This study examined the feasibility of simultaneously determining the cellular water efflux rate (k<sub>ie</sub>), the intracellular longitudinal relaxation rate (R<sub>10i</sub>), and the intracellular volume fraction (v<sub>i</sub>) in a cell suspension, leveraging multiple samples featuring varying concentrations of gadolinium. Numerical simulation experiments were carried out to investigate the variability in the determination of k ie, R 10i, and v i from saturation recovery data using either single or multiple concentrations of gadolinium-based contrast agent (GBCA). Experiments using 4T1 murine breast cancer and SCCVII squamous cell cancer models at 11T were carried out in vitro to evaluate the parameter estimation performance of the SC protocol in comparison to the MC protocol. The impact of treatment on k ie, R 10i, and vi was determined by exposing cell lines to digoxin, a Na+/K+-ATPase inhibitor. For parameter estimation, data analysis was undertaken using the two-compartment exchange model. The simulation data highlight a significant advantage of the MC method over the SC method in estimating k ie. The reduction in uncertainty is observed through a decrease in interquartile ranges (from 273%37% to 188%51%) and median differences from ground truth (from 150%63% to 72%42%), while also estimating R 10 i and v i concurrently. Within cellular studies, the MC method demonstrated a lower level of uncertainty in overall parameter estimation compared to the standard cellular approach, which utilized the SC method. Using the MC method to assess parameter changes, digoxin treatment increased R 10i by 117% (p=0.218) and k ie by 59% (p=0.234) in 4T1 cells, respectively, but decreased R 10i by 288% (p=0.226) and k ie by 16% (p=0.751) in SCCVII cells, respectively. The treatment failed to produce any noteworthy modification in v i $$ v i $$. Employing saturation recovery data from multiple samples with differing GBCA concentrations, this study supports the feasibility of simultaneously determining the cellular water efflux rate, the intracellular volume fraction, and the longitudinal relaxation rate within cancer cells.
Dry eye disease (DED) is prevalent worldwide, affecting nearly 55% of the population, with some studies indicating a correlation between central sensitization, neuroinflammation, and the development of corneal neuropathic pain in DED; further studies are required to understand the mechanisms involved. The dry eye model was definitively established upon the excision of extra-orbital lacrimal glands. The open field test, designed to measure anxiety, was combined with chemical and mechanical stimulation to examine corneal hypersensitivity. To ascertain the anatomical involvement of brain regions, a resting-state fMRI (rs-fMRI), a functional magnetic resonance imaging method, was conducted. The amplitude of low-frequency fluctuation (ALFF) indicated the level of brain activity. Immunofluorescence testing and quantitative real-time polymerase chain reaction were additionally applied to confirm the observed data. ALFF signals in the supplemental somatosensory area, secondary auditory cortex, agranular insular cortex, temporal association areas, and ectorhinal cortex were elevated in the dry eye group when contrasted with the Sham group. The insular cortex's ALFF variations were noted to be interconnected with a rise in corneal hypersensitivity (p<0.001), c-Fos (p<0.0001), brain-derived neurotrophic factor (p<0.001), and noticeably higher TNF-, IL-6, and IL-1 (p<0.005). A contrasting trend was observed in the dry eye group, where IL-10 levels decreased, with a statistically significant result (p<0.005). By administering cyclotraxin-B, a tyrosine kinase receptor B agonist, into the insular cortex, the DED-induced corneal hypersensitivity and accompanying rise in inflammatory cytokines were mitigated, demonstrating a statistically significant effect (p<0.001), leaving anxiety levels unaffected. Our findings suggest a potential link between the activity of brain regions associated with corneal neuropathic pain and neuroinflammation, particularly within the insular cortex, and the occurrence of dry eye-related corneal neuropathic pain.
Significant attention is devoted to the bismuth vanadate (BiVO4) photoanode in the study of photoelectrochemical (PEC) water splitting. Yet, the fast rate of charge recombination, low electron conductivity, and sluggish electrochemical kinetics have impeded the PEC performance. A higher temperature during the water oxidation reaction proves to be an effective means of improving the carrier kinetics in BiVO4. A layer of polypyrrole (PPy) was subsequently added to the BiVO4 film. The near-infrared light could be harvested by the PPy layer, raising the temperature of the BiVO4 photoelectrode and enhancing charge separation and injection efficiencies. In parallel, the PPy conductive polymer layer effectively facilitated the transfer of photogenerated holes from BiVO4, promoting their movement to the electrode/electrolyte contact point. Hence, the modification of PPy materials led to a substantial advancement in their water oxidation performance. Upon application of the cobalt-phosphate co-catalyst, the photocurrent density increased to 364 mA cm-2 at 123 V relative to the reversible hydrogen electrode, resulting in an incident photon-to-current conversion efficiency of 63% at a wavelength of 430 nm. This research demonstrated an effective method for designing a photoelectrode with integrated photothermal materials to achieve superior water splitting.
