Search Results (1,951)

Dye-sensitized solar cells based on Hagfeldt donor sensitizers achieve high open-circuit voltages through effective suppression of interfacial charge recombination. However, their absorption remains largely confined to the visible region, which limits further gains in the photocurrent and overall efficiency. This study addresses the issue of spectral limitation by designing six D-A-π-A organic dyes, HJ101~HJ106. These dyes are derived from the reference sensitizer XY1 through systematic modification of the donor unit with anthracene and squaraine moieties combined with two benzothiadiazole-type auxiliary acceptors. Geometric structures, frontier molecular orbitals, absorption spectra, and excited-state charge transfer characteristics were investigated using density functional theory and time-dependent density functional theory. The results demonstrate that donor and acceptor modifications act synergistically to control the spectral direction and magnitude, with several dyes achieving pronounced redshifts extending into the near-infrared region while retaining thermodynamically favorable electron injection and regeneration driving forces. Among the designed structures, HJ106, which combines a squaraine-modified donor with a redshifting acceptor, exhibits the largest bathochromic shift and an extended excited-state lifetime. HJ105 delivers the highest molar extinction coefficient and light-harvesting efficiency. Collectively, these findings identify squaraine-based donor engineering as the most promising strategy for near-infrared-responsive Hagfeldt-type sensitizers. These findings offer practical structural guidance for the development of next-generation dye-sensitized solar cell sensitizers with broadened spectral coverage. Full article

Plastic waste has become a serious global issue. Thermal treatment of waste PET faces critical drawbacks including severe reactor clogging and low-value oxygen-rich bio-oil, restricting large-scale chemical recycling. Co-pyrolysis with hydrogen-rich low-density polyethylene (LDPE) over modified zeolite provides a viable route to overcome these barriers. In this study, reaction parameters including temperature, plastic/catalyst ratio and PET/LDPE ratio were optimized, and Fe-Ni bimetallic modified HZSM-5 was fabricated via impregnation to boost monocyclic aromatic hydrocarbons (MAHs) production. LDPE served as a hydrogen donor to facilitate PET deoxygenation via synergistic effects. At 550 °C with a plastic/catalyst ratio of 1:4 and PET/LDPE ratio of 2:3, the liquid yield hit 80.2%, and all detectable organic compounds in the liquid phase identified by GC–MS were aromatic hydrocarbons. Among all prepared mono- and bimetallic zeolites, 3Fe7Ni/HZ delivered optimal MAHs selectivity at 80.5%. This 20% promotion over unmodified HZSM-5 stems from balanced metal dispersion and tuned acid sites unique to Fe–Ni co-loading. This work offers a feasible strategy for converting waste plastics into high-value aromatics and further trials with varied metal contents will be needed to extend industrial applicability. Full article

Background/Objectives: Hypothermic oxygenated perfusion (HOPE) improves graft preservation in whole liver transplantation, yet evidence supporting its use in split grafts for pediatric transplantation remains limited. Mitochondrial injury assessed during HOPE through spectroscopic measurement of flavin mononucleotide (FMN) has been associated with graft function in whole-organ transplantation. Here, we evaluate a human liver assessment pathway integrating mitochondrial viability testing with ex situ liver splitting during HOPE. Methods: Following standard procurement and transport, twelve discarded extended criteria human donor livers were evaluated for split feasibility and underwent HOPE (VitaSmart^®). Donors were between 40 and 72 years with a BMI of 23.4–42.7 kg/m² and 4–22 h of cold storage prior to HOPE. After two hours of portal-venous HOPE treatment, different split procedures were performed. Perfusates and tissues were analyzed for mitochondrial injury and inflammatory responses. Results: Four grafts met previously reported FMN thresholds for transplant suitability in whole-graft HOPE studies (FMN ≤ 0.02 μg/mL at 60 min). Livers with low FMN release demonstrated lower Complex I and II injury, greater ATP recovery, and reduced inflammatory signaling during HOPE. Conclusions: These findings indicate that mitochondrial injury during HOPE can be monitored during ex situ splitting and suggest that FMN-guided metabolic assessment may support graft evaluation within split liver transplantation pathways for pediatric recipients. Full article

