scholarly journals A Review on Montmorillonite-Supported Nanoscale Zerovalent Iron for Contaminant Removal from Water and Soil

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Yaru Yin ◽  
Wenjuan Zheng ◽  
An Yan ◽  
Chenxi Zhang ◽  
Yuxuan Gou ◽  
...  
Keyword(s):  
Water Treatment ◽  
Soil Remediation ◽  
Zerovalent Iron ◽  
Great Promise ◽  
Contaminant Removal ◽  
Future Directions ◽  
Practical Applications ◽  
The Past ◽  
Nanoscale Zerovalent Iron ◽  
Soil And Water

Nanoscale zerovalent iron (nZVI) has shown great promise for water treatment and soil remediation. However, the rapid aggregation of nZVIs significantly affects their mobility and reactivity, which considerably limits the practical applications. Montmorillonite- (Mt-) supported nZVI (Mt-nZVI) has received increasing attention for the past decade because it can prevent the aggregation of nZVI and incorporate the advantages of both nZVI and Mt in soil and water treatment. This work thus had a comprehensive review on the use of Mt-nZVI for soil and water treatment. We first summarized existing methods used to prepare Mt-nZVI, indicating the advantages of using Mt to support nZVI (e.g., increase of the dispersion and mobility of nZVI, reduction of the size and oxidation tendency of nZVI). We then presented the reaction mechanisms of Mt-nZVI for contaminant removal and evaluated the critical factors that influence the removal (e.g., pH, temperature, and dosage of the adsorbent). We further presented examples of applications of Mt-nZVI for the removal of typical contaminants such as heavy metals and organic compounds in soil and water. We finally discussed the limitations of the use of Mt-nZVI for water treatment and soil remediation and presented future directions for the application of nZVI technology for soil and water treatment.

scholarly journals A Technical Study on UAV Characteristics for Precision Agriculture Applications and Associated Practical Challenges

2021 ◽  
Vol 13 (6) ◽  
pp. 1204
Author(s):  
Nadia Delavarpour ◽  
Cengiz Koparan ◽  
John Nowatzki ◽  
Sreekala Bajwa ◽  
Xin Sun
Keyword(s):  
Precision Agriculture ◽  
Weather Conditions ◽  
Future Directions ◽  
Radiometric Correction ◽  
Practical Applications ◽  
The Past ◽  
Field Crops ◽  
Advanced Technologies ◽  
Technical Study ◽  
Agricultural Operations

The incorporation of advanced technologies into Unmanned Aerial Vehicles (UAVs) platforms have enabled many practical applications in Precision Agriculture (PA) over the past decade. These PA tools offer capabilities that increase agricultural productivity and inputs’ efficiency and minimize operational costs simultaneously. However, these platforms also have some constraints that limit the application of UAVs in agricultural operations. The constraints include limitations in providing imagery of adequate spatial and temporal resolutions, dependency on weather conditions, and geometric and radiometric correction requirements. In this paper, a practical guide on technical characterizations of common types of UAVs used in PA is presented. This paper helps select the most suitable UAVs and on-board sensors for different agricultural operations by considering all the possible constraints. Over a hundred research studies were reviewed on UAVs applications in PA and practical challenges in monitoring and mapping field crops. We concluded by providing suggestions and future directions to overcome challenges in optimizing operational proficiency.

scholarly journals Wavefront manipulation by acoustic metasurfaces: from physics and applications

Nanophotonics ◽  
2018 ◽  
Vol 7 (6) ◽  
pp. 1191-1205 ◽  
Author(s):  
Bin Liang ◽  
Jian-chun Cheng ◽  
Cheng-Wei Qiu
Keyword(s):  
Acoustic Waves ◽  
Review Paper ◽  
Three Dimensional ◽  
New Physics ◽  
Research Field ◽  
Acoustic Metamaterials ◽  
Future Directions ◽  
Practical Applications ◽  
The Past ◽  
Recent Developments

