Transient Exciton-Charge Interconversion in Single-Crystal Hybrid Perovskites.

Ultrafast oscillatory transient absorption (TA) dynamics are observed in single crystals of hybrid organic-inorganic perovskite (CH3NH3)PbX3 with X = I, Br, Cl. High-density photoinduced charges, low binding energy of the excitons, efficient generation and high mobility of charges, and long diffusion length of both excitons and charges led to transient interconversion between excitons and charges with high efficiency, which is responsible for the oscillatory TA dynamics at re-excitation by the probe pulses. The pump pulses initiated a quasi-equilibrium scheme of coexisting excitons and charges with high densities, the probe pulse triggered a perturbation through interconversion between these two kinds of excited "particles," which was overlapped on the intrinsic exciton relaxation dynamics, producing an oscillatory modulation with time delay. This not only reveals important photoelectronic processes with determined time scales, but also supplies physics for applications of this group of materials.

The Impact of Social Participation on Frailty among Older Adults: The Mediating Role of Loneliness and Sleep Quality.

BACKGROUND: Frailty has become a common health issue among older adults, imposing a burden on both society and individuals. The relationship between social participation and frailty has received widespread attention, but the mechanism remains to be explored. The aim of this study is to explore the impact of social participation on frailty among older adults and to analyze the mediating role of loneliness and sleep quality, providing suggestions to alleviate frailty. METHODS: Data related to social participation, loneliness, sleep quality, and frailty from 7779 older adults were collected from the Chinese Longitudinal Healthy Longevity Survey (CLHLS 2018). The chain mediation model was conducted to explore the relationship between variables, and the Bootstrap method was used to examine the path coefficients. RESULTS: Social participation negatively affected frailty (ß = -0.00391049, 95% CI = [-0.042296, -0.035465]); the indirect effect of social participation on frailty mediated by loneliness was -0.0019505 (95% CI = [-0.002551, -0.001371]); the indirect effect of social participation on frailty mediated by sleep quality was -0.0011104 (95%CI = [-0.001692, -0.000557]); the effect mediated by both loneliness and sleep quality was -0.0004263 (95% CI = [-0.000593, -0.000304]). CONCLUSIONS: Social participation negatively affected frailty. Loneliness and sleep quality not only mediated independently, but also played a chain mediating role. This suggested that encouraging older adults to engage in more social participation, reducing loneliness, and improving sleep quality are feasible measures to improve frailty.

Pre-diagnostic trajectory of pediatric hemophagocytic lymphohistiocytosis: observations from hematological and hepatic parameters.

Understanding the early features and characteristics of hemophagocytic lymphohistiocytosis (HLH) is essential for identifying high-risk individuals and also providing valuable pathological insights. This study aims to investigate the characteristics and trends of blood and hepatic parameters before an HLH diagnosis was established. Longitudinal hematological and hepatic test results from pediatric patients with HLH and an age- and sex-matched control group were analyzed. According to the length of time between hospital admission and the establishment of the HLH diagnosis, the HLH cases were divided into early-onset (≤ 7 days) and late-onset (> 7days) groups. Among the 229 pediatric HLH patients, the length of time between hospital admission and the establishment of an HLH diagnosis ranged from 0 to 41 days (median = 4 days). Over 80% of pediatric HLH patients presented abnormal laboratory results for aspartate aminotransferase (AST), triglycerides, lactate dehydrogenase (LDH), and hemoglobin at admission. The abnormal rates in the initial platelet count, neutrophil count, and fibrinogen tests were 67.3%, 48.3%, and 52.2%, respectively. The initial test results for AST, alanine aminotransferase (ALT), LDH, serum sodium, and albumin showed AUCs > 80% for discriminating early-onset HLH. For the discrimination of late-onset HLH, the performance of initial test results was poor. To conclude, abnormalities in AST, triglycerides, LDH, and hemoglobin are early presentations of pediatric HLH; platelet, neutrophil, and fibrinogen levels may become abnormal at a relatively late stage of the HLH disease trajectory; and the initial test results for AST, ALT, LDH, serum sodium, and albumin can be used to identify suspected early-onset HLH.