Photosystem II (PSII) contains several cofactors involved in light harvesting, charge separation, electron transfer, and catalysis. The initial charge separation in the reaction center of PSII creates the strongest known redox-cofactor oxidant in biology, a cationic radical distributed over a “special pair” of chlorophyll molecules (P680^•+). Two redox-active tyrosines, Y_Z and Y_D, located at opposite sides of the special pair, are the principal residues that reduce this cationic radical. Y_Z, in turn, oxidizes the manganese cluster of the oxygen-evolving complex to drive water oxidation, whereas Y_D forms a stable radical facilitated by local water translocation. The details of this asymmetry and the role of nearby protein residues in mediating branch-specific electron/hole-transfer pathways remain incompletely understood. Here, we investigate pathways for electron transfer (ET) from Y_Z and Y_D to P680^•+ and identify specific residues that are likely responsible for mediating ET. Graph-based analysis predicts aromatic residue-assisted pathways on both branches but also reveals a distinct tryptophan (D2-Trp191) that connects Y_D with P680^•+, whereas the corresponding D1-side position is occupied by a non-aromatic D2-Ile192. This suggests a possible role of this tryptophan as an ET mediator, thereby differentiating the nature of electronic connectivity between Y_Z/Y_D and the reaction center. Residue conservation analysis indicates retention of D2-Trp191 across various organisms. Molecular dynamics show that the predicted donor–mediator and mediator–acceptor contacts remain structurally persistent over the simulation, while QM/MM calculations show appreciable spin-density localization capacity, providing strong computational support for an ET mediator role of D2-Trp191. Together, these results suggest that ET between the redox-active tyrosines and the reaction-center chlorophylls occurs via distinct mechanisms—direct vs. mediated—with D2-Trp191 being a D2-specific mediator for the branch-selective electron/hole-transfer connectivity in PSII. Full article

Background: In liver transplantation, maintaining donor organ viability is a critical factor determining transplant outcomes. The aim of this study was to evaluate liver metabolic activity under ex vivo perfusion in the presence of magnetite magnetic nanoparticles using mathematical modeling. Methods: Ex vivo liver perfusion was performed with nanoparticles added to the perfusate; the concentration of nanoparticles in the inflowing and outflowing perfusate was determined by mass spectrometry. A stoichiometric model of hepatic metabolic fluxes was constructed, and the distribution of energy resources was assessed using the Zipf–Pareto law and its linear approximation, the Zipf–Pareto–Mandelbrot distribution. Results: It was shown that nanoparticle uptake by the liver increased from 26.5% to 54.4% over the course of perfusion. The introduction of magnetic nanocomposites altered metabolic fluxes, including glycolysis, the respiratory chain, and oxygen exchange across the surface, leading to redistribution of energy resources within liver cells. Zipf–Pareto analysis showed that energy was optimally distributed among all metabolic fluxes both in the control condition and in the presence of nanoparticles. Conclusions: Magnetic nanoparticles alter liver metabolic activity, but the functional state of the organ remains intact. Full article

Direct-acting antiviral (DAA) therapy has dramatically transformed the management of hepatitis C virus (HCV) infection in chronic kidney disease (CKD). Severe renal impairment and dialysis dependence are no longer considered major barriers to virologic cure. The main difficulties have shifted toward efficient diagnosis, choosing the regimen in the presence of cirrhosis and drug interactions, coordinating treatment with kidney transplantation, managing HCV-associated immune-complex kidney disease, and providing treatment in dialysis and resource-limited settings. This narrative review aims to discuss these issues in a decision-oriented manner, using verified guidelines, systematic reviews, important clinical trials, transplant cohorts, and studies of cryoglobulinemic disease, while explicitly comparing the strength and consistency of the underlying evidence and highlighting areas of genuine clinical uncertainty. Present evidence supports using the recommended DAA regimens without renal dose adjustment, while ribavirin needs dose modification when kidney function is reduced and can result in hemolytic anemia. Kidneys from HCV-viremic donors can be transplanted to recipients without HCV infection when proper informed consent, rapid access to DAA treatment, and organized post-transplant monitoring are available, although the minimum effective duration of peri-transplant antiviral prophylaxis remains unresolved. Antiviral therapy is the first-line treatment for HCV-associated glomerular disease, while rituximab-based immunosuppression is largely reserved for severe, rapidly progressive, or persistent cryoglobulinemic vasculitis. Future progress will depend less on proving antiviral efficacy and more on closing the gaps between screening, confirmatory testing, starting treatment, transplantation pathways, and long-term follow-up, gaps that stem from inequities in diagnostic infrastructure, drug reimbursement, and healthcare-system organization as much as from any remaining biomedical uncertainty. Full article

