Search Results (141)

The scattering interaction between a circularly polarized Bessel pincer light-sheet beam and a chiral particle is investigated within the framework of generalized Lorenz–Mie theory (GLMT). The incident electric field distribution is rigorously derived via the vector angular spectrum decomposition method (VASDM), with subsequent determination of the beam-shape coefficients (BSCs) $p_{mn}^u$ and $q_{mn}^u$ through multipole expansion in the basis of vector spherical wave functions (VSWFs). The expansion coefficients for the scattered field ($A_{mn}^s$$B_{mn}^s$) and interior field ($A_{mn}$$B_{mn}$) are derived by imposing boundary conditions. Simulations highlight notable variations in the scattering field, near-surface field distribution, and far-field intensity, strongly influenced by the dimensionless size parameter $ka$, chirality $\kappa$, and beam parameters (beam order l and beam scaling parameter ${\alpha }_0$). These findings provide insights into the role of chirality in modulating scattering asymmetry and localization effects. The results are particularly relevant for applications in optical manipulation and super-resolution imaging in single-molecule microbiology. Full article

In this study, two color morphs (red and green) of Asian swimming crab (Charybdis japonica) commonly distributed in the China Sea area were analyzed for their L*a*b* values, carapace and inner membrane histology, morphological characteristics, mitochondrial DNA sequences, muscle texture, and amino acid composition. The results showed that compared with the green morph group, the red morph group exhibits higher aggregation of melanocytes and fewer pigment cells in the inner membrane. In addition, L* and b* of the carapace, and L* values of the inner membrane were lower in red morph group. Both populations of C. japonica also exhibit significant differences in their morphological parameters, including carapace length, body weight, and pincer width. However, the coefficient of variation for these morphological parameters did not correspond to the subspecies level. The mitochondrial DNA analysis also revealed sequence identity of COI (98.96%) and ITS-1 (99.71%) genes in both groups, supporting them to belong to the same species. Both groups also presented significant differences in their muscle texture characteristics, including adhesiveness, springiness, and gumminess, but no significant differences were observed in the muscle amino acid composition. Overall, red and green morphs of C. japonica show differences in their body color, morphological characteristics, and muscle quality, but still belong to the same species. Full article

Objective: A self-management telehealth program to improve hand strength and function in systemic sclerosis (SSc) patients may improve their quality of life, so we investigated its efficacy. Methods: A 6-week prospective randomized controlled study was conducted in adults with SSc with a hand mobility in scleroderma (HAMIS) score > 1 or a limited range of motion in at least one hand joint. Participants were randomly allocated into three groups for six weeks of health education: (a) typical education, (b) watching video guides as needed, in addition to typical education, and (c) watching video guides and receiving weekly telephone notifications, in addition to typical education. The endpoints were the differences in self-management behavior, HAMIS scores, hand grip strength (HGS), and quality of life (QoL) using the European Quality of Life-5 Dimensions between groups, as well as the changes in these parameters compared to baseline. Results: A total of 24 patients per group were enrolled, with the majority diagnosed with diffuse cutaneous SSc (79.2%). Six weeks post-intervention, HGS improved significantly in both the video guide and telephone notification groups compared to typical education in both hands (p = 0.028, p = 0.044). Pincer grip differed between the groups in the non-dominant hand. Household modifications were more frequent in the video guide and telephone notification groups than in the typical education group (p = 0.023). All groups showed significant improvements in HGS and HAMIS scores in both hands, as well as in self-management behaviors, compared to baseline. QoL, as measured using a visual analog scale, improved significantly after the intervention in both the video guide and telephone notification groups, but not in the typical education group. Conclusions: Self-management telehealth programs effectively enhance hand strength, function, and self-management behaviors in patients with SSc with limited hand function. Weekly telephone notifications further reinforced continuity and engagement in these patients. Full article

N-heterocyclic carbenes (NHCs) were first isolated as stable species by Arduengo in 1991. Since then, they have expanded the boundaries of carbene chemistry and sparked extensive research. Utilizing NHCs to modify the electronic properties of transition metal complexes represents a significant advancement in the field. Pincer-type NHCs, which occupy half or more of the vacant sites on metal centers, typically result in structurally well-defined molecular platforms with specific active sites for a variety of applications. This review provides an overview of late transition metal complexes based on pincer-type NHCs, discussing their synthetic strategies, reactivities, and electronic properties, as well as their applications. Additionally, some perspectives will be presented to highlight future directions in this rapidly growing field. Full article