Despite their significance in numerous chemical and biological systems, short-range noncovalent interactions (NCIs) are often confined to the van der Waals envelope, thereby posing a significant challenge to current computational methods. We present SNCIAA, a database compiling 723 benchmark interaction energies for short-range noncovalent interactions between neutral or charged amino acids, derived from protein x-ray crystal structures. These energies are calculated at the gold standard coupled-cluster with singles, doubles, and perturbative triples/complete basis set (CCSD(T)/CBS) level of theory, exhibiting a mean absolute binding uncertainty below 0.1 kcal/mol. selleck inhibitor A systematic computational analysis, subsequently performed, examines common methods like second-order Møller-Plesset perturbation theory (MP2), density functional theory (DFT), symmetry-adapted perturbation theory (SAPT), composite electronic structure methods, semiempirical approaches, and physical-based potentials integrated with machine learning (IPML) within the context of SNCIAA. selleck inhibitor The incorporation of dispersion corrections proves indispensable, even though electrostatic forces, including hydrogen bonding and salt bridges, are the primary drivers in these dimers. The most reliable methods for describing short-range non-covalent interactions (NCIs), even in the presence of strong attractive or repulsive forces within complexes, were ultimately found to be MP2, B97M-V, and B3LYP+D4. selleck inhibitor SAPT's description of short-range NCIs is considered valid only when the MP2 correction is explicitly included. The favorable performance of IPML on dimers at close-to-equilibrium and long distances is not replicated in the short-range. We are confident that SNCIAA will participate in the improvement, development, and validation of computational methods, encompassing DFT, force fields, and machine learning models, to characterize NCIs across the full potential energy surface (short-, intermediate-, and long-range) consistently.
A first experimental application of coherent Raman spectroscopy (CRS) is demonstrated on the ro-vibrational two-mode spectrum of methane (CH4). Ultrabroadband femtosecond/picosecond (fs/ps) CRS is performed in the 1100-2000 cm-1 molecular fingerprint region, with fs laser-induced filamentation facilitating the creation of ultrabroadband excitation pulses for supercontinuum generation. We develop a time-domain model for the CH4 2 CRS spectrum, including all five ro-vibrational branches permitted by the v = 1, J = 0, 1, 2 selection rules. The model includes collisional linewidths, calculated by a modified exponential gap scaling law and validated through experimental observations. By performing CRS measurements across the laminar flame front in the fingerprint region of a laboratory CH4/air diffusion flame, the simultaneous detection of CH4, molecular oxygen (O2), carbon dioxide (CO2), and molecular hydrogen (H2) is demonstrated, showcasing the potential of ultrabroadband CRS for in situ CH4 chemistry monitoring. Fundamental physicochemical processes are detectable in the Raman spectra of these chemical species, notably in cases like the pyrolysis of methane (CH4) for hydrogen (H2) production. Besides that, we detail ro-vibrational CH4 v2 CRS thermometry, and we assess its accuracy through comparison with CO2 CRS measurements. This innovative diagnostic approach, inherent in the current technique, enables in situ monitoring of CH4-rich environments, particularly within plasma reactors employed for CH4 pyrolysis and H2 production.
DFT-1/2's efficient bandgap rectification of DFT calculations is particularly noteworthy when using the local density approximation (LDA) or the generalized gradient approximation (GGA). In the case of highly ionic insulators, such as LiF, it was proposed to use non-self-consistent DFT-1/2, contrasting with the continued use of self-consistent DFT-1/2 for other compounds. Still, no quantifiable metric exists for pinpointing the correct implementation across all insulator types, leading to major ambiguity in this procedure. We evaluate the consequences of self-consistency in DFT-1/2 and shell DFT-1/2 calculations on the electronic structure of insulators and semiconductors featuring ionic, covalent, or intermediate bonding, concluding that self-consistency remains crucial, even for highly ionic insulators, to achieve a more comprehensive depiction of the global electronic structure. Self-energy adjustments within the self-consistent LDA-1/2 approach lead to a more concentrated arrangement of electrons near the anions. The delocalization error, characteristic of the LDA approach, is corrected, yet with an overcorrection effect due to the presence of the additional self-energy potential term.