Article
Chemistry, Organic
Benjamin H. Rajewski, Madison M. Wright, Taylor A. Gerrein, Juan R. Del Valle
Summary: The identification of unnatural residues that stabilize polyproline type 2 (PPII) folds can aid in the design of peptidomimetics targeting PPII-binding domains. N-aminoglycine (aGly) is found to be an effective PPII promoter. Further derivatization of an aGly-containing peptide affords N'-alkylated analogues with increased helical propensity. Backbone N-amination of glycine represents a convenient approach to stabilize PPII conformation and allows for the diversity-oriented synthesis of optimally constrained folds.
Article
Food Science & Technology
Alejandro Londono-Moreno, Zayra Mundo-Franco, Margarita Franco-Colin, Carolina Buitrago-Arias, Martha Lucia Arenas-Ocampo, Antonio Ruperto Jimenez-Aparicio, Edgar Cano-Europa, Brenda Hildeliza Camacho-Diaz
Summary: The aim of this study was to develop a microencapsulate of a complex matrix using polysaccharides to protect and control the release of CPC. The results showed that the encapsulation efficiency of the matrix-type encapsulates increased as more components were added to the mixtures. Therefore, matrix M4 exhibited an encapsulation efficiency for CPC of 98% and a bioaccessibility of 10.65 +/- 0.65% after the passage of encapsulates through in vitro digestion.
Article
Multidisciplinary Sciences
Jianwei Li, Xin Xu, Jian Shi, Juan A. Hermoso, Lok-To Sham, Min Luo
Summary: This study reveals the regulatory mechanism of Mycobacterium tuberculosis FtsEX as a non-canonical regulator in peptidoglycan degradation. The cryo-EM structures of the FtsEX system and its complex with RipC, as well as the ATP-activated state, provide detailed insights into the signal transduction mechanism leading to the activation of RipC. The findings contribute to the understanding of FtsEX and RipC regulation and offer guidance for drug design targeting peptidoglycan remodeling.
NATURE COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Evgeny A. Mashkovich, Kirill A. Grishunin, Roman M. Dubrovin, Anatoly K. Zvezdin, Roman Pisarev, Alexey Kimel
Summary: Understanding spin-lattice coupling is crucial in modern condensed matter physics, and a efficient nonlinear mechanism of spin-lattice coupling driven by terahertz light pulses has been reported. The study reveals the distinctive functionality of antiferromagnets allowing ultrafast spin-lattice coupling using light.
Review
Chemistry, Multidisciplinary
Milad Hadidi, Chen Tan, Elham Assadpour, Mohammad Saeed Kharazmi, Seid Mahdi Jafari
Summary: The high prevalence of chronic illnesses has become a concern, and bioactive compounds have shown potential as health-enhancing substances. However, their application is limited due to solubility and bioavailability issues. Plant proteins have emerged as green alternatives for designing nanocarriers, offering compatibility with bioactives and unique functional properties. Recent studies have demonstrated the use of emerging plant proteins as nanocarriers for protection and delivery of bioactives. These proteins can improve solubility, stability, and bioavailability, especially when combined with other biopolymers. This review covers the sources and importance of plant proteins, encapsulation techniques, and their application as nanocarriers for food bioactives.
JOURNAL OF CONTROLLED RELEASE
(2023)
Article
Biochemical Research Methods
Ziyang Zhang, Fei Fan, Weinan Shi, Tianrui Zhang, Shengjiang Chang
Summary: Researchers proposed a sensing method using THz spectroscopy to characterize protein denaturation, which can achieve thermal denaturation sensing, concentration sensing, and type identification with high detection sensitivity and accuracy.
BIOMEDICAL OPTICS EXPRESS
(2022)
Article
Biochemistry & Molecular Biology
M. Mompean, B. S. McAvan, S. S. Felix, M. A. Trevino, J. Oroz, R. Lopez-Sanchez, D. Pantoja-Uceda, E. J. Cabrita, A. J. Doig, D. V. Laurents
Summary: The study suggests that Gly-rich proteins may form polyproline II helices to stabilize biomolecular condensates.
ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS
(2021)
Article
Chemistry, Physical
Swarnadeep Bakshi, V. M. Vaisakh, Ritwick Sarkar, Sayantan Majumdar
Summary: The study investigates the yielding dynamics of in vitro reconstituted networks of uncrosslinked type-I collagen using shear rheology and high-resolution boundary imaging. The differential shear modulus of the network initially increases with applied strain in the non-linear regime, then drops as the network starts to yield beyond a critical strain. Strong strain-localization and slippage between the network and the rheometer plate sets in beyond the peak of the shear modulus, eventually leading to detachment.
Article
Plant Sciences
Yixue Zhang, Xinzhong Wang, Yafei Wang, Lian Hu, Pei Wang
Summary: China's tomato cultivation area and annual tomato output are significant, representing 15 thousand km(2) and 55 million tons respectively. Due to the high drought sensitivity of tomatoes, the accurate detection of water status is crucial for effective tomato management. In this study, we proposed a method using terahertz spectroscopy to detect tomato leaf moisture content and explored the relationship between water stress and terahertz spectral data.
FRONTIERS IN PLANT SCIENCE
(2023)
Article
Multidisciplinary Sciences
Daquan Yang, Weiguang Wang, Erpeng Lv, Haiming Wang, Bingchao Liu, Yanzhao Hou, Jin-Hui Chen
Summary: A programmable vanadium dioxide metasurface is proposed for THz frequencies, which can switch between insulating and metallic states via external electrical stimulation, allowing for dynamic modulation of the electromagnetic response. By controlling the voltages of different columns, phase gradients are achieved for THz beam steering. Different coding methods offer varying degrees of optical phase control and improved diffraction efficiency.
Article
Chemistry, Multidisciplinary
Siyu Chen, Wenlu Shi, W. Ho
Summary: We demonstrate rectification spectroscopy (RS) for single molecules using continuous-wave terahertz (CW THz) radiation at the tunneling junction of a scanning tunneling microscope (STM) at 8 K. CW THz-RS offers a new technique for studying single-molecule vibrational and magnetic excitation spectroscopy, alongside inelastic electron tunneling spectroscopy (IETS). By comparing IETS and THz RS, we find that CW THz induces a sinusoidal bias modulation with an amplitude that is linearly dependent on the THz far-field amplitude. This THz-induced bias modulation amplitude appears to be sensitive to the alignment of the THz beam but insensitive to changes in the tunneling gap smaller than the THz wavelength.
Article
Polymer Science
Manjot Kaur, Deenan Santhiya
Summary: The study presents a comprehensive analysis of zein film blended with glycerol and essential oils, showcasing excellent UV shielding and antimicrobial properties against spoilage microorganisms. The incorporation of essential oils significantly reduces microbial growth on fruit samples from day 3 onwards. The fabricated films possess good barrier properties and mechanical strength, making them suitable for extending the shelf life of food and drug products.
JOURNAL OF APPLIED POLYMER SCIENCE
(2021)
Article
Polymer Science
Punyawee Kachaanun, Apon Numnuam, Jaruwan Mayakun, Kaewta Kaewtatip
Summary: In this study, brown alga was used as a reinforcement material to produce wheat gluten biocomposites. By adding brown alga powder and applying sonication treatments, the properties of the biocomposites were improved, showing a significant enhancement in tensile strength compared to the neat wheat gluten.
JOURNAL OF APPLIED POLYMER SCIENCE
(2022)
Article
Polymer Science
Marco Bontempi, Rosario Capozza, Andrea Visani, Milena Fini, Gianluca Giavaresi, Alessandro Gambardella
Summary: In this study, the near-surface elasticity of semicrystalline polyether ether ketone (PEEK) at room temperature was quantitatively mapped using a standard atomic force microscopy setup in nanoindentation mode. Two localized moduli distributions were observed at approximately 0.6 and 0.9 GPa below the plastic threshold of the polymer, at indentation loads ranging from 120-450 nN. The localization of the amorphous and crystalline phases on the free surface of the polymer was detected with unprecedented detail. This study provides insights into quantitatively characterizing complex biopolymer systems on the nanoscale and guiding the optimal design of micro- and nanostructures for advanced biomedical applications.
Article
Optics
Tobias Pfeiffer, Jens Klier, Georg von Freymann, Daniel Molter
Summary: Nonlinear frequency conversion provides an elegant method for detecting low-energy photons with different wavelengths from the pump wavelength while providing phase information. We propose a phase-sensitive measurement method in the terahertz spectral range using visible light, which enables fast determination of layer thicknesses and achieves phase-resolved detection of terahertz pulses with standard equipment.
