On-Site Detection of Neonicotinoid Pesticides Using Functionalized Gold Nanoparticles and Halogen Bonding.

Neonicotinoid (NN) pesticides have emerged globally as one of the most widely used agricultural tools for protecting crops from pest damage and boosting food production. Unfortunately, some NN compounds, such as extensively employed imidacloprid-based pesticides, have also been identified as likely endangering critical pollinating insects like honey bees. To this end, NN pesticides pose a potential threat to world food supplies. As more countries restrict or prohibit the use of NN pesticides, tools are needed to effectively and quickly identify the presence of NN compounds like imidacloprid on site (e.g., in storage areas on farms or pesticide distribution warehouses). This study represents a proof-of-concept where the colloidal properties of specifically modified gold nanoparticles (Au-NPs) able to engage in the rare intermolecular interaction of halogen bonding (XB) can result in the detection of certain NN compounds. Density functional theory and diffusion-ordered NMR spectroscopy (DOSY NMR) are used to explore the fundamental XB interactions between strong XB-donor structures and NN compounds, with the latter found to possess multiple XB-acceptor binding sites. A fundamental understanding of these XB interactions allows for the functionalization of alkanethiolate-stabilized Au-NPs, known as monolayer-protected gold clusters (MPCs), with XB-donor capability (f-MPCs). In the presence of certain NN compounds such as imidacloprid, the f-MPCs subsequently exhibit visual XB-induced aggregation that is also measured with absorption (UV-vis) spectroscopy and verified with transmission electron microscopy (TEM) imaging. The demonstrated f-MPC-aggregation detection scheme has a number of favorable attributes, including quickly reporting the presence of the NN target, requiring only micrograms of suspect material, and being highly selective for imidacloprid, the most prevalent and most important NN insecticide compound. Requiring no instrumentation, the presented methodology can be envisioned as a simple screening test in which dipping a cotton swab of an unknown powder from a surface in a f-MPC solution causes f-MPCs to aggregate and yield a preliminary indication of imidacloprid presence.

Nanomaterial-Doped Xerogels for Biosensing Measurements of Xanthine in Clinical and Industrial Applications.

First-generation amperometric xanthine (XAN) biosensors, assembled via layer-by-layer methodology and featuring xerogels doped with gold nanoparticles (Au-NPs), were the focus of this study and involved both fundamental exploration of the materials as well as demonstrated usage of the biosensor in both clinical (disease diagnosis) and industrial (meat freshness) applications. Voltammetry and amperometry were used to characterize and optimize the functional layers of the biosensor design including a xerogel with and without embedded xanthine oxidase enzyme (XOx) and an outer, semi-permeable blended polyurethane (PU) layer. Specifically, the porosity/hydrophobicity of xerogels formed from silane precursors and different compositions of PU were examined for their impact on the XAN biosensing mechanism. Doping the xerogel layer with different alkanethiol protected Au-NPs was demonstrated as an effective means for enhancing biosensor performance including improved sensitivity, linear range, and response time, as well as stabilizing XAN sensitivity and discrimination against common interferent species (selectivity) over time-all attributes matching or exceeding most other reported XAN sensors. Part of the study focuses on deconvoluting the amperometric signal generated by the biosensor and determining the contribution from all of the possible electroactive species involved in natural purine metabolism (e.g., uric acid, hypoxanthine) as an important part of designing XAN sensors (schemes amenable to miniaturization, portability, or low production cost). Effective XAN sensors remain relevant as potential tools for both early diagnosis of diseases as well as for industrial food monitoring.

Rheumatic Immune-Related Adverse Events due to Immune Checkpoint Inhibitors-A 2023 Update.

With the aging of the population, malignancies are becoming common complications in patients with rheumatoid arthritis (RA), particularly in elderly patients. Such malignancies often interfere with RA treatment. Among several therapeutic agents, immune checkpoint inhibitors (ICIs) which antagonize immunological brakes on T lymphocytes have emerged as a promising treatment option for a variety of malignancies. In parallel, evidence has accumulated that ICIs are associated with numerous immune-related adverse events (irAEs), such as hypophysitis, myocarditis, pneumonitis, and colitis. Moreover, ICIs not only exacerbate pre-existing autoimmune diseases, but also cause de novo rheumatic disease-like symptoms, such as arthritis, myositis, and vasculitis, which are currently termed rheumatic irAEs. Rheumatic irAEs differ from classical rheumatic diseases in multiple aspects, and treatment should be individualized based on the severity. Close collaboration with oncologists is critical for preventing irreversible organ damage. This review summarizes the current evidence regarding the mechanisms and management of rheumatic irAEs with focus on arthritis, myositis, and vasculitis. Based on these findings, potential therapeutic strategies against rheumatic irAEs are discussed.

Monolayer-Protected Gold Nanoparticles Functionalized with Halogen Bonding Capability─An Avenue for Molecular Detection Schemes.

