Hospitals are important sources of pollutants resulted from diagnostic, laboratory and research activities as well as medicine excretion by patients, which include active component of drugs and ...metabolite, chemicals, residues of pharmaceuticals, radioactive markers, iodinated contrast media, etc. The discharge of hospital wastes and wastewater, especially those without appropriate treatment would expose the public in danger of infection. In particular, under the Coronavirus Disease 2019 (COVID-19) pandemic context in China, it is of great significance to reduce the health risks to the public and environment. In this study, technologies of different types of hospital wastes and wastewater disinfection have been summarized. Liquid chlorine, sodium hypochlorite, chlorine dioxide, ozone, and ultraviolet irradiation disinfection are commonly used for hospital wastewater disinfection. While incineration, chemical disinfection, and physical disinfection are commonly used for hospital wastes disinfection. In addition, considering the characteristics of various hospital wastes, the classification and selection of corresponding disinfection technologies are discussed. On this basis, this study provides scientific suggestions for management, technology selection, and operation of hospital wastes and wastewater disinfection in China, which is of great significance for development of national disinfection strategy for hospital wastes and wastewater during COVID-19 pandemic.
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•O3, UV, chlorine disinfectants are used for hospital wastewater disinfection.•Incineration, chemical and physical techniques are used to disinfect hospital wastes.•Providing suggestions for hospital wastes and wastewater disinfection during COVID-19.•The chlorine disinfection and incineration are primarily recommended.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The incorporation of hydroxyapatite (HAP) into poly-l-lactic acid (PLLA) matrix serving as bone scaffold is expected to exhibit bioactivity and osteoconductivity to those of the living bone. While ...too low degradation rate of HAP/PLLA scaffold hinders the activity because the embedded HAP in the PLLA matrix is difficult to contact and exchange ions with body fluid. In this study, biodegradable polymer poly (glycolic acid) (PGA) was blended into the HAP/PLLA scaffold fabricated by laser 3D printing to accelerate the degradation. The results indicated that the incorporation of PGA enhanced the degradation rate of scaffold as indicated by the weight loss increasing from 3.3% to 25.0% after immersion for 28 days, owing to the degradation of high hydrophilic PGA and the subsequent accelerated hydrolysis of PLLA chains. Moreover, a lot of pores produced by the degradation of the scaffold promoted the exposure of HAP from the matrix, which not only activated the deposition of bone like apatite on scaffold but also accelerated apatite growth. Cytocompatibility tests exhibited a good osteoblast adhesion, spreading and proliferation, suggesting the scaffold provided a suitable environment for cell cultivation. Furthermore, the scaffold displayed excellent bone defect repair capacity with the formation of abundant new bone tissue and blood vessel tissue, and both ends of defect region were bridged after 8 weeks of implantation.
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•PGA was blended into HAP/PLLA scaffold fabricated by laser 3D printing to accelerate degradation.•A lot of pores produced by scaffold degradation promoted the exposure of HAP from the matrix.•Scaffold provided a suitable environment for cell cultivation.•Scaffold displayed excellent bone repair capacity with the formation of abundant new bone tissue and blood vessel tissue.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Mg and its alloys have been identified as promising bone implant materials owing to their natural degradability, good biocompatibility and favorable mechanical properties. Nevertheless, the too fast ...degradation rate usually results in a premature disintegration of mechanical integrity and local hydrogen accumulation, which limit their clinical bone repair application. In this work, the current research status regarding Mg bone implants was systematically reviewed. The relevant strategies to enhance the corrosion resistance, including purification, alloying treatment, surface coating and Mg-based metal matrix composite, are comprehensively discussed. The fabricating techniques for Mg bone implants are also presented. Particularly, laser additive manufacturing can fabricate customized shape and complex porous structure basing on its unique additive manufacturing concept. More importantly, it can achieve rapid heating and cooling due to the characteristics of high laser energy density and good controllability, thereby regulating the microstructure and performance. Furthermore, the current challenges and future research perspectives are put forward. This work aims to offer some meaningful guidelines for researchers on the future study of Mg bone implants.
