43,489 results match your criteria properties corresponding


A stochastic micro to macro mechanical model for the evolution of bone-implant interface stiffness.

Acta Biomater 2021 Jun 12. Epub 2021 Jun 12.

Department of Biomaterials, Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden.

Upon placement of an implant into living bone, an interface is formed through which various biochemical, biological, physical and mechanical processes and interactions take place. This interface evolves over time as the mechanical properties of peri-implant bone increase. Owing to the multifactorial nature of interfacial processes, it is challenging to devise a comprehensive model for predicting the mechanical behavior of the bone-implant interface. Read More

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A deep convolutional visual encoding model of neuronal responses in the LGN.

Brain Inform 2021 Jun 15;8(1):11. Epub 2021 Jun 15.

Computer and Systems Engineering Department, Faculty of Engineering, Ain Shams University, 1 El-Sarayat St., Abbassia, Cairo, Egypt.

The Lateral Geniculate Nucleus (LGN) represents one of the major processing sites along the visual pathway. Despite its crucial role in processing visual information and its utility as one target for recently developed visual prostheses, it is much less studied compared to the retina and the visual cortex. In this paper, we introduce a deep learning encoder to predict LGN neuronal firing in response to different visual stimulation patterns. Read More

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Superhydrophobic Polymer Topography Design Assisted by Machine Learning Algorithms.

ACS Appl Mater Interfaces 2021 Jun 15. Epub 2021 Jun 15.

Digital Manufacturing and Design (DManD), Engineering Product Development Pillar, Singapore University of Technology and Design, 8 Somapah Road, Singapore 487372, Singapore.

Superhydrophobic surfaces have been largely achieved through various surface topographies. Both empirical and numerical simulations have been reported to help understand and design superhydrophobic surfaces. Many such successful surfaces have also been achieved using bioinspired and biomimetic designs. Read More

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Thermoresponsive properties of polymer hydrogels induced by copolymerization of hydrophilic and hydrophobic monomers: comprehensive study of monomer sequence and water affinity.

Soft Matter 2021 Jun 15. Epub 2021 Jun 15.

Department of Materials Science, Faculty of Engineering, The University of Shiga Prefecture, 2500 Hassaka, Hikone, Shiga 522-8533, Japan.

In order to raise the possibility of the practical use of thermoresponsive hydrogels in various fields, it is imperative to achieve on-demand control of responsive behavior especially by using a simple synthetic method with common monomers. To this end, we synthesized various hydrophilic/hydrophobic copolymer hydrogels from common acrylamide derivatives and acrylate monomers via free radical copolymerization, and examined the correlation between the structure and the swelling properties of the obtained gels, specifically from the viewpoint of the monomer sequence in the network chains and the affinity to water molecules. The obtained gels with a hydrophobic acrylamide monomer were shown to exhibit a sharp volume change in water upon heating at suitable monomer compositions. Read More

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Assigning confidence to molecular property prediction.

Expert Opin Drug Discov 2021 Jun 15:1-15. Epub 2021 Jun 15.

Chemical Physics Theory Group, Department of Chemistry, University of Toronto, Toronto, Canada.

: Computational modeling has rapidly advanced over the last decades. Recently, machine learning has emerged as a powerful and cost-effective strategy to learn from existing datasets and perform predictions on unseen molecules. Accordingly, the explosive rise of data-driven techniques raises an important question: What confidence can be assigned to molecular property predictions and what techniques can be used?: The authors discuss popular strategies for predicting molecular properties, their corresponding uncertainty sources and methods to quantify uncertainty. Read More

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Synthesis and properties of hypervalent electron-rich pentacoordinate nitrogen compounds.

Chem Sci 2020 Apr 22;11(19):5082-5088. Epub 2020 Apr 22.

Department of Materials Engineering Science, Graduate School of Engineering Science, Osaka University Toyonaka Osaka 560-8531 Japan.

Isolation and structural characterization of hypervalent electron-rich pentacoordinate nitrogen species have not been achieved despite continuous attempts for over a century. Herein we report the first synthesis and isolation of air stable hypervalent electron-rich pentacoordinate nitrogen cationic radical () species from oxidation of their corresponding neutral () species. In the cationic radical species, the nitrogen centers adopt a trigonal bipyramidal geometry featuring a 3-center-5-electron hypervalent attractive interaction. Read More

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Highly efficient non-doped blue fluorescent OLEDs with low efficiency roll-off based on hybridized local and charge transfer excited state emitters.

