Browse Articles

Transforming Single‐Atom Site to Dual‐Atom Site in Fe–N–C Catalysts: A Universal Strategy for Enhancing Durability in Proton‐Exchange Membrane Fuel Cells

Abstract Fe–N–C catalyst is the most promising non‐noble metal oxygen reduction catalyst for proton‐exchange membrane fuel cells (PEMFCs); however, their practical applications are still limited by unsatisfactory long‐term stability. This is because the N atoms of the active FeN 4 moiety are easy to protonate, leading to the leaching of Fe atoms, and the H 2 O 2 generated during oxygen reduction reaction (ORR) process triggers the Fenton reaction, further accelerating the dissolution of Fe. To address these critical stability challenge, we developed a general strategy to transform FeN 4 single‐atom sites to Fe 2 N 6 dual‐atom sites in Fe–N–C catalysts with various carbon substrates. This is achieved by treating the presynthesized Fe–N–C catalysts in a H 2 /Ar atmosphere to break the C─N bonds near the FeN 4 sites while introducing Fe and N precursors to form the Fe 2 N 6 sites. Our theoretical calculations and experimental results demonstrate that the newly formed Fe 2 N 6 sites are structurally more stable in acidic ORR and produce negligible H 2 O 2 (<1%). Therefore, the transformed Fe–N–C catalyst exhibits an extremely low Fe demetalation ratio (0.61 at%) in 0.1 M HClO 4 after 80k cycling. More surprisingly, the transformed Fe–N–C catalyst can effectively decompose H 2 O 2 with a high decomposition rate of 15.7 mmol min −1 , approaching that of the state‐of‐the art Pt/C catalyst (17 mmol min −1 ). As a result, the transformed Fe–N–C catalyst assembled PEMFC operates stably for 300 h with only 7% current density attenuation, whereas that of the pristine Fe–N–C catalyst‐based device declines by 84% within 100 h.

Ziziphus spina-christi alleviates paracetamol-induced hepatorenal toxicity in rats through in vivo and computational approaches

Visible Light‐Driven Deracemization of Cyclic Sulfonamides by Quinuclidine and Chiral Arylthiol Catalysis

Abstract A photocatalytic system comprising an achiral tertiary amine and a chiral C 2 ‐symmetric arylthiol was developed for the deracemization of various cyclic sulfonamides. This protocol exhibited high yields, good to excellent enantioselectivity, and broad substrate scope. The resulting products can be readily transformed into diverse diarylmethylamines, presenting a viable alternative to metal‐catalyzed asymmetric methods. The reaction pathway involving a relay of non‐enantioselective hydrogen‐atom abstraction (HAA) and enantioselective hydrogen‐atom delivery (HAD).

TIPE2 suppresses ferroptosis and pro-inflammatory polarization in macrophages triggered by SARS-CoV-2 spike protein

Spatiotemporal Regulation in Porous Organic Cage Salt–Metal Cluster Hybrids for Efficient Orthogonal Tandem Catalysis

Abstract Developing artificial biomimetic catalysts with precise spatiotemporal control remains challenging. Here, we present a pH‐responsive organic cage salt containing quaternary ammonium moieties ([QA‐Cage]‐12X, X═Cl or Br counteranions) as a platform for constructing such catalysts. Thermally induced electron transfer from counteranions to ammonium moieties generates radicals throughout cage skeletons ([QA‐Cage] • ‐12X), which, combined with nanocavity confinement, facilitates metal precursor reduction and Pd cluster encapsulation, yielding the hybrid catalyst, Pd@[QA‐Cage] • ‐12X. The pH‐responsive cages enable switching between two catalytic states: Pd@[QA‐Cage] • ‐12X, where radicals serve as active sites while Pd accessibility is hindered by numerous counteranions, and Pd@A‐Cage, where neutralization of ammonium cages to non‐radical amine cages (A‐Cage) restores Pd accessibility by removing counteranions and modulating Pd surface charge. This dynamic switching allows real‐time modulation of site‐specific activity in single‐step reactions. Sequential activation of dual active sites by acid‐base stimuli enables tandem catalysis. Moreover, fine‐tuning the protonation degrees of quaternary ammonium groups with base stimuli unveils an optimized catalyst, Pd@[PQA‐Cage] • ‐6X (where PQA‐Cage refers to partially quaternized ammonium cages). Such a spatiotemporal control maximizes cooperative performance by balancing spatially isolated radicals and Pd sites for efficient orthogonal tandem catalysis of incompatible oxidation and reduction reactions in one pot.

