4,351 results
Search Results
2. A Paper‐Like Hydrogel for Versatile Information Encryption and Decryption Via Chemical‐Induced Phase Separation.
- Author
-
Hou, Jun‐Bo, Chen, Xin‐Shi, and Zhao, Yue
- Subjects
- *
PHASE separation , *SMALL molecules , *POLYMERS , *MOLECULES - Abstract
Information coding, recording, encryption, and decryption are of great importance in the field of anti‐counterfeiting, especially in the current AI information era. Herein, a paper‐like hydrogel composed of solely H‐bonded poly(vinyl alcohol) (PVA) and poly(n‐vinylcaprolactam) (PNVCL), namely VAPN, is developed for multiple ways of encryption and decryption based on chemical‐induced phase separation. It not only exhibits excellent ability of ink absorption and retention by the noncovalent H‐bonds and n−π* interactions and good mechanical strength but also maintains a negligible volume change during the phase separation that is crucial for the information fidelity. Given that the noncovalent interactions are the driving force to trigger the phase separation in the hydrogel, available chemical inks are numerous ranging from small molecules to polymers. Furthermore, together with thermally induced phase separation, the different dynamic processes of the association and dissociation between ink molecules and the hydrogel endow the latter with reversible information recording and self‐erasing, temporary or permanent, and customized encryption and decryption. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
3. Diffusive dynamics on paper matrix.
- Author
-
Chaudhury, Kaustav, Chakraborty, Suman, and Kar, Shantimoy
- Subjects
- *
DIFFUSION , *PAPER , *FLUID dynamics , *DIAGNOSIS , *MOLECULES - Abstract
Writing with ink on a paper and the rapid diagnostics of diseases using paper cartridge, despite their remarkable diversities from application perspective, both involve the motion of a liquid from a source on a porous hydrophilic substrate. Here we bring out a generalization in the pertinent dynamics by appealing to the concerned ensemble-averaged transport with reference to the underlying molecular picture. Our results reveal that notwithstanding the associated complexities and diversities, the resultant liquid transport characteristics on a paper matrix, in a wide variety of applications, resemble universal diffusive dynamics. Agreement with experimental results from diversified applications is generic and validates our unified theory. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
4. Unveiling the Hidden Therapeutic Potential of Carnosine, a Molecule with a Multimodal Mechanism of Action: A Position Paper.
- Author
-
Caruso, Giuseppe
- Subjects
- *
CARNOSINE , *REACTIVE nitrogen species , *REACTIVE oxygen species , *MICROGLIA , *MOLECULES , *IN vivo studies - Abstract
Carnosine (β-alanyl-L-histidine) is a naturally occurring endogenous dipeptide and an over-the-counter food supplement with a well-demonstrated multimodal mechanism of action that includes the detoxification of reactive oxygen and nitrogen species, the down-regulation of the production of pro-inflammatory mediators, the inhibition of aberrant protein formation, and the modulation of cells in the peripheral (macrophages) and brain (microglia) immune systems. Since its discovery more than 100 years ago, a plethora of in vivo preclinical studies have been carried out; however, there is still substantial heterogeneity regarding the route of administration, the dosage, the duration of the treatment, and the animal model selected, underlining the urgent need for "coordinated/aligned" preclinical studies laying the foundations for well-defined future clinical trials. The main aim of the present position paper is to critically and concisely consider these key points and open a discussion on the possible "alignment" for future studies, with the goal of validating the full therapeutic potential of this intriguing molecule. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
5. Water molecules migration at oil-paper interface under the coupling fields of electric and temperature: a molecular dynamics study.
- Author
-
Wang, Wei, Dong, Wenyan, Jiang, Da, and Ning, Zhongzheng
- Subjects
- *
MOLECULES , *DIFFUSION , *ELECTRIC transformers , *ATOMS , *HYDROGEN bonding - Abstract
Moisture is an important factor affecting the insulation properties of transformers. Due to the limitations of macroscopic experimental methods, the diffusion of water at oil-paper interface cannot be accurately measured. Therefore, molecular dynamics method was used in this work to establish oil-paper layer model of 105 atoms. Through jointly analysing the aggregation degree, diffusion coefficient, free volume as well as radial distribution function of water molecules, the diffusion mechanism of water molecules at oil-paper interface was studied. The results show that when the initial water content in paper was high, water molecules would accumulate at oil-paper interface to form the local high-water region during heating. The polarisation of the electric field strengthened the hydrogen bonding interaction between water molecules and increased the probability of occurrence of the high-water region. Meanwhile, electric field reduced the free volume and diffusion coefficient of water molecules and rendered its diffusion coefficient anisotropic. What’s more, when the electric field was combined with the temperature field, the electric field played a leading role in the diffusion of water molecules while the temperature field was less affected. Diffusion coefficients of water molecules at different temperatures from molecular dynamics simulations were well consistent with experimental results, which verified the rationality of the model. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
6. Large‐Scale, Mechanically Robust, Solvent‐Resistant, and Antioxidant MXene‐Based Composites for Reliable Long‐Term Infrared Stealth.
- Author
-
Guo, Bi‐Fan, Wang, Ye‐Jun, Cao, Cheng‐Fei, Qu, Zhang‐Hao, Song, Jiang, Li, Shi‐Neng, Gao, Jie‐Feng, Song, Pingan, Zhang, Guo‐Dong, Shi, Yong‐Qian, and Tang, Long‐Cheng
- Subjects
HYALURONIC acid ,ANTIOXIDANTS ,EMISSIVITY ,MOLECULES ,COATED vesicles - Abstract
MXene‐based thermal camouflage materials have gained increasing attention due to their low emissivity, however, the poor anti‐oxidation restricts their potential applications under complex environments. Various modification methods and strategies, e.g., the addition of antioxidant molecules and fillers have been developed to overcome this, but the realization of long‐term, reliable thermal camouflage using MXene network (coating) with excellent comprehensive performance remains a great challenge. Here, a MXene‐based hybrid network comodified with hyaluronic acid (HA) and hyperbranched polysiloxane (HSi) molecules is designed and fabricated. Notably, the presence of appreciated HA molecules restricts the oxidation of MXene sheets without altering infrared stealth performance, superior to other water‐soluble polymers; while the HSi molecules can act as efficient cross‐linking agents to generate strong interactions between MXene sheets and HA molecules. The optimized MXene/HA/HSi composites exhibit excellent mechanical flexibility (folded into crane structure), good water/solvent resistance, and long‐term stable thermal camouflage capability (with low infrared emissivity of ≈0.29). The long‐term thermal camouflage reliability (≈8 months) under various outdoor weathers and the scalable coating capability of the MXene‐coated textile enable them to disguise the IR signal of various targets in complex environments, indicating the great promise of achieved material for thermal camouflage, IR stealth, and counter surveillance. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
7. Graphene Paper Decorated with a 2D Array of Dendritic Platinum Nanoparticles for Ultrasensitive Electrochemical Detection of Dopamine Secreted by Live Cells.
- Author
-
Zan, Xiaoli, Bai, Hongwei, Wang, Chenxu, Zhao, Faqiong, and Duan, Hongwei
- Subjects
BIOSENSOR research ,BIOMOLECULES ,NANOPARTICLES ,GRAPHENE ,ELECTRODES ,MOLECULES - Abstract
To circumvent the bottlenecks of non-flexibility, low sensitivity, and narrow workable detection range of conventional biosensors for biological molecule detection (e.g., dopamine (DA) secreted by living cells), a new hybrid flexible electrochemical biosensor has been created by decorating closely packed dendritic Pt nanoparticles (NPs) on freestanding graphene paper. This innovative structural integration of ultrathin graphene paper and uniform 2D arrays of dendritic NPs by tailored wet chemical synthesis has been achieved by a modular strategy through a facile and delicately controlled oil-water interfacial assembly method, whereby the uniform distribution of catalytic dendritic NPs on the graphene paper is maximized. In this way, the performance is improved by several orders of magnitude. The developed hybrid electrode shows a high sensitivity of 2 μA cm
−2 μ m−1 , up to about 33 times higher than those of conventional sensors, a low detection limit of 5 n m, and a wide linear range of 87 n m to 100 μ m. These combined features enable the ultrasensitive detection of DA released from pheochromocytoma (PC 12) cells. The unique features of this flexible sensor can be attributed to the well-tailored uniform 2D array of dendritic Pt NPs and the modular electrode assembly at the oil-water interface. Its excellent performance holds much promise for the future development of optimized flexible electrochemical sensors for a diverse range of electroactive molecules to better serve society. [ABSTRACT FROM AUTHOR]- Published
- 2016
- Full Text
- View/download PDF
8. Building pH Sensors into Paper-Based Small-Molecular Logic Systems for Very Simple Detection of Edges of Objects.
- Author
-
Jue Ling, Gaowa Naren, Kelly, Jessica, Moody, Thomas S., and de Silva, A. Prasanna
- Subjects
- *
HYDROGEN-ion concentration , *BACTERIA , *DNA , *DIFFUSION , *MOLECULES - Abstract
Genetically engineered bacteria and reactive DNA networks detect edges of objects, as done in our retinas and as also found within computer vision. We now demonstrate that simple molecular logic systems (a combination of a pH sensor, a photo acid generator, and a pH buffer spread on paper) without any organization can achieve this relatively complex computational goal with good fidelity. This causes a jump in the complexity achievable by molecular logic-based computation and extends its applicability. The molecular species involved in light dose-driven "off--on--off" fluorescence is diverted in the "on" state by proton diffusion from irradiated to unirradiated regions where it escapes a strong quencher, thus visualizing the edge of a mask. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
9. Two-dimensional viologen-based lanthanide coordination polymers as multi-stimuli responsive materials to light and amines with a fluorescence response.
