Silver Chain Research Articles

Reconciling mean-squared radius differences in the silver chain through improved measurement and ab initio calculations

Nuclear charge radius differences in the silver isotopic chain have been reported through different combinations of experiment and theory, exhibiting a tension of two combined standard errors. This study investigates this issue by combining high-accuracy calculations for six low-lying states of atomic silver with an improved measurement of the 5s2S1/2−5p2P3/2 transition optical isotope shift. Our calculations predict measured electronic transition energies in Ag at the 0.3% level, the highest accuracy achieved in this system so far. We calculate electronic isotope shift factors by employing analytical response relativistic coupled-cluster theory and find that a consistent charge radius difference between Ag107,109 is returned when combining our calculations with the available optical isotope shift measurements. We therefore recommend an improved value for the mean-squared charge radius difference between Ag107 and Ag109 as 0.207(6) fm2, within one combined error from the value derived from muonic Ag experiments, and an updated set of charge radii differences across the isotopic chain. Published by the American Physical Society 2024

THE TYPICAL STATE MEDALS AND REWARDS AS AN OPTION OF ENCOURAGEMENT OF ODESA CITY MAYORS IN THE CITY SELF- GOVERNMENT STRUCTURE WITHIN THE PERIOD FROM THE SECOND HALF OF THE 19TH CENTURY TO THE BEGINNING OF THE 20TH CENTURY

The article considers one of the possible characteristics for encouraging the activity of historical figures in the professional field as awards and honors. Preference was given primarily to the state award system, which extended to various sectors of the population, including professional groups – elected positions of city mayors. In the second half of the 19th – at the beginning of the 20th century the municipal self-government of Odesa was headed by nine people – Semen Vorontsov, Mykola Novoselskyi, Grigory Marazli (Grigorios Maraslis), Valerian Ligin, Petro Kryzhanovskyi, Pavlo Zelenyi, Vasyl Protopopov, Mykola Moiseyev and Borys Pelikan. On the basis of the collected sources and the works of researchers, a list of the most typical state orders among the figures of city heads with a chronological reference and brief generalizations regarding the conditions of awarding was revealed. With the beginning of the creation of the post of city mayor, the duties performed did not provide for a normalized and regular financial reward, which is one of the motivating elements in the work process of a person. Awards were one of the options for encoura- gement – thanks from the government, provincial administration, national awards, distinctions, etc. According to the City Regulation of 1870, to represent the power and status of the mayor, was introduced a badge with the image of the city coat of arms on a large silver chain, with the right to the 5th category uniform of the Ministry of Internal Affairs to the heads of provincial cities and cities that were equated to them. Over the years of their life and various activities, Odessa mayors could receive many awards and distinctions that affected their status and position. Among the typical national awards, the following three orders were identified: St. Volodymyr (2nd and 3rd degrees), St. Anna (1st, 2nd and 3rd degrees) and St. Stanislav (1st degree). During the years of activity in the post of mayor, only five people received orders – M. Novoselskyi, G. Marazli, V. Ligin, M. Moiseyev and B. Pelikan. P. Zelenyi worked for a long time in self-governing institutions at the zemstvo level. P. Kryzhanovskyi and V. Protopopov are known for their professional judicial career, which contributed to receiving orders. The first mayor of the post-reform period, S. Vorontsov, was a military man, and he won his main awards on the battlefield.

A supersensitive electrochemical sensor based on RCA amplification-assisted “silver chain”-linked gold interdigital electrodes and CRISPR/Cas9 for the detection of Staphylococcus aureus in food

With the rising emphasis on food safety, technology to rapidly identify Staphylococcus aureus (S. aureus) is of great significance. Herein, we developed a novel electrochemical biosensor based on the CRISPR/Cas9 system and rolling circle amplification (RCA)-assisted “silver chain”-linked gold interdigital electrodes (Au-IDE). This sensor utilizes RCA to create DNA long chains that span the Au-IDE, and CRISPR/Cas9 as a recognition component to recognize capture/target dsDNA. Additionally, we used silver staining technology to improve detection sensitivity. Then, we detected S. aureus through impedance changes that occurred when the silver chain between the Au-IDE was connected or broke, with a limit of detection (LOD) of 7 CFU/mL and a detection time of 1.5 h. Lastly, we successfully employed this sensor to detect S. aureus in real food samples, making it a promising tool for food monitoring.