This article reconstructs the brief history of the Academia para la Historia de la Iglesia Latina (APHILA), a short-lived but revealing experiment in Latinx Protestant historiography in the early 1990s. Drawing on archival sources from the Justo L. González papers, it contextualizes APHILA within the boom of Latinx theological education that followed González’s booklet The Theological Education of Hispanics, as foundations invested heavily in new Latinx initiatives. The essay first narrates the network-building and grant-writing processes that led to APHILA’S creation and its only major conference at McCormick Theological Seminary in 1993. It then analyzes the organization’s internal tensions over methodology, language policy, institutional location, and lay versus professional participation, together with the external pressures of donor expectations. Finally, it argues that APHILA’S collapse exposes both the possibilities and the structural fragilities of Latinx Protestant projects seeking to craft an autochthonous historiography in the United States. Full article

Carbohydrates are among the most highly oxygenated biomolecules in nature, possessing dense arrays of hydroxyl, ether, carbonyl, carboxylate, phosphate, and sulfate functionalities that govern hydration, hydrogen bonding, molecular recognition, and supramolecular organization. Their stereochemically organized oxygen-donor groups provide numerous appropriately oriented diol motifs capable of selective and reversible coordination with boric acid and borate ions. This review examines the structural and physicochemical principles underlying carbohydrate–borate interactions, with particular emphasis on oxygen-rich biological interfaces. Pentoses, hexoses, oligosaccharides, polysaccharides, glycolipids, and membrane-associated glycoconjugates are considered to illustrate how hydroxyl-group orientation, molecular conformation, pH, hydration, and local environment determine borate recognition, complex stability, and dynamic assembly. Evidence from NMR and other spectroscopic methods, crystallography, mass spectrometry, calorimetry, and molecular simulations demonstrates that borate coordination follows common stereochemical and thermodynamic principles despite the remarkable structural diversity of carbohydrates. Biological examples include borate-mediated crosslinking in plant cell walls and interactions involving microbial carbohydrates, marine polysaccharides and glycoconjugates, photosynthetic membrane lipids, and cyanobacterial heterocyst glycolipids. Particular attention is given to distinguishing experimentally established borate complexes from membrane-associated interactions that remain proposed and require further characterization. Reversible borate crosslinking of oxygen-rich carbohydrate networks also provides the chemical basis for emerging applications in responsive hydrogels, biosensors, supramolecular assemblies, drug-delivery systems, and functional biomaterials. Collectively, the available evidence indicates that the spatial organization of oxygen donor atoms within carbohydrates provides the molecular basis for selective borate recognition, whereas boron can convert this functionality into reversible higher-order organization. This oxygen-centered perspective integrates coordination chemistry, glycobiology, membrane biology, and materials science into a unified framework for understanding carbohydrate–borate interactions in natural and engineered systems. Full article

Polyphosphate (PolyP) is an inorganic polymer composed of orthophosphate units linked by high-energy phosphate anhydride bonds, widely found in various organisms from bacteria to mammals. In recent years, PolyP has attracted widespread attention in the field of bone tissue engineering due to its unique biological characteristics, possessing both osteoinductive activity and metabolic energy supply functions. This article systematically reviews the molecular structure, physicochemical properties, and multiple mechanisms by which PolyP promotes osteogenic differentiation, as well as biomaterial design strategies based on PolyP. PolyP can synergistically promote osteogenic differentiation through multiple mechanisms, including by acting as a phosphate donor, providing metabolic energy, regulating signaling pathways such as Wnt/β-catenin, and modulating the osteoprotegerin/receptor activator of nuclear factor κB ligand (OPG/RANKL) balance. In terms of material design, PolyP can form nano/microparticles with metal ions such as Ca²⁺, Sr²⁺, and Mg²⁺ and can also be compounded with polymers to construct various forms such as hydrogels, bone cement, and three-dimensional (3D)-printed scaffolds. Preclinical studies have shown that PolyP-incorporated materials exhibit excellent osteogenic performance and biocompatibility in bone defect repair, and preliminary clinical studies have also confirmed its feasibility. This article aims to provide a comprehensive overview of the current applications of PolyP-incorporated materials and delineate future directions, challenges, and necessary pathways for their clinical translation. Full article

