incomplete as compared with the participants facing objects. To fully explore the influence of physical and pictorial examples on design novices, we investigated design fixation and design quality when they were provided with multiperspective pictures having information remarkably similar to physical objects. Specifically, two novice groups individually created their own designs after observing several examples by the way of the above two presentation modes. These designs were evaluated by two evaluators in terms of similarity, originality, and completeness. Statistical analysis showed that no significant difference was found in similarity and originality between the two groups, whereas the designs of the physical group outperformed those of the pictorial group in terms of completeness. This finding indicated that the two groups showed the same degree of design fixation, as multiperspective pictures presented most of the form information of the physical object. The results suggest that when instructing design novices, it is essential to control how to present design examples at different stages of the design process.

Using Participatory Design Methods to Explore Changes in the Self-Efficacy of Students with Visual Impairments After Playing Exergames.

Objective: To explore changes in task/scheduling self-efficacy in children with visual impairments after playing exergames, using the participatory design (PD) method to guide students with visual impairments to engage in the design and test of exergames. Materials and Methods: A pre-/post-test was used with two experimental groups (nine high school students with visual impairments aged 18-21, nine junior high school students with visual impairments aged 14-17). Data were analyzed by an independent-/paired-sample t-test to assess changes in task/scheduling self-efficacy of different groups after gameplay. Data of three dimensions (psychological emotion, physical activity, and social interaction) were collected through texts, participative observations, live notetaking, and video recordings. These dimensions provide opportunities for children with visual impairments to improve their self-efficacy. Results: Exergames helped children with visual impairments to improve their task and scheduling self-efficacy. It confirmed that exergames can be useful to promote their psychological emotion, enhance levels of positive physical activity, and increase social opportunities to improve self-efficacy. Conclusion: Participants of various ages who engaged in exergames reported an improvement in both task and scheduling self-efficacy in terms of psychological emotion, physical activity, and social interaction. The PD approach may be useful in the design of products for people with visual impairments and may ultimately be helpful in supporting the social and physical needs of people with disabilities.

Sequential activation of heterogeneous macrophage phenotypes is essential for biomaterials-induced bone regeneration.

Macrophage has been gradually recognized as a central regulator in tissue regeneration, and the study of how macrophage mediates biomaterials-induced bone regeneration through immunomodulatory pathway becomes popular. However, the current understanding on the roles of different macrophage phenotypes in regulating bone tissue regeneration remains controversial. In this study, we demonstrate that sequential infiltration of heterogeneous phenotypes of macrophages triggered by bio-metal ions effectively facilitates bone healing in bone defect. Indeed, M1 macrophages promote the recruitment and early commitment of osteogenic and angiogenic progenitors, while M2 macrophages and osteoclasts support the deposition and mineralization of the bone matrix, as well as the maturation of blood vessels. Moreover, we have identified a group of bone biomaterial-related multinucleated cells that behave similarly to M2 macrophages with wound-healing features rather than participate in the bone resorption cascade similarly to osteoclasts. Our study shows how sequential activation of macrophage-osteoclast lineage contribute to a highly orchestrated immune response in the bone tissue microenvironment around biomaterials to regulate the complex biological process of bone healing. Therefore, we believe that the temporal activation pattern of heterogeneous macrophage phenotypes should be considered when the next generation of biomaterials for bone regeneration is engineered.

Biomimicking Bone-Implant Interface Facilitates the Bioadaption of a New Degradable Magnesium Alloy to the Bone Tissue Microenvironment.

The most critical factor determining the success of biodegradable bone implants is the host tissue response, which greatly depends on their degradation behaviors. Here, a new magnesium-based implant, namely magnesium-silicon-calcium (Mg-0.2Si-1.0Ca) alloy, that coordinates its biodegradation along with the bone regenerative process via a self-assembled, multilayered bone-implant interface is designed. At first, its rapid biocorrosion contributes to a burst release of Mg2+ , leading to a pro-osteogenic immune microenvironment in bone. Meanwhile, with the simultaneous intervention of Ca and Si in the secondary phases of the new alloy, a hierarchical layered calcified matrix is rapidly formed at the degrading interface that favored the subsequent bone mineralization. In contrast, pure Mg or Mg-0.2Si alloy without the development of this interface at the beginning will unavoidably induce detrimental bone loss. Hence, it is believed this biomimicking interface justifies its bioadaptability in which it can modulate its degradation in vivo and accelerate bone mineralization.

Regulation of extracellular bioactive cations in bone tissue microenvironment induces favorable osteoimmune conditions to accelerate in situ bone regeneration.

The design of orthopedic biomaterials has gradually shifted from "immune-friendly" to "immunomodulatory," in which the biomaterials are able to modulate the inflammatory response via macrophage polarization in a local immune microenvironment that favors osteogenesis and implant-to-bone osseointegration. Despite the well-known effects of bioactive metallic ions on osteogenesis, how extracellular metallic ions manipulate immune cells in bone tissue microenvironments toward osteogenesis and subsequent bone formation has rarely been studied. Herein, we investigate the osteoimmunomodulatory effect of an extracellular bioactive cation (Mg2+) in the bone tissue microenvironment using custom-made poly lactic-co-glycolic acid (PLGA)/MgO-alendronate microspheres that endow controllable release of magnesium ions. The results suggest that the Mg2+-controlled tissue microenvironment can effectively induce macrophage polarization from the M0 to M2 phenotype via the enhancement of anti-inflammatory (IL-10) and pro-osteogenic (BMP-2 and TGF-ß1) cytokines production. It also generates a favorable osteoimmune microenvironment that facilitates the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells. The in vivo results further verify that a large amount of bony tissue, with comparable bone mineral density and mechanical properties, has been generated at an early post-surgical stage in rat intramedullary bone defect models. This study demonstrates that the concept of in situ immunomodulated osteogenesis can be realized in a controlled magnesium tissue microenvironment.