The use of functionalized nanoparticles (NPs) and their aggregation in the presence of a targeted analyte is a well-established molecular detection strategy predicated on harnessing specific molecular interactions to the NP periphery. Molecules able to specifically interact with the functionalized NPs alter the unique optical and electrochemical properties of the NPs as a function of interparticle spacing. While many intermolecular interactions have been successfully exploited in this manner in conjunction with aqueous NP systems, the use of non-aqueous NPs in the same capacity is significantly less explored. A fundamental interaction that has not been previously investigated in NP schemes is halogen bonding (XB). XB is an orthogonal, electrostatic interaction between a region of positive electrostatic potential (δ+) on a halogen atom (i.e., XB donor) and a negative (δ-) Lewis base (XB acceptor) molecule. To couple XB with NP systems, ligands featuring a molecular structure that promotes XB interactions need to be identified, optimized, and synthesized for subsequent attachment to NPs. Herein, density functional theory (DFT) and NMR techniques are used to identify a strong XB-donor moiety (-C6F4I) and a synthetic scheme for a thiolate ligand featuring that functionality is devised and executed with high purity/yield (78%). Ligand-exchange reactions allow functionalization of non-aqueous alkanethiolate-protected gold NPs or monolayer-protected clusters (MPCs) with the XB-donor ligands. Functionalized MPCs (f-MPCs), within both assembled films and in solution, are shown to engage in XB interactions with target XB-acceptor molecules. Molecular recognition events, including induced aggregation of the f-MPCs, are characterized with UV-vis spectroscopy, cyclic voltammetry, TEM imaging, and diffusion-ordered spectroscopy NMR with limits of detection of 50-100 nM for strong XB acceptors. While fundamental exploration of XB interactions is ongoing, this study represents a step toward utilizing XB within molecular detection schemes, an application with implications for supramolecular chemistry, forensic, and environmental chemical sensing.

Combination of Reverse Shoulder Prosthesis, Elbow Prosthesis, and Polyetheretherketone: A Modified Total Humeral Replacement for Osteosarcoma Humerus Treatment.

Total humeral replacement is a complex surgery that requires many challenges to overcome such as the weight of the implant material and the shoulder function due to extensive resection of the rotator cuff. Improvements in implants material that is lighter than usual can lead to higher surgery success rates. We present a patient who was diagnosed with osteosarcoma of the right humerus. The patient received 2 cycles of MAP chemotherapy (included: doxorubicin, cisplatin, and methotrexate) before surgery. He underwent radical resection of osteosarcoma and total humerus replacement with a modified total humeral material. The purpose of this improvement was to reduce the implant's weight and to improve postoperative recovery. Six months after the surgery, the weight-bearing ability of the patient's shoulder within a wide range of movement has restored; the shoulder, elbow, and hand can move in a controlled way. Despite the short postoperative follow-up time, the improvement in the modified technique has brought many positive results. Total humerus replacement, which combines the reverse shoulder prosthesis, elbow prosthesis, and polyetheretherketone, is an appropriate solution for patients with osteosarcoma of the humerus instead of custom-made humerus megaprosthesis.

Reverse shoulder megaprosthesis replacement for aggressive aneurysm bone cyst of proximal humerus: Case report and literature review.

INTRODUCTION: and importance: Wide resection in the surgical treatment of aneurysms bone cysts is often performed in cases where the tumor is large, recurrent, growing, and intensely invasive. Reshaping the defect after tumor removal is a necessary issue to restore shape and maintain function for the patient. CASE PRESENTATION: A 26-year-old male patient, diagnosed with an aneurysm bone cyst in the proximal humerus, underwent surgery for curettage and bone grafting twice. After surgery, there was still pain in the shoulder area, the tumor progressed aggressively with limited shoulder movement. Based on the imaging re-evaluation, it was shown that the tumor increased rapidly in size, invaded the soft tissue, and completely changed the normal structure of the shoulder joint, and the proximal humerus. We used a reverse shoulder joint with an additional module to restore the bone defect of the tumor and the function of the shoulder joint. Follows-up showed that patient no longer pain in shoulder area, shoulder joint function recovery is progressing well, Musculoskeletal Tumor Society (MSTS) score is 25 & 28, shoulder joint function score according to ASES scale: 80 & 93.33 respectively at 3 months and 6 months after surgery. CLINICAL DISCUSSION: Aggresive aneurysm bone cyst of proximal humerus is not common and still a challenge to the treatment. Due to the bone and joint destruction, the indication of tumor resection and reconstruct the joint and bone loss is required. Among several solution, reverse shoulder megaprosthesis is a newest one can favor the purpose of our treatment. Up to now, this solution is mainly used to preserving for malignant bone tumor. CONCLUSIONS: Tumor wide resection with modular reverse shoulder replacement with the modular segment is a reasonable intervention option in cases of large aneurysm bone cysts, with rapid recurrence, aggressive progression, and soft tissue invasion.

Evaluating Halogen-Bond Strength as a Function of Molecular Structure Using Nuclear Magnetic Resonance Spectroscopy and Computational Analysis.

Halogen bonding (XB) is a highly directional, non-covalent intermolecular interaction between a molecule (XB donor) presenting a halogen with an electron-deficient region or sigma hole (σ-hole) and an electron-rich or Lewis-base molecule (XB acceptor). A systematic, experimental, and theoretical study of solution-phase XB strength as a function of the molecular structure for both XB donor and acceptor molecules is presented. The impact of specific structural features is assessed using 19F and 1H nuclear magnetic resonance (NMR) titrations to determine association constants, density functional theory calculations for interaction energies and bond lengths, as well as 19F-1H HOESY NMR measurements of intermolecular cross-relaxation between the interacting XB donor-acceptor adducts. For XB donor molecules (perfluoro-halogenated benzenes), results indicate the critical importance of iodine coupled with electron-withdrawing entities. Prominent structural components of XB acceptor molecules include a central atom working in conjunction with a Lewis-base atom to present high electron density directed at the σ-hole (e.g., tributylphosphine oxide). Additionally, larger surrounding aliphatic R groups (e.g., butyl and octyl) were found to significantly stabilize strong XB, particularly in solvents that promote the interaction. With a more thorough understanding of structure-optimized XB, one can envision harnessing XB interactions more strategically for specific design of optimal materials and chemical applications.