Editorial

In Jonathan Swift's 1726 satire Gulliver's Travels, the diminutive Lilliputians present to their emperor an inventory of what they find in the pockets of their prisoner, “the Great Man-Mountain” Gulliver. Prominent among the contents of those pockets is “a wonderful kind of engine” on a silver chain. The Lilliputians were baffled at it, conjecturing it is “the god that he worships . . . because he assures us . . . that he seldom did any thing without consulting it: he called it his oracle.”1

Complex-k modes of plasmonic chain waveguides

Nanoparticle chain waveguide based on negative-epsilon material is investigated through a generic 3D finite-element Bloch-mode solver which derives complex propagation constant (k). Our study starts from waveguides made of non-dispersive material, which not only singles out ‘waveguide dispersion’ but also motivates search of new materials to achieve guidance at unconventional wavelengths. Performances of gold or silver chain waveguides are then evaluated; a concise comparison of these two types of chain waveguides has been previously missing. Beyond these singly-plasmonic chain waveguides, we examine a hetero-plasmonic chain system with interlacing gold and silver particles, inspired by a recent proposal; the claimed enhanced energy transfer between gold particles appears to be a one-sided view of its hybridized waveguiding behavior—energy transfer between silver particles worsens. Enabled by the versatile numerical method, we also discuss effects of inter-particle spacing, background medium, and presence of a substrate. Our extensive analyses show that the general route for reducing propagation loss of e.g. a gold chain waveguide is to lower chain-mode frequency with a proper geometry (e.g. smaller particle spacing) and background material setting (e.g. high-permittivity background or even foreign nanoparticles). In addition, the possibility of building mid-infrared chain waveguides using doped silicon is commented based on numerical simulation.

Mixed Propagation Modes in Three Bragg Propagation Periods of Variable Chain Structures

In this article, we studied the characteristics of multi-mode propagation and electric field distribution for a single layered and multi-layered periodic infinite-length square chain structures. We also studied the characteristics of mode propagation in silver and dielectric circular-rod chain structures. This article examines three modes of propagation in three Bragg propagation periods of a square chain structure. Each mode exhibits different forms in each of the three propagation periods, including the propagation, leaky, and cut-off modes. We also consider multiple complex characteristics. For example, the directions of wave and energy propagation paths have two forms: syntropy and reverse (one-way and two-way). The leaky wave has a variety of distribution states, for instance, attenuation and divergence. By analyzing these new physical properties, we have established a solid foundation for better development and application of leaky antennas and other applications. The method in this article was designed and validated for general metal structure applications.

Missed opportunity? Worsening breathlessness as a harbinger of death: acohort study.

The aim of the study was to explore trajectories of breathlessness intensity by function and life-limiting illness diagnosis in the last 3 weeks of life in palliative care patients.A prospective, consecutive cohort study obtained point-of-care data of patients of Silver Chain Hospice Care Service (Perth, Australia) over the period 2011-2014 (n=6801; 51 494 data-points). Breathlessness intensity (0-10 numerical rating scale) and physical function (Australia-modified Karnofsky Performance Status (AKPS)) were measured at each visit. Time was anchored at death. Breathlessness trajectory was analysed by physical function and diagnosis using mixed effects regression.Mean±sd age was 71.5±15.1 years and 55.2% were male, most with cancer. The last recorded AKPS was >40 for 26.8%. Breathlessness was worst in people with cardiorespiratory disease and AKPS >40, and breathlessness in the last week of life increased most in this group (adjusted mean 2.92 versus all others 1.51; p=0.0001). The only significant interaction was with diagnosis and function in the last week of life (p<0.0001).Breathlessness is more intense and increases more in people with better function and cardiorespiratory disease immediately before death. Whether there are reversible causes for these people should be explored prospectively. Omitting function from previous population estimates may have overestimated breathlessness intensity for many patients in the days preceding death.