- Author
-
Wang, Hao, Sun, Xiao-Han, Wang, Tian-Tian, Li, Yu-Xin, Xu, Ying-Ming, and Sun, Wen-Bin
- Subjects
FLUORESCENCE ,POLYMERS ,AMINES ,MOLECULES - Abstract
Integrating multi-stimuli response properties in one molecule is challenging. This study presents two 2D polymers, [(Bpydp)Ln(H
2 O)(BDC)]·NO3 ·2H2 O (Ln = Eu(1), Tb(2)), exhibiting rapid photo-responsiveness and the ability to detect specific small-molecule amines. In particular, complex 1 combines the functions of inkless printing, amine detection, anti-counterfeiting, and fluorescence recognition. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
10. Synthesis, photophysical characterisation, quantum-chemical study and in vitro antiproliferative activity of cyclometalated Ir(III) complexes based on 3,5-dimethyl-1-phenyl-1H-pyrazole and N,N-donor ligands.
- Author
-
Masternak, Joanna, Okła, Karol, Kubas, Adam, Voller, Jiří, Kozlanská, Karolína, Zienkiewicz-Machnik, Małgorzata, Gilewska, Agnieszka, Sitkowski, Jerzy, Kamecka, Anna, Kazimierczuk, Katarzyna, and Barszcz, Barbara
- Subjects
LIGANDS (Biochemistry) ,SCHIFF bases ,NAD (Coenzyme) ,DRUG target ,IN vitro studies ,MOLECULES ,CELL lines - Abstract
In this paper, we present the synthesis of four new complexes: the dimeric precursor [Ir(dmppz)
2 (μ-Cl)]2 (1) (Hdmppz -- 3,5-dimethyl-1-phenyl-1H-pyrazole) and heteroleptic bis-cyclometalated complexes: [Ir(dmppz)2 (Py2 CO)]PF6 •½ CH2 Cl2 (2), [Ir(dmppz)2 (H2 biim)]PF6 •H2 O (3), and [Ir(dmppz)2 (PyBIm)]PF6 (4), with auxiliary N,N-donor ligands: 2-di(pyridyl)ketone (Py2 CO), 2,2'-biimidazole (H2 biim) and 2-(2'-pyridyl)benzimidazole (PyBIm). In the obtained complexes, SC-X-ray analysis revealed that Ir(III) has an octahedral coordination sphere with chromophores of the type {IrN2 C2 Cl2 } (1) or {IrN4 C2 } (2-4). The complexes obtained, which have been fully characterised by physicochemical methods (CHN, TG, FTIR, UV-Vis, PL and ¹H,13 C,15 N NMR), were used to continue our studies on the factors influencing the cytotoxic properties of potential chemotherapeutic agents (in vitro). To this end, the following studies are presented: (i) comparative analysis of the effects on the biological properties of N,N-donor ligands and C,N-donor ligands in the studied complexes, (ii) studies of the interactions of the compounds with the selected molecular target: DNA and BSA (UV-Vis, CD and PL methods), (iii) and the reactivity towards redox molecules: GSH, NADH (UV-Vis and/or ESI-MS methods), (iv) cytotoxic activity (IC50 ) of potential chemotherapeutics against MCF-7, K-562 and CCRF-CEM cell lines. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
11. Comment on Naef, R.; Acree, W.E., Jr. Revision and Extension of a Generally Applicable Group-Additivity Method for the Calculation of the Standard Heat of Combustion and Formation of Organic Molecules. Molecules 2021, 26 , 6101.
- Author
-
Meier, Robert J.
- Subjects
HEAT of formation ,ACTIVITY coefficients ,NEUTRINO mass ,MOLECULES ,HEAT of combustion ,GIBBS' free energy ,SUBLIMATION (Chemistry) ,ISOBARIC heat capacity ,PHASE equilibrium - Abstract
The suggestion that the paper by Naef and Acree is the first one with the capability to treat "any molecule under the sun" is simply totally incorrect. In Ref. [[7]] (Neaf and Acree), reference to GC methods are only the previous publications by Naef and Acree. 10.3390/molecules25051147 7 Naef R., Acree W.E. Jr. Calculation of the Vapour Pressure of Organic Molecules by Means of a Group-Additivity Method and their Resultant Gibbs Free Energy and Entropy of Vaporization at 298.15 K. References 1 Naef R., Acree W.E. Jr. Revision and Extension of a Generally Applicable Group-Additivity Method for the Calculation of the Standard Heat of Combustion and Formation of Organic Molecules. [Extracted from the article]
- Published
- 2023
- Full Text
- View/download PDF
12. Biomimetic Graphene Actuators Enabled by Multiresponse Graphene Oxide Paper with Pretailored Reduction Gradient.
- Author
-
Han, Dong‐Dong, Liu, Yu‐Qing, Ma, Jia‐Nan, Mao, Jiang‐Wei, Chen, Zhao‐Di, Zhang, Yong‐Lai, and Sun, Hong‐Bo
- Subjects
- *
MOLECULES , *GRAPHENE oxide , *ACTUATORS , *ULTRAVIOLET radiation , *PHOTOREDUCTION - Abstract
The strong interaction between water molecules and graphene oxide (GO) enables moisture‐responsive graphene actuators, revealing great potential for soft robots. However, current strategies for developing smart graphene actuators fail to tailor their material property gradient in a controlled manner, and the driving manner is usually limited to single stimulus actuation. Here, a facile preparation of humidity/thermal/light multiresponsive graphene actuators by sequential vacuum filtration of GO and reduced GO (RGO) aqueous solutions is reported. The photoreduction degree of RGO layer is tuned precisely beforehand by changing ultraviolet (UV) light irradiation time, and thus a pretailored reduction gradient along the normal direction of the GO/RGO bilayer paper would form in a highly controlled manner. Taking advantage of the competitive water adsorption between the GO and RGO layers, as well as the thermal‐, light‐promoted desorption, the GO/RGO bilayers deform in response to moisture, light, and temperature changes; and the deformation degree can be modulated by controlling the gradient of oxygen‐containing groups (OCGs). As a proof of principle, a humidity‐responsive graphene mimosa and a humidity/thermal/light multiresponsive graphene actuators are fabricated. The GO/RGO bilayer paper with pretailored reduction gradient holds great promise for easy fabrication of biomimetic actuators that enable performing predictable deformation. Humidity/thermal/light multiresponsive graphene actuators are prepared by sequential vacuum filtration of graphene oxide (GO) and reduced GO (RGO) with a pretailored reduction gradient. GO/RGO bilayer actuators with tunable curving performance are achieved by controlling the photoreduction degree. Humidity responsive mimosa and multiresponsive paper robot are designed based on the competitive water adsorption between GO/RGO layers and the thermal‐, light‐promoted water desorption. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
13. Comment on the papers: Journal of Molecular Liquids 224 (2016) 1341–1347, Journal of Molecular Liquids 222 (2016) 854–862 and Journal of Molecular Liquids 225 (2017) 569–576.
- Author
-
Pantokratoras, Asterios
- Subjects
- *
HOMOTOPY theory , *EQUATIONS , *DIFFERENTIAL equations , *MOLECULES , *LIQUIDS - Abstract
The present comment concerns some doubtful results included in the above papers. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
14. Dynamic behavior of DNA molecules in microchannels: exploring deflective, elliptical, and spin motions induced by Saffman and Magnus forces.