Nonlinear optical (NLO) active chromophores and their applications in photothermal therapy (PTT) demonstrate great potential in modern theragnostics, owing to their efficient light–matter interactions. A recognized D–π–A chromophore, FTC-3f, which is reported to exhibit a high photothermal conversion efficiency (~51.11%), was structurally modified with various spacers and acceptors to elucidate enhanced PTT and NLO behavior through DFT and TD-DFT simulations. Molecular geometries were optimized at the B3LYP/6-31G (d, p) level. Their electronic properties, charge separation, and efficient transition pathways were analyzed using frontier molecular orbitals (FMOs), density of states (DOS), UV–visible spectroscopy, photon-induced electron transfer (PET), and transition density matrix (TDM) analysis. Among all the derivatives, D4 exhibited the smallest HOMO–LUMO energy gap (1.701 eV). The highest first-order hyperpolarizability (β) values are found for D4 (1.50 × 10⁵ in the gas phase, 7.40 × 10⁵ in water, 3.06 × 10⁵ in benzene solvent). The β_HRS is found to be in the range 5.11 × 10⁴ to 2.97 × 10⁴ and DR (3.65 × 10⁵ to 4.53 × 10⁴) supports the strong NLO response and strong synergistic donor–acceptor interactions. The designed chromophores exhibit much higher SHG and EOPE responses at 532, 1907.21, and 1064 nm than FTC-3F, indicating great potential for the synthesis of effective NLO nanomedicine. Molecular docking with bovine serum albumin (PDB ID: 4F5S) and Bcl-2 (PDB ID: 2W3L) suggested favorable binding conformations, consistent with a potential for transport and apoptotic-targeting behavior. All 3D molecular descriptor parameters indicate that the designed chromophores have potential for preferential targeting in PTT. This study investigates how structural modifications of donor–π–acceptor chromophores influence their electronic, optical, nonlinear optical, and theragnostic properties, providing insights into molecular design strategies for advanced NLO-based nanomedicine applications. Full article

The increasing demand for high-efficiency photovoltaic technologies has intensified research into tandem solar cells (TSCs) as a promising strategy to surpass the performance limits of single-junction devices. In this study, a comprehensive optoelectronic simulation using a Silvaco ATLAS TCAD simulator is employed to design, optimize, and compare two tandem architectures: all-organic and hybrid organic/silicon TSCs. The all-organic configuration consists of polymer donors comprising a PBDB-T:F-M top sub-cell stacked with a PTB7-Th:CO_i8DFIC:PC₇₁BM bottom sub-cell, while the hybrid configuration integrates a PBDB-T:F-M organic top cell with a crystalline Si bottom cell. Calibrated device models, validated against experimental data of the individual sub-cells, are used to evaluate tandem performance and guide systematic optimization. The two tandem architectures employ the same PBDB-T:F-M wide-bandgap organic top absorber (E_g~1.60 eV), while the rear sub-cell consists of either the PTB7-Th:CO_i8DFIC:PC₇₁BM organic absorber (E_g~1.20 eV) or crystalline silicon (E_g~1.12 eV). The initial organic/organic tandem device accomplishes a power conversion efficiency (PCE) of 15.70% and J_SC of 10.96 mA/cm², whereas the organic/silicon tandem structure exhibits a higher initial PCE of 16.85% and J_SC of 12.26 mA/cm². Following absorber-thickness optimization, the all-organic and hybrid OSC/Si tandems achieve PCEs of 19.44% and 21.13%, respectively. Rather than constituting a simple efficiency ranking, the comparison reveals distinct optical, electrical, and technological trade-offs. The hybrid architecture benefits from the broader spectral utilization and efficient carrier collection of thin crystalline Si, whereas the all-organic configuration offers advantages associated with low-temperature solution processing, reduced material consumption, and potentially fully solution-processed photovoltaic fabrication. The calibrated comparative framework therefore provides design guidance for selecting and optimizing TSCs according to both performance and application requirements. Full article

Donor-derived infections (DDIs), particularly fungal DDIs, are uncommon but serious complications of solid organ transplantation. We report a case of a 52-year-old woman who underwent deceased donor kidney transplantation complicated by probable donor-derived Candida albicans candidemia with native aortic valve endocarditis, managed medically with prolonged echinocandin therapy followed by suppressive fluconazole. Approximately 14 months post-transplant, she developed progressive rhino-orbital mucormycosis due to Rhizopus oryzae, requiring extensive surgical debridement and prolonged antifungal therapy. Initial treatment with liposomal amphotericin B was limited by nephrotoxicity, prompting transition to isavuconazole for long-term management. Immunosuppression was discontinued to control infection, resulting in graft failure. This case illustrates the complex interplay between donor-derived infection, antifungal exposure, and immunosuppression in transplant recipients. It highlights the potential contribution of antifungal selective pressure to breakthrough mold infections and underscores the importance of early recognition, aggressive multidisciplinary management, and individualized antifungal strategies in this high-risk population. Full article

