抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

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Self-assembled monolayers of thiolates on metals as a form of nanotechnology.

Microfabricated integrated circuits revolutionized computation by vastly reducing the space, labor, and time required for calculations. Microfluidic systems hold similar promise for the large-scale automation of chemistry and biology, suggesting the possibility of numerous experiments performed rapidly and in parallel, while consuming little reagent. While it is too early to tell whether such a vision will be realized, significant progress has been achieved, and various applications of significant scientific and practical interest have been developed. Here a review of the physics of small volumes (nanoliters) of fluids is presented, as parametrized by a series of dimensionless numbers expressing the relative importance of various physical phenomena. Specifically, this review explores the Reynolds number Re, addressing inertial effects; the Peclet number Pe, which concerns convective and diffusive transport; the capillary number Ca expressing the importance of interfacial tension; the Deborah, Weissenberg, and elasticity numbers De, Wi, and El, describing elastic effects due to deformable microstructural elements like polymers; the Grashof and Rayleigh numbers Gr and Ra, describing density-driven flows; and the Knudsen number, describing the importance of noncontinuum molecular effects. Furthermore, the long-range nature of viscous flows and the small device dimensions inherent in microfluidics mean that the influence of boundaries is typically significant. A variety of strategies have been developed to manipulate fluids by exploiting boundary effects; among these are electrokinetic effects, acoustic streaming, and fluid-structure interactions. The goal is to describe the physics behind the rich variety of fluid phenomena occurring on the nanoliter scale using simple scaling arguments, with the hopes of developing an intuitive sense for this occasionally counterintuitive world.

/pdf/microfluidics-fluid-physics-at-the-nanoliter-scale-4bpahtd8qa.pdf

Microfluidics: Fluid physics at the nanoliter scale

Detection of chemical and biological agents plays a fundamental role in biomedical, forensic and environmental sciences1–4 as well as in anti bioterrorism applications.5–7 The development of highly sensitive, cost effective, miniature sensors is therefore in high demand which requires advanced technology coupled with fundamental knowledge in chemistry, biology and material sciences.8–13

In general, sensors feature two functional components: a recognition element to provide selective/specific binding with the target analytes and a transducer component for signaling the binding event. An efficient sensor relies heavily on these two essential components for the recognition process in terms of response time, signal to noise (S/N) ratio, selectivity and limits of detection (LOD).14,15 Therefore, designing sensors with higher efficacy depends on the development of novel materials to improve both the recognition and transduction processes. Nanomaterials feature unique physicochemical properties that can be of great utility in creating new recognition and transduction processes for chemical and biological sensors15–27 as well as improving the S/N ratio by miniaturization of the sensor elements.28

Gold nanoparticles (AuNPs) possess distinct physical and chemical attributes that make them excellent scaffolds for the fabrication of novel chemical and biological sensors (Figure 1).29–36 First, AuNPs can be synthesized in a straightforward manner and can be made highly stable. Second, they possess unique optoelectronic properties. Third, they provide high surface-to-volume ratio with excellent biocompatibility using appropriate ligands.30 Fourth, these properties of AuNPs can be readily tuned varying their size, shape and the surrounding chemical environment. For example, the binding event between recognition element and the analyte can alter physicochemical properties of transducer AuNPs, such as plasmon resonance absorption, conductivity, redox behavior, etc. that in turn can generate a detectable response signal. Finally, AuNPs offer a suitable platform for multi-functionalization with a wide range of organic or biological ligands for the selective binding and detection of small molecules and biological targets.30–32,36 Each of these attributes of AuNPs has allowed researchers to develop novel sensing strategies with improved sensitivity, stability and selectivity. In the last decade of research, the advent of AuNP as a sensory element provided us a broad spectrum of innovative approaches for the detection of metal ions, small molecules, proteins, nucleic acids, malignant cells, etc. in a rapid and efficient manner.37



Figure 1

Physical properties of AuNPs and schematic illustration of an AuNP-based detection system.