- Author
-
Li, Zhiwei, Wang, Qiong, Niu, Yong, Wang, Ruiyu, Zhao, Wei, Zhang, Chen, Wang, Guiren, and Wang, Kaige
- Subjects
MICROCHANNEL flow ,MOLECULES ,GENETIC translation ,ELECTRIC fields ,ELECTRON configuration ,ION channels - Abstract
Precise manipulation of individual DNA molecules entering and leaving the channel ports, as well as their smooth passage across the channel, is essential for the detection and screening of DNA molecules using nano-/micro-fluidic technologies. In this paper, by combining single-molecule fluorescence imaging and numerical simulations, the motion states of DNA molecules translocating through a microfluidic channel under the action of the applied electric field are monitored and analyzed in detail. It is found that, under certain conditions of the applied electric field DNA molecules exhibit various motion states, including translation crossing, deflection outflow, reverse outflow, reciprocal movement, and elliptical movement. Simulations indicate that, under the action of Saffman force, DNA molecules can only undergo deflective motion when they experience a velocity gradient in the microchannel flow field; and they can only undergo elliptical motion when their deflective motion is accompanied by a spin motion. In this case, the Magnus force also plays an important role. The detailed study and elucidation of the movement states, dynamic characteristics and mechanisms of DNA molecules such as the deflective and elliptical motions under the actions of Saffman and Magnus forces have helpful implications for the development of related DNA/gene nano-/microfluidic chips, and for the separation, screening and detection of DNA molecules. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
15. A database of thermally activated delayed fluorescent molecules auto-generated from scientific literature with ChemDataExtractor.
- Author
-
Huang, Dingyun and Cole, Jacqueline M.
- Subjects
SCIENTIFIC literature ,DATABASES ,TEXT mining ,MOLECULES - Abstract
A database of thermally activated delayed fluorescent (TADF) molecules was automatically generated from the scientific literature. It consists of 25,482 data records with an overall precision of 82%. Among these, 5,349 records have chemical names in the form of SMILES strings which are represented with 91% accuracy; these are grouped in a subsidiary database. Each data record contains one of the following four properties: maximum emission wavelength (λ
EM ), photoluminescence quantum yield (PLQY), singlet-triplet energy splitting (ΔEST ), and delayed lifetime (τD ). The databases were created through text mining using ChemDataExtractor, a chemistry-aware natural-language-processing toolkit, which has been adapted for TADF research. The text-mined corpus consisted of 2,733 papers from the Royal Society of Chemistry and Elsevier. To the best of our knowledge, these databases are the first databases that have been auto-generated for TADF molecules from existing publications. The databases have been publicly released for experimental and computational applications in the TADF research field. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
16. Scent of knowledge: The molecular fingerprint of volatiles in an emblematic historical library in Italy.
- Subjects
DNA fingerprinting ,HISTORICAL libraries ,ODORS ,VOLATILE organic compounds ,ALIPHATIC compounds ,ALIPHATIC alcohols ,MOLECULES ,FURFURAL - Abstract
Heritage guidelines recognize odors as a value associated with a place. This study aims to clarify the connection between heritage and volatile organic compounds at the molecular level. At variance with previous studies, usually focused only on book‐related compounds from accelerated degradation tests, the whole air of one of the most significant historical libraries in Italy was studied. A sampling of the volatiles off‐gassing from the two most iconic rooms, respectively open and forbidden to visitors, was performed via a non‐invasive, nondestructive green method, solid‐phase‐micro‐extraction. The gas‐chromatographic analyses resulted in the appraisal of olfactory contributions from books, storage environment, and, for the first time, anthropic activities and pollution.Concerning the paper decay process, for the very first time, the presence of 2‐ethyl‐1‐hexanol in the chromatographic signature of the library air is rationalized according to the Guerbet reaction. The presence of all other compounds is explained by the paper decay process, anthropic sources, and pollution. Indoor air comprises analytes related to paper decay, identified by previous studies, and additional compounds never found before.Most volatile compounds are aliphatic and aromatic hydrocarbons, aldehydes, alcohols, terpenes, and terpenoids. Odor contributions from a selected number of analytes were pinpointed. Alkanes dominate the volatiles chromatographic signature, and impart a slight hydrocarbon smell. Aromatics supplement their characteristic aromatic odor. Aldehydes' very low odor threshold makes them strongly contribute to both fruity and fatty descriptors. Benzaldehyde, furfural, vanillin, and camphor add, respectively, an hint of almond, bread, vanilla, and camphor. Alcohols such as 2‐ethyl hexanol have a floral scent. Wood‐related terpenes and terpenoids contribute to the woody smell of the library.The digital molecular fingerprint of the "scent of knowledge" enables documentation, conservation, and future chemical reproduction of the historical library odor. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
17. On the centennials of the discoveries of the hydrogen bond and the structure of the water molecule: the short life and work of Eustace Jean Cuy (1897–1925).
- Subjects
CHEMICAL bonds ,HYDROGEN bonding ,ELECTRIC dipole moments ,HISTORY of chemistry ,ELECTRON pairs ,MOLECULES - Abstract
The bent structure of the water molecule, and its hydrogen‐bonding properties, arguably rank among the most impactful discoveries in the history of chemistry. Although the fact that the H—O—H angle must deviate from linearity was inferred early in the 20th century, notably from the existence of the electric dipole moment, it was not clear what that angle should be and why. One hundred years ago, a young PhD student at the University of California, Berkeley, Eustace J. Cuy, rationalized the V‐shape structure of a water molecule using the Lewis theory of a chemical bond, i.e. a shared electron pair, and its tetrahedral stereochemistry. He was inspired, in part, by the proposal of a weak (hydrogen) bond in water by two colleagues at Berkeley, Wendell Latimer and Worth Rodebush, who published their classic paper a year earlier. Cuy went on to suggest that other molecules, notably H2S and NH3, have similar structures, and presciently predicted that this architecture has broader consequences for the structure of water as a liquid. This short, but brilliant paper has been completely forgotten, perhaps due to the tragic death of the author at the age of 28; the hydrogen‐bond study is also rarely recognized. One of the most impactful publications on the structure of liquid water, a classic treatise published in 1933 by John Bernal and Ralph Fowler, does not mention either of the two pioneering papers. In this essay, the background for the two discoveries is described, including the brief history of Lewis's research on the nature of the chemical bond, and the history of the discovery of the hydrogen bond, which inspired Cuy to look at the structure of the water molecule. This is – to the best of the author's knowledge – the first biographical sketch of Eustace J. Cuy. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
18. Advances in Amylases—What's Going on?
- Author
-
Janeček, Štefan
- Subjects
RICE flour ,AMYLASES ,LIBRARY users ,DATABASES ,LIBRARY resources ,MOLECULES - Abstract
The document titled "Advances in Amylases—What's Going on?" provides an overview of the classification and research on amylolytic enzymes, specifically α-amylases. It discusses the classification of α-amylase families within the CAZy database, highlighting GH13 and GH57 as the main families, and mentions the existence of subfamilies within GH13. The document also mentions a special issue of the journal Molecules, titled "Advances in Amylases," which includes thirteen papers covering various aspects of amylolytic enzymes. The papers discuss topics such as enzyme hydrolysis of starch granules, inactivation of α-amylase, protein content in rice flour, and the structure and function of different α-amylase subfamilies. The document concludes by expressing appreciation to the contributors and reviewers of the special issue. This article by Å tefan JaneÄek explores the topic of molecules and their properties, providing an in-depth analysis of various types of molecules, their structures, functions, and interactions. It emphasizes the importance of understanding molecules in fields such as chemistry, biology, and medicine. The article is a valuable resource for library patrons conducting research on molecular science and its applications. [Extracted from the article]
- Published
- 2023
- Full Text
- View/download PDF
19. van der Waals interactions on semiconducting single-walled carbon nanotubes filled with porphyrin molecules: structure optimisation and Raman analysis.