Advances in carbohydrate-based nanoparticles for targeted therapy of inflammatory bowel diseases: A review.

The incidence of inflammatory bowel disease (IBD), a chronic gastrointestinal disorder, is rapidly increasing worldwide. Unfortunately, the current therapies for IBD are often hindered by premature drug release and undesirable side effects. With the advancement of nanotechnology, the innovative targeted nanotherapeutics are explored to ensure the accurate delivery of drugs to specific sites in the colon, thereby reducing side effects and improving the efficacy of oral administration. The emphasis of this review is to summarize the potential pathogenesis of IBD and highlight recent breakthroughs in carbohydrate-based nanoparticles for IBD treatment, including their construction, release mechanism, potential targeting ability, and their therapeutic efficacy. Specifically, we summarize the latest knowledge regarding environmental-responsive nano-systems and active targeted nanoparticles. The environmental-responsive drug delivery systems crafted with carbohydrates or other biological macromolecules like chitosan and sodium alginate, exhibit a remarkable capacity to enhance the accumulation of therapeutic drugs in the inflamed regions of the digestive tract. Active targeting strategies improve the specificity and accuracy of oral drug delivery to the colon by modifying carbohydrates such as hyaluronic acid and mannose onto nanocarriers. Finally, we discuss the challenges and provide insight into the future perspectives of colon-targeted delivery systems for IBD treatment.

Direct Writing of SERS Substrates Using Femtosecond Laser Pulses.

Achieving a high-density, repeatable, and uniform distribution of "hotspots" across the entire surface-enhanced Raman scattering (SERS) substrate is a current challenge in facilitating the efficient preparation of large-area SERS substrates. In this study, we aim to produce homogeneous surface-enhanced Raman scattering (SERS) substrates based on the strong interaction between femtosecond laser pulses and a thin film of colloidal gold nanoparticles (AuNPs). The SERS substrate we obtained consists of irregularly shaped and sharp-edged gold nanoparticle aggregates with specially extruding features; meanwhile, a large number of three-dimensional AuNP stacks are produced. The advantages of such configurations lie in the production of a high density of hotspots, which can significantly improve the SERS performance. When the laser fluence is 5.6 mJ/cm2, the substrate exhibits the best SERS enhancement effect, and a strong SERS signal can still be observed when testing the concentration of R6G at 10-8 mol/L. The enhancement factor of such SERS substrates prepared using femtosecond laser direct writing is increased by 3 orders of magnitude compared to the conventional furnace annealing process. Furthermore, the relative standard deviation for the intensities of the SERS signals was measured to be 5.1% over an area of 50 × 50 µm2, indicating a highly homogeneous SERS performance and excellent potential for practical applications.

Ginkgo Biloba Bioactive Phytochemicals against Age-Related Diseases: Evidence from a Stepwise, High-Throughput Research Platform.

The seeds of ginkgo biloba L (GB) have been widely used worldwide. This study investigated the bioefficacies of whole GB seed powder (WGP) retaining the full nutrients of ginkgo against aging, atherosclerosis, and fatigue. The experimental results indicated that WGP lowered brain monoamine oxidase and serum malondialdehyde levels, enhanced thymus/spleen indexes, and improved learning ability, and delayed aging in senescent mice. WGP regulated lipid levels and prevented atherosclerosis by reducing triglycerides, lowering low-density lipoprotein cholesterol, increasing high-density lipoprotein cholesterol, and decreasing the atherosclerosis index. WGP improved exercise performance by reducing blood lactate accumulation and extending exhaustive swimming and climbing times, improved energy storage by increasing muscle/liver glycogen levels, and relieved physical fatigue. Network pharmacology analysis revealed 270 potential targets of WGP that play roles in cellular pathways related to inflammation inhibition, metabolism regulation, and anti-cellular senescence, etc. Protein-protein interaction analysis identified 10 hub genes, including FOS, ESR1, MAPK8, and SP1 targets. Molecular docking and molecular dynamics simulations showed that the bioactive compounds of WGP bound well to the targets. This study suggests that WGP exerts prominent health-promoting effects through multiple components, targets, and pathways.