Chem Sci 2020 Apr 28;11(19):5058-5065. Epub 2020 Apr 28.

Key Laboratory of Rubber-Plastics of the Ministry of Education/Shandong Province (QUST), School of Polymer Science & Engineering, Qingdao University of Science &Technology 53-Zhengzhou Road Qingdao 266042 P. R. China

Designing a donor-acceptor (D-A) molecule with a hybridized local and charge transfer (HLCT) excited state is a very effective strategy for producing an organic light-emitting diode (OLED) with a high exciton utilization efficiency and external quantum efficiency. Herein, a novel twisting D-π-A fluorescent molecule (triphenylamine-anthracene-phenanthroimidazole; TPAAnPI) is designed and synthesized. The excited state properties of the TPAAnPI investigated through photophysical experiments and density functional theory (DFT) analysis reveal that its fluorescence is due to the HLCT excited state. Read More

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Soft-matter properties of multilayer chromosomes.

Authors:
Joan-Ramon Daban

Phys Biol 2021 Jun 14. Epub 2021 Jun 14.

Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Facultat de Biociències, Bellaterra, Barcelona, 08193, SPAIN.

This perspective aims to identify the relationships between the structural and dynamic properties of chromosomes and the fundamental properties of soft-matter systems. Chromatin is condensed into metaphase chromosomes during mitosis. The resulting structures are elongated cylinders having micrometer-scale dimensions. Read More

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Generating Acute and Chronic Experimental Models of Motor Tic Expression in Rats.

J Vis Exp 2021 May 27(171). Epub 2021 May 27.

The Leslie & Susan Goldschmied (Gonda) Multidisciplinary Brain Research Center, Bar-Ilan University;

Motor tics are sudden, rapid, recurrent movements that are the key symptoms of Tourette syndrome and other tic disorders. The pathophysiology of tic generation is associated with abnormal inhibition of the basal ganglia, particularly its primary input structure, the striatum. In animal models of both rodents and non-human primates, local application of GABAA antagonists, such as bicuculline and picrotoxin, into the motor parts of the striatum induces local disinhibition resulting in the expression of motor tics. Read More

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Selective Discrimination of VOCs Applying Gas Sensing Kinetic Analysis over a Metal Oxide-Based Chemiresistive Gas Sensor.

ACS Sens 2021 Jun 14. Epub 2021 Jun 14.

Advanced Technology Development Centre, Indian Institute of Technology Kharagpur, Kharagpur 721302, India.

Semiconducting metal oxide-based gas sensors have inadequate selectivity as they are responsive toward a variety of gases. Here, we report the implementation of gas sensing kinetic analysis of the sensor to identify the tested volatile organic compounds (VOCs) (2-propanol, formaldehyde, methanol, and toluene) precisely. A single chemiresistive sensor was employed having tin oxide-based hollow spheres as the sensing material, which were obtained by chemical synthesis. Read More

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Applications of 3D bioprinting in tissue engineering: advantages, deficiencies, improvements, and future perspectives.

J Mater Chem B 2021 Jun 14. Epub 2021 Jun 14.

Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, China.

Over the past decade, 3D bioprinting technology has progressed tremendously in the field of tissue engineering in its ability to fabricate individualized biological constructs with precise geometric designability, which offers us the capability to bridge the divergence between engineered tissue constructs and natural tissues. In this work, we first review the current widely used 3D bioprinting approaches, cells, and materials. Next, the updated applications of this technique in tissue engineering, including bone tissue, cartilage tissue, vascular grafts, skin, neural tissue, heart tissue, liver tissue and lung tissue, are briefly introduced. Read More

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Combining Experimental Isotherms, Minimalistic Simulations, and a Model to Understand and Predict Chemical Adsorption onto Montmorillonite Clays.

ACS Omega 2021 Jun 26;6(22):14090-14103. Epub 2021 May 26.

Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, Texas 77843-3122, United States.

An attractive approach to minimize human and animal exposures to toxic environmental contaminants is the use of safe and effective sorbent materials to sequester them. Montmorillonite clays have been shown to tightly bind diverse toxic chemicals. Due to their promise as sorbents to mitigate chemical exposures, it is important to understand their function and rapidly screen and predict optimal clay-chemical combinations for further testing. Read More

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Towards understanding non-equivalence of α and β subunits within human hemoglobin in conformational relaxation and molecular oxygen rebinding.

Chem Sci 2021 Apr 15;12(20):7033-7047. Epub 2021 Apr 15.