Synthesis and PPy loading for enhanced visible-light photocatalytic activity of new POMOFs containing silver chains

A new polyoxometalate based hybrid compound containing Ag-Ag chain, [Ag29(trz)18][SiWV7WVI5O40] (Ag29SiW12), was synthesized by the simple one-step hydrothermal reaction of silver nitrate, 1, 2, 3- triazole (trz), and [SiW12O40]4- polyanion. Single crystal X-ray diffraction analysis shows that the [SiW12O40]4- polyanions as coordinating guests were successfully encapsulated into the metal-organic framework host matrix. The Keggin [SiW12O40]n- polyanions as templates and trz molecules as the small and delicate ligands play the decisive factors to the formation of silver chain. In addition, to improve the photocatalytic activity of the new compound Ag29SiW12, its polypyrrole (PPy) composite (PPy@Ag29SiW12) has been prepared and exhibits excellent photocatalytic activity (93.1% for MB and 48.8% for RhB) and selectivity adsorption (16.2 mg/g for MB and 1.60 mg/g for RhB) for organic dyes under the visible light radiation.

Effects of different carboxylates and pyrazine ligands on silver(I) coordination polymers: Syntheses, crystal structures, thermal stabilities and photoluminescent properties

Four silver(I) coordination polymers (CPs), namely {Ag3(cpyz)(btc)}n (1), {Ag2(cpyz)(pta)}n (2), {Ag3(mpyz)2(btc)·2(H2O)}n (3), {Ag2(mpyz)(pta)·2(H2O)}n (4), [cpyz=2-chloropyrazine, H3btc=1,3,5-benzene tricarboxylic, mpyz=2,6-dimethylpyrazine, H2pta=phthalic acid] have been synthesized and characterized. X-ray diffraction indicates that, 1 shows a 3D supramolecular structure with a 1D silver chain containing an infinite Ag3 units; 2 features a 3D supramolecular framework with Ag-O and Ag-Ag interaction and cpyz ligand adopts monodentate mode making no contribution to the dimensionality; in 3, the silver atom links mpyz ligand and btc anion into a 2D layer connected by Ag-Ag interaction between neighboring layers into the 3D network, with Zigzag Ag4 units; in 4, Ag(I) coordinates pta benzene dicarboxylates to generate a one-dimensional infinite chain, connecting by nitrogen ligand to exhibit a 2D 44-sql network. The results suggest that benzene dicarboxylates and the kinds of pyrazine derivatives play significant roles in the formation of such coordination architectures. The photoluminescence and thermogravimetric analysis (TGA) of the complexes were measured.

Molecular Vibration Induced Plasmon Decay

Noble metal nanoparticles, when interacting with an external electric field, give rise to a phenomenon called surface plasmon resonance characterized by collective valence electron oscillations, and because of this unique feature, these systems are employed for a large and heterogeneous number of applications. To improve their performance, it is necessary to develop a deep knowledge of the main factors affecting the plasmon lifetime. In order to answer this question, in this work a linear silver chain is investigated as a simplified model for silver nanorods. Through a nonadiabatic molecular dynamics approach the role of nuclear dynamics on transverse plasmon lifetime is investigated. A strong dependence of plasmon dynamics on the specific nature of nuclear motions is found: nuclear motions along the chain do not affect the transverse plasmon lifetime while motions causing a deviation from linearity of the wire have an important impact on the plasmon dynamics causing its decay. As the vibrational energy i...

Silver(I) Cage and Infinite Chain Stabilized by Bowl-Shaped Resorcin[4]arene Tetraethynide Ligands

We present a new family of Ag(I) complexes bearing calixarene-based tetraethynide ligands, namely, [Ag12(L1)2·(CH3CN)4·(NO3)4]·2H2O (1), [Ag4L1·(AgCF3CO2)4·(CH3OH)] (2), [Ag4L2·(AgCF3CO2)4]·H2O (3), and [Ag4L3·(AgCF3CO2)4]·0.75CH3COCH3 (4), which were obtained from the reaction of newly synthesized tetraethynyl functionalized resorcin[4]arenes with silver(I) salts. Complex 1 features a 4/m assembly comprising a Ag12 cage sandwiched by two bowl-shaped resorcin[4]arene tetraethynides, while 2–4 exhibit similar silver(I) chain structures each stabilized by an alternate attachment of bowl-shaped resorcin[4]arene tetraethynide units. This work provides the successful example of the use of calixarene-based ligands for the construction of multinuclear silver(I)–ethynide supramolecular frameworks.