Suppressed concentration quenching and tunable photoluminescence in Eu2+-activated Rb3Y(PO4)2 phosphors for full-spectrum lighting.

Highly efficient inorganic phosphors are desirable for lighting-emitting diode light sources, and increasing the doping concentration of activators is a common approach for enhancing the photoluminescence quantum yield (PLQY). However, the constraint of concentration quenching poses a great challenge for improving the PLQY. Herein, we propose a fundamental design principle by separating activators and prolonging their distance in Eu2+-activated Rb3Y(PO4)2 phosphors to inhibit concentration quenching, in which different quenching rates are controlled by the Eu distribution at various crystallographic sites. The blue-violet-emitting Rb3Y(PO4)2:xEu (x = 0.1%-15%) phosphors, with the occupation of Rb1, Rb2 and Y sites by Eu2+, exhibit rapid luminescence quenching with optimum external PLQY of 10% due to multi-channel energy migration. Interestingly, as the Eu concentration increases above 20%, Eu2+ prefer to occupy the Rb1 and Y sites with separated polyhedra and large interionic distances, resulting in green emission with suppressed concentration quenching, achieving an improved external PLQY of 41%. Our study provides a unique design perspective for elevating the efficiency of Eu2+-activated phosphors toward high-performance inorganic luminescent materials for full-spectrum lighting.

Corydalis yanhusuo extract and its pharmacological substances alleviate food allergy by inhibiting mast cells activation via PLC/PKC/STAT3 pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Food allergies have increasingly become a disease that affects global health and need for corresponding therapeutic drugs urgently. As a traditional Chinses medicine with a wide range of pharmacological effects, however, there was no clear research confirming therapeutic effect and pharmacological substances of Corydalis yanhusuo (YHS) on food allergies. Mast cells (MCs) are the main effector cells which mediate allergic and pseudo-allergic reactions. MATERIALS AND METHODS: In this study, we investigated the effect of YHS extract on treating food allergy and its underlying mechanism. The inhibitory effect of YHS on MCs activation in vitro was evaluated by Ca2+ influx, degranulation, and cytokine release detection. The in vivo effect was investigated using the passive cutaneous anaphylaxis (PCA), active systemic allergy as well as OVA-induced food allergy mice. Western blot was performed to reveal the signaling pathway. RESULTS: YHS extract showed an inhibitory effect on MCs activation and food allergy both in vitro and in vivo. PLC/PKC/STAT3 signaling pathway was suppressed by YHS extract in the disease. HPLC analysis revealed YHS extract contains corydaline and tetrahydropalmatine, and both compounds inhibited MCs activation induced by C48/80 in vitro. CONCLUSION: YHS extract inhibited the MCs activation and food allergy via PLC/PKC/STAT3 pathway.

An Organic Microcavity Laser Amplifier Integrated on the End Facet of an Optical Fiber.

We report a thin-film optical amplifier integrated on a fiber facet based on polymer-coated distributed feedback (DFB) microcavities, which are fabricated on a planar substrate and then transferred onto fiber tips by means of a flexible transfer technique. The amplified light directly couples into the fiber and is detected when coupled out at the other end after propagating along the fiber for about 20 cm. A prominently amplification factor of about 4.33 at 578.57 nm is achieved by sending supercontinuum pulses into the hundreds of micrometers' DFB microcavities along the normal direction, which is also the axis direction of the fiber. The random distortions of grating lines generated during the transfer process result in a larger amplification spectral range and a less strict polarization dependence for injected light. Benefitting from the device size of hundreds of micrometers and the ease of integration, polymer amplifiers based on DFB microcavities demonstrate significant application potentials in optical communication systems and miniaturized optical devices.