B. I. Stepanov Institute of Physics, National Academy of Sciences of Belarus 68 Nezavisimosti Ave Minsk 220072 Belarus

Picosecond to millisecond laser time-resolved transient absorption spectroscopy was used to study molecular oxygen (O) rebinding and conformational relaxation following O photodissociation in the α and β subunits within human hemoglobin in the quaternary R-like structure. Oxy-cyanomet valency hybrids, α(Fe-O)β(Fe-CN) and α(Fe-CN)β(Fe-O), were used as models for oxygenated R-state hemoglobin. An extended kinetic model for geminate O rebinding in the ferrous hemoglobin subunits, ligand migration between the primary and secondary docking site(s), and nonexponential tertiary relaxation within the R quaternary structure, was introduced and discussed. Read More

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Rational design of an "all-in-one" phototheranostic.

Chem Sci 2020 Jul 21;11(31):8204-8213. Epub 2020 Jul 21.

Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University Beijing 100871 P. R. China

We report here porphodilactol derivatives and their corresponding metal complexes. These systems show promise as "all-in-one" phototheranostics and are predicated on a design strategy that involves controlling the relationship between intersystem crossing (ISC) and photothermal conversion efficiency following photoexcitation. The requisite balance was achieved by tuning the aromaticity of these porphyrinoid derivatives and forming complexes with one of two lanthanide cations, namely Gd and Lu. Read More

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Acid-catalyzed proton exchange as a novel approach for relaxivity enhancement in Gd-HPDO3A-like complexes.

Chem Sci 2020 Jul 6;11(30):7829-7835. Epub 2020 Jul 6.

Department of Science and Technological Innovation, Università del Piemonte Orientale Viale T. Michel 11 15121 Alessandria Italy

A current challenge in medical diagnostics is how to obtain high MRI relaxation enhancement using Gd-based contrast agents (CAs) containing the minimum concentration of Gd ions. We report that in GdHPDO3A-like complexes a primary amide group located in close proximity to the coordinated hydroxyl group can provide a strong relaxivity enhancement at slightly acidic pH. A maximum relaxivity of = 9. Read More

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Supramolecular catalysis by recognition-encoded oligomers: discovery of a synthetic imine polymerase.

Chem Sci 2020 Jul 6;11(28):7408-7414. Epub 2020 Jul 6.

Department of Chemistry, University of Cambridge Lensfield Road Cambridge CB2 1EW UK

All key chemical transformations in biology are catalysed by linear oligomers. Catalytic properties could be programmed into synthetic oligomers in the same way as they are programmed into proteins, and an example of the discovery of emergent catalytic properties in a synthetic oligomer is reported. Dynamic combinatorial chemistry experiments designed to study the templating of a recognition-encoded oligomer by the complementary sequence have uncovered an unexpected imine polymerase activity. Read More

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Stationary distribution and density function expression for a stochastic SIQRS epidemic model with temporary immunity.

Nonlinear Dyn 2021 Jun 8:1-25. Epub 2021 Jun 8.

Nonlinear Analysis and Applied Mathematics(NAAM)-Research Group, Department of Mathematics, King Abdulaziz University, Jeddah, Saudi Arabia.

Recently, considering the temporary immunity of individuals who have recovered from certain infectious diseases, Liu et al. (Phys A Stat Mech Appl 551:124152, 2020) proposed and studied a stochastic susceptible-infected-recovered-susceptible model with logistic growth. For a more realistic situation, the effects of quarantine strategies and stochasticity should be taken into account. Read More

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Sequence dependence of Pd(II)-mediated base pairing by palladacyclic nucleobase surrogates.

J Inorg Biochem 2021 Jun 2;222:111506. Epub 2021 Jun 2.

Department of Chemistry, University of Turku, Vatselankatu 2, 20014 Turku, Finland. Electronic address:

A C-nucleoside derivative of phenylpyridine or the respective palladacycle was incorporated at either 3'- or 5'-terminus of a short oligodeoxynucleotide. Hybridization properties of these modified oligonucleotides were studied in a fluorescence-based competition assay in addition to conventional UV melting temperature analysis and compared with those of a previously prepared analogue featuring the modified nucleoside in the middle of the sequence. With the unpalladated phenylpyridine oligonucleotides, UV melting temperature qualitatively correlated with the ability to displace a strand from a double helix in the competition assay, decreasing in the order 5' > 3' > middle. Read More

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Evaluating the added value of multi-input atmospheric transport ensemble modeling for applications of the Comprehensive Nuclear Test-Ban Treaty organization (CTBTO).

