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Excited-state proton transfer (ESPT) from pyranine (8-hydroxypyrene-1,3,6-trisulfonate, HPTS) to acetate was studied in [gamma]-cyclodextrin ([gamma]-CD) and 2-hydroxypropyl-[gamma]-cyclodextrin (HP-[gamma]-CD). It was found that, in both the cyclodextrins, ESPT from HPTS to acetate was much slower than in bulk water and ESPT of HPTS in substituted [gamma]-cyclodextrin was slower than that in the unsubstituted one.

Two compact denatured states of glutaminyl-tRNA synthetase (GInRS) under equilibrium conditions in the presence of a naturally occurring osmolyte, L-glutamate are characterized. Dynamic light scattering studies reveal that both the compact denatured states are aggregated under the measurement conditions.

Fluorescence anisotropy decay and solvation dynamics of coumarin 153 (C153) are studied in dimethyl beta-cyclodextrin (DIMEB) and trimethyl beta-cyclodextrin (TRIMEB) nanocavity in water. Solvation dynamics of C153 in DIMEB exhibits a very fast (2.4 ps) component (41%) and two slower components of 50 ps (29%) and 1450 ps (30%).

Solvation dynamics of coumarin 480 (C480) is studied in a nanoporous sol-gel matrix. Its effect in the presence of cetyltrimethylammonium bromide is studied.

Femtosecond emission spectroscopy is used for studying excited-state proton transfer (ESPT) of pyranine (8-hydroxypyrene-1,3,6-trisulfonate, HPTA) in a polymer-surfactant aggregate. The polymer-surfactant aggregate is a supramolecular assembly that has a triblock copolymer [(PEO).sub.20]-[(PPO).sub.70]-[(PEO).sub.20] (P123) and a cationic surfactant, cetyltrimethylammonium chloride (CTAC).

Femtosecond upconversion is used to study the excitation wavelength dependence of the solvation dynamics of coumarin 480 (C480) in a triblock copolymer [(PEO).sub.20]-[(PPO).sub.70]-[(PEO).sub.20] (P123)-sodium dodecyl sulfate (SDS) aggregate. The magnitude of the [[lambda].sub.ex] dependence in P123-SDS is shown to be much smaller than that of P123 micelle, thus providing better insights on the difference between the properties of the core and the corona region than static absorption and emission spectra.

Photoinduced electron transfer (PET) from N,N-dimethylaniline (DMA) to four coumarin dyes inside the cavity of hydroxypropyl gamma-cyclodextrin (hpCD) is explored using femtosecond upconversion. Results indicate that inside the nanocavity of hpCD, photoinduced PET from DMA to coumarin dyes exhibits a component in a few picosecond time scales.

Study is conducted using femtosecond time-resolved fluorescence spectroscopy, to show that the solvation dynamics in the two partially folded states (I(sub s)(super ') and I(sub s)(super '') of a protein, cytochrome C, are very different. Solvation dynamics of I(sub s)(super '') displays a major component of 1.3 ps which indicates that the structure of I(sub s)(super '') is much more open and exposed compared to that of I(sub s)(super ').

Effect of temperature on the fluorescence anisotropy decay and the ultraslow component of solvation dynamics of coumarin 153 (C153) in a gamma-cyclodextrin (gamma-CD) nanocavity are studied using a picosecond set up. The ultraslow component and the temperature dependence of solvation dynamics are attributed to a dynamic exchange between free and bound water molecules.

Solvation dynamics at the active site of an enzyme, glutaminyl-tRNA synthetase are studied using a fluorescence probe, acrylodan, site-specifically attached at cysteine residue C229, near the active site. The picosecond time-dependent fluorescence Stokes shift indicates slow solvation dynamics at the active site of the enzyme in the absence of any substrate.

Deep learning (DL) is becoming more popular as a useful tool in various scientific domains, especially in chemistry applications. In the infrared spectroscopy field, where identifying functional groups in unknown compounds poses a significant challenge, there is a growing need for innovative approaches to streamline and enhance analysis processes. This study introduces a transformative approach leveraging a DL methodology based on transformer attention models. With a data set containing approximately 8677 spectra, our model utilizes self-attention mechanisms to capture complex spectral features and precisely predict 17 functional groups, outperforming conventional architectures in both functional group prediction accuracy and compound-level precision. The success of our approach underscores the potential of transformer-based methodologies in enhancing spectral analysis techniques.

