Hepatocellular carcinoma (HCC) is the most common malignancy of the liver, posing a significant threat to public health. Although liver transplantation (LT) is an effective treatment for HCC, ischemia-reperfusion (I/R) injury, transplant rejection, and complications after LT can greatly reduce its effectiveness. In recent years, transplant oncology has come into being, a comprehensive discipline formed by the intersection and integration of surgery, oncology, immunology, and other related disciplines. Gut microbiota, an emerging field of research, also plays a crucial role. Through the microbiome-gut-liver axis, the gut microbiota has an impact on the onset and progression of HCC as well as LT. This review summarizes the mechanisms by which the gut microbiota affects HCC and its bidirectional interactions with chronic liver disease that can develop into HCC as well as the diagnostic and prognostic value of the gut microbiota in HCC. In addition, gut microbiota alterations after LT were reviewed, and the relationship between the gut microbiota and liver I/R injury, the efficacy of immunosuppressive drugs used, and complications after LT were discussed. In the era of LT oncology, the role of the gut microbiota in HCC and LT should be emphasized, which can provide new insights into the management of HCC and LT via gut microbiota modulation.
Disturbed cholesterol and glucose homeostasis play crucial roles in the development of various diseases such as cardiovascular diseases, cerebrovascular diseases, central nervous system diseases, and cancer. An increasing number of studies have shown that excessive body fat accumulation is associated with type 2 diabetes or insulin resistance in a vicious cycle. This vicious cycle promotes the occurrence and development of the aforementioned diseases. Therefore, stabilizing the blood lipids and blood glucose of patients is the predominant strategy for improving the symptoms of patients with cardiovascular, cerebrovascular, and central nervous system diseases. Traditional Chinese medicine, mainly Chinese herbal medicine (CHM), has a history of more than 2000 years in China, which has established a unique theory and accumulated a great wealth of clinical experience. Moreover, CHM has been widely used in China and other countries for the treatment of cardiovascular and cerebrovascular diseases, with the advantages of preventing and curing hyperlipidemia, diabetes, hypertension, and other diseases. However, the use of CHM in Western countries remains rather limited, partly because of the incomplete understanding of multiple complex components and uncertain pharmacological mechanisms. Herein, we review and discuss the benefits, molecular mechanisms, and clinical research progress of bioactive components of CHM and their preparations as therapeutics for hyperlipidemia and hyperglycemia.
The transplantation of full-thickness skin grafts (FTSGs) is important for reconstructing skin barrier and promoting wound healing. Sufficient oxygen supply is closely related to the success of skin grafting. However, full-thickness oxygen delivery is limited by the poor oxygen permeability of skin. Oxygen-releasing sutures (O2 sutures) were developed to facilitate oxygen penetration through full-thickness skin. The O2 sutures delivered 100 times more oxygen than topical gaseous oxygen therapy at a 15 mm depth in the skin model. Under extreme hypoxia (< 0.5% O2, v/v), O2 sutures could also promote endothelial cell proliferation. After the transplantation of FTSGs in mice, O2 sutures accelerated blood re-perfusion and increased the survival area of the skin graft. It is expected that O2 sutures will be adopted in clinical applications to increase the success rate of full-thickness skin transplantation.
Brucellosis, caused by Brucella, is one of the most common zoonosis. However, there is still no vaccine for human use. Although some live attenuated vaccines have been approved for animals, the protection effect is not ideal. In this study, we developed a dual-antigen nanoconjugate vaccine containing both polysaccharide and protein antigens against Brucella. First, the antigenic polysaccharide was covalently coupled to the outer membrane protein Omp19 using protein glycan coupling technology, and then it was successfully loaded on a nano-carrier through the SpyTag/SpyCatcher system. After confirming the efficient immune activation and safety performance of the dual-antigen nanoconjugate vaccine, the potent serum antibody response against the two antigens and remarkable protective effect in non-lethal and lethal Brucella infection models were further demonstrated through different routes of administration. These results indicated that the dual-antigen nanoconjugate vaccine enhanced both T helper 1 cell (Th1) and Th2 immune responses and protected mice from Brucella infection. Furthermore, we found that this protective effect was maintained for at least 18 weeks. To our knowledge, this is the first Brucella vaccine bearing diverse antigens, including a protein and polysaccharide, on a single nanoparticle. Thus, we also present an attractive technology for co-delivery of different types of antigens using a strategy applicable to other vaccines against infectious diseases.
