Effective Control of Enzyme Activity Based on a Subtle Nanoreactor: A Promising Strategy for Biomedical Applications in the Future

2017 ◽  
Vol 1 (1) ◽  
pp. 302-309 ◽  
Author(s):  
Ronghua Jin ◽  
Zhongning Liu ◽  
Yongkang Bai ◽  
Yongsheng Zhou ◽  
Xin Chen
Keyword(s):  
Enzyme Activity ◽  
Biomedical Applications ◽  
Effective Control ◽  
Promising Strategy ◽  
The Future

scholarly journals Surface Structuring via Additive Manufacturing to Improve the Performance of Metal and Polymer Joints

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 567
Author(s):  
Xin Zou ◽  
Lifu Huang ◽  
Ke Chen ◽  
Muyang Jiang ◽  
Shanyong Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electron Beam Melting ◽  
Biomedical Applications ◽  
Surface Structures ◽  
Joint Performance ◽  
Ti6al4v Titanium Alloy ◽  
Promising Strategy ◽  
Surface Structuring ◽  
Ultra High Molecular Weight ◽  
Metal Polymer

In order to enhance the joint performance of Ti6Al4V titanium alloy (TC4) and ultra-high molecular weight polyethylene (UHMWPE) for biomedical applications, different structures were fabricated on TC4 surfaces via electron beam melting (EBM) method in this study. Macromorphologies and microinterfaces of TC4–UHMWPE joints produced via hot pressing technique were carefully characterized and analyzed. The effects of different surface structures on mechanical properties and fractured surfaces were investigated and compared. Strong direct bonding (1751 N) between UHMWPE and TC4 was achieved. The interfacial bonding behavior of TC4–UHMWPE joints was further discussed. This study demonstrates the importance of combining macro- and micromechanical interlocking, which is a promising strategy for improving metal–polymer joint performance. It also provides guidance for metal surface structuring from both theoretical and practical perspectives.

Screening for Highly Active Plasmid Promoters via Fusion to β-Galactosidase Gene

1982 ◽  
Vol 37 (5-6) ◽  
pp. 441-444
Author(s):  
Arie Rosner ◽  
Marian Gorecki ◽  
Haim Aviv
Keyword(s):  
Enzyme Activity ◽  
Enzyme Activities ◽  
Polyacrylamide Gel ◽  
Highly Active ◽  
Red Color ◽  
Wide Range ◽  
The Future ◽  
Active Promoter

Abstract A plasmid containing promoter-deleted inactive β-galactosidase gene [1] was used to select promoters of the pEP121 plasmid [2]. Colonies of cells harboring reactivated β-galactosidase gene were identified by their red color on McConkey plates. The quantitative amounts of β-galactosidase produced in each clone were estimated by assaying enzyme activity and by measuring the specific β-galactosidase protein following fractionation of total cells′ proteins on polyacrylamide gel. A wide range of enzyme activities was observed. The most active promoter isolated was shown to promote β-galactosidase production more efficiently, compared with the original β-galactosidase promoter, amounting to 20% of all cell proteins. Such highly active promoters may be utilized in the future, to promote expression of cloned genes in bacteria.

scholarly journals Real-Time Mode Switching and Beam Scanning of High-Gain OAM Waves Using a 1-Bit Reconfigurable Reflectarray Antenna

Electronics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2181
Author(s):  
Ziyang Wang ◽  
Xiaotian Pan ◽  
Fan Yang ◽  
Shenheng Xu ◽  
Maokun Li
Keyword(s):  
Real Time ◽  
Dimensional Space ◽  
Large Angle ◽  
High Gain ◽  
Mode Switching ◽  
Effective Control ◽  
Vortex Beam ◽  
Beam Scanning ◽  
The Future ◽  
Reflectarray Antenna