Article
Chemistry, Analytical
Johanna Kolbel, Qi Li, Terence L. Threlfall, J. Axel Zeitler
Summary: A versatile setup based on a microfluidic platform is developed for investigating liquid samples at various temperatures using terahertz spectroscopy. This setup allows for concentration measurements of both pure liquid phase solutions and semicrystalline systems, with equivalent solute concentration calculated from low frequency absorption during crystallization. The MgSO4-water system is used as an example to illustrate this novel method.
ANALYTICAL CHEMISTRY
(2022)
Article
Medicine, Research & Experimental
Qi Li, Andrew D. Bond, Timothy M. Korter, J. Axel Zeitler
Summary: Terahertz time-domain spectroscopy was used to investigate two polymorphs of aspirin and confirmed their similar crystal structures and spectral features. Unique vibrational modes were identified for each polymorph, allowing for their discrimination. It was also found that form II had a greater degree of structural disorder and was expected to be more stable at higher temperatures.
MOLECULAR PHARMACEUTICS
(2022)
Article
Chemistry, Multidisciplinary
Qi Li, Johanna Kolbel, Margaret P. Davis, Timothy M. Korter, Andrew D. Bond, Terrence Threlfall, J. Axel Zeitler
Summary: Terahertz time-domain spectroscopy in a transmission geometry combined with visual analysis was used to investigate the crystallization process of MgSO4 solution. The method allowed the extraction of information about the liquid phase before and during crystallization, aiding the investigation of solvation dynamics and the behavior of molecular species at phase boundaries.
CRYSTAL GROWTH & DESIGN
(2022)
Article
Pharmacology & Pharmacy
Runqiao Dong, J. Axel Zeitler
Summary: The dissolution of coated pharmaceutical tablets is a complex process that depends on the structure of the coating and its interaction with the tablet core. This study used terahertz pulsed imaging to investigate the penetration of the dissolution medium into coated tablets. The analysis revealed a discontinuity in density at the interface between the coating and core, which affected the liquid transport and dissolution performance. The study provides insights into the role of coating in tablet dissolution.
INTERNATIONAL JOURNAL OF PHARMACEUTICS
(2022)
Article
Chemistry, Physical
Mizuki Mohara, Margaret P. Davis, Timothy M. Korter, Kei Shimura, Touya Ono, Kenji Aiko
Summary: Understanding the solid-state transitions of active pharmaceutical ingredients (APIs) is crucial for quality control and bioavailability. Terahertz spectroscopy is a powerful tool for investigating the crystal structures of APIs. The study found that the ezetimibe monohydrate (EZT-MH) crystal has greater anharmonic character and is more stable than pure ezetimibe (EZT) and water. Additionally, the presence of excipients in the formulation tablets slows down the hydration process of the API.
JOURNAL OF PHYSICAL CHEMISTRY A
(2022)
Article
Engineering, Electrical & Electronic
Qi Li, Johanna Kolbel, Terry Threlfall, J. Axel Zeitler
Summary: A versatile setup based on terahertz time-domain spectroscopy has been developed to monitor crystallization process, characterize crystal structures, and investigate solvent dynamics. This setup allows investigation of crystallization processes at different temperatures under static or continuous flow conditions, while an attached optical imaging probe enables real-time monitoring.
IEEE TRANSACTIONS ON TERAHERTZ SCIENCE AND TECHNOLOGY
(2022)
Article
Medicine, Research & Experimental
Margaret P. Davis, Timothy M. Korter
Summary: Crystal polymorphism is a common phenomenon in pharmaceutical solids and can significantly affect the formulation of drug therapeutics. Low-frequency vibrational spectroscopy is a sensitive method to detect polymorphic content. In this study, the crystalline ribavirin, a widely applicable antiviral, was studied using terahertz time-domain spectroscopy and low-frequency Raman spectroscopy. The results showed that Form II of ribavirin is more stable at all temperatures due to a stronger cohesive energy, but Form I has a significantly lower conformational energy. This study provides important insights into the thermodynamic relationship of crystals.