Research on microecology has been carried out with broad perspectives in recent decades, which has enabled a better understanding of the gut microbiota and its roles in human health and disease. It is of great significance to routinely acquire the status of the human gut microbiota; however, there is no method to evaluate the gut microbiome through small amounts of fecal microbes. In this study, we found ten predominant groups of gut bacteria that characterized the whole microbiome in the human gut from a large-sample Chinese cohort, constructed a real-time quantitative polymerase chain reaction (qPCR) method and developed a set of analytical approaches to detect these ten groups of predominant gut bacterial species with great maneuverability, efficiency, and quantitative features. Reference ranges for the ten predominant gut bacterial groups were established, and we found that the concentration and pairwise ratios of the ten predominant gut bacterial groups varied with age, indicating gut microbial dysbiosis. By comparing the detection results of liver cirrhosis (LC) patients with those of healthy control subjects, differences were then analyzed, and a classification model for the two groups was built by machine learning. Among the six established classification models, the model established by using the random forest algorithm achieved the highest area under the curve (AUC) value and sensitivity for predicting LC. This research enables easy, rapid, stable, and reliable testing and evaluation of the balance of the gut microbiota in the human body, which may contribute to clinical work.
The rapid cooling of a metallic liquid (ML) results in short-range order (SRO) among the atomic arrangements and a disordered structure in the resulting metallic glass (MG). These phenomena cause various possible features in the microscopic structure of the MG, presenting a puzzle about the nature of the MGs’ microscopic structure beyond SRO. In this study, the nanoscale density gradient (NDG) originating from a sequential arrangement of clusters with different atomic packing densities (APDs), representing the medium-range structural heterogeneity in Zr60Cu30Al10 MG, was characterized using electron tomography (ET) combined with image simulations based on structure modeling. The coarse polyhedrons with distinct facets identified in the three-dimensional images coincide with icosahedron-like clusters and represent the spatial positions of clusters with high APDs. Rearrangements of the different clusters according to descending APD order in the glass-forming process are responsible for the NDG that stabilizes both the supercooled ML and the amorphous states and acts as a hidden rule in the transition from ML to MG.
DNA molecules are green materials with great potential for high-density and long-term data storage. However, the current data-writing process of DNA data storage via DNA synthesis suffers from high costs and the production of hazards, limiting its practical applications. Here, we developed a DNA movable-type storage system that can utilize DNA fragments pre-produced by cell factories for data writing. In this system, these pre-generated DNA fragments, referred to herein as “DNA movable types,” are used as basic writing units in a repetitive way. The process of data writing is achieved by the rapid assembly of these DNA movable types, thereby avoiding the costly and environmentally hazardous process of de novo DNA synthesis. With this system, we successfully encoded 24 bytes of digital information in DNA and read it back accurately by means of high-throughput sequencing and decoding, thereby demonstrating the feasibility of this system. Through its repetitive usage and biological assembly of DNA movable-type fragments, this system exhibits excellent potential for writing cost reduction, opening up a novel route toward an economical and sustainable digital data-storage technology.