Synthesis and properties of antibacterial polyurethane with novel Bis(3-pyridinemethanol) silver chain extender

To synthesize antibacterial polyurethane (PU) films, a novel chain extender, bis(3-pyridinemethanol) silver (BPDS), and a PU prepolymer were also synthesized through coordination and covalent reactions. The effects of incorporating different amounts of BPDS were investigated by characterizing the BPDS/PU films using various instruments: FTIR, TGA, DSC, DMA, XRD, EDX, universal testing machine, contact angle goniometer, and positron annihilation spectroscopy (PALS). With a higher BPDS content, the glass transition temperature, final degradation temperature, and Young's modulus were all enhanced; however, the tensile strength and elongation at break were both reduced. PALS analysis revealed that the more rigid and randomly packed structure of the BPDS/PU films at a higher BPDS content was characterized by a broader free volume size distribution that consisted largely of much smaller free volume holes. Quantitative tests with Staphylococcus aureus and Escherichia coli indicated excellent antibacterial properties, suggesting that the PU films could be used repeatedly.

Characterization and cytotoxic property of a ladder-like polymeric silver(I) complex derived from 3-aminopyrazine-2-carboxylic acid

A novel ladder-like polymeric silver(I) complex, [Ag2L2] n •2nH2O, where L is 3-aminopyrazine- 2-carboxylate, was obtained by the reaction of 3-aminopyrazine-2-carboxylic acid and silver oxide in aqueous ammonia. The complex was characterized by elemental analysis, IR spectra and single crystal X-ray determination. The smallest repeat unit contains a [Ag2L2] moiety and two water molecules. The Ag•••Ag distance is 3.176(1) A. Each Ag atom is in a Y-shaped coordination, with one carboxylate O and two pyrazine N atoms from two ligands. In the crystal structure of the complex, the dinuclear silver moieties are linked through 3-aminopyrazine-2-carboxylate ligands, to form 1D ladder-like chain along the b axis. The water molecules are linked to the silver chain through hydrogen bonds. There are π•••π interactions between the chains. The complex showed effective cytotoxic property on human lung cancer cell line A549.

Synthesis, characterization and antibacterial activity of a new silver(I) complex based on a flexible dicarboxylic acid ligand

A novel silver(I) complex sustained by a flexible dicarboxylic acid ligand, [Ag2(L)]n (1, H2L = 2,2′-{[1,2-phenylenebis(methylene)]-bis(sulfanediyl)}dibenzoic acid), has been synthesized and structurally characterized. In 1, four anti conformation L2− ligands bind three silver(I) ions to form a trinuclear subunit through S···Ag and Ag···Ag interactions, and then those trinuclear subunits are further extended to an infinite 1D silver(I) chain through the anti L2− ligands. Thus, the thermal stability, luminescent behavior and antibacterial activity of 1 were also discussed.

A review of patient and skin characteristics associated with skin tears.

Skin tears are the most common wound among the elderly and have the potential to cause infection, form chronic wounds, reduce quality of life and increase health-care costs. Our aim was to identify studies that reviewed patient and skin characteristics associated with skin tears. A review of skin tear studies reported in the English literature between 1980 and 2013 was undertaken using the following electronic databases: PubMed, Medline, CINAHL, Embase, Scopus, Evidence Based and Medicine Reviews (EBM). Search terms included aged, skin, tears or lacerations, skin tearing, geri tear, epidermal tear and prevalence. There were 343 articles found with using the search terms. After abstract review nine were found to be relevant to the search. The principle findings from these eight published articles and one unpublished study revealed that the most common patient characteristics were a history of skin tears, impaired mobility and impaired cognition. Skin characteristics associated with skin tears included senile purpura, ecchymosis and oedema. This review provides an overview of identified patient and skin characteristics that predispose the elderly to skin tears and exposes the lack of research within this domain. R. Rayner is a recipient of a 2013 Australian Postgraduate Award, Curtin University Postgraduate Scholarship and a Wound Management Cooperative Research Centre (CRC) PhD stipend. The School of Nursing, Midwifery and Paramedicine, Curtin University and the Silver Chain Group, Western Australia are participants in the Wound Management Innovation CRC. No conflict of interest exists among the authors.