In this current review, we have highlighted the several synthetic routes and properties of AuNPs that make them excellent probes for different sensing strategies. Furthermore, we will discuss various sensing strategies and major advances in the last two decades of research utilizing AuNPs in the detection of variety of target analytes including metal ions, organic molecules, proteins, nucleic acids, and microorganisms.

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Gold nanoparticles in chemical and biological sensing.

5.1. Detection Formats 475 5.2. Food Quality and Safety Analysis 477 5.2.1. Pathogens 477 5.2.2. Toxins 479 5.2.3. Veterinary Drugs 479 5.2.4. Vitamins 480 5.2.5. Hormones 480 5.2.6. Diagnostic Antibodies 480 5.2.7. Allergens 481 5.2.8. Proteins 481 5.2.9. Chemical Contaminants 481 5.3. Medical Diagnostics 481 5.3.1. Cancer Markers 481 5.3.2. Antibodies against Viral Pathogens 482 5.3.3. Drugs and Drug-Induced Antibodies 483 5.3.4. Hormones 483 5.3.5. Allergy Markers 483 5.3.6. Heart Attack Markers 484 5.3.7. Other Molecular Biomarkers 484 5.4. Environmental Monitoring 484 5.4.1. Pesticides 484 5.4.2. 2,4,6-Trinitrotoluene (TNT) 485 5.4.3. Aromatic Hydrocarbons 485 5.4.4. Heavy Metals 485 5.4.5. Phenols 485 5.4.6. Polychlorinated Biphenyls 487 5.4.7. Dioxins 487 5.5. Summary 488 6. Conclusions 489 7. Abbreviations 489 8. Acknowledgment 489 9. References 489

Surface Plasmon Resonance Sensors for Detection of Chemical and Biological Species

Due to the climate change such as high temperature in summer and low sunlight in winter, vegetable seedling growers have been facing difficulties to produce uniform seedlings in all four seasons. A plant factory with an artificial lighting (PFAL) would be considered as an effective alternative tool in that it can control environment conditions and produce uniform seedlings without outside weather conditions. Therefore, this study investigated changes of environment parameters, such as light uniformity, temperature and the relative humidity and uniformity of seedlings cultivated in a PFAL to evaluate plant factory transplant production system with an artificial lighting. Cucumber seedlings were grown in a PFAL at the light intensity 250 μmol·m -2 ·s -1 , the photoperiod 16/8h, the temperature 25/2 0°C and the relative humidity 70/85%. In the light intensity uniformity, as closer to the light source from 255 to 105mm, the amount of light increased by 11 and 23%, respectively, but the standard deviation increased by 1.8 times. For the temperature and the relative humidity by four different height positions (615, 980, 1,345, 1,710 mm distance from the floor), temperature did not show much difference at each location, 24.7/19.5, 24.6/19.5, 24.7/19.4 and 24.7/19.6°C, respectively. Also, the relative did not differ by locations (71/84%). Additionally, cucumber seedling characteristics of plant height, leaf area, fresh weight and dry weight of cucumber seedlings 8 days after sowing showed highly uniform quality, 4.1 ± 0.1 cm, 24.1 ± 3.7 cm 2 , 0.7 ± 0.13 g and 0.05 ± 0.008 g, respectively. Considering the results of environment parameter profiling and cucumber seedling uniformity, vegetable seedling production in a PFAL can be a promise tool in the era of climate change. Additional key words : PPFD, scion, sturdy transplants, plug tray *Corresponding author: skkim76@knu.ac.kr Received April 14, 2021; Revised April 20, 2021; Accepted April 20, 2021 Journal of Bio-Environment Control, Vol. 30, No. 2:126-132, April (2021) DOI https://doi.org/10.12791/KSBEC.2021.30.2.126 pISSN 1229-4675 eISSN 2765-3641

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Profiles of Environmental Parameters in a Plant Factory with Artificial Lighting and Evaluation on Growth of Cucumber Seedlings

Ultrasensitive Microarray Detection of DNA using Enzymatically Amplified SPR Imaging