Recently, various nanomaterials based on hydroxyapatite (HAp) have been developed for bioimaging applications. In particular, HAp doped with rare-earth elements has attracted significant attention, owing to its enhanced bioactivity and imaging properties. In this study, the wet precipitation method was used to synthesize HAp codoped with Yb and Gd. The synthesized Yb x -Gd x -HAp nanoparticles (NPs) were characterized via various techniques to analyze the crystal phase, functional groups, thermal characteristics, and particularly, the larger surface area. The IR783 fluorescence dye and a folic acid (FA) receptor were conjugated with the synthesized Yb x -Gd x -HAp NPs to develop an effective imaging contrast agent. The developed FA/IR783/Yb-Gd-HAp nanomaterial exhibited improved contrast, sensitivity, and tumor-specific properties, as demonstrated by using the customized LUX 4.0 fluorescence imaging system. An in vitro cytotoxicity study was performed to verify the biocompatibility of the synthesized NPs using MTT assay and fluorescence staining. Photodynamic therapy (PDT) was also applied to determine the photosensitizer properties of the synthesized Yb x -Gd x -HAp NPs. Further, reactive oxygen species generation was confirmed by Prussian blue decay and a 2',7'-dichlorofluorescin diacetate study. Moreover, MDA-MB-231 breast cancer cells were used to evaluate the efficiency of Yb x -Gd x -HAp NP-supported PDT.

The nematode Caenorhabditis elegans, with tractable genetics and a well-defined nervous system, provides a unique whole-animal model system to identify novel drug targets and therapies for neurodegenerative diseases. Large-scale drug or target screens in models that recapitulate the subtle age- and cell-specific aspects of neurodegenerative diseases are limited by a technological requirement for high-throughput analysis of neuronal morphology. Recently, we developed a single-copy model of amyloid precursor protein (SC_APP) induced neurodegeneration that exhibits progressive degeneration of select cholinergic neurons. Our previous work with this model suggests that small molecule ligands of the sigma 2 receptor (σ2R), which was recently cloned and identified as transmembrane protein 97 (TMEM97), are neuroprotective. To determine structure-activity relationships for unexplored chemical space in our σ2R/Tmem97 ligand collection, we developed an in vivo high-content screening (HCS) assay to identify potential drug leads. The HCS assay uses our recently developed large-scale microfluidic immobilization chip and automated imaging platform. We discovered norbenzomorphans that reduced neurodegeneration in our C. elegans model, including two compounds that demonstrated significant neuroprotective activity at multiple doses. These findings provide further evidence that σ2R/Tmem97-binding norbenzomorphans may represent a new drug class for treating neurodegenerative diseases.

The triblock copolymer (PEO)20-(PPO)70-(PEO)20 (P123) forms a supramolecular aggregate with sodium dodecyl sulfate (SDS). The solvation dynamics and anisotropy decay of coumarin 480 (C480) in different regions of a P123-SDS aggregate are studied through variation of the excitation wavelength (lambdaex) using femtosecond upconversion. In a P123 micelle, because of the drastic differences in polarity between the hydrophilic corona region (PEO block) and the hydrophobic PPO core, C480 exhibits a pronounced red edge excitation shift (REES) of emission maximum by 24 nm. In the P123-SDS aggregate, SDS penetrates the core of the P123 micelle. This increases the polarity of the core and reduces the difference in the polarity between the core and the corona region. In a P123-SDS aggregate, the REES is much smaller (5 nm) which suggests a reduced difference between the core and the corona. Solvation dynamics in a P123 micelle displays a bulklike ultrafast component (<0.3 and 1 ps) in the PEO corona region, a 200 ps component arising from dynamics of polymer segments, and a very long component (5000 or 3000 ps) due to the highly restricted PPO core. In a P123-SDS aggregate, at lambdaex = 375 and 405 nm, the solvation dynamics is found to be faster than that in P123 micelle. In this case, the component (3000 ps) arising from the core region is faster than that (5000 ps) in P123 micelle. In both P123 micelle and P123-SDS aggregate, the relative contribution of the core region decreases and that of the corona region increases with an increase in lambdaex. At lambdaex = 435 nm, which probes the hydrophilic corona, the solvation dynamics for both P123 micelle and P123-SDS aggregate are almost similar.