Multiscale feature tuned trans-DeepLabV3+ based semantic segmentation of aerial images using improved red piranha optimization algorithm

Automated fractal analysis for mandibular bone evaluation in type 1 diabetes mellitus using a novel single click approach

Prevalence and molecular characterization of multidrug resistant Campylobacter isolated from animals and humans as a one health approach

Abstract Campylobacteriosis is a significant zoonosis with major public health implications. This study aimed to investigate the prevalence, molecular characteristics, and antimicrobial resistance of Campylobacter spp. in animal (rectal swabs and milk), environmental (fecal, water, and wall swabs), and human samples (stool and hand swabs) in New Valley Governorate, Egypt. Among 573 samples analyzed, Campylobacter spp. prevalence was highest in rectal swabs (32.9%) and human stool samples (74.2%), with lower rates in fecal samples (25.9%), milk (25.7%), wall swabs (13.1%), and water (10%). All isolates showed 100% resistance to clindamycin, while being completely sensitive to imipenem and amikacin. Multidrug resistance was found in 90.1% of the isolates, and 16S rRNA was detected in 90% of randomly selected Campylobacter spp. The hipO, cadF, and ceuE genes were detected in 77.8%, 33.3%, and 22.2% of the isolates, respectively. Phylogenetic analysis of the 16S rRNA gene showed significant congruence either between the tested isolates and each other or with other isolates in the gene bank, confirming the zoonotic transmission of multi-drug-resistant Campylobacter spp. This highlights the urgent need for improved biosecurity on farms, better food handling practices, and heightened public health awareness to mitigate the risk of Campylobacteriosis.

Exact wave structures with stochastic effects in birefringent optical fibers modeled by cubic-quintic-septic nonlinear Schrödinger equation

Resiquimod‐Induced Nanovaccine (RINV) for Personalized Cancer Immunotherapy

Abstract Cancer nanovaccines have emerged as a promising modality for cancer immunotherapy due to their capability of eliciting robust tumor‐specific immune responses. However, structural complexity and insufficient spatiotemporal coordination of immune activation pose substantial challenges for optimizing the therapeutic potential of nanovaccines. Herein, a resiquimod‐induced nanovaccine (RINV) is devised for personalized cancer immunotherapy. Toll‐like receptor (TLR) 7/8 agonist resiquimod (R848) was covalently conjugated to fifth‐generation polyamidoamine (G5‐PAMAM) dendrimer through a disulfide linker to obtain the vaccine carrier G5‐R848. In this design, R848 not only fulfills its biological role as a vaccine adjuvant but facilitates uniform nanovaccine formation with the model protein antigen ovalbumin (OVA) due to its distinctive chemical structure. Redox‐triggered intracellular R848 release further promotes cytosolic delivery of antigen and subsequent antigen cross‐presentation. In vivo studies demonstrated that the nanovaccine induces remarkable prophylactic and therapeutic effects in the B16F10‐OVA melanoma model. Moreover, G5‐R848 forms personalized nanovaccines by complexing with cell lysates from resected B16F10 and 4T1 tumor tissues, effectively inhibiting postoperative tumor recurrence and metastasis.