Bio-inspired micropatterned thermochromic hydrogel for concurrent smart solar transmission and rapid visible-light stealth at all-working temperatures.

Thermochromic hydrogels exhibit a smart capacity for regulating solar spectrum transmission, enabling automatically change their transmissivity in response to the ambient temperature change. This has great importance for energy conservation purposes. Military and civilian emergency thermochromic applications require rapid visible-light stealth (VLS); however, concurrent smart solar transmission and rapid VLS is yet to be realized. Inspired by squid-skin, we propose a micropatterned thermochromic hydrogel (MTH) to realize the concurrent control of smart solar transmittance and rapid VLS at all-working temperatures. The MTH possesses two optical regulation mechanisms: optical property regulation and optical scattering, controlled by temperature and pressure, respectively. The introduced surface micropattern strategy can arbitrarily switch between normal and diffuse transmission, and the VLS response time is within 1 s compared with previous ~180 s. The MTH also has a high solar-transmission regulation range of 61%. Further, the MTH preparation method is scalable and cost-effective. This novel regulation mechanism opens a new pathway towards applications with multifunctional optical requirements.

Structure, Functional Properties, and Applications of Foxtail Millet Prolamin: A Review.

Foxtail millet prolamin, one of the major protein constituents of foxtail millet, has garnered attention due to its unique amino acid composition and function. Foxtail millet prolamin exhibits specific physicochemical and functional characteristics, such as solubility, surface hydrophobicity, emulsifying, and foaming properties. These characteristics have been exploited in the preparation and development of products, including plant-based alternative products, nutritional supplements, and gluten-free foods. Additionally, because of the favorable biocompatibility and biodegradability, foxtail millet prolamin is frequently used as a carrier for encapsulation and targeted delivery of bioactive substances. Moreover, studies have shown that foxtail millet prolamin is highly nutritious and displays various biological activities like antioxidant effects, anti-inflammatory properties, and anti-diabetic potential, making it a valuable ingredient in medicinal products and contributing to its potential role in therapeutic diets. This review summarizes the current knowledge of the amino acid composition and structural characteristics of foxtail millet prolamin, as well as the functional properties, biological activities, and applications in functional food formulation and drug delivery strategy. Challenges and future perspectives for the utilization of foxtail millet prolamin are also pointed out. This review aims to provide novel ideas and broad prospects for the effective use of foxtail millet prolamin.

[Analysis of a Chinese pedigree with Bw subtype due to a novel variant of α-1,3-N-acetylgalactosaminyltransferase gene].

OBJECTIVE: To explore the serological characteristics and genetic variant in a Chinese pedigree with Bw subtype. METHODS: A 32-year-old female proband who had undergone prenatal examination on December 10, 2020 at the 960th Hospital of the PLA Joint Logistics Support Force and five members from her pedigree were selected as the study subjects. Peripheral blood samples were collected and subjected to ABO blood group phenotyping with serological methods and ABO blood group genotyping with fluorescent PCR. Genetic testing and haplotype analysis were carried out by direct sequencing of the entire coding region of the ABO gene in the proband and cloned sequencing of exons 1-7. RESULTS: The blood type serology of the proband showed Bw, and her ABO blood type genotype determined by fluorescence PCR was B/O. The direct sequencing results showed that the proband had matched the ABO*O.01.01/ABO*B.01 genotype and carried a c.1A>G variant. Cloned sequencing has confirmed the c.1A>G variant to have occurred in the ABO*B.01 allele. Family analysis revealed that the mother of the proband had an O blood type, her husband had a B phenotype, and her three children had a normal B blood type. DNA sequencing showed that the two sons of the proband had a genotype of ABO*B.01 and c.1A>G/ABO*B.01. The daughter of the proband was ABO*O.01.01/ABO*B.01, whilst her mother was ABO*O.01.01/ABO *O.01.02. The novel c.1A>G variant sequence has been registered with the database with a number MZ076785 1. CONCLUSION: The novel c.1A>G variant of exon 1 of α- 1,3 galactose aminotransferase gene probably underlay the reduced expression of B antigen in this pedigree.