The development of new, more effective, and selective anticancer agents is one of the most important tasks of modern medicinal chemistry. Recently, we have found that non-classical Pd(II) pincer complexes derived from thiophosphoryl-appended picolinamides exhibit promising cytotoxic properties. In this work, the potential of this class of metal-based derivatives was studied on an extended family of Pd(II) complexes with a deprotonated amide core featuring thiophosphoryl pendant arms, readily obtained by the direct cyclopalladation of new functionalized amide ligands upon interaction with PdCl₂(NCPh)₂ under mild conditions. The ligands, in turn, were obtained by conventional amide coupling methods using (aminobenzyl)- and (aminomethyl)diphenylphosphine sulfides as the key precursors and different N- and S-donor-substituted carboxylic acids. The effect of an acid component and carbon chirality in the ligand framework on the bioactivity of the resulting Pd(II) pincer complexes was elucidated by evaluating their cytotoxicity against different solid and blood cancer cell lines, apoptosis induction ability, and P-glycoprotein (P-gp) affinity, which revealed the high anticancer potential of some of them, and in particular, the potential to overcome drug resistance associated with P-gp overexpression. The representative palladocycle was also shown to possess moderate antibacterial activity. Full article

Introduction: The present study investigates the five-year outcomes of hip arthroscopy for cam or pincer-type femoroacetabular impingement (FAI) and associated labral tears in a defined patient population. Methods: Patients who underwent hip arthroscopy for cam or pincer-type arthroscopy femoroacetabular impingement (FAI) and labral tears at our hospital in the past five years were included. All patients who underwent revision—like a total hip arthroplasty (THA), a subsequent hip arthroscopy at another hospital, or had primary osseous diseases—were excluded. Patients were contacted via mail and asked to answer a clinical questionnaire called the “Hip Osteoarthritis Outcome Score” (HOOS) and to indicate whether there was a second surgery like a subsequent arthroscopy or THA. Results: There were 77 hip arthroscopies in 75 patients the last 5 years. A total of 29 patients responded. Those who did not respond were contacted via phone. All in all, we obtained the results of 49 patients (50 hips—29 right, 19 left, and 1 bilateral) who underwent hip arthroscopy over the past five years. The mean age at the time of operation was 41 years. Our results were as follows: 24 hips had an isolated labral tear, 49 hips a combined FAI pathology with cam and/or pincer-type impingement and labral tears, 3 patients had a posttraumatic FAI, and 1 patient suffered from hip chondromatosis, who was subsequently excluded; further, 22 patients (23 procedures) were lost to follow-up. HOOS contains various subscales; only the postoperative result of subscale 1 (symptoms) did not show a statistically significant improvement compared with the preoperative value. All other subscales showed a statistically significant improvement in comparison with the preoperative condition. Five patients (10.2%) still experienced symptoms, so we performed a total hip arthroplasty (THA) as a second surgical procedure. One patient was revised due to chondromatosis. One patient was revised at another center, and another was excluded because of chondromatosis. Conclusions: The five-year follow-up results of hip arthroscopy proved successful outcomes. Hip arthroscopy is an effective treatment for FAI in order to delay primary THA, regaining mobility and range of motion and reducing pain. Longer-term studies with a larger cohort are necessary. Full article

2-(2′-aminophenyl)benzothiazole is a readily tunable fluorescent core with widespread applications in coordination chemistry, sensing, light-emitting processes, medicinal chemistry, and catalysis. This review provides an overview of the synthetic methodologies to access 2-(2′-aminophenyl)benzothiazole and its organic derivatives, including various phosphorous and silane pincer ligands. The luminescent properties will be discussed, with a special focus on ESIPT and AIE processes. The coordination of transition metals and lanthanides is presented, as well as their influence on biological and light-emitting properties. 2-(2′-aminophenyl)benzothiazole derivatives have also been employed as sensors for a range of cations and anions due to their various binding modes, as well as for bioimaging purposes. Recently, the first application in photocatalysis has emerged, showing one of the many openings for these organic building blocks in the future. Full article

Several CNN pincer Pd(II) complexes including chiral complexes 1a–e with 2-phenyl-6-(oxazolinyl)pyridines and achiral ones 2a–c with N-substituted-2-aminomethyl-6-phenylpyridines were prepared. In addition, the preparation of the achiral PCN pincer Pd(II) complexes 3a–e with aryl-based phosphinite–imine ligands and chiral 4a–c with aryl-based phosphinite–imidazoline ligands was also performed. Among them, the PCN Pd(II) pincers 3a–e were new complexes and were readily synthesized from commercially available materials in only two steps. The new complexes were characterized through elemental analyses, namely ¹H NMR, ¹³C{¹H} NMR, and ³¹P{¹H} NMR spectroscopies. Furthermore, the molecular structure of complex 3a was determined via X-ray single-crystal diffraction analysis. In the presence of EtAlCl₂, Et₂AlCl, or methylaluminoxane (MAO), the CNN pincer Pd(II) complexes and PCN pincer Pd(II) complexes exhibited excellent activities and monomer conversion rates in norbornene addition polymerization. Surprisingly, the CNN pincer Pd(II) complexes exhibited a higher conversion rate (99.5%) with Et₂AlCl as the cocatalyst, while the PCN pincer Pd(II) complexes showed a higher conversion rate (98.8%) with MAO. Full article