Deep fusion of incomplete multi-omic data for molecular mechanism of Alzheimer’s disease

Adaptive deep SVM for detecting early heart disease among cardiac patients

Abstract Heart attack is one of the most common heart diseases, which causes more deaths worldwide. Early detection and continuous monitoring are essential in reducing the death rate caused by heart diseases. Machine learning gives a promising solution for early and accurate heart disease detection by analyzing the data from healthcare devices. Although existing studies have employed various machine learning techniques to detect heart disease, most of the techniques still face challenges in handling large healthcare datasets that affect the prediction outcomes. To solve this issue, the research work focuses on developing a novel framework for detecting heart disease in its early stages by using machine learning techniques. In the initial phase, the significant data required for the validation is collected from benchmark resources, and it is subjected to the weighted optimal features selection phase. Here, from the input data, the features are selected optimally and their weights are tuned using Enhanced Arbitrary Variable-based Ship Rescue Optimization (EAVSRO). Further, the optimally selected weighted features are fed into the detection phase. In this phase, an Adaptive Deep Support Vector Machine (AD-SVM) is employed to detect heart diseases. Once heart disease is detected, the Atrial Fibrillation (AF) rate is determined using the Adaptive Multiscale Convolution Capsule Network (AMCCNet). Finally, the AF rate is obtained from the developed AMCCNet, and its parameters are tuned using the same EAVSRO. Later, various experiments are performed in the recommended heart disease detection model over existing models to verify its effectiveness. The accuracy of the designed framework is 96.07%, which is enhanced than the other existing frameworks like CNN-LSTM, DCNN, Adaboost and SVM, respectively. Thus, the results proved that the developed model can effectively detect heart disease at the early stages and identify the AF rate, providing timely treatments.

Periodate oxidation of tragacanth gum and evaluation of physicochemical and biological properties of oxidized tragacanth gum

Proteomic pathways across the ejection fraction spectrum in patients with heart failure and diabetes mellitus: an EXSCEL trial substudy

Association between opioid use and survival in advanced non small cell lung cancer patients treated with immune checkpoint inhibitors

Abstract Cancer-related pain is a frequent challenge among non-small cell lung (NSCLC) cancer patients, particularly for those with advanced disease and/or bone metastases. Opioids are the mainstay of treatment for moderate to severe cancer-related pain. However, emerging lines of evidence suggest that concomitant opioid use may be associated with poor survival outcomes in advanced NSCLC patients treated with immune checkpoint inhibitors (ICIs). We analyzed the impact of concomitant opioid use on survival outcomes of advanced NSCLC patients treated with ICIs. Correlations between baseline clinical-pathological characteristics and survival outcomes were assessed using log-rank tests while multivariate survival analyses were performed using the Cox proportional hazards model. Among patients treated with ICI as monotherapy and those treated with ICI as second or subsequent lines of treatment, concomitant opioid use was correlated with decreased progression-free survival (PFS) (p = 0.0460 and p = 0.0490) and overall survival (OS) (p = 0.0380 and p = 0.0230) in univariate analyses. However, in multivariate analyses, concomitant opioid use was not independently correlated with survival outcomes. Instead, ECOG PS ≥ 2 and bone metastases emerged as strong predictors of decreased PFS and OS. Despite limitations, our findings highlight that concomitant opioid use does not independently correlate with poor survival outcomes in this setting of patients.

Dual Chemical Scissors Strategy Enables 1D Antimony Selenates with Ultraviolet Nonlinear Optical Properties

Abstract The rational, function‐driven design of advanced inorganic functional materials remains a significant challenge, primarily attributed to their inherently complex and highly connected 3D frameworks of most oxide‐based systems. Herein, we report a “dual chemical scissors” strategy that synergistically combines the effects of fluoride ions and stereochemically active lone pairs to precisely modulate local coordination environments and enable controlled dimensional reduction. Using this approach, we successfully synthesized the first series of non‐centrosymmetric 1D antimony selenates—RbSbF 2 SeO 4 (I), Rb 2 Sb 2 F 6 SeO 4 (II), and Rb 2 Sb 3 F 9 SeO 4 (III). These compounds feature well‐defined helical chain structures constructed from SbO x F y polyhedra and SeO 4 tetrahedra, resulting in pronounced optical anisotropy and robust nonlinear optical (NLO) properties. Among the series, RbSbF 2 SeO 4 (I) stands out with an exceptional combination of a broad optical transparency window (0.26–10 µm), a strong second‐harmonic generation response (5.4 × KDP), and moderate birefringence (0.12 at 546 nm), positioning it as a highly promising candidate for ultraviolet NLO applications. This work establishes a powerful and generalizable structural design paradigm for constructing polar low‐dimensional architectures and underscores the effectiveness of targeted coordination modulation in advancing high‐performance optical materials.