Polarization and wavelength routers based on diffractive neural network.

In the field of information processing, all-optical routers are significant for achieving high-speed, high-capacity signal processing and transmission. In this study, we developed three types of structurally simple and flexible routers using the deep diffractive neural network (D2NN), capable of routing incident light based on wavelength and polarization. First, we implemented a polarization router for routing two orthogonally polarized light beams. The second type is the wavelength router that can route light with wavelengths of 1550, 1300, and 1100 nm, demonstrating outstanding performance with insertion loss as low as 0.013 dB and an extinction ratio of up to 18.96 dB, while also maintaining excellent polarization preservation. The final router is the polarization-wavelength composite router, capable of routing six types of input light formed by pairwise combinations of three wavelengths (1550, 1300, and 1100 nm) and two orthogonal linearly polarized lights, thereby enhancing the information processing capability of the device. These devices feature compact structures, maintaining high contrast while exhibiting low loss and passive characteristics, making them suitable for integration into future optical components. This study introduces new avenues and methodologies to enhance performance and broaden the applications of future optical information processing systems.

Hierarchical pore structure with a confined resonant mode for improving the solar energy utilizing efficiency of ultra-thin perovskite solar cells.

The perovskite solar cell (PSC) has the benefits of flexibility, inexpensiveness, and high efficiency, and has important prospective applications. However, serious optical losing and low solar energy-utilizing efficiency remain a challenge for the ultra-thin PSCs because of the interface reflection of traditional planar structure. In this study, a hierarchical pore structure with a confined resonant mode is introduced and optimized by electromagnetic theory to improve the solar energy absorbing and utilizing efficiency of ultra-thin PSCs. The large pores in the top layer that support a whispering gallery mode can focus and guide the incident light into the solar cell. The small pores in the bottom layer enable backward scattering of the unabsorbed light and can improve the effective absorption of active layer. The finite-difference time-domain method is employed to optimize the geometric parameters of hierarchical pore structure to improve the light absorption of PSCs. The proposed resonant hierarchical pore structure can greatly improve sunlight absorption of ultra-thin PSCs, and the effective light absorption and photocurrent of PSCs with a hierarchical pore structure is 20.7% higher than that of PSCs with traditional planar structure. This work can offer a beneficial guideline for improving solar energy utilizing efficiency of various thin-film solar cells.

Hyperbaric oxygen enhances tumor penetration and accumulation of engineered bacteria for synergistic photothermal immunotherapy.

Bacteria-mediated cancer therapeutic strategies have attracted increasing interest due to their intrinsic tumor tropism. However, bacteria-based drugs face several challenges including the large size of bacteria and dense extracellular matrix, limiting their intratumoral delivery efficiency. In this study, we find that hyperbaric oxygen (HBO), a noninvasive therapeutic method, can effectively deplete the dense extracellular matrix and thus enhance the bacterial accumulation within tumors. Inspired by this finding, we modify Escherichia coli Nissle 1917 (EcN) with cypate molecules to yield EcN-cypate for photothermal therapy, which can subsequently induce immunogenic cell death (ICD). Importantly, HBO treatment significantly increases the intratumoral accumulation of EcN-cypate and facilitates the intratumoral infiltration of immune cells to realize desirable tumor eradication through photothermal therapy and ICD-induced immunotherapy. Our work provides a facile and noninvasive strategy to enhance the intratumoral delivery efficiency of natural/engineered bacteria, and may promote the clinical translation of bacteria-mediated synergistic cancer therapy.