- Author
-
El Fatimy, Anass, Boutahir, Mourad, Rahmani, Abdelhai, and Rahmani, Abdelali
- Subjects
CARBON nanotubes ,VAN der Waals forces ,HYBRID systems ,CHARGE transfer ,PORPHYRINS ,MOLECULES ,DENSITY functional theory ,MOMENTS method (Statistics) - Abstract
We present in this paper the stability of SWCNT hybrid systems with Py molecules. vdW type interactions are therefore the main interaction mechanism between encapsulated molecules and nanotubes, and the simplest model to describe these interactions is the Lennard-Jones potential. We have therefore performed energy minimization calculations on hybrid SWCNTs in a very wide range of diameters and of all chirality using the Lennard-Jones potential. The structure of the carbon nanotube is obtained from the winding of graphene on itself to form a hollow cylinder described by the pair of integers (n, m) entirely determining its structural characteristics, while the optimization of the geometry of the Py molecule is obtained by SIESTA using the exchange–correlation functional LDA. After minimisation, an approach that combines density functional theory, molecular mechanics, bond polarizability model, and spectral moment's method has been used to compute Raman spectra. Two types of vibration modes of SWCNTs attract our attention. Initially, the modifications of the modes of Py after encapsulation will be analyzed. In the following discussion, we examine how the vibrational properties of single-walled carbon nanotubes (SWCNTs) are affected by encapsulation, specifically in relation to the RBM and tangential modes. Our analysis of the Raman active modes supports the notion that the structural integrity of the SWCNTs remains intact and indicates the occurrence of a charge transfer between the Py molecules and SWCNTs. This charge transfer depends on the geometric position of Py in the SWCNT. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
20. Emerging opportunities of using large language models for translation between drug molecules and indications.
- Author
-
Oniani, David, Hilsman, Jordan, Zang, Chengxi, Wang, Junmei, Cai, Lianjin, Zawala, Jan, and Wang, Yanshan
- Subjects
LANGUAGE models ,GENERATIVE artificial intelligence ,DRUG discovery ,MOLECULES ,EVIDENCE gaps - Abstract
A drug molecule is a substance that changes an organism's mental or physical state. Every approved drug has an indication, which refers to the therapeutic use of that drug for treating a particular medical condition. While the Large Language Model (LLM), a generative Artificial Intelligence (AI) technique, has recently demonstrated effectiveness in translating between molecules and their textual descriptions, there remains a gap in research regarding their application in facilitating the translation between drug molecules and indications (which describes the disease, condition or symptoms for which the drug is used), or vice versa. Addressing this challenge could greatly benefit the drug discovery process. The capability of generating a drug from a given indication would allow for the discovery of drugs targeting specific diseases or targets and ultimately provide patients with better treatments. In this paper, we first propose a new task, the translation between drug molecules and corresponding indications, and then test existing LLMs on this new task. Specifically, we consider nine variations of the T5 LLM and evaluate them on two public datasets obtained from ChEMBL and DrugBank. Our experiments show the early results of using LLMs for this task and provide a perspective on the state-of-the-art. We also emphasize the current limitations and discuss future work that has the potential to improve the performance on this task. The creation of molecules from indications, or vice versa, will allow for more efficient targeting of diseases and significantly reduce the cost of drug discovery, with the potential to revolutionize the field of drug discovery in the era of generative AI. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
21. Introduction of new guest molecules into BEDTTTF radical-cation salts with tris(oxalato)ferrate.
- Author
-
Blundell, Toby J., Rusbridge, Elizabeth K., Pemberton, Rebecca E., Brannan, Michael J., Morritt, Alexander L., Ogar, Joseph O., Wallis, John D., Hiroki Akutsu, Yasuhiro Nakazawa, Shusaku Imajo, and Martin, Lee
- Subjects
SUPERCONDUCTING transitions ,SALTS ,MOLECULES ,BENZONITRILE ,CRYSTAL structure ,ETHANOL ,BENZALDEHYDE - Abstract
Radical-cation salts of formula β?-(BEDT-TTF)
4 [(H3 O)Fe(C2 O4 )3 ]·guest have produced a large number of superconductors and provided a route to introduce magnetism and chirality into the same multifunctional material. A relationship has been found in these salts between the length of the b axis and the superconducting Tc. Increasing the b axis length by introducing larger guest molecules, such as benzonitrile and nitrobenzene, gives the highest superconducting Tcs in this family of salts. Smaller guests such as pyridine show no superconducting transition, whilst asymmetrical guests which are larger than nitrobenzene have given a different bilayered structure. Other potential guest molecules have been limited by their ability to be used as the solvent in which the crystals are grown via electrocrystallisation. This paper reports a method which introduces guest molecules into the crystal which are a solid or liquid additive within the crystal-growing solvent 1,2,4-trichlorobenzene:ethanol. We present the crystal structures of five new BEDT-TTF radical-cation salts with tris(oxalato)ferrate anions using guest molecules toluene, phenol, benzaldehyde, 4-bromobenzaldehyde, and kojic acid. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
22. Targeting Group 3 Medulloblastoma by the Anti-PRUNE-1 and Anti-LSD1/KDM1A Epigenetic Molecules.
- Author
-
Bibbò, Francesca, Asadzadeh, Fatemeh, Boccia, Angelo, Sorice, Carmen, Bianco, Orazio, Saccà, Carmen Daniela, Majello, Barbara, Donofrio, Vittoria, Bifano, Delfina, De Martino, Lucia, Quaglietta, Lucia, Cristofano, Adriana, Covelli, Eugenio Maria, Cinalli, Giuseppe, Ferrucci, Veronica, De Antonellis, Pasqualino, and Zollo, Massimo
- Subjects
GLIAL fibrillary acidic protein ,CADHERINS ,MEDULLOBLASTOMA ,SMALL molecules ,EPIGENETICS ,MOLECULES - Abstract
Medulloblastoma (MB) is a highly malignant childhood brain tumor. Group 3 MB (Gr3 MB) is considered to have the most metastatic potential, and tailored therapies for Gr3 MB are currently lacking. Gr3 MB is driven by PRUNE-1 amplification or overexpression. In this paper, we found that PRUNE-1 was transcriptionally regulated by lysine demethylase LSD1/KDM1A. This study aimed to investigate the therapeutic potential of inhibiting both PRUNE-1 and LSD1/KDM1A with the selective inhibitors AA7.1 and SP-2577, respectively. We found that the pharmacological inhibition had a substantial efficacy on targeting the metastatic axis driven by PRUNE-1 (PRUNE-1-OTX2-TGFβ-PTEN) in Gr3 MB. Using RNA seq transcriptomic feature data in Gr3 MB primary cells, we provide evidence that the combination of AA7.1 and SP-2577 positively affects neuronal commitment, confirmed by glial fibrillary acidic protein (GFAP)-positive differentiation and the inhibition of the cytotoxic components of the tumor microenvironment and the epithelial–mesenchymal transition (EMT) by the down-regulation of N-Cadherin protein expression. We also identified an impairing action on the mitochondrial metabolism and, consequently, oxidative phosphorylation, thus depriving tumors cells of an important source of energy. Furthermore, by overlapping the genomic mutational signatures through WES sequence analyses with RNA seq transcriptomic feature data, we propose in this paper that the combination of these two small molecules can be used in a second-line treatment in advanced therapeutics against Gr3 MB. Our study demonstrates that the usage of PRUNE-1 and LSD1/KDM1A inhibitors in combination represents a novel therapeutic approach for these highly aggressive metastatic MB tumors. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
23. Computational modelling studies on in silico missenses in COVID-19 proteins and their effects on ligand–protein interactions.
- Author
-
Sule, Laxmi, Gupta, Swagata, Jain, Nilanjana, and Sapre, Nitin S.
- Subjects
AMINO acid residues ,PROTEIN engineering ,COVID-19 ,MOLECULES ,PROTEINS - Abstract
The paper presents the incorporation of in silico missenses and studies the effect of missenses to understand its effect on the ligand–protein interactions, of COVID-19 protein. In silico protein–ligand interaction, studies are being used to understand and investigate the drug-likeness of various molecules. 19 novel COVID-19 proteins are designed by inducing in silico missenses by mutating N691 amino acid residue in 7bv2 protein, the only residue forming H-bond with the ligand molecule in the parent protein. The work illustrates the effects of in silico-induced mutation on various interactions such as H-Bond, VDW, π-alkyl interactions, and changes in the number and type of surrounding amino acid residues. The results have suggested a common pattern of behaviour on mutation with T, V, W, and Y. Further, it is observed that the number and type of amino acid residues increase on mutation, suggesting the effect of mutation on the ligand–protein binding. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
24. Advances in the synthesis and application of gold nanoparticles for laser mass spectrometry: a mini review.
- Author
-
Płaza-Altamer, Aneta and Kołodziej, Artur
- Subjects
MOLECULES ,GOLD nanoparticles ,MOLECULAR weights ,SIGNAL detection ,NANOSTRUCTURED materials ,MASS spectrometry - Abstract
Laser desorption/ionization mass spectrometry (LDI-MS) techniques have emerged as powerful tools for analyzing compounds of natural and synthetic origins. However, conventional methods like matrix-assisted laser desorption/ionization (MALDI) often suffer from background signals and limited detection capabilities, particularly for low molecular weight compounds. Surface-assisted laser desorption/ionization (SALDI) methodologies, utilizing nanomaterials, have shown promise in overcoming these limitations. Gold nanoparticles (AuNPs) are among the most widely utilized nanomaterials in SALDI-MS applications. AuNPs offer several advantages over traditional MALDI matrices, such as reduced interference, internal calibration potential, and enhanced stability. They have been successfully employed for analyzing a diverse range of analytes, from low molecular weight (LMW) compounds to peptides, proteins, and biological entities. This paper provides a comprehensive overview of various synthesis methods, morphological properties, and comparisons with conventional MALDI matrices. Furthermore, it explores the application of AuNPs for analyzing LMW compounds and imaging various surfaces using LDI-MS techniques. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
25. Multiple soliton, soliton molecules and the other diverse wave solutions to the (2+1)-dimensional Kadomtsev–Petviashvili equation.