Deep learning for retinal non-perfusion and foveal avascular zone analysis in wide-field OCTA in diabetic retinopathy

Exploring Mesoionic Imine‐Carbodiimide (MII‐CDI) Adducts: 1,3 H‐Shift, N(I) Compounds and Guanidinate‐Type Ligands

Abstract In this study, we report our recent findings on the synthesis and reactivity of a novel 1,2,3‐triazolin‐5‐imine‐type mesoionic imine‐carbodiimide ( MII‐CDI ) adduct. Unlike reported NHC‐CDI adducts, formed by the reactions of N ‐heterocyclic carbene ( NHC ) with CDI , these zwitterionic compounds undergo a spontaneous 1,3‐hydrogen shift (1,3‐H shift), resulting in guanidine‐type compounds. The mechanism of this 1,3‐H shift has been investigated through quantum chemical calculations. The MII‐CDI adduct serves as a valuable synthon for the synthesis of mesoionic carbene‐acyclic diamino carbene (MIC‐ADC)‐based nitreone ( N(I) ) compounds. We have conducted a detailed investigation into the electronic properties, chemical reactivity, and electrochemical behavior of these nitreone ( N(I) ) compounds. Additionally, the potential of these MII‐CDI adducts as guanidinate ligands is explored. Our investigations here display the distinct reactivities of MII in contrast to their N ‐heterocyclic imine ( NHI ) congeners.

First Chiral Catalan Solid Based on Molybdenum Halide with Efficient Circularly Polarized Luminescence in the Deep‐Red Region

Abstract The design of novel chiral metal halides with exceptional chiroptical properties has attracted significant research attention due to their potential applications in chiral optoelectronics and spintronics. However, developing the deep‐red circularly polarized luminescence (CPL) emitters is still challenging. In this work, we presented the first chiral molybdenum halide clusters by incorporating chiral methylbenzylammonium ( R / S ‐MBA) for the design of ( R ‐MBA) 2 Mo 6 Cl 14 and ( S ‐MBA) 2 Mo 6 Cl 14 tetrakis hexahedra, which adopt the unique Catalan solid structure. These chiral tetrakis hexahedra exhibit 24 unique 3 c ‐2 e Mo─Mo─Cl bonds, which are scarcely reported. Notably, these ( R ‐MBA) 2 Mo 6 Cl 14 and ( S ‐MBA) 2 Mo 6 Cl 14 tetrakis hexahedra demonstrated pronounced circularly polarized luminescence in the deep‐red region, accompanied by an extended emission lifetime of 114.14 µs at room temperature. Additionally, these chiral molybdenum halide tetrakis hexahedra are optically stable for 3 months. The four‐state spin sublevel model was employed to investigate the emission mechanism and found that the temperature‐dependent exciton dynamics lead to the dual‐band emission of the designed chiral tetrakis hexahedra. Our study expands the family of lead‐free chiral metal halides and develops a novel strategy to design a high‐performance deep‐red CPL emitter.

Ligand‐Controlled Chemoselectivity in the Rhodium‐Catalyzed Synthesis of Pentafulvenes via (2 + 2 + 1) Alkyne Cyclotrimerization

Abstract The synthesis of pentafulvenes with varied substituents has been efficiently achieved using novel rhodium‐based catalysts via (2 + 2 + 1) alkyne cyclotrimerization. A rational design of the catalyst structure, including pyridonato, NHC, and CO ligands, ensures the alkyne chemoselectivity and prevents the formation of robust rhodium‐fulvene species. Furthermore, the judicious choice of acidity and steric properties of different alkynes enables the preparation of cross‐coupled fulvene derivatives. Stoichiometric and deuteration experiments, as well as DFT calculations, shed light on the reaction mechanism, showing that it includes an initial alkyne deprotonation, two successive alkyne insertions, cyclization, and protonolysis, the first insertion being the rate‐determining step.