A series of novel NNN pincer manganese complexes based on pyrazole skeleton 4 were efficiently synthesized in a two-step process. All of the new complexes were fully characterized by ¹H, ¹³C NMR spectra. Furthermore, the molecular structures of complexes 4a and 4c were also determined by X-ray single-crystal diffraction. The manganese(I) catalysts obtained showed efficient catalytic activity in the α-alkylation reaction of ketones with alcohols. Under optimal reaction conditions, the expected products were procured with moderate to high yields. Full article

Bulky NCN aryl-diamides featuring methyl groups in the benzyl positions were synthesized with the aim of creating a new class of meta-xylene-based trianionic pincer ligands where the common decomposition pathway of metal pincer complexes via C-H activation is prevented. Sterically demanding substituents on the ligands furthermore provide steric protection of the metal centre and can help prevent the dimerization of the complexes. While a double deprotonation of the ligands and the formation of a dilithium salt was straightforward, difficulties were encountered when attempting to deprotonate the ipso-CH proton on the central aryl ring to yield trianionic ligands. This stands in contrast to related pincer ligands without methyl groups in the benzylic positions. Experimental and theoretical investigations led to the conclusion that the challenges encountered when attempting the third deprotonation are likely caused by an interplay of increased electron density at the nitrogen atoms and steric hindrance. Both effects originate in the introduction of methyl groups in the benzylic positions, which make the targeted proton less accessible. These results provide further insight into the impact of methyl groups in the benzyl positions on both steric and electronic properties of NCN pincer ligands, which may find utility in coordination chemistry applications where metalation can be achieved by direct C-H activation rather than requiring triple deprotonation. Full article

We have synthesized novel cobalt(II) and nickel(II) pincer ligand complexes containing novel tridentate ligand precursors that coordinate via oxygen, nitrogen, and oxygen donor atoms. The novel tridentate ONO ligands, which are neutral, incorporate a carbonyl-substituted imidazole functionality and contain R groups of ethyl, isopropyl, or tert-butyl. The ligand precursors were thoroughly characterized using NMR spectroscopy, ESI-MS, and IR spectroscopy. The metal complexes were thoroughly characterized using single crystal X-ray diffraction, elemental analysis, ESI-MS, and cyclic voltammetry. The nickel(II) and cobalt(II) complexes with ethyl, isopropyl, and t-butyl wingtip groups had a pseudo-octahedral geometry about the metal center. The nickel(II) complex with R = isopropyl had a monoclinic lattice with C121 space group (a = 21.7639(8); b = 11.0649(5); c = 10.9225(4); alpha = 90.0 degrees; beta = 90.609(3) degrees; gamma = 90.0 degrees). The cobalt(II) complex with R = ethyl had a monoclinic lattice with P2₁/n space group (a = 17.7907(7); b = 21.5278(6); c = 21.8597(7); alpha = 90.0 degrees; beta = 95.063(3) degrees; gamma = 90.0 degrees). The cobalt(II) complexes were paramagnetic with μ_eff = 1.59 BM (R = ethyl) and 6.67 BM (R = t-butyl). The nickel(II) complex was paramagnetic with μ_eff = 2.59 BM. The ligand precursors and metal complexes are redox-active. Full article

The knotter, as a core module for the knotting function of a rice electric binder, has structural parameters and spatial configurations that significantly impact the efficiency and quality of rice collection, making the in-depth analysis and optimization of these parameters, and their spatial relationships, crucial for enhancing the operational quality of the rice electric binder. At present, rice binders still face the issues of a low bundling efficiency and quality, which affect the progress of rice harvesting during the harvest season. Through theoretical analysis and calculation, this study determined the main parameters affecting the knotter’s knotting process and their value ranges. Based on the ADAMS software, a simulation model of the knotter operation was constructed. Using the Box–Behnken design (BBD) method and response surface analysis of variance, a regression prediction model for knotter operation evaluation indicators was established, and the multi-objective optimization of the knotter’s operation quality was performed. The prediction results showed that, under the optimal structural parameter combination of a 30.23° angle between the knotting pincer and rope guard axes, a −3.75 mm rope clamping board position, and a 40.75° inclination angle of the knotting pincer convex platform, the knotter’s knotting quality reached the best state, with an average knot end protrusion of 9.10 mm and a maximum tension of 134.25 N on the knotting rope. The field tests results showed an average knot end protrusion of 9.60 mm and a maximum tension of 127.87 N on the knotting rope, with average relative errors of 5.82% and 4.72% compared to the theoretical values, respectively. After optimizing the knotter, the average knot end protrusion increased by 14.48% and the maximum tension of the knot rope was reduced by 11.27%. Meanwhile, the knotter achieved an average bundling rate as high as 99.3%. The bundling success rate also increased by 2.7%. These results fully verify the reliability and accuracy of the regression model, and demonstrate the reasonableness of the knotter structural parameter optimization design, providing a theoretical basis and reference for improving the operational quality of the rice electric binder. Full article