- Author
-
Wang, Kang-Jia, Shi, Feng, and Xu, Peng
- Subjects
- *
KADOMTSEV-Petviashvili equation , *SOLITONS , *MOLECULES , *ELASTIC waves - Abstract
The central purpose of this paper is to explore the nonlinear dynamics of the (2+1)-dimensional Kadomtsev–Petviashvili equation (KPE). The multiple soliton solutions (MSSs) are constructed via applying the Hirota method. Then the soliton molecules on the (x , y) -, (x , t) - and (y , t) -planes are extracted via imposing the velocity resonance conditions to the MSSs. Eventually, two effective techniques, the sub-equation approach (SEA) and the variational approach (VA), are employed to probe some other diverse wave solutions, which are the bright wave, dark wave, singular wave and the singular periodic wave solutions. The dynamics of the extracted solutions are unveiled graphically to exhibit the physical attributes. The attained solutions in this paper can enlarge the exact solutions of the (2+1)-dimensional KPE and enable us to understand the nonlinear dynamic behaviors better. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
26. Advancements in the preparation technology of small molecule artificial antigens and their specific antibodies: a comprehensive review.
- Author
-
Chen, Yaya, Ma, Shuo, Zhou, Meiling, Yao, Yuming, Gao, Xun, Fan, Xiaobo, and Wu, Guoqiu
- Subjects
SMALL molecules ,MOLECULES ,ANTIGENS ,ANALYTICAL chemistry ,IMMUNE response ,IMMUNOGLOBULINS - Abstract
Small molecules find extensive application in medicine, food safety, and environmental studies, particularly in biomedicine. Immunoassay technology, leveraging the specific recognition between antigens and antibodies, offers a superior alternative to traditional physical and chemical analysis methods. This approach allows for the rapid and accurate detection of small molecular compounds, owing to its high sensitivity, specificity, and swift analytical capabilities. However, small molecular compounds often struggle to effectively stimulate an immune response due to their low molecular weight, weak antigenicity, and limited antigenic epitopes. To overcome this, coupling small molecule compounds with macromolecular carriers to form complete antigens is typically required to induce specific antibodies in animals. Consequently, the preparation of small-molecule artificial antigens and the production of efficient specific antibodies are crucial for achieving precise immunoassays. This paper reviews recent advancements in small molecule antibody preparation technology, emphasizing the design and synthesis of haptens, the coupling of haptens with carriers, the purification and identification of artificial antigens, and the preparation of specific antibodies. Additionally, it evaluates the current technological shortcomings and limitations while projecting future trends in artificial antigen synthesis and antibody preparation technology. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
27. 3D cell aggregates amplify diffusion signals.
- Author
-
Arjmandi, Hamidreza, Kanebratt, Kajsa P., Vilén, Liisa, Gennemark, Peter, and Noel, Adam
- Subjects
MASS transfer ,PILOT projects ,GLUCOSE ,MOLECULES ,LIVER - Abstract
Biophysical models can predict the behavior of cell cultures including 3D cell aggregates (3DCAs), thereby reducing the need for costly and time-consuming experiments. Specifically, mass transfer models enable studying the transport of nutrients, oxygen, signaling molecules, and drugs in 3DCA. These models require the defining of boundary conditions (BC) between the 3DCA and surrounding medium. However, accurately modeling the BC that relates the inner and outer boundary concentrations at the border between the 3DCA and the medium remains a challenge that this paper addresses using both theoretical and experimental methods. The provided biophysical analysis indicates that the concentration of molecules inside boundary is higher than that at the outer boundary, revealing an amplification factor that is confirmed by a particle-based simulator (PBS). Due to the amplification factor, the PBS confirms that when a 3DCA with a low concentration of target molecules is introduced to a culture medium with a higher concentration, the molecule concentration in the medium rapidly decreases. The theoretical model and PBS simulations were used to design a pilot experiment with liver spheroids as the 3DCA and glucose as the target molecule. Experimental results agree with the proposed theory and derived properties. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
28. Cyclization Through Dual C(sp3)−H Functionalization.
- Author
-
Sadeghi, Masoud
- Subjects
- *
BIOCHEMICAL substrates , *CATALYSIS , *MOLECULES - Abstract
C(sp3)−H functionalization methods have been widely employed in many organic transformations such as cyclization reactions, heterocycle synthesis, cross‐coupling protocols, and photochemical transformations. Among these transformations, cyclization reaction through C(sp3)−H functionalization offers a direct route to convert simple linear substrates to complex products. There are three common modes of utilizing C(sp3)−H bonds in cyclization reactions including single, double, and dual C(sp3)−H functionalization. As the most challenging mode, dual C(sp3)−H functionalization refers to converting two separate C(sp3)−H bonds in one molecule into desired C−Z bonds which can be employed in cyclization reactions. Cyclization reaction via dual functionalization of C(sp3)−H bonds can be classified based on the C−H reactivities. Therefore, these reactions can be categorized into three classes based on the types of C(sp3)−H bonds including activated‐activated, activated‐unactivated, and unactivated‐unactivated C(sp3)−H bonds. Most published reports for cyclization reactions through dual C(sp3)−H functionalization involve activated‐activated C(sp3)−H bonds. However, the number of reported papers on the other two classes has been growing. This review focuses on the dual C(sp3)−H functionalization protocols used for cyclization reactions and categorizes the published papers based on the types of C(sp3)−H bonds. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
29. Bioactive Molecules Delivery through Ferritin Nanoparticles: Sum Up of Current Loading Methods.
- Author
-
Lucignano, Rosanna and Ferraro, Giarita
- Subjects
FERRITIN ,INDUSTRIAL costs ,SCIENTIFIC community ,THERMAL stability ,MOLECULES - Abstract
Ferritin (Ft) is a protein with a peculiar three-dimensional architecture. It is characterized by a hollow cage structure and is responsible for iron storage and detoxification in almost all living organisms. It has attracted the interest of the scientific community thanks to its appealing features, such as its nano size, thermal and pH stability, ease of functionalization, and low cost for large-scale production. Together with high storage capacity, these properties qualify Ft as a promising nanocarrier for the development of delivery systems for numerous types of biologically active molecules. In this paper, we introduce the basic structural and functional aspects of the protein, and summarize the methods employed to load bioactive molecules within the ferritin nanocage. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
30. On the Multiplicative Reformulated First Zagreb Index of n-Vertex Trees with Respect to Matching Number.
- Author
-
Yousaf, Shamaila and Naeem, Anisa
- Subjects
GRAPHIC methods ,BAND gaps ,OPTICAL properties ,QUANTUM perturbations ,MOLECULES - Abstract
The multiplicative first Zagreb index is the product of the square of the degree of vertices in a graph G. The multiplicative reformulated first Zagreb index is defined as Π
1, e (G) = Πx12x2∈E(G) (dG(x1) +dG(x1) - 2)²,where E(G) is the edge set of a graph G and dG(x1 ) is the degree of a vertex x1 in a graph G. In this paper, we characterize the minimum and maximum trees and unicyclic graphs with respect to matching and perfect matching using this graph invariant Π1,e (G) among the collection of all n-vertex graphs. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
31. Comment on Naef, R.; Acree, W.E., Jr. Calculation of the Three Partition Coefficients logPow, logKoa and logKaw of Organic Molecules at Standard Conditions at Once by Means of a Generally Applicable Group Additivity Method. Preprints 2023 , 2023120275.