The gut microbiota plays an important role in host health and disease. Our understanding of the fish microbiota lags far behind our knowledge of that of humans and other mammals. Nevertheless, research has highlighted the importance of the microbiota in the health, performance, and various physiological functions of fish. The microbiota has been studied in various fish species, including model animals, economic fish, and wild fish species. The composition of the fish microbiota depends on host selection, diet, and environmental factors. The intestinal microbiota affects the nutritional metabolism, immunity, and disease resistance of the fish host, while the host regulates the intestinal microbiota in a reciprocal way through both immune and non-immune factors. Improved and novel gnotobiotic fish models have been developed, which are important for the mechanistic study of host-microbiota interactions in fish. In this review, we discuss recent progress in fish microbiota research. We describe various aspects of this research, including both studies on fish microbiota variations and fundamental research extending our knowledge of host-microbiota interaction in fish. Perspectives on how fish microbiota research may benefit fish health and industrial sustainability are also discussed.
As a major solution to climate change, the low-carbon transition of energy systems has received growing attention in the past decade. This paper presents a bibliometric review of the literature on the low-carbon transition of energy systems from an engineering management perspective. First, the definition and boundaries of the energy system transition are clarified, covering transformation of the energy structure, decarbonization of fossil fuel utilization, and improvement in energy efficiency. Second, a systematic search of the related literature and a bibliometric analysis are conducted to reveal the research trends. It is found that the number of related publications has been growing exponentially during the past decade, with researchers from China, the United Kingdom, the United States, Germany, and the Netherlands comprising the majority of authors. Related studies with interdisciplinary characteristics appear in journals focusing on energy engineering, environmental science, and social science related to energy issues. Four major research themes are identified by clustering the existing literature: ① low-carbon transition pathways with different spatiotemporal scales and transition constraints; ② low-carbon technology diffusion with a focus on renewable energy technologies, pollution control technologies, and other technologies facilitating the energy transition; ③ infrastructure network planning for energy systems covering various sectors and regions; and ④ transition-driving mechanisms from the political, economic, social, and natural perspectives. These four topics play distinct but mutually supportive roles in facilitating the low-carbon transition of energy systems, and require more in-depth research on designing resilient low-carbon transition pathways with coordinated goals, promoting low-carbon technologies with cost-effective and reliable infrastructure network deployment, and balancing multi-level risks in various systems. Finally, business models, nongovernment actors, energy justice, deep decarbonization, and zero-energy buildings are recognized as emerging hot topics.
Microplastics (MPs) are important exempla of the Anthropocene and are exerting an increasing impact on Earth’s carbon cycle. The huge imbalance between the MPs floating on the marine surface and those that are estimated to have been introduced into the ocean necessitates a detailed assessment of marine MP sinks. Here, we demonstrate that cold seep sediments, which are characterized by methane fluid seepage and a chemosynthetic ecosystem, effectively capture and accommodate small-scale (< 100 μm) MPs, with 16 types of MPs being detected. The abundance of MPs in the surface of the sediment is higher in methane-seepage locations than in non-seepage areas. Methane seepage is beneficial to the accumulation, fragmentation, increased diversity, and aging of MPs. In turn, the rough surfaces of MPs contribute to the sequestration of the electron acceptor ferric oxide, which is associated with the anaerobic oxidation of methane (AOM). The efficiency of the AOM determines whether the seeping methane (which has a greenhouse effect 83 times greater than that of CO2 over a 20-year period) can enter the atmosphere, which is important to the global methane cycle, since the deep-sea environment is regarded as the largest methane reservoir associated with natural gas hydrates.