AbstractMolding the wavefront of acoustic waves into the desired shape is of paramount significance in acoustics, which however are usually constrained by the acoustical response of naturally available materials. The emergence of acoustic metamaterials built by assembling artificial subwavelength elements provides distinct response to acoustic waves unattainable in nature. More recently, acoustic metasurfaces, a class of metamaterials with a reduced dimensionality, empower new physics and lead to extended functionalities different from their three-dimensional counterparts, enabling controlling, transmitted or reflected acoustic waves in ways that were not possible before. In this review paper, we present a comprehensive view of this rapidly growing research field by introducing the basic concepts of acoustic metasurfaces and the recent developments that have occurred over the past few years. We review the interesting properties of acoustic metasurfaces and their important functionalities of wavefront manipulation, followed by an outlook for promising future directions and potential practical applications.

scholarly journals Biosynthesis of Polyketides in Heterologous Hosts

2001 ◽  
Vol 65 (1) ◽  
pp. 106-118 ◽  
Author(s):  
Blaine A. Pfeifer ◽  
Chaitan Khosla
Keyword(s):  
State Of The Art ◽  
Streptomyces Coelicolor ◽  
Polyketide Synthases ◽  
Great Promise ◽  
Technological Opportunity ◽  
Future Directions ◽  
Polyketide Biosynthesis ◽  
The Past ◽  
Biochemical Studies ◽  
Multifunctional Enzymes

SUMMARY Polyketide natural products show great promise as medicinal agents. Typically the products of microbial secondary biosynthesis, polyketides are synthesized by an evolutionarily related but architecturally diverse family of multifunctional enzymes called polyketide synthases. A principal limitation for fundamental biochemical studies of these modular megasynthases, as well as for their applications in biotechnology, is the challenge associated with manipulating the natural microorganism that produces a polyketide of interest. To ameliorate this limitation, over the past decade several genetically amenable microbes have been developed as heterologous hosts for polyketide biosynthesis. Here we review the state of the art as well as the difficulties associated with heterologous polyketide production. In particular, we focus on two model hosts, Streptomyces coelicolor and Escherichia coli. Future directions for this relatively new but growing technological opportunity are also discussed.

scholarly journals Progress in Modern Marine Biomaterials Research

Marine Drugs ◽  
2020 ◽  
Vol 18 (12) ◽  
pp. 589 ◽  
Author(s):  
Yuliya Khrunyk ◽  
Slawomir Lach ◽  
Iaroslav Petrenko ◽  
Hermann Ehrlich
Keyword(s):  
Natural Products ◽  
Selection Pressure ◽  
Materials Science ◽  
Raw Materials ◽  
Structural Composites ◽  
Future Directions ◽  
Practical Applications ◽  
Evolutionary Selection ◽  
The Past ◽  
Adaptation Processes

The growing demand for new, sophisticated, multifunctional materials has brought natural structural composites into focus, since they underwent a substantial optimization during long evolutionary selection pressure and adaptation processes. Marine biological materials are the most important sources of both inspiration for biomimetics and of raw materials for practical applications in technology and biomedicine. The use of marine natural products as multifunctional biomaterials is currently undergoing a renaissance in the modern materials science. The diversity of marine biomaterials, their forms and fields of application are highlighted in this review. We will discuss the challenges, solutions, and future directions of modern marine biomaterialogy using a thorough analysis of scientific sources over the past ten years.

Nanolaser arrays: toward application-driven dense integration

Nanophotonics ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 149-169
Author(s):  
Suruj S. Deka ◽  
Sizhu Jiang ◽  
Si Hui Pan ◽  
Yeshaiahu Fainman
Keyword(s):  
Room Temperature ◽  
Mode Switching ◽  
Future Directions ◽  
Practical Applications ◽  
The Past ◽  
Emission Behavior ◽  
Nanoscale Lasers ◽  
Beam Directionality ◽  
Constituent Elements ◽  
Room Temperature Operation

AbstractThe past two decades have seen widespread efforts being directed toward the development of nanoscale lasers. A plethora of studies on single such emitters have helped demonstrate their advantageous characteristics such as ultrasmall footprints, low power consumption, and room-temperature operation. Leveraging knowledge about single nanolasers, the next phase of nanolaser technology will be geared toward scaling up design to form arrays for important applications. In this review, we discuss recent progress on the development of such array architectures of nanolasers. We focus on valuable attributes and phenomena realized due to unique array designs that may help enable real-world, practical applications. Arrays consisting of exactly two nanolasers are first introduced since they can serve as a building block toward comprehending the behavior of larger lattices. These larger-sized lattices can be distinguished depending on whether or not their constituent elements are coupled to one another in some form. While uncoupled arrays are suitable for applications such as imaging, biosensing, and even cryptography, coupling in arrays allows control over many aspects of the emission behavior such as beam directionality, mode switching, and orbital angular momentum. We conclude by discussing some important future directions involving nanolaser arrays.