- Author
-
Meier, Robert J.
- Subjects
SUBLIMATION (Chemistry) ,PARTITION coefficient (Chemistry) ,PREPRINTS ,MOLECULES - Abstract
The article discusses a group contribution (GC) method used to calculate the partition coefficients of organic molecules. The GC method assumes that certain aspects of chemical groups are consistent across different molecules. The authors of the article criticize previous publications by Naef and Acree for overlooking relevant research and not providing a rebuttal. They also compare Naef and Acree's results on the octanol-water partition coefficient to previous studies and highlight the limitations of their method. The authors suggest that Naef and Acree's claims of unmatched versatility are not supported by the literature. [Extracted from the article]
- Published
- 2024
- Full Text
- View/download PDF
32. 40.1L: Late-News Paper: A Novel RGB Color Patterning Method for Organic Light-Emitting-Diodes: Joule-heating Induced Color Patterning (JICP).
- Author
-
Hong, Won‐Eui, Jang, In-Goo, Lee, Hae‐Jin, Park, Doo‐Jung, Kim, Young‐Kwan, Lee, Ho‐Won, Lee, Song‐Eun, Lassiter, Brian, Haas, Dieter, and Ro, Jae‐Sang
- Subjects
ELECTRIC admittance ,LIGHT emitting diodes ,SUBSTRATES (Materials science) ,MOLECULES ,SUBLIMATION (Chemistry) - Abstract
A novel RGB color patterning method for the fabrication of AMOLEDs was demonstrated on a lab scale in this work. Jouleheating Induced Color Patterning (JICP) is a high resolution patterning process where sublimation of small organic molecules is induced by applying electric pulse to a pre-patterned conductive layer on a donor glass. It was found that the JICP process has a potential for high resolution patterning of >700 ppi and for patterning large-sized panels such as Gen. 8 glass substrate. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
33. The impact of vibrational Raman scattering of air on DOAS measurements of atmospheric trace gases.
- Author
-
Lampel, J., Frieß, U., and Platt, U.
- Subjects
LIGHT absorption ,ATMOSPHERIC pressure ,LIGHT scattering ,FRAUNHOFER lines ,SPECTRUM analysis ,REMOTE sensing ,MOLECULES ,WAVELENGTHS - Abstract
In remote sensing applications, such as differential optical absorption spectroscopy (DOAS), atmospheric scattering processes need to be considered. After inelastic scattering on N
2 and O2 molecules, the scattered photons occur as additional intensity at a different wavelength, effectively leading to filling-in of both solar Fraunhofer lines and absorptions of atmospheric constituents. Measured spectra in passive DOAS applications are typically corrected for rotational Raman scattering (RRS), also called Ring effect, which represents the main contribution to inelastic scattering. In contrast to that, vibrational Raman scattering (VRS) of N2 and O2 has often been thought to be negligible, but also contributes. Consequences of VRS are red-shifted Fraunhofer structures in scattered light spectra and filling-in of Fraunhofer lines, additional to RRS. We describe how to calculate VRS correction spectra in analogy to the Ring spectrum. We discuss further the impact of VRS cross-sections for O2 and N2 on passive DOAS measurements. The relevance of VRS is shown for the first time in spectral evaluations of Multi-Axis DOAS data. This measurement data yields in agreement with calculated scattering cross-sections, that the observed VRS cross-section amounts to 2.2±0.4% of the cross-section of RRS under tropospheric conditions. It is concluded, that this phenomenon has to be included in the spectral evaluation of weak absorbers as it reduces the measurement error significantly and can cause apparent differential optical depth of up to 2.5 × 10-4 . Its influence on the spectral retrieval of IO, Glyoxal, water vapour and NO2 in the blue wavelength range is evaluated. For measurements with a large Ring signal a significant and systematic bias of NO2 dSCDs up to (-3.8±0.4) × 1014 molec cm-2 at low elevation angles is observed if this effect is not considered. [ABSTRACT FROM AUTHOR]- Published
- 2015
- Full Text
- View/download PDF
34. Advanced resonator mass sensor for molecule detection in droplet.
- Author
-
Eidi, Amin, Shamsi, Mousa, and Badri Ghavifekr, Habib
- Subjects
DETECTORS ,MOLECULES ,RESONANCE - Abstract
Purpose: This paper aims to a novel fabricated resonator structure which consists of some single mechanical resonators as a mass sensor. Design/methodology/approach: The structure is proposed to detect the target molecules and cells in a droplet. Also, at this design the mechanical coupling springs of the proposed structure are designed in such a way that it resonates in shear resonance mode which minimizes the damping effect. Findings: This proposed design can be fabricated in different sizes due to the requirements of an application. Originality/value: The proposed design is fabricated in mesoscale and its mass sensitivity is evaluated and reported in this paper. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
35. Mechanism of antifreeze protein functioning and the "anchored clathrate water" concept.
- Author
-
Zielkiewicz, Jan
- Subjects
ANTIFREEZE proteins ,MOLECULAR dynamics ,HYDROGEN bonding ,SOLVATION ,MOLECULES ,ICE - Abstract
In liquid water, there is a natural tendency to form aggregates that consist of water molecules linked by hydrogen bonds. Such spontaneously formed aggregates are surrounded by a "sea" of disordered water molecules, with both forms remaining in equilibrium. The process of creating water aggregates also takes place in the solvation water of proteins, but in this case, the interactions of water molecules with the protein surface shift the equilibrium of the process. In this paper, we analyze the structural properties of the solvation water in antifreeze proteins (AFPs). The results of molecular dynamics analysis with the use of various parameters related to the structure of solvation water on the protein surface are presented. We found that in the vicinity of the active region responsible for the binding of AFPs to ice, the equilibrium is clearly shifted toward the formation of "ice-like aggregates," and the solvation water has a more ordered ice-like structure. We have demonstrated that a reduction in the tendency to create "ice-like aggregates" results in a significant reduction in the antifreeze activity of the protein. We conclude that shifting the equilibrium in favor of the formation of "ice-like aggregates" in the solvation water in the active region is a prerequisite for the biological functionality of AFPs, at least for AFPs having a well-defined ice binding area. In addition, our results fully confirm the validity of the "anchored clathrate water" concept, formulated by Garnham et al. [Proc. Natl. Acad. Sci. U. S. A. 108, 7363 (2011)]. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
36. Theory of entangled two-photon emission/absorption [E2P-EA] between molecules.
- Author
-
Chiang, Tse-Min and Schatz, George C.
- Subjects
QUANTUM interference ,QUANTUM dots ,PERTURBATION theory ,ABSORPTION ,MOLECULES ,PHOTON pairs ,ELECTRON donors - Abstract
This paper presents a comprehensive study of the theory of entangled two-photon emission/absorption (E2P-EA) between a many-level cascade donor and a many-level acceptor (which could be quantum dots or molecules) using second-order perturbation theory and where the donor–acceptor pair is in a homogeneous but dispersive medium. To understand the mechanism of E2P-EA, we analyze how dipole orientation, radiative lifetime, energy detuning between intermediate states, separation distance, and entanglement time impact the E2P-EA rate. Our study shows that there are quantum interference effects in the E2P-EA rate expression that lead to oscillations in the rate as a function of entanglement time. Furthermore, we find that the E2P-EA rate for a representative system consisting of two quantum dots can be comparable to one-photon emission/absorption (OP-EA) when donor and acceptor are within a few nm. However, the E2P-EA rate falls off much more quickly with separation distance than does OP-EA. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
37. A new superposition between lump, breather and line waves of the (2+1)-dimensional generalized Korteweg–de Vries equation in fluid mechanics.
- Author
-
Ma, Hongcai, Yue, Shupan, and Deng, Aiping
- Subjects
KORTEWEG-de Vries equation ,FLUID mechanics ,RESONANCE ,BOUND states - Abstract
This paper focuses on a new superposition between a single lump wave, breather waves and line solitons of the (2 + 1) -dimensional generalized Korteweg–de Vries (gKdV) equation. After deriving the N-soliton solutions, a new constraint, the long-wave limit and mode resonance method are used to construct a new hybrid solution. Further, a new velocity resonance condition is proposed to obtain a velocity resonance solution consisting of a single lump wave, a line soliton and breather waves, which remains relatively stationary and form a new bound state. It is worth pointing out that in most of the previous literature, lump wave and other waves will separate after they collide, but this paper derives a different result. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
38. New assignments of Raman spectra of tetrahedra and the effects of electronegativity. I. P4O10 and Si-containing molecules.