J Environ Radioact 2021 Jun 9;237:106649. Epub 2021 Jun 9.

Comprehensive Nuclear Test-Ban Treaty Organization, Wagramerstrasse 5, 1400, Vienna, Austria.

The Comprehensive Nuclear Test-Ban Treaty Organization (CTBTO) runs to date operationally an atmospheric transport modeling chain in backward mode based on operational deterministic European Centre for Medium-Range Weather Forecasts-Integrated Forecasting System (ECMWF-IFS) and on National Centers for Environmental Prediction-Global Forecast System (NCEP-GFS) input data. Meanwhile, ensemble dispersion modeling is becoming more and more widespread due to the ever increasing computational power and storage capacities. The potential benefit of this approach for current and possible future CTBTO applications was investigated using data from the ECMWF-Ensemble Prediction System (EPS). Read More

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Mechanical property characterization of partially crystalline Poly-Ether-Ether-Ketone.

J Mech Behav Biomed Mater 2021 Jun 1;121:104600. Epub 2021 Jun 1.

CAS Key Laboratory for Mechanical Behavior and Design of Materials, Department of Modern Mechanics. University of Science and Technology of China, Hefei, Anhui, 230027, China.

The present study investigates the mechanical properties of partially crystalline Poly-Ether-Ether-Ketone between the glass transition and the cold crystallization. Biaxial tension, uniaxial tension, and DMA experiments were conducted to investigate the influence of temperature-induced crystallization on mechanical properties, and three stiffening behaviors are observed. Firstly, a 'U' type mechanical property is observed for all three experiments with first softening and then significant stiffening behavior with increasing temperature. Read More

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Mechanism and microstructure based concept to predict skull fracture using a hybrid-experimental-modeling-computational approach.

J Mech Behav Biomed Mater 2021 Jun 1;121:104599. Epub 2021 Jun 1.

SURVICE Engineering Company, 4695 Millennium Dr, Belcamp, MD, 21017, USA.

Cellular and tissue-scale indent/impact thresholds for different mechanisms of functional impairments to the brain would be the preferred method to predict head injuries, but a comprehensive understanding of the dominant possible injury mechanisms under multiaxial stress-states and rates is currently not available. Until then, skull fracture could serve as an indication of head injury. Therefore the ability to predict the initiation of skull fracture through finite element simulation can serve as an in silico tool for assessing the effectiveness of various head protection scenarios. Read More

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Dataset of enhanced UV-C emitting properties of Pr-activated rare earth phosphates driven by structural lattice distortion through a substitutional doping strategy.

Authors:
Junsang Cho

Data Brief 2021 Aug 17;37:107145. Epub 2021 May 17.

Department of Chemistry, Duksung Women's University, Seoul 01369, South Korea.

Ongoing global pandemic crisis of coronavirus (COVID-19) and its fast- and wide-spreading into entire worlds, critically intimidating our current and future lives, put more emphasis on the development of efficient UV-C emitting phosphors for the germicidal and medical applications due to the intense UV-C emission, which can effectively deactivate such viruses. In this regard, UV-C emitting Pr-activated three presentative rare earth phosphate such as YPO, LaPO, and La ( mol.%, =0-0. Read More

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1T-Phase Dirac Semimetal PdTe Nanoparticles for Efficient Photothermal Therapy in the NIR-II Biowindow.

ACS Appl Mater Interfaces 2021 Jun 10. Epub 2021 Jun 10.

International Collaborative Laboratory of 2D Materials for Optoelectronic Science & Technology, Engineering Technology Research Center for 2D Materials Information Functional Devices and Systems of Guangdong Province, Institute of Microscale Optoelectronics, Shenzhen University, No. 3688 Nanhai Avenue, Shenzhen 518060, China.

1T-phase transition-metal dichalcogenides (TMDs) nanomaterials are one type of emerging and promising near-infrared II (NIR-II) photothermal agents (PTAs) derived from their distinct metallic electronic structure, but it is still challenging to synthesize these nanomaterials. Herein, PdTe nanoparticles (PTNs) with a 1T crystal symmetry and around 50 nm in size are prepared by an electrochemical exfoliation method, and the corresponding photothermal performances irradiated under a NIR-II laser have been explored. The encapsulation of 1,2-distearoyl--glycero-3-phosphoethanolamine-poly(ethylene glycol) (DSPE-PEG) endows PTNs with water solubility, enhanced photothermal stability, and high biocompatibility. Read More

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Anisotropically Fatigue-Resistant Hydrogels.

