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71.
植物-土壤反馈可以在一定程度上阐明入侵植物入侵及维持的机制.通过比较入侵植物喜旱莲子草(Alternanthera philoxeroides)预培养的土壤与本地植物莲子草(Alternanthera sessilis)预培养的土壤对入侵植物喜旱莲子草与本地植物莲子草生长的影响,从土壤肥力、微生物群落及化感物质等角度阐明喜旱莲子草入侵过程中的植物 土壤反馈作用及可能机制,为入侵植物入侵机理的阐明提供理论依据.喜旱莲子草预培养土壤与莲子草预培养土壤对自身及彼此的叶生物量、茎生物量、根生物量和总生物量均无显著影响.喜旱莲子草预培养土壤的碱解氮显著高于莲子草预培养土壤,但是2种土壤肥力对喜旱莲子草以及莲子草的生物量均不存在显著相关.喜旱莲子草预培养土壤经灭菌处理后可以显著地促进莲子草的根生物量、茎生物量及总生物量,显著地抑制莲子草的叶生物量,但对喜旱莲子草的生长无显著影响,表明喜旱莲子草预培养土壤中的微生物群落对莲子草的生长具有一定的抑制作用.喜旱莲子草预培养土壤经添加活性碳处理后对喜旱莲子草与莲子草的生物量均无显著影响,表明喜旱莲子草预培养土壤中的化感物质对莲子草的生长不具有显著作用. 相似文献
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Hydrogen-Powered Microswimmers for Precise and Active Hydrogen Therapy Towards Acute Ischemic Stroke
Shuanghu Wang Kun Liu Quan Zhou Cong Xu Junbin Gao Zhen Wang Fei Wang Bin Chen Yicheng Ye Juanfeng Ou Jiamiao Jiang Daniela A. Wilson Shuwen Liu Fei Peng Yingfeng Tu 《Advanced functional materials》2021,31(19):2009475
Biodegradable microswimmers offer great potential for minimally invasive targeted therapy due to their tiny scale, multifunctionality, and versatility. However, most of the reported systems focused on the proof-of-concept on the in vitro level. Here, the successful fabrication of facile hydrogen-powered microswimmers (HPMs) for precise and active therapy of acute ischemic stroke is demonstrated. The hydrogen (H2) generated locally from the designed magnesium (Mg) microswimmer functions not only as a propellant for motion, but also as an active ingredient for reactive oxygen species (ROS) and inflammation scavenging. Due to the continuous detachment of the produced H2, the motion of the microswimmers results in active H2 delivery that allows for enhanced extracellular and intracellular reducibility. With the help of a stereotaxic apparatus device, HPMs were injected precisely into the lateral ventricle of middle cerebral artery occlusion (MCAO) rats. By scavenging ROS and inflammation via active H2, MCAO rats exhibit significant decrease in infarct volume, improved spatial learning and memory capability with minimal adverse effects, demonstrating efficient efficacy on anti-ischemic stroke. The as-developed HPMs with excellent biocompatibility and ROS scavenging capability holds great promise for the treatment of acute ischemic stroke or other oxidative stress induced diseases in clinic in the near future. 相似文献
76.
《Macromolecular bioscience》2017,17(12)
Sutures are one of the most widely used devices for adhering separated tissues after injury or surgery. However, most sutures require knotting, which can create a risk of inflammation, and can act as mechanically weak points that often result in breakage and slipping. Here, an anchoring suture is presented with a design that facilitates its propagation parallel to the suturing direction, while maximizing its resistive force against the opposite direction of external force to lock its position in tissues. Different microstructures of suture anchors are systematically designed using orthogonal arrays, and selected based on shape factors associated with mechanical strength. 3D printing is used to fabricate different types of hollow microstructured suture anchors, and optimize their structure for the effective shaping of tissues. To define the structural design for fixing tissues, the maximum force required to pull 3D printed anchors in different directions is examined with tissues. The tissue reshaping function of suture anchors is further simulated ex vivo by using swine ear, nose, and skin, and bovine muscle tendon. This study provides advantages for building functional sutures that can be used for permanently reshaping tissues with enhanced mechanical strength, eliminating the need for knotting to improve surgical efficiency. 相似文献
77.
Federico Tasca Cristina Tortolini Paolo Bollella Riccarda Antiochia 《Current Opinion in Electrochemistry》2019
Many research efforts over the last decade have been devoted to the development of microneedle-based diagnostic devices for minimally invasive transdermal biosensing and for long-term health monitoring. Transdermal biosensing via microneedle allows the development of minimally invasive easy-to-use point-of-care biodevices. The main objective of this short review is to provide a general overview of the most immediate and relevant progress in microneedle-based transdermal biosensing in the last five years. A critical analysis of the recent literature is finally presented. 相似文献
78.
Cheng Guo Li Yonghao Ma Inyoung Huh Shayan Fakhraei Lahiji Sang‐Guk Lee Hyungil Jung 《Advanced functional materials》2017,27(2)
Subcutaneous (SC) insulin injection has been demonstrated to be the most effective method for treatment of diabetes mellitus but is conventionally performed by hypodermic needles, leading to poor management of diabetes because of the pain, needle phobia, and tissue trauma. Identification of a viable, safe, and pain‐free alternative method has been a longstanding challenge in modern health care. Here, the thermoplastic droplet stretching technique is developed to create an ultrahigh‐aspect‐ratio needle mold with simple microstructure control. The optimized ultrafine needle (UN) with 4 mm length, minimized 120 µm outer diameter, and 15° sharp bevel angle is formed via electroplating of a metallic layer on the surface of a needle mold with forcing sharp tip. This novel UN enables minimally invasive 4 mm skin insertion to deliver insulin in the targeted SC layer. The similar relative areas under the curves of insulin concentration within UN and 31G needle in vivo insulin administration indicate that UN can ensure stable insulin absorption for secure blood glucose management. Additionally, the proposed fabrication method may facilitate industrialization and commercialization of the UN, holding great promise for replacement of hypodermic needles and for improvement of quality of life among patients with diabetes. 相似文献
79.
Enumerating Constrained Non-crossing Minimally Rigid Frameworks 总被引:2,自引:1,他引:1
David Avis Naoki Katoh Makoto Ohsaki Ileana Streinu Shin-ichi Tanigawa 《Discrete and Computational Geometry》2008,40(1):31-46
In this paper we present an algorithm for enumerating without repetitions all the non-crossing generically minimally rigid
bar-and-joint frameworks under edge constraints, which we call constrained non-crossing Laman frameworks, on a given set of
n points in the plane. Our algorithm is based on the reverse search paradigm of Avis and Fukuda. It generates each output graph
in O(n
4) time and O(n) space, or, with a slightly different implementation, in O(n
3) time and O(n
2) space. In particular, we obtain that the set of all the constrained non-crossing Laman frameworks on a given point set is
connected by flips which preserve the Laman property.
D. Avis’s research was supported by NSERC and FQRNT grants.
N. Katoh’s, M. Ohsaki’s and S.-i. Tanigawa’s research was supported by NEXT Grant-in-Aid for Scientific Research on priority
areas of New Horizons in Computing.
I. Streinu’s research was supported by NSF grant CCF-0430990 and NSF-DARPA CARGO CCR-0310661. 相似文献
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