A reconfigurable electromagnetic surface has been studied to realize the adjustable orbital angular momentum (OAM) beams for real-time wireless communication and dynamic target detection in the future. OAM mode switching realized by many previous designs suffers from low gains without OAM beam scanning. In this article, a 1-bit reconfigurable reflectarray antenna is designed, fabricated, and tested for the real-time control of OAM mode switching and large-angle vortex beam scanning in three-dimensional space. The proposed reflectarray surface is composed of 1-bit electronically reconfigurable cells, and the size is 24 λ × 24 λ with 2304 units. The reconfigurable element is designed by using a radiation patch loading a PIN diode with effective control of two states, “ON” and “OFF”, for the demand of 180° phase difference. The reflectarray surface can be assigned to a code sequence of 0 or 1 by the Field-Programmable Gate Array (FPGA) in real time. Henceforth, the coding surface can dynamically control the generation of high-gain OAM beams, where only the optimized phase distributions on the surface need to be changed according to demand. To verify the concept, a large-scale reflectarray surface is fabricated and measured with an oblique feed at 15°. Different OAM-carrying phase distributions for different OAM beam states are calculated and tested. The test results show that the OAM mode switching between l = 1 and l = 2 is realized, and other variable modes such as l = 3 or l = 5 can also be achieved by modifying the phase encoding sequence. Furthermore, the direction of the vortex beams can be accurately controlled with gains over 20 dBi, and the large-angle vortex beam scanning is verified. Therefore, all results demonstrate that the proposed 1-bit reconfigurable reflectarray is efficient for the regulation and control of OAM-carrying beams for the demand of real-time dynamic wireless communications in the future.

Azobenzene switch with a long-lived cis-state to photocontrol the enzyme activity of a histone deacetylase-like amidohydrolase

2014 ◽  
Vol 395 (4) ◽  
pp. 401-412 ◽  
Author(s):  
Michael Korbus ◽  
Ganesh Balasubramanian ◽  
Florian Müller-Plathe ◽  
Harald Kolmar ◽  
Franz-Josef Meyer-Almes
Keyword(s):  
Enzyme Activity ◽  
Enzymatic Activity ◽  
Histone Deacetylase ◽  
Chemical Reactions ◽  
Broad Spectrum ◽  
Active Site ◽  
Biomedical Applications ◽  
Pulse Switching ◽  
Spatial Regulation ◽  
Temporal And Spatial

Abstract The control of enzymes by use of an external stimulus such as light enables the temporal and spatial regulation of defined chemical reactions in a highly precise manner. In this work we investigated and characterized the reversible photocontrol of a bacterial histone deacetylase-like amidohydrolase (HDAH) from Bordetella/Alcaligenes strain FB188, which holds great potential to control deacetylation reactions of a broad spectrum of substrates in biotechnological and biomedical applications. Several HDAH variants with a single surface accessible cysteine close to the active site were developed and covalently modified by a monofunctional azobenzene-based photoswitch [4-phenylazomaleinanil (4-PAM)]. The enzymatic activity of three HDAH variants (M30C, S20C and M150C) were shown to be controlled by light. The thermal cis-to-trans relaxation of azobenzene conjugated to HDAH was up to 50-fold retarded compared to unbound 4-PAM allowing light pulse switching rather than continuing irradiation to maintain the thermodynamically less stable cis-state of covalently attached 4-PAM.

Transgenic perspectives in livestock science: a review

2004 ◽  
Vol 44 (11) ◽  
pp. 1113 ◽  
Author(s):  
M. B. Nottle ◽  
A. C. Boquest ◽  
S. J. Harrison ◽  
C. G. Grupen ◽  
R. A. Faast ◽  
...  
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Biomedical Applications ◽  
Genetic Material ◽  
Embryonic Stem ◽  
Full Potential ◽  
Transgenic Technology ◽  
Artificial Chromosomes ◽  
Fetal Fibroblasts ◽  
The Future