MOLECULAR PHARMACEUTICS
(2022)
Article
Chemistry, Multidisciplinary
Amberley D. Stephens, Johanna Koelbel, Rani Moons, Chyi Wei Chung, Michael T. Ruggiero, Najet Mahmoudi, Talia A. Shmool, Thomas M. McCoy, Daniel Nietlispach, Alexander F. Routh, Frank Sobott, J. Axel Zeitler, Gabriele S. Kaminski Schierle
Summary: The solvation shell plays a crucial role in protein folding and function, but its involvement in protein misfolding and aggregation is still not fully understood. We found that the mobility of water molecules within the solvation shell affects the aggregation rate of alpha-synuclein, a protein associated with Parkinson's disease. Decreasing the mobility of water molecules by the presence of NaCl increases alpha-synuclein aggregation, while increasing solvation shell mobility with CsI decreases aggregation. Changing the solvent from H2O to D2O also promotes aggregation, indicating a solvent-driven effect.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Review
Chemistry, Multidisciplinary
Peter A. Banks, Elyse M. Kleist, Michael T. Ruggiero
Summary: Terahertz spectroscopy is a crucial tool for studying condensed phase materials. It explores the low-frequency vibrational dynamics of atoms and molecules in the condensed phase, which are linked to various bulk phenomena. The misnomer "terahertz gap" has been associated with the terahertz region of the electromagnetic spectrum, but there are now cost-effective instruments available for terahertz studies. This Review presents exciting applications of terahertz vibrational spectroscopy, provides an in-depth overview of its methods, and highlights its utility in the chemical sciences.
NATURE REVIEWS CHEMISTRY
(2023)
Article
Humanities, Multidisciplinary
Mary N. Boyden, Courtney K. Hicks, Timothy M. Korter
Summary: Crystopal is a mechanically strong and highly decorative plastic with a unique translucent and crackled appearance. Raman spectroscopy was used to determine the polymer composition of Crystopal artifacts, which were found to be composed of an unsaturated polyester crosslinked with styrene. This discovery adds Crystopal to the polymer database and provides a pathway for identifying and preserving objects made from this unique plastic.
Article
Chemistry, Multidisciplinary
Joshua Kirkham, Timothy M. Korter, Karlis Berzins, Cushla M. McGoverin, Keith C. Gordon, Sara J. Fraser-Miller
Summary: Low-frequency Raman spectroscopy and solid-state density functional theory were used to characterize variably substituted hydroxyapatites with Sr2+, F-, and CO3 (2-) as the substituting species in the crystalline and amorphous forms. The study demonstrated clear differences between amorphous and crystalline forms and systematic changes in the crystalline spectra with the level of substitution. A new crystallinity index (CI) based on low-frequency Raman intensities was proposed and showed better correlation with the XRPD-based CI compared to previous methods.
CRYSTAL GROWTH & DESIGN
(2023)
Article
Medicine, Research & Experimental
ShiZhe Shao, Michael W. Stocker, Salvatore Zarrella, Timothy M. Korter, Abhishek Singh, Anne Marie Healy
Summary: The aim of this study was to investigate the effect of different polymers on the dissociation of cocrystals prepared by co-spray-drying API, coformer, and polymer. It was found that the inclusion of certain polymers, such as PVP and PVPVA, in solid dispersions with the cocrystal DPCC effectively improved its physical stability and prevented dissociation in a high-humidity environment. This improvement is attributed to the efficient mixing between the polymer and cocrystal at the molecular level. The results suggest that polymer-based solid dispersions have the potential to enhance the stability of cocrystals.
MOLECULAR PHARMACEUTICS
(2023)
Correction
Engineering, Electrical & Electronic
Peter A. Banks, Zihui Song, Michael T. Ruggiero
JOURNAL OF INFRARED MILLIMETER AND TERAHERTZ WAVES
(2022)
Correction
Engineering, Electrical & Electronic
Michael T. Ruggiero
JOURNAL OF INFRARED MILLIMETER AND TERAHERTZ WAVES
(2022)
Article
Chemistry, Multidisciplinary
Peter A. Banks, Adam M. Dyer, Adam C. Whalley, Michael T. Ruggiero
Summary: This study investigates the influence of cyclic groups directly bonded to pi-conjugated cores on low-frequency vibrations and electronic dynamics. The results demonstrate a direct relationship between equilibrium geometry, electronic structure, and detrimental electron-phonon coupling, which holds important implications for the design of improved organic optoelectronic materials.
CHEMICAL COMMUNICATIONS
(2022)