Background: The right renal vein is about half the length of the right renal artery and is shortened further by endovascular stapling at laparoscopic donor nephrectomy. Right-sided living-donor grafts carry roughly twice the adjusted risk of delayed graft function and of early graft loss, a penalty absent from deceased donation, where the inferior vena cava accompanies the graft. The deficit is one of venous length, not of the organ; extension is the remedy, and no guideline specifies how the conduit should be obtained. Methods and cases: Three consecutive recipients of right living-donor kidneys had the renal vein extended with a deceased-donor iliac vein. Conduits were recovered at multiorgan retrieval from ABO-identical or ABO-compatible donors, immersed in University of Wisconsin solution at 4 °C, and used within seven days; elective right donor nephrectomy was booked to follow a suitable retrieval within that window. Extension was an end-to-end back-table anastomosis with continuous 5-0 or 6-0 polypropylene, converting a short-vein implantation into a routine end-to-side anastomosis to the external iliac vein. All three grafts functioned immediately, without venous thrombosis, technical graft loss, or delayed graft function; the last serum creatinine was 0.91, 1.22, and 1.42 mg/dL. Conclusions. A calibre- and ABO-matched deceased-donor iliac vein, held in University of Wisconsin solution at 4 °C and used within seven days, makes venous extension a scheduled step of an elective right living-donor operation and requires no cryopreservation infrastructure. Where a donor’s safety mandates right nephrectomy, a short right renal vein need not preclude donation. Three cases establish feasibility; the low thrombotic risk of venous extension rests on published series rather than on this report. Full article

Background: Elevated plasma homocysteine (HCY) is a risk factor for Alzheimer’s disease (AD), but its relationship with structural brain changes across the AD continuum remains unclear. The choroid plexus (CP) regulates cerebrospinal fluid homeostasis and may interface with peripheral metabolic signals. Whether HCY relates to CP structural alterations and disease progression remains unknown. Methods: We analyzed 819 Alzheimer’s Disease Neuroimaging Initiative (ADNI) participants (229 cognitively normal (CN), 397 with mild cognitive impairment (MCI), and 193 with AD dementia). Multinomial logistic regression assessed associations between HCY and diagnosis under stepwise covariate adjustment. Phenotype-wide structural magnetic resonance imaging (MRI) mapping identified HCY-associated signals. Cox models evaluated associations of CP volume (CPV) with CN-to-MCI and MCI-to-AD dementia conversion and whether CPV added prognostic discrimination beyond baseline disease-severity markers. Independent human CP single-nucleus and spatial transcriptomic datasets were reanalyzed to characterize epithelial expression states and their spatial organization in a hypothesis-generating analysis. Results: Higher HCY was associated with MCI and AD dementia; however, the AD association attenuated after adjustment for renal function, vitamin B12, and medications, whereas the MCI association remained stable. CPV was among the HCY-associated MRI signals that persisted after progressive covariate adjustment. Right and bilateral CPV showed model-dependent associations with MCI-to-AD dementia conversion. In the disease-severity sensitivity analysis, larger right and bilateral CPV remained associated with a higher risk of progression from MCI to AD dementia. Single-nucleus analysis identified two CP epithelial states with relatively high expression of one-carbon metabolism-related genes, termed one-carbon metabolism-enriched epithelial state A (OCM-Epi-A) and state B (OCM-Epi-B). Donor-level pseudobulk analysis did not identify pathway enrichment after false discovery rate correction, whereas OCM-Epi-A–like spots were located near endothelial spots more often than expected by chance in three of the four spatial samples. Conclusions: Circulating HCY was associated with larger CPV, and larger CPV showed model-dependent associations with MCI-to-AD dementia progression. Independent transcriptomic reanalysis identified one-carbon metabolism-enriched epithelial states and their spatial organization in postmortem CP tissue, providing hypothesis-generating tissue-level context for the ADNI associations. Full article

Organic solar cells are widely recognized for their flexibility, light weight and semitransparency, all relevant for niche applications. A significant challenge in their development lies in the accurate prediction of their power conversion efficiency depending on the combination of the donor and acceptor selected in the bulk heterojunction. To address this issue, we developed a robust machine learning (ML) framework designed to establish correlations between molecular structure and device performance. A feature selection strategy, incorporating SHapley Additive exPlanations and Boruta algorithms, was employed to extract the most informative descriptors. Among the regression models that were systematically evaluated on a curated dataset comprising 1575 experimentally characterized donor–acceptor pairs, histogram-based gradient boosting demonstrated superior predictive performance, giving an R² score of 0.79, with a low root mean square error of 2.16. Subsequently, the optimized model was used to predict new donor–acceptor pairs with PCEs above 20% and identify prospective candidates for further experimental validation. Full article