Degradation behaviors and in-vivo biocompatibility of a rare earth- and aluminum-free magnesium-based stent.

Biodegradable stents can provide scaffolding and anti-restenosis benefits in the short term and then gradually disappear over time to free the vessel, among which the Mg-based biodegradable metal stents have been prosperously developed. In the present study, a Mg-8.5Li (wt.%) alloy (RE- and Al-free) with high ductility (> 40%) was processed into mini-tubes, and further fabricated into finished stent through laser cutting and electropolishing. In-vitro degradation test was performed to evaluate the durability of this stent before and after balloon dilation. The influence of plastic deformation and residual stress (derived from the dilation process) on the degradation was checked with the assistance of finite element analysis. In addition, in-vivo degradation behaviors and biocompatibility of the stent were evaluated by performing implantation in iliac artery of minipigs. The balloon dilation process did not lead to deteriorated degradation, and this stent exhibited a decent degradation rate (0.15 mm/y) in vitro, but divergent result (> 0.6 mm/y) was found in vivo. The stent was almost completely degraded in 3 months, revealing an insufficient scaffolding time. Meanwhile, it did not induce possible thrombus, and it was tolerable by surrounding tissues in pigs. Besides, endothelial coverage in 1 month was achieved even under the severe degradation condition. In the end, the feasibility of this stent for treatment of benign vascular stenosis was generally discussed, and perspectives on future improvement of Mg-Li-based stents were proposed.

PDLLA-Zn-nitrided Fe bioresorbable scaffold with 53-µm-thick metallic struts and tunable multistage biodegradation function.

Balancing the biodegradability and mechanical integrity of a bioresorbable scaffold (BRS) with time after implantation to match the remodeling of the scaffolded blood vessel is important, but a key challenge in doing so remains. This study presents a novel intercalated structure of a metallic BRS by introducing a nanoscale Zn sacrificial layer between the nitrided Fe platform and the sirolimus-carrying poly(d,l-lactide) drug coating. The PDLLA-Zn-FeN BRS shows a multistage biodegradation behavior, maintaining mechanical integrity at the initial stage and exhibiting accelerated biodegradation at the subsequent stage in both rabbit abdominal aortas and human coronary arteries, where complete biodegradation was observed about 2 years after implantation. The presence of the nanoscale Zn sacrificial layer with an adjustable thickness also contributes to the tunable biodegradation of BRS and allows the reduction of the metallic strut thickness to 53 µm, with radial strength as strong as that of the current permanent drug-eluting stents.

Magnetic resonance (MR) safety and compatibility of a novel iron bioresorbable scaffold.

Fully bioresorbable scaffolds have been designed to overcome the limitations of traditional drug-eluting stents (DESs), which permanently cage the native vessel wall and pose possible complications. The ultrathin-strut designed sirolimus-eluting iron bioresorbable coronary scaffold system (IBS) shows comparable mechanical properties to traditional DESs and exhibits an adaptive degradation profile during target vessel healing, which makes it a promising candidate in all-comers patient population. For implanted medical devices, magnetic resonance (MR) imaging properties, including MR safety and compatibility, should be evaluated before its clinical use, especially for devices with intrinsic ferromagnetism. In this study, MR safety and compatibility of the IBS scaffold were evaluated based on a series of well-designed in-vitro, ex-vivo and in-vivo experiments, considering possible risks, including scaffold movement, over-heating, image artifact, and possible vessel injury, under typical MR condition. Traditional ASTM standards for MR safety and compatibility evaluation of intravascular devices were referred, but not only limited to that. The unique time-relevant MR properties of bioresorbable scaffolds were also discussed. Possible forces imposed on the scaffold during MR scanning and MR image artifacts gradually decreased along with scaffold degradation/absorption. Rigorous experiments designed based on a scientifically based rationale revealed that the IBS scaffold is MR conditional, though not MR compatible before complete absorption. The methodology used in the present study can give insight into the MR evaluation of magnetic scaffolds (bioresorbable) or stents (permanent).

Nitrogen transformation during pyrolysis of oilfield sludge with high polymer content.

Oilfield sludge is recognized as a hazardous solid waste in China because of its considerable hydrocarbon content and other toxic components. In this study, the nitrogen transformation during pyrolysis of typical oil sludge samples produced in the Daqing oilfield (the largest oilfield in China), was experimentally investigated. X-ray photoelectron spectroscopy (XPS) and thermos gravimetric (TG) were used in laboratory-scale experiments and batch pyrolysis experiments were conducted at 200-800 °C in a tubular reactor to obtain quantitative information on the change of nitrogen conversion in the char, tar, and gas fractions. The thermal decomposition of amine-N compounds contributed to NH3 release below 250 °C. However, the amine-N compounds in the char were converted to amine-N and imine-N compounds in the tar, and no obvious nitrogenous gases were found when the temperature increased from 250 to 500 °C. Between 500 and 800 °C, a large amount of NH3 and a small portion of HCN were found owing to the secondary cracking of tar and ring opening of heterocyclic-N compounds in the char. Therefore, NH3, HCN, and NO emissions can be reduced by accurate control of the pyrolysis temperature. A temperature of 400 °C was determined to be the optimal temperature for oilfield sludge pyrolysis, with 24.5% residual char and 43.0% tar produced. The results indicated that a suitable oilfield sludge pyrolysis temperature is helpful for reducing nitrogenous pollutant emissions, volume reduction, and energy recovery, which are beneficial for environmentally friendly production practices.