Advanced oxidation processes (AOPs) have been reported as alternative ways for treating reverse osmosis (RO) concentrate which is the primary concern for water reclamation plants. AOPs are known to oxidize recalcitrant organic compounds by a highly reactive and nonselective oxidant, hydroxyl radical (&lt;sup&gt;&lt;/sup&gt;OH). Researchers showed that AOPs such as the conventional Fenton, UV/H&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt;, ozonation, electrochemical oxidation processes could remove organics in RO concentrate. However, comparing different AOPs has been rarely performed for the treatment of RO concentrate. In addition, the cost of these processes has not been fully explored. In this study, five different AOPs (i.e., the conventional Fenton, UV/H&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt;, ozonation, anodic oxidation, and electro-Fenton processes) were evaluated for the removal of dissolved organic carbon (DOC) in RO concentrate. The operation costs for DOC removal by these AOPs were also calculated. The results indicated that the conventional Fenton and ozonation processes were the most cost-efficient among the processes tested. 

/pdf/elimination-of-doc-in-ro-concentrate-from-a-wastewater-2jp6wy63.pdf

Elimination of DOC in RO concentrate from a wastewater reclamation plant: Cost comparison of different AOPs

The transfer of ionisable lomefloxacin (LOM) across a polarized interface between two immiscible electrolyte solutions (ITIES) was studied using cyclic and differential pulse voltammetry (DPV). The pH values of water (ionic strength = 0.02 M) interfacing with the 1,2-dichloroethane phase were varied to investigate the transfer behavior of differently charged LOM species, including protonated, neutral, and zwitterionic forms of LOM, namely HLOM+, LOM0, and H+LOM-. An ionic partition diagram for LOM was drawn with DPV response at various pH values, and the distinctive features of LOM were compared to those of fluoroquinolone antibiotics, which have similar pKa values. Physical and thermodynamic properties, including the formal transfer potential, lipophilicity, and Gibbs free energy of transfer LOM transfer were also evaluated. Furthermore, the photodegradation properties of differently charged LOM species and ophthalmic LOM drop samples (pH 5.0) were investigated after exposure to a UV (λ= 365 nm) source. Quantitative analysis of HLOM+ concentrations in buffer and diluted commercial eye drop solutions containing LOM was finally demonstrated using differential pulse stripping voltammetric responses at pH 3.0 and 5.0 involving the transfer of HLOM+ at a polarized microhole-water/polyvinylchloride-2-nitropheyloctylether gel interface. 

Voltammetric Study of Lomefloxacin Transfer at the Interface between Two Immiscible Electrolyte Solutions: Ionic Partition, Photodegradation, and Sensing Applications

Objectives: The aim of the study was to examine the influence of empathic ability and ego resilience on the ability of dental hygiene students to maintain good interpersonal relationships. 
Methods: Data were collected between March 1 and March 31, 2021, through a self-report questionnaire. The subjects for the study were 189 dental hygiene students who were selected using convenience sampling. 
Results: Ability in interpersonal relationships was found to have a statistically positive correlation with empathic ability (r = 0.338, p < .01 ) and ego resilience (r = 0.649, p < .01). Stepwise multiple regression revealed that ego resilience (β = 0.521, p = 0.001) was a significant predictor and accounted for 45.8% of ability in interpersonal relationships. 
Conclusions: The ability to conduct good interpersonal relationships needs to be increased in dental hygiene students by conducting an efficient program to teach ego resilience.

Hye Jin Lee

Papers

Profiles of Environmental Parameters in a Plant Factory with Artificial Lighting and Evaluation on Growth of Cucumber Seedlings

Ultrasensitive Microarray Detection of DNA using Enzymatically Amplified SPR Imaging

Elimination of DOC in RO concentrate from a wastewater reclamation plant: Cost comparison of different AOPs

Voltammetric Study of Lomefloxacin Transfer at the Interface between Two Immiscible Electrolyte Solutions: Ionic Partition, Photodegradation, and Sensing Applications

Influence of Empathic Ability and Ego Resilience on the Interpersonal Relationships of Dental Hygiene Students