- Author
-
Bancroft, G. Michael, Dean, Philip A. W., Henderson, Grant S., and Nesbitt, H. Wayne
- Subjects
ELECTRONEGATIVITY ,X-ray photoelectron spectroscopy ,CHEMICAL bond lengths ,TETRAHEDRA ,BOND angles ,MOLECULES ,ASSIGNMENT problems (Programming) ,RAMAN spectroscopy - Abstract
Our new density functional theory calculations by Gaussian reproduce the bond lengths and Raman spectra of a number of model tetrahedral Si and P compounds [the ten compounds in the SiH
x D4−x and SiFx Cl4−x (x = 0–4) series, and the tetramer P4 O10 ]. The number of symmetric A1 peaks is determined by group theory, and the center of mass is especially important for the assignment of the three A1 peaks for P4 O10 to the two P–O stretches and the O–P–O bend. Additional Gaussian calculations on isolated C3v PO4 tetrahedra, using the P–O bond lengths and O–P–O bond angles from the P4 O10 optimization, also reproduce the three peak P4 O10 Raman spectra and provide an important guide to the assignment of the two low energy peaks at ∼500 and ∼700 cm−1 to the P–BO (BO = P–O–P) stretch and BO–P–BO bend, respectively, in contrast to all earlier assignments. In the SiFx Cl4−x series, there is a regular increase in the Si–F A1 frequency and a decrease in the Si–Cl A1 frequency across the series. Similar trends are seen in the SiClx (CH3 )4−x series, and these trends are due to changes in the electron densities in the tetrahedron when an electronegative F or Cl is replaced by a less electronegative Cl or CH3 , as measured by previous Si 2p, F 1s, Cl 2p, and C 1s x-ray photoelectron spectroscopy. These considerations serve as a guide for the interpretation of the Raman spectra of silicate glasses in Paper II [Bancroft et al., AIP Adv. 13, 125216 (2023)]. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
39. Metabolite Composition of Paper Birch Buds after Eleven Growing Seasons of Exposure to Elevated CO2 and O3.
- Author
-
Riikonen, Johanna, Kivimäenpää, Minna, Ossipov, Vladimir, Saunier, Amelie, and Marquardt, Paula
- Subjects
GROWING season ,PLANT metabolites ,BUDS ,BIRCH ,PHENOLS ,MOLECULES - Abstract
Research Highlights: Long-term exposure of paper birch to elevated carbon dioxide (CO
2 ) and ozone (O3 ) modified metabolite content of over-wintering buds, but no evidence of reduced freezing tolerance was found. Background and Objectives: Atmospheric change may affect the metabolite composition of over-wintering buds and, in turn, impact growth onset and stress tolerance of perennial plant species in spring. Materials and Methods: Low molecular weight compounds of paper birch (Betula papyrifera) buds, including lipophilic, polar and phenolic compounds were analyzed, and freezing tolerance (FT) of the buds was determined prior to bud break after 11 growing seasons exposure of saplings to elevated concentrations of CO2 (target concentration 560 µL L−1 ) and O3 (target concentration 1.5 × ambient) at the Aspen FACE (Free-Air CO2 and O3 Enrichment) facility. Results: The contents of lipophilic and phenolic compounds (but not polar compounds) were affected by elevated CO2 and elevated O3 in an interactive manner. Elevated O3 reduced the content of lipids and increased that of phenolic compounds under ambient CO2 by reallocating carbon from biosynthesis of terpenoids to that of phenolic acids. In comparison, elevated CO2 had only a minor effect on lipophilic and polar compounds, but it increased the content of phenolic compounds under ambient O3 by increasing the content of phenolic acids, while the content of flavonols was reduced. Conclusions: Based on the freezing test and metabolite data, there was no evidence of altered FT in the over-wintering buds. The impacts of the alterations of bud metabolite contents on the growth and defense responses of birches during early growth in spring need to be uncovered in future experiments. [ABSTRACT FROM AUTHOR]- Published
- 2020
- Full Text
- View/download PDF
40. Advances in the study of AIE polymers.
- Author
-
Yiran Pei, Leixin Liu, Xinfeng Cao, Jian Zhou, and Cuiyun Liu
- Subjects
DETECTORS ,MOLECULES ,LUMINESCENCE ,POLYMERS - Abstract
Aggregation-induced emission (AIE) can exhibit different properties in different situations, such as non-emission and highly fluorescent in the dissolved state of the molecule and in the aggregate or solid state, respectively. This property of AIE is distinguished from aggregation-induced quenching (ACQ) or even the opposite. Combining the AIE phenomenon with different polymers yields different polymers with corresponding AIE properties. In this paper, the mechanism, synthesis, branching and application of AIE in the fields of optoelectronic functional materials, sensors, biology, and environment are reviewed. It is hoped that this review will stimulate more research on molecular aggregates and promote further cross-fertilisation and greater development in the disciplines of materials, chemistry and biomedicine. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
41. Transient motion classification and segment analysis of diffusive trajectories of G proteins and coupled-receptors in a living cell.
- Author
-
Stanislavsky, Aleksander A. and Weron, Aleksander
- Subjects
G proteins ,LAPLACE distribution ,SIGNAL processing ,STATISTICS ,MOLECULES - Abstract
The molecular movement in single particle tracking (SPT) experiments shows a crucial role of diffusion in many biological processes such as signaling, cellular organization, transport mechanisms, and more. The SPT analysis detects not only classical Brownian motion but diffusion with other features. These include directed diffusion and confined motion. The behavior remains a challenging problem for several reasons. Due to the action of many physical processes, random trajectories of cellular molecules are segmented in different diffusive modes. Often their study requires sophisticated algorithms for the analysis of statistical properties. In this paper we consider the segment analysis for trajectories of G proteins and coupled-receptors in living cells. Their movement is often transient and switches among free diffusion, confined diffusion, directed diffusion, and immobility. Moreover, the confined segments can have both Gaussian and non-Gaussian statistics. The types of alternation of diffusive modes along the trajectories of G proteins and coupled-receptors are analyzed. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
42. Empirical rovibronic energy levels of C3.
- Author
-
Tennyson, Jonathan
- Subjects
ENERGY levels (Quantum mechanics) ,PLASMA astrophysics ,ELECTRONIC structure ,CARBON ,MOLECULES - Abstract
The carbon trimer, $ \hbox {C}_3 $ C 3 also known as propadienediylidene, is a quasi-linear molecule with an unusual electronic structure and a very flat bending potential in its ground electronic state. $ \hbox {C}_3 $ C 3 is an important species in astrophysics and carbon plasmas. Observed transition wavenumbers within and between the $ \tilde {X}\,^1\Sigma ^+_{\rm g} $ X ~ 1 Σ g + and $ \tilde {A}\,^1\Pi _{\rm u} $ A ~ 1 Π u states of $ \hbox {C}_3 $ C 3 are extracted from 21 papers and then subjected to a Measured Active Rotational-Vibrational Energy Levels (MARVEL) analysis: a corrected list of 4940 transitions are inverted to yield 1887 empirical energy levels. Uncertainties for these levels are determined using a newly implemented bootstrap method. These levels will provide input for developing a full spectroscopic model for $ \hbox {C}_3 $ C 3 which can used to generate a line list for the $ \tilde {X}\,^1\Sigma ^+_{\rm g} $ X ~ 1 Σ g + and $ \tilde {A}\,^1\Pi _{\rm u} $ A ~ 1 Π u states. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
43. Performance Degradation Caused by Ionization of the Released Gas Molecules in W-Band Gyrotron Traveling Wave Tube Based on a Simplified Ionization Model.