Background: Femoroacetabular impingement (FAI) is a condition caused by abnormal contact between the femur head and the acetabulum, which damages the labrum and articular cartilage. While the prevalence and the type of impingement may vary across human groups, the variability among populations with short height or with a high prevalence of overweight has not yet been explored. Latin American studies have rarely been conducted in reference to this condition, including the Mayan and mestizo populations from the Yucatan Peninsula. Objective: We aimed to describe the prevalence of morphological changes in femoroacetabular impingement by measuring radiological angles in abdominopelvic tomography studies in a sample of patients from a population with short height. Methods: In this prospective study, patients with programmed abdominopelvic tomography unrelated to femoroacetabular impingement but with consistent symptoms were included. Among the 98 patients, the overall prevalence of unrelated femoroacetabular impingement was 47%, and the pincer-type was the most frequent. The cam-type occurred more frequently among individuals with taller stature compared to their peers. Alpha and Wiberg angles predicted cam- and pincer-type, respectively, with over 0.95 area under the curve values in ROC analyses. The inter-rater agreement in the study was >91%. Conclusions: In a patient population from Yucatan, Mexico, attending ambulatory consultations unrelated to femoroacetabular impingement, an overall morphological changes prevalence of 47% was observed. Angle measurements using tomographic techniques can be used to predict cam- and pincer-type femoroacetabular impingement. Average stature was observed to be shorter in patients with cam-type femoroacetabular impingement, but body mass index did not vary between groups. Full article

Different supramolecular motifs are formed by the crystallisation of amino-substituted derivatives of quinoxaline, pyrimidine and pyridazine. These were made from the corresponding mono- or dichlorinated heterocycles by a nucleophilic displacement reaction. The pyridine-type nitrogen atoms activate the chlorine atoms because they can stabilise a negative charge, which forms when the amine attacks the ring. One amino group can be attached under mild conditions in hot ethanol or acetonitrile, but the first then deactivates the ring so the second requires more forceful conditions using a pressure vessel at 150 °C. Butylamine is frequently used because it reduces the polarity of the product, making it easier to purify and isolate. The extended structure of the quinoxaline derivatives 16–18 show a common ‘pincer’ hydrogen-bond motif, with a quinoxaline nitrogen atom accepting two N–H···N hydrogen bonds, giving a spiral or helical axis. The chain symmetries are 4₁, 2₁ and 3₁, respectively, depending on the substituents. A stereoview of each is shown. The pyrimidine derivatives 19, 12, 20, 14 and 21 form hydrogen-bonded tapes and compound 20 forms inversion dimers. Full article

The crystal structure and topology analyses of a new bromo-Mn(II) complex with 2,4-bis(3,5dimethyl-1H-pyrazol-1-yl)-6-methoxy-1,3,5-triazine (MBPT) were reported. Its structure was confirmed using single-crystal X-ray diffraction to create the formula [Mn(MBPT)Br(H₂O)₂]ClO₄. Its crystal system was monoclinic and its space group was p2₁. The Mn(II) was coordinated with MBPT as a NNN-pincer ligand, with one bromide ion in the equatorial plane. The two axial terminals were occupied by two trans water molecules. H…H, N…H, Br…H, C…H and O…H were the predominant intermolecular contacts, while Br…H, O…H and C…O were the significant contacts based on Hirshfeld analysis. Moreover, anion–ᴨ interaction was found between C(s-triazine) and O(perchlorate). This complex had better antioxidant activity than the free ligand (MBPT). In addition, the cytotoxicity of the [Mn(MBPT)Br(H₂O)₂]ClO₄ complex showed better results against HepG-2 and MCF-7 cells, recording IC₅₀ values of 31.11 ± 2.04 and 50.05 ± 2.16 µM, respectively, compared to the free ligand (IC₅₀ = 671.44 ± 21.41 and 1113.55 ± 29.77 µM). In comparison to cis-platin as a reference drug, the IC₅₀ values were 63 and 80 μM, respectively, which indicated the promising anticancer activity of the studied compound against both cell lines. In terms of the safety of normal cells, the Mn(II) complex recorded a high IC₅₀ value of 359.10 ± 8.72 µM against the WI-38 non-cancerous cell line. The complex showed better activity towards Staphylococcus aureus, Bacillus subtilis, and Proteus vulgaris relative to the free MBPT, but had low to moderate activity compared to Gentamycin as an antibacterial positive control. Full article