On Future Directions in Pathology

1982 ◽  
Vol 40 ◽  
pp. 274-277
Author(s):  
Benjamin F. Trump ◽  
Irene K. Berezesky ◽  
Raymond T. Jones
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Clinical Pathology ◽  
Future Directions ◽  
Diagnostic Pathology ◽  
The Past ◽  
Transmission Electron ◽  
Organ Systems ◽  
The Many

The role of electron microscopy and associated techniques is assured in diagnostic pathology. At the present time, most of the progress has been made on tissues examined by transmission electron microscopy (TEM) and correlated with light microscopy (LM) and by cytochemistry using both plastic and paraffin-embedded materials. As mentioned elsewhere in this symposium, this has revolutionized many fields of pathology including diagnostic, anatomic and clinical pathology. It began with the kidney; however, it has now been extended to most other organ systems and to tumor diagnosis in general. The results of the past few years tend to indicate the future directions and needs of this expanding field. Now, in addition to routine EM, pathologists have access to the many newly developed methods and instruments mentioned below which should aid considerably not only in diagnostic pathology but in investigative pathology as well.

Comparison and Analysis of Computational Methods for Identifying N6 - methyladenosine Sites in Saccharomyces Cerevisiae

2020 ◽  
Vol 26 ◽  
Author(s):  
Pengmian Feng ◽  
Lijing Feng ◽  
Chaohui Tang
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Computational Methods ◽  
Computational Analysis ◽  
Computational Prediction ◽  
Experimental Methods ◽  
Biological Processes ◽  
Biological Functions ◽  
Precise Location ◽  
Future Directions ◽  
The Past

Background and Purpose: N 6 -methyladenosine (m6A) plays critical roles in a broad set of biological processes. Knowledge about the precise location of m6A site in the transcriptome is vital for deciphering its biological functions. Although experimental techniques have made substantial contributions to identify m6A, they are still labor intensive and time consuming. As good complements to experimental methods, in the past few years, a series of computational approaches have been proposed to identify m6A sites. Methods: In order to facilitate researchers to select appropriate methods for identifying m6A sites, it is necessary to give a comprehensive review and comparison on existing methods. Results: Since researches on m6A in Saccharomyces cerevisiae are relatively clear, in this review, we summarized recent progresses on computational prediction of m6A sites in S. cerevisiae and assessed the performance of existing computational methods. Finally, future directions of computationally identifying m6A sites were presented. Conclusion: Taken together, we anticipate that this review will provide important guides for computational analysis of m 6A modifications.

scholarly journals The Use of Autogenous Teeth for Alveolar Ridge Preservation: A Literature Review

2021 ◽  
Vol 11 (4) ◽  
pp. 1853
Author(s):  
João Cenicante ◽  
João Botelho ◽  
Vanessa Machado ◽  
José João Mendes ◽  
Paulo Mascarenhas ◽  
...  
Keyword(s):  
Ridge Preservation ◽  
Graft Material ◽  
Alveolar Ridge ◽  
Natural Consequence ◽  
Oral Rehabilitation ◽  
Future Directions ◽  
The Past ◽  
Alveolar Ridge Preservation ◽  
Functional Consequences ◽  
Teeth Extraction

Alveolar ridge resorption is a natural consequence of teeth extraction, with unpleasant aesthetic and functional consequences that might compromise a future oral rehabilitation. To minimize the biological consequences of alveolar ridge resorption, several surgical procedures have been designed, the so-called alveolar ridge preservation (ARP) techniques. One important characteristic is the concomitant use of biomaterial in ARP. In the past decade, autogenous teeth as a bone graft material in post-extraction sockets have been proposed with very interesting outcomes, yet with different protocols of preparation. Here we summarize the available evidence on autogenous teeth as a biomaterial in ARP, its different protocols and future directions.

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