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•The advantages and current application of Mg bone implants are described.•The fabrication methods for Mg bone implants are discussed comprehensively.•The strategies to enhance the corrosion resistance of Mg bone implant are evaluated.•The future perspectives are presented to provide some guidelines for researchers.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Polyvinylidene fluoride (PVDF)/barium titanate (BaTiO3) composites are becoming increasingly attractive in bone repair since it combines the advantage of polymer flexibility and ceramic piezoelectric ...constant. Herein, silver (Ag) nanoparticles were decorated on polydopamine functioned BaTiO3 (Ag-pBT) by in situ growth. Then the strawberry-like structured Ag-pBT nanoparticles were introduced into PVDF scaffold fabricated by selective laser sintering. On one hand, Ag nanoparticles would act as a conductive phase to enhance the strength of the polarized electric field on BaTiO3, thereby forcing more domains to be aligned in the direction of the electric field and make piezoelectric effect of BaTiO3 fully play in composite scaffold. On the other hand, Ag nanoparticles would attack multiple targets in bacteria by release of Ag+ and production of reactive oxygen species. In fact, the antibacterial activity is highly desirable for bone repair. Results demonstrated that the PVDF/4Ag-pBT scaffold exhibited enhanced piezoelectric properties with output current and voltage increased by 50% and 40% than that of PVDF/pBT, respectively. In vitro cell culture confirmed that the enhanced electric output further promoted cell proliferation and differentiation. Meanwhile, the scaffold presented robust antibacterial activity against E.coli.
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•A strawberry-like Ag-decorated BaTiO3 nanoparticles were prepared by in situ growth.•A novel three-dimensional porous PVDF/Ag-pBT scaffolds were fabricated by selective laser sintering technique.•The Ag nanoparticles could enhance the electric output performance of the scaffold.•The improved surface electric charges significantly promoted proliferation and differentiation of MG-63 cell.•The scaffold inhibited the growth of Escherichia coli by releasing Ag+.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Almost the entire world, not only China, is currently experiencing the outbreak of a novel coronavirus that causes respiratory disease, severe pneumonia, and even death. The outbreak began in Wuhan, ...China, in December of 2019 and is currently still ongoing. This novel coronavirus is highly contagious and has resulted in a continuously increasing number of infections and deaths that have already surpassed the SARS-CoV outbreak that occurred in China between 2002 and 2003. It is now officially a pandemic, announced by WHO on the 11th of March. Currently, the 2019 novel coronavirus (SARS-CoV-2) can be identified by virus isolation or viral nucleic acid detection; however, false negatives associated with the nucleic acid detection provide a clinical challenge and thus make the imaging examination crucial. Imaging exams have been a main clinical diagnostic criteria for the 2019 novel coronavirus disease (COVID-19) in China. Imaging features of multiple patchy areas of ground glass opacity and consolidation predominately in the periphery of the lungs are characteristic manifestations on chest CT and extremely helpful in the early detection and diagnosis of this disease, which aids prompt diagnosis and the eventual control of this emerging global health emergency.
Key Points
• In December 2019, China, an outbreak of pneumonia caused by a novel, highly contagious coronavirus raised grave concerns and posed a huge threat to global public health.
• Among the infected patients, characteristic findings on CT imaging include multiple, patchy, ground-glass opacity, crazy-paving pattern, and consolidation shadows, mainly distributed in the peripheral and subpleural areas of both lungs, which are very helpful for the frontline clinicians.
• Imaging examination has become the indispensable means not only in the early detection and diagnosis but also in monitoring the clinical course, evaluating the disease severity, and may be presented as an important warning signal preceding the negative RT-PCR test results.
Zinc (Zn) alloys are promising bone repair materials due to their inherent degradability, favorable mechanical property and biocompatibility. In this investigation, laser powder bed fusion (LPBF) ...known as a representative additive manufacturing technique was applied to fabricate Zn-2Al (wt.%) part for bone repair application. A low energy density (Ev) led to the formation of pores and resultant insufficient densification rate due to the high liquid viscosity within the molten pool. In contrast, a high Ev caused the evaporation of Zn powder and resultant failure of LPBF. With Ev increasing, the obtained grains and the precipitated lamellar eutectic structure contained η-Zn and α-Al phase became coarsened, which could be attributed to the enhanced heat accumulation and consequently decreased cooling rate. At optimized Ev of 114.28 J/mm3, fully dense Zn-2Al part with a densification rate of 98.3 ± 1.4% was achieved, which exhibited an optimal hardness of 64.5 ± 1.8 Hv, tensile strength of 192.2 ± 5.4 MPa and a moderate corrosion rate of 0.14 mm/year. In addition, in vitro cell tests confirmed its good biocompability. This study indicated that LPBF processed Zn-2Al part was a potential material for bone repair.
•Zn-2Al part is successfully built using laser additive manufacturing process.•High densification rate and fine microstructure is achieved at optimized Ev.•It exhibits superior mechanical properties and suitable degradation rate.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The deep sea remains the largest unknown territory on Earth because it is so difficult to explore
. Owing to the extremely high pressure in the deep sea, rigid vessels
and pressure-compensation ...systems
are typically required to protect mechatronic systems. However, deep-sea creatures that lack bulky or heavy pressure-tolerant systems can thrive at extreme depths
. Here, inspired by the structure of a deep-sea snailfish
, we develop an untethered soft robot for deep-sea exploration, with onboard power, control and actuation protected from pressure by integrating electronics in a silicone matrix. This self-powered robot eliminates the requirement for any rigid vessel. To reduce shear stress at the interfaces between electronic components, we decentralize the electronics by increasing the distance between components or separating them from the printed circuit board. Careful design of the dielectric elastomer material used for the robot's flapping fins allowed the robot to be actuated successfully in a field test in the Mariana Trench down to a depth of 10,900 metres and to swim freely in the South China Sea at a depth of 3,224 metres. We validate the pressure resilience of the electronic components and soft actuators through systematic experiments and theoretical analyses. Our work highlights the potential of designing soft, lightweight devices for use in extreme conditions.