Adv Mater 2021 Jun 10:e2102011. Epub 2021 Jun 10.

Department of Mechanical and Energy Engineering, Southern University of Science and Technology, Shenzhen, 518055, China.

Nature builds biological materials from limited ingredients, however, with unparalleled mechanical performances compared to artificial materials, by harnessing inherent structures across multi-length-scales. In contrast, synthetic material design overwhelmingly focuses on developing new compounds, and fails to reproduce the mechanical properties of natural counterparts, such as fatigue resistance. Here, a simple yet general strategy to engineer conventional hydrogels with a more than 100-fold increase in fatigue thresholds is reported. Read More

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Variational Discrete Action Theory.

Phys Rev Lett 2021 May;126(20):206402

Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027, USA.

Here we propose the variational discrete action theory (VDAT) to study the ground state properties of quantum many-body Hamiltonians. VDAT is a variational theory based on the sequential product density matrix (SPD) ansatz, characterized by an integer N, which monotonically approaches the exact solution with increasing N. To evaluate the SPD, we introduce a discrete action and a corresponding integer time Green's function. Read More

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Structural and functional characterization of a plant alpha-actinin.

FEBS Open Bio 2021 Jun 10. Epub 2021 Jun 10.

Departments of Chemistry, Umeå University, SE-901 87, Umeå, Sweden.

The Australian tree malletwood (Rhodamnia argentea) is unique. The genome of malletwood is the only known plant genome that contains a gene coding for an α-actinin-like protein. Several organisms predating the animal-plant bifurcation express an α-actinin or α-actinin-like protein. Read More

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Mechanochromic luminescence properties of fluoro-substituted pinene-containing cyclometalated platinum(II) complexes with multiple triplet excited states.

Dalton Trans 2021 Jun 10. Epub 2021 Jun 10.

College of Chemistry and Chemical Engineering, Key Laboratory of Water Pollution Treatment & Resource Reuse of Hainan Province, Hainan Normal University, Haikou 571158, P.R. China.

The structure-mechanochromism relationship is explored with respect to packing patterns and corresponding intermolecular interactions that are affected by the number and location of -F. The distinct and reversible mechanochormic luminescence (Δλem up to ca. 90 nm) of yellow solids (-)-1-Yg, (-)-2-Yg, and (-)-3-Yg was displayed with a simultaneous crystal-to-amorphous transformation. Read More

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Efficient N- and O-Sensing Properties of PtSe With Proper Intrinsic Defects.

Front Chem 2021 24;9:676438. Epub 2021 May 24.

School of Physics and Optoelectronic Engineering, Xidian University, Xi'an, China.

Developing efficient N and O gas sensors is of great importance to our daily life and industrial technology. In this work, first-principles calculations are performed to study the N and O gas-sensing properties of pure and defected PtSe. It is found that both N and O adsorb weakly on pure PtSe, and adsorption of the molecules induces negligible changes in the electrical and optical properties. Read More

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Preparation of autoxidative water-reducible alkyd resins from waste polyethylene terephthalate.

R Soc Open Sci 2021 Jun 2;8(6):202375. Epub 2021 Jun 2.

Department of Coatings and Polymeric Materials, College of Chemistry and Chemical Engineering, Jiangxi Science and Technology Normal University, Nanchang 330013, People's Republic of China.

In this paper, the waste polyethylene terephthalate (PET) was glycolysed by trimethylolpropane with zinc acetate as catalyst. The effects of different content glycolysis product of waste PET on the appearance, viscosity, particle size and molecular weight of autoxidative water-reducible alkyd resins and the corresponding film adhesion, flexibility, impact resistance, gloss, hardness and chemical resistance were studied. Meanwhile, experimental results were compared with commercial water-reducible alkyd and water-reducible alkyd without the glycolysis product of waste PET. Read More

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Estimation of important binding sites in compounds that interact with proteins.

Comput Biol Chem 2021 May 19;93:107511. Epub 2021 May 19.

Department of Information and Intelligence Engineering, Kobe University, Japan. Electronic address:

Proteins are one of the important substances in understanding biological activity, and many of them express the function by binding to other proteins or small molecules (ligands) on the molecular surface. This interaction often occurs in the hollows (pockets) on the molecular surface of the protein. It is known that when pockets are similar in structure and physical properties, they are likely to express similar functions and to bind similar ligands. Read More

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