Citrate and low-dose heparin combined anticoagulation in pediatric continuous renal replacement therapy.

There remains no optimal anticoagulation protocol for continuous renal replacement therapy (CRRT) with regional citrate anticoagulation (RCA) in pediatric patients with elevated D-dimer levels. We aimed to assess the effects of different anticoagulation strategies on the risk of CRRT filter clotting in these patients. Pediatric patients undergoing CRRT were retrospectively grouped based on pre-CRRT D-dimer levels and anticoagulant: D-RCA group (normal D-dimer, RCA only, n = 22), D+ RCA group (elevated D-dimer, RCA only, n = 50), and D+ RCA+ systemic heparin anticoagulation (SHA) group (elevated D-dimer, RCA combined with SHA, n = 55). The risk of filter clotting and incidence of bleeding were compared among the groups. Among the groups, the D+ RCA+ SHA group had the longest filter lifespan; further, the incidence of bleeding was not increased by concurrent use of low-dose heparin for anticoagulation. Moreover, concurrent heparin anticoagulation was associated with a decreased risk of filter clotting. Contrastingly, high pre-CRRT hemoglobin and D-dimer levels and post-filter ionized calcium level > 0.4 mmol/L were associated with an increased risk of filter clotting. RCA combined with low-dose heparin anticoagulation could reduce the risk of filter clotting and prolong filter lifespan without increasing the risk of bleeding in patients with elevated D-dimer levels undergoing CRRT.

Social control is associated with increased reproductive skew in a wild mammal.

In group-living species, reproductive variation among individuals of the same sex is widespread. By identifying the mechanisms underlying this reproductive skew, we gain fundamental insights into the evolution and maintenance of sociality. A common mechanism, social control, is typically studied by quantifying dominance, which is one of many attributes of sociality that describes how individuals exert influence on others and is an incomprehensive measure of social control as it accounts only for direct relationships. Here, we use the global reaching centrality (GRC), which quantifies the degree of hierarchy in a social network by accounting for both direct and indirect social relationships. Using a wild, free-living population of adult female yellow-bellied marmots (Marmota flaviventris), we found a positive relationship between the reproductive skew index and GRC: more despotic social groups have higher reproductive skew. The GRC was stronger predictor for skew than traditional measures of social control (i.e. dominance). This allows deeper insights into the diverse ways individuals control other group members' reproduction, a core component in the evolution of sociality. Future studies of skew across taxa may profit by using more comprehensive, network-based measures of social control.

Unveiling the Diagnostic Value of Strain Parameters Across All 4 Cardiac Chambers in Patients With Acute Myocarditis With Varied Ejection Fraction: A Cardiovascular Magnetic Resonance Feature-Tracking Approach.

BACKGROUND: This study assesses the diagnostic utility of strain parameters from cardiovascular magnetic resonance feature tracking across all cardiac chambers in patients with acute myocarditis, stratified by ejection fraction. METHODS AND RESULTS: Our cohort included 65 patients with acute myocarditis and 25 healthy controls; all underwent cardiac magnetic resonance imaging. Patients were divided into 2 groups based on left ventricular ejection fraction (EF)with a 55% cutoff: acute myocarditis with preserved EF, EF ≥55%, n=48; and acute myocarditis with reduced EF, EF <55%, n=17. The control group matched for age and sex. Cardiovascular magnetic resonance feature tracking evaluated strain parameters across all cardiac chambers. Both acute myocarditis with preserved EF and acute myocarditis with reduced EF groups showed significant decreases in left atrial peak early negative strain rate compared with controls. The acute myocarditis with reduced EF group had significantly reduced left ventricular circumferential strain relative to acute myocarditis with preserved EF and controls. Receiver operating characteristic curve analysis confirmed the diagnostic accuracy in distinguishing patients with acute myocarditis with preserved EF from controls, with left atrial peak early negative strain rate achieving 92.9% specificity, left ventricular circumferential strain demonstrating an area under the curve of 0.832, and similarly effective results for left ventricular longitudinal strain and right ventricular longitudinal strain. Additionally, left atrial peak early negative strain rate and left ventricular circumferential strain showed significant correlations with troponin I levels, indicating myocardial injury. CONCLUSIONS: Cardiovascular magnetic resonance feature-tracking-derived strain parameters, particularly left atrial peak early negative strain rate and left ventricular circumferential strain, effectively diagnose acute myocarditis across different EFs, enhancing diagnostic accuracy and facilitating early detection, notably in patients with preserved EF.