The limitations of existing transgenic technology, the potential of cloning technology to overcome these, as well as technologies which may be available in the future for inserting new genetic material are discussed. Currently, transgenic livestock are produced by injecting hundreds to thousands of copies of a particular transgene into the pronucleus of a fertilised egg. This method suffers from a number of inherent limitations that prevent the full potential of this technology from being explored. Most of these limitations stem from the fact that it is impossible to control the site at which the transgene becomes inserted. Transgenic technology holds considerable promise for the livestock industries as well as having important biomedical applications. However, before any of these possibilities can be realised, technology is required whereby a single copy of a particular transgene can be inserted or ‘knocked in’ at a site that does not interfere with expression, as well as having the capacity to ‘knockout’ existing genes. This is possible in mice using a combination of homologous recombination and embryonic stem cell technologies. However, despite considerable effort worldwide, embryonic stem cells are yet to be isolated from any of the livestock species. The ability to clone these now means that somatic cells most notably fetal fibroblasts, can used for gene targeting purposes instead of embryonic stem cells. However, this method is not without its limitations and it is possible that more efficient methods will be developed in the future. In particular, the use of mammalian artificial chromosomes will extend this technology to allow combinations of transgenes as well as chromosomal segments to be incorporated, allowing us to explore the full potential of transgenic technology for agricultural as well as biomedical applications.

Protein/peptide-templated biomimetic synthesis of inorganic nanoparticles for biomedical applications

2017 ◽  
Vol 5 (3) ◽  
pp. 401-417 ◽  
Author(s):  
Weitao Yang ◽  
Weisheng Guo ◽  
Jin Chang ◽  
Bingbo Zhang
Keyword(s):  
Metal Nanoparticles ◽  
Biomedical Applications ◽  
Inorganic Nanoparticles ◽  
Biomimetic Synthesis ◽  
Biomimetic Mineralization ◽  
Promising Strategy

Currently, protein/peptide-based biomimetic mineralization has been demonstrated to be an efficient and promising strategy for synthesis of inorganic/metal nanoparticles (NPs) for bioapplications.

scholarly journals Optimum contribution selection using differential evolution

2010 ◽  
Vol 39 (7) ◽  
pp. 1429-1436 ◽  
Author(s):  
Roberto Carvalheiro ◽  
Sandra Aidar de Queiroz ◽  
Brian Kinghorn
Keyword(s):  
Differential Evolution ◽  
Objective Function ◽  
Overlapping Generations ◽  
Selection Response ◽  
Effective Control ◽  
Computationally Efficient ◽  
Genetic Merit ◽  
Practical Applications ◽  
The Future

A program to determine optimum contribution selection using differential evolution was developed. The objective function to be optimized was composed by the expected merit of the future progeny and the coancestry among selected parents. Simulated and real datasets of populations with overlapping generations were used to validate and test the performance of the program. The program was computationally efficient and feasible for practical applications. The expected consequences of using the program, in contrast to empirical procedures to control inbreeding and/or to selection based exclusively on expected genetic merit, would be the improvement of the selection response and a more effective control of inbreeding.

scholarly journals Recent Developments in Ring-Opening Copolymerization of Epoxides With CO2 and Cyclic Anhydrides for Biomedical Applications

2021 ◽  
Vol 9 ◽  
Author(s):  
Xue Liang ◽  
Fei Tan ◽  
Yunqing Zhu
Keyword(s):  
Ring Opening ◽  
Biomedical Applications ◽  
Organometallic Complexes ◽  
Controlled Polymerization ◽  
Catalyst Development ◽  
Metal Free ◽  
Narrow Scope ◽  
Recent Advances ◽  
The Future ◽  
Recent Developments

The biomedical applications of polyesters and polycarbonates are of interest due to their potential biocompatibility and biodegradability. Confined by the narrow scope of monomers and the lack of controlled polymerization routes, the biomedical-related applications of polyesters and polycarbonates remain challenging. To address this challenge, ring-opening copolymerization (ROCOP) has been exploited to prepare new alternating polyesters and polycarbonates, which would be hard to synthesize using other controlled polymerization methods. This review highlights recent advances in catalyst development, including the emerging dinuclear organometallic complexes and metal-free Lewis pair systems. The post-polymerization modification methods involved in tailoring the biomedical functions of resultant polyesters and polycarbonates are summarized. Pioneering attempts for the biomedical applications of ROCOP polyesters and polycarbonates are presented, and the future opportunities and challenges are also highlighted.

Sign in / Sign up

Export Citation Format

Share Document