Tetrasphaera have been recently identified based on the 16S ribosomal RNA (rRNA) gene as among the most abundant polyphosphate-accumulating organisms (PAOs) in global full-scale wastewater treatment plants (WWTPs) with enhanced biological phosphorus removal (EBPR). However, it is unclear how Tetrasphaera PAOs are selectively enriched in the context of the EBPR microbiome. In this study, an EBPR microbiome enriched with Tetrasphaera (accounting for 40% of 16S sequences on day 113) was built using a top-down design approach featuring multicarbon sources and a low dosage of allylthiourea. The microbiome showed enhanced nutrient removal (phosphorus removal ∼85% and nitrogen removal ∼80%) and increased phosphorus recovery (up to 23.2 times) compared with the seeding activated sludge from a local full-scale WWTP. The supply of 1 mg·L−1 allylthiourea promoted the coselection of Tetrasphaera PAOs and Microlunatus PAOs and sharply reduced the relative abundance of both ammonia oxidizer Nitrosomonas and putative competitors Brevundimonas and Paracoccus, facilitating the establishment of the EBPR microbiome. Based on 16S rRNA gene analysis, a putative novel PAO species, EBPR-ASV0001, was identified with Tetrasphaera japonica as its closest relative. This study provides new knowledge on the establishment of a Tetrasphaera-enriched microbiome facilitated by allylthiourea, which can be further exploited to guide future process upgrading and optimization to achieve and/or enhance simultaneous biological phosphorus and nitrogen removal from high-strength wastewater.
The degree of polymer chain orientation is a key structural parameter that determines the mechanical and physical properties of fibers. However, understanding and significantly tuning the orientation of fiber macromolecular chains remain elusive. Herein, we propose a novel electrospinning technique that can efficiently modulate molecular chain orientation by controlling the electric field. In contrast to the typical electrospinning method, this technique can piecewise control the electric field by applying high voltage to the metal ring instead of the needle. Benefiting from this change, a new electric field distribution can be realized, leading to a non-monotonic change in the drafting force. As a result, the macromolecular chain orientation of polyethylene oxide (PEO) nanofibers was significantly improved with a record-high infrared dichroic ratio. This was further confirmed by the sharp decrease in the PEO jet fineness of approximately 80% and the nanofiber diameter from 298 to 114 nm. Interestingly, the crystallinity can also be adjusted, with an obvious drop from 74.9% to 31.7%, which is different from the high crystallinity caused by oriented chains in common materials. This work guides a new perspective for the preparation of advanced electrospun nanofibers with optimal orientation-crystallinity properties, a merited feature for various applications.
In the past 20 years, recycled aggregate concrete (RAC), as a type of low-carbon concrete, has become a worldwide focus of research. However, the design methodology for RAC structural components remains a challenge. Consequently, demands for a unified design of natural aggregate concrete (NAC) and RAC components have been presented. Accordingly, this study analyses the necessity of a unified design theory and provides an in-depth demonstration of the strength determination, compressive constitutive relationship, and design method of concrete components. The coefficient of variation of RAC strength is found to be generally higher than that of NAC strength. The compressive and tensile strengths of RAC can be defined and determined using the same method as that used for NAC. The uniaxial compressive constitutive relationship between NAC and RAC has a unified mathematical expression. However, the elastic modulus of RAC decreases, and its brittleness exhibits an increasing trend compared with that of NAC. Finally, to unify the design formulae of RAC and NAC components for bearing capacity, modification factors for RAC components are proposed considering safety and reliability. Additionally, the feasibility of the proposed unified time-dependent design theory is demonstrated in terms of conceptual design and structural measures considering the effects of strength degradation and reinforcement corrosion. It is believed that this study enriches and develops the basic theory of concrete structures.
Transparent microwave absorbers that exhibit high optical transmittance and microwave absorption capability are ideal, although having a fixed absorption performance limits their applicability. Here, a simple, transparent, and thermally tunable microwave absorber is proposed, based on a patterned vanadium dioxide (VO2) film. Numerical calculations and experiments demonstrate that the proposed VO2 absorber has a high optical transmittance of 84.9% at 620 nm; its reflection loss at 15.06 GHz can be thermally tuned from -4.257 to -60.179 dB, and near-unity absorption is achieved at 523.750 K. Adjusting only the patterned VO2 film duty cycle can change the temperature of near-unity absorption. Our VO2 absorber has a simple composition, a high optical transmittance, a thermally tunable microwave absorption performance, a large modulation depth, and an adjustable temperature tuning range, making it promising for application in tunable sensors, thermal emitters, modulators, thermal imaging, bolometers, and photovoltaic devices.