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GEOZS, IJS, IMTLJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK, ZAGLJ
Aim: Recent advances in the availability of species distributional and high-resolution environmental data have facilitated the investigation of species richness—environment relationships. However, ...even exhaustive distributional databases are prone to geographical sampling bias. We aim to quantify the inventory incompleteness of vascular plant data across 2377 Chinese counties and to test whether inventory incompleteness affects the analysis of richness—environment relationships and spatial predictions of species richness. Location: China. Methods: We used the most comprehensive database of Chinese vascular plants, which includes county-level occurrences for 29,012 native species derived from 4,236,768 specimen and literature records. For each county, we computed smoothed species accumulation curves and used the mean slope of the last 10% of the curves as a proxy for inventory incompleteness. We created a series of data subsets with different levels of inventory incompleteness by excluding successively more under-sampled counties from the full data set. We then applied spatial and non-spatial regression models to each of these subsets to investigate relationships between the species richness of subsets and environmental factors, and to predict spatial patterns of vascular plant species richness in China. Results: Log 10 -transformed numbers of records and documented species were strongly correlated (r = 0.97). In total, 91% of Chinese counties were identified as under-sampled. After controlling for inventory incompleteness, the overall explanatory power of environmental factors markedly increased, and the strongest predictor of species richness switched from elevational range to annual wet days. Environmental models calibrated with more complete inventories yielded better spatial predictions of species richness. Main conclusions: Our results indicate that inventory incompleteness strongly affects the explanatory power of environmental factors, the main determinants of species richness obtained from regression analyses, and the reliability of environment-based spatial predictions of species richness. We conclude that even large distributional databases are prone to geographical sampling bias, with far-reaching implications for the perception of and inferences about macroecological patterns.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NMLJ, NUK, OILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
Innate lymphoid cells (ILCs) and CD4
T cells produce IL-22, which is critical for intestinal immunity. The microbiota is central to IL-22 production in the intestines; however, the factors that ...regulate IL-22 production by CD4
T cells and ILCs are not clear. Here, we show that microbiota-derived short-chain fatty acids (SCFAs) promote IL-22 production by CD4
T cells and ILCs through G-protein receptor 41 (GPR41) and inhibiting histone deacetylase (HDAC). SCFAs upregulate IL-22 production by promoting aryl hydrocarbon receptor (AhR) and hypoxia-inducible factor 1α (HIF1α) expression, which are differentially regulated by mTOR and Stat3. HIF1α binds directly to the Il22 promoter, and SCFAs increase HIF1α binding to the Il22 promoter through histone modification. SCFA supplementation enhances IL-22 production, which protects intestines from inflammation. SCFAs promote human CD4
T cell IL-22 production. These findings establish the roles of SCFAs in inducing IL-22 production in CD4
T cells and ILCs to maintain intestinal homeostasis.
In present study, a strategy is presented to construct a magnetic micro-environment in poly-l-lactide/polyglycolic acid (PLLA/PGA) scaffolds fabricated via selective laser sintering by incorporating ...Fe3O4 magnetic nanoparticles (MNPs), aiming to enhance cell viability and promote bone regeneration. In the micro-environment, each nanoparticle provides a nanoscale magnetic field to activate cellular responses. The results in vitro demonstrated that the magnetic scaffolds not only stimulated cell adhesion and viability, but also enhanced proliferation rate and alkaline phosphatase activity. Meanwhile, the compressive strength and modulus were increased by 81.9% and 71.6%, respectively, which were determined by the rigid enhancement effect of MNPs. Moreover, the magnetic scaffolds were implanted into rabbit radius bone defect in vivo, and the results indicated that the magnetic scaffolds significantly induced substantial blood vessel tissue, fibrous tissue and new bone tissue formation at 2 months post-implantation, revealing the excellent bone regeneration capability. These positive results indicate that the construction of magnetic micro-environment in scaffolds is a working countermeasure to promote bone regeneration.
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•A magnetic micro-environment was constructed in PLLA/PGA scaffolds by incorporating Fe3O4 MNPs.•The magnetic nanoparticle provides a nanoscale magnetic field to activate cellular responses.•Magnetic scaffolds promoted cell adhesion, proliferation and differentiation.•The new bone tissue formation was significantly accelerated.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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