Inhibition of pseudo-allergic reactions by vitamin K3 directly targeting GAB1 in mast cells.

BACKGROUND: Vitamin K3 (VK3), a fat-soluble synthetic analog of the vitamin K family, has coagulant, anti-inflammatory, antibacterial, and anticancer properties. Pseudo allergy is a IgE-independent immune response associated with mast cells. This study investigated the role of VK3 in IgE-independent mast cell activation. METHODS: Substance P (SP) was used to induce LAD2-cell activation in order to analyze the effects of VK3 in vitro. Cutaneous allergy and systemic allergy mouse models were used to analyze the anti-pseudo-allergic effects of VK3. Proteome microarray assays were used to analyze VK3-binding protein. Biolayer interferometry and immunoprecipitation were used to verify interaction between VK3 and its key targets. RNA interference was used to determine the role of GAB1 in LAD2cell activation. RESULTS: VK3 inhibited SP-induced LAD2-cell activation, and resulted in the release of ß-hexosaminidase, histamine and cytokines; VK3 inhibited SP-induced pseudo allergic reactions in mice, and serum histamine and TNF-α levels decreased. Degranulation of skin mast cells was reduced; GAB1 in mast cells was stably bound to VK3. GAB1 participated in SP-induced LAD2-cell activation. GAB1 knockdown in LAD2 cells prevented SP-induced ß-hexosaminidase release, calcium mobilization and cell skeletal remodeling. VK3 directly binds to GAB1 and reduces its expression to inhibited SP-induced LAD2 cell activation. CONCLUSION: The anti-pseudo-allergic activity of VK3 was confirmed in vitro and in vivo. VK3 can inhibit SP-induced mast cell activation by directly targeting GAB1. This study provides new insights on the activity of VK3 and the mechanism of pseudoallergic reaction.

Mono-, di- and trimetallic coinage nanoparticles prepared via the Brust-Schiffrin method.

The Brust-Schiffrin two-phase method is a facile way to prepare thiolate-protected metal nanoparticles, but its mechanism remains controversial. In this work, we demonstrate the use of the Brust-Schiffrin method based on coordination compound theory. We confirmed that the formation of stable complexes is the driving force for a series chemical reaction in the organic phase. We found that the stable Cu(I)-thiolate complex decreased the half-cell reduction potential of Cu(I)/Cu(0). Thus, when thiol ligands were in excess, thiolate-protected Cu(I) clusters formed rather than Cu(0)-cored nanoparticles. The thiolate-protected metal-hydride nanoclusters were the intermediate between the metal complexes and nanoparticles. The "metallophilic" interactions of the d10 closed-shell electronic configuration of the metal coordination centers were proposed as the driving force for nanocluster and nanoparticle formation. To confirm this mechanism, we synthesized Au, Ag, and Cu monometallic nanoparticles and bi- and trimetallic nanoparticles. We found that although thiolate-protected Cu(I) nanoclusters are not easily reduced, they can combine with Au and/or Ag nanoclusters to form nanoparticles. The proposed mechanism is expected to provide deeper insight into the Brust-Schiffrin method and further extend its application to metals other than Au, Ag and Cu.