- Author
-
Wang, Yu, Liu, Guo, Jiang, Wei, Yao, Yelei, Wang, Jianxun, and Luo, Yong
- Subjects
TRAVELING-wave tubes ,COLLISIONS (Nuclear physics) ,GLOW discharges ,ION sources ,POTENTIAL well ,MOLECULES - Abstract
Analysis of the performance degradation for W-band lossy ceramic-loaded gyrotron traveling wave tubes (gyro-TWTs) caused by ionization of the released gas molecules is presented in this paper. The gas is released from the lossy ceramics during high average or continuous wave operation and ionized by colliding with the high-energy gyrating electrons. A potential well will be formed by the diffusion and accumulation of the ionization particles after the collision and then degrade the gyro-TWT performance. This process has been simulated based on a simplified model by introducing an equivalent ionization source combining ions and electrons. With a vacuum of 5.1 × 10 - 5 Pa, the theoretically calculated initial energy and equivalent ionization current are 0.01 eV and 0.5 A, respectively. It leads to a deterioration in the output power stability of the gyro-TWT. The performance degradation including spectrum and field pattern caused by gas ionization is also given and analyzed. One of the primary causes is the quality (pitch factor and velocity spread) degradation of the electron beam. According to the simulation and hot test experiments, the vacuum should be maintained below 2.1 × 10 - 6 Pa for stabilizing the amplified operation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
44. Associations amongst genes, molecules, cells, and organs in breast cancer metastasis.
- Author
-
Nathanson, S. David, Dieterich, Lothar C., Zhang, Xiang H-F., Chitale, Dhananjay A., Pusztai, Lajos, Reynaud, Emma, Wu, Yi-Hsuan, and Ríos-Hoyo, Alejandro
- Abstract
This paper is a cross fertilization of ideas about the importance of molecular aspects of breast cancer metastasis by basic scientists, a pathologist, and clinical oncologists at the Henry Ford Health symposium. We address four major topics: (i) the complex roles of lymphatic endothelial cells and the molecules that stimulate them to enhance lymph node and systemic metastasis and influence the anti-tumor immunity that might inhibit metastasis; (ii) the interaction of molecules and cells when breast cancer spreads to bone, and how bone metastases may themselves spread to internal viscera; (iii) how molecular expression and morphologic subtypes of breast cancer assist clinicians in determining which patients to treat with more or less aggressive therapies; (iv) how the outcomes of patients with oligometastases in breast cancer are different from those with multiple metastases and how that could justify the aggressive treatment of these patients with the hope of cure. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
45. Dynamic control of circumrotation of a [2]catenane by acid‐base switching.
- Author
-
Shi, Kelun, Jia, Guohui, Wu, Ying, Zhang, Shilong, and Chen, Jiawen
- Subjects
CROWN ethers ,SALTS ,MOLECULES ,MACHINERY - Abstract
Dynamic control of the motion in a catenane remains a big challenge as it requires precise design and sophisticated well‐organized structures. This paper reports the design and synthesis of a donor‐acceptor [2]catenane through mechanical interlocking, employing a crown ether featuring two dibenzylammonium salts on its side arms as the host and a cyclobis(paraquat‐p‐phenylene) (CBPQT ⋅ 4PF6) ring as the guest molecule. By addition of external acid or base, the catenane can form self‐complexed or decomplexed compounds to alter the cavity size of the crown ether ring, consequently affecting circumrotation rate of CBPQT ⋅ 4PF6 ring of the catenane. This study offers insights for the design and exploration of artificial molecular machines with intricate cascading responsive mechanisms. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
46. Domination and power domination in a one-pentagonal carbon nanocone structure.
- Author
-
Pandian, Shoba, N., Mohana, M., Arulperumjothi, and Ullah, Asad
- Subjects
NUCLEOTIDE sequence ,CARBON nanotubes ,NANOTECHNOLOGY ,CHEMICAL structure ,MOLECULES - Abstract
Domination is an important factor in determining the robustness of a graph structure. A thorough examination of the graph's topological structure is necessary for analyzing and examining it for various aspects. Understanding the stability of a chemical compound is a significant criterion in chemistry, which necessitates conducting numerous experimental tests. The domination number and power domination number are pivotal in defining a wide range of physical properties, which include physiochemical properties, thermodynamic properties, chemical activities, and biological activities. The one-pentagonal carbon nanocone (1-PCNC) is a member of the carbon nanocone family and has a structure similar to that of honeycomb networks, which are renowned for their robustness. In this paper, we find the domination number and power domination number of 1-PCNC by considering it as an (m-1)-layered infinite graph. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
47. Spasmolytic Activity of 1,3-Disubstituted 3,4-Dihydroisoquinolines.
- Author
-
Milusheva, Miglena, Stoyanova, Mihaela, Gledacheva, Vera, Stefanova, Iliyana, Todorova, Mina, and Nikolova, Stoyanka
- Subjects
DRUG discovery ,SMOOTH muscle ,RUTIN ,MUSCLE relaxants ,MOLECULES ,ABSORPTION - Abstract
This article concerns the spasmolytic activities of some novel 1,3-disubstituted 3,4-dihydroisoquinolines. These compounds can be evaluated as potential therapeutic candidates according to Lipinski's rule of five, showing high gastrointestinal absorption and the ability to cross the blood–brain barrier, which is a very important parameter in the drug discovery processes. In silico simulation predicted smooth muscle relaxant activity for all the compounds. Since smooth muscle contractile failure is a characteristic feature of many disorders, in the current paper, we concentrate on the parameters of the spontaneous contractile responses of smooth muscle (SM) cells compared to the well-known drug mebeverine. Two of the newly synthesized substances can be identified as essential modulating regulators and potentially used as therapeutic molecules. One of these molecules also showed significant DPPH antioxidant activity compared to rutin. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
48. ATP binding to Nerve Growth Factor (NGF) and pro-Nerve Growth Factor (proNGF): an endogenous molecular switch modulating neurotrophins activity.
- Author
-
Paoletti, Francesca
- Subjects
NERVE growth factor ,NEUROTROPHIN receptors ,MOLECULAR switches ,NEUROTROPHINS ,MOLECULAR interactions ,MOLECULES - Abstract
ATP has recently been reconsidered as a molecule with functional properties which go beyond its recognized role of the energetic driver of the cell. ATP has been described as an allosteric modulator as well as a biological hydrotrope with anti-aggregation properties in the crowded cellular environment. The role of ATP as a modulator of the homeostasis of the neurotrophins (NTs), a growth factor protein family whose most known member is the nerve growth factor (NGF), has been investigated. The modulation of NTs by small endogenous ligands is still a scarcely described area, with few papers reporting on the topic, and very few reports on the molecular determinants of these interactions. However, a detailed atomistic description of the NTs interaction landscape is of urgent need, aiming at the identification of novel molecules as potential therapeutics and considering the wide range of potential pharmacological applications for NGF and its family members. This mini-review will focus on the unique cartography casting the interactions of the endogenous ligand ATP, in the interaction with NGF as well as with its precursor proNGF. These interactions revealed interesting features of the ATP binding and distinct differences in the binding mode between the highly structured mature NGF and its precursor, proNGF, which is characterized by an intrinsically unstructured domain. The overview on the recent available data will be presented, together with the future perspectives on the field. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
49. Supercapacitors: Improving the Performance of Paper Supercapacitors Using Redox Molecules from Plants (Adv. Sustainable Syst. 8/2019).
- Author
-
Edberg, Jesper, Brooke, Robert, Granberg, Hjalmar, Engquist, Isak, and Berggren, Magnus
- Subjects
SUPERCAPACITOR performance ,DYE-sensitized solar cells ,ORGANIC electronics ,MOLECULES ,OXIDATION-reduction reaction ,ENERGY storage - Abstract
In article number 1900050, Jesper Edberg and co-workers use the redox-active dye molecule alizarin to enhance the energy storage capacity of all-organic paper-supercapacitors. The electrochemical performance and secondary doping effect of the dye on the conductive polymer PEDOT:PSS is investigated, and symmetric redox-enhanced supercapacitor devices are demonstrated. [Extracted from the article]
- Published
- 2019
- Full Text
- View/download PDF
50. Improving the Performance of Paper Supercapacitors Using Redox Molecules from Plants.
- Author
-
Edberg, Jesper, Brooke, Robert, Granberg, Hjalmar, Engquist, Isak, and Berggren, Magnus
- Subjects
SUPERCAPACITOR performance ,CONDUCTING polymers ,ENERGY storage ,DYE-sensitized solar cells ,MOLECULES ,PHOTOVOLTAIC cells ,CLEAN energy ,NATURAL dyes & dyeing - Abstract
A supercapacitor made from organic and nature‐based materials, such as conductive polymers (PEDOT:PSS), nanocellulose, and an the organic dye molecule (alizarin), is demonstrated. The dye molecule, which historically was extracted from the roots of the plant rubia tinctorum, is here responsible for the improvement in energy storage capacity, while the conductive polymer provides bulk charge transport within the composite electrode. The forest‐based nanocellulose component provides a mechanically strong and nonporous network onto which the conductive polymer self‐organizes. The electrical and electrochemical properties of the material composition are investigated and prototype redox‐enhanced supercapacitor devices with excellent specific capacitance exceeding 400 F g−1 and an operational stability over >1000 cycles are demonstrated. This new class of supercapacitors, which in part are based on organic materials from plants, represents an important step toward a green and sustainable energy technology. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.