Plasmon-induced dynamics of H2 splitting on a silver atomic chain

Localized surface plasmon resonances (LSPR) supported in metal nanostructures can be efficiently harnessed to drive photocatalytic reactions, whose atomic scale mechanism remains a challenge. Here, real-time dynamics of H2 photosplitting on a linear silver atomic chain, upon exposure to femtosecond laser pulses, has been investigated using time-dependent density functional theory. The wavelength dependent H2 splitting process is strongly coupled to LSPR excitation in silver chain. We identify that hot electrons produced in the silver chain by plasmon excitation are transferred to the antibonding state of the adsorbed H2 and trigger H2 dissociation, consistent with experimental observations. Increasing illumination intensity and the length of atomic chain promote H2 splitting, thanks to stronger LSPR. Dynamic electronic response can be quantitatively described within the present approach, providing insights towards a complete fundamental understanding on plasmon-induced chemical reactions at the microscopic scale.

New silver(I) coordination polymers constructed from pyrazine derivatives and aromatic carboxylic acids: Syntheses, structures and photoluminescence

Five one-dimensional to three-dimensional coordination polymers have been synthesized by 2-chlorobenzoic acid (HL1), 2-nitrobenzoic acid (HL2), o-toluic acid (HL3), 2,3,5-trimethylpyrazine (tpyz) and 2,3,5,6-tetramethylpyrazine (mpyz) in the presence of NH3·H2O in mixed solvents systems, namely, {Ag4(tpyz)2(L1)4}n (1), {Ag2(tpyz) (L2)2}n (2), {Ag2(tpyz) (L3)2}n (3), {Ag2(mpyz) (L1)2}n (4), {Ag(mpyz) (L2) (H2O)}n (5). All the complexes have been characterized by elemental analyses, IR spectra and X-ray diffraction. Compound 1 shows a 3D framework. The tpyz ligand links 1D chain which was connected by silver atom and L1 anion into 3D framework. Compounds 2 and 4 possess a similar 2D network with (4, 4) topology. Complex 3 also exhibits a two-dimensional structure. There is a 1D silver chain in 3, which is the main difference from 2 and 4. So, 3 shows three-connected (4 8, 3) topology. For 5, only one oxygen of L2 coordinated to Ag(I) ions. The L2 anions were arranged in both sides of the chain, which was connected by silver atoms and mpyz ligands. Then, the uncoordinated carboxylate oxygen with coordinated water 1molecule oxygen through the hydrogen bond made the resultant structure to a 3D framework. Complexes 1–5 spanning from one-dimensional chains to three-dimensional framework suggest that carboxylates and the kinds of pyrazine derivatives play significant roles in the formation of such coordination architectures. The photoluminescence and thermogravimetric analysis (TGA) of the complexes were also investigated.

Symptom burden of haematological malignancies as death approaches in a community palliative care service: a retrospective cohort study of a consecutive case series

Patients with haematological malignancies are less likely to use palliative care services than are patients with solid tumours. This difference might stem from differing symptom burden, care needs, disease trajectories, or a combination of these factors. We described symptom burden and physical decline over time for people with haematological malignancies compared with people with solid tumours in a consecutive case series. We included patients admitted to Silver Chain Hospice Care Service who died between Jan 1, 2011, and Dec 31, 2013, and who completed the eight-item Symptom Assessment Scale (0-10, with 0=no distress and 10=worst distress) at each clinical encounter. Physical function was assessed with the Australia-modified Karnofsky performance scale. Symptom and functional assessments were analysed at 7 days, 30 days, 60 days, and 90 days before death, by descriptive statistics. We included 4638 participants. For people with haematological malignancies (n=224), the most troublesome symptoms were fatigue (mean score 5·2, SD 2·7) and loss of appetite (2·3, SD 2·9), and both worsened significantly near death (p=0·0035 for fatigue, p=0·016 for appetite). Other symptoms were often absent, and changed little over time. Compared with patients with solid tumours (n=4414), there were no significant differences in individual or cumulative symptom scores, changes over time, or the pattern of functional decline. Community patients with haematological malignancies receiving palliative care have similar symptoms and patterns of physical decline at the end of life to people with solid tumours, suggesting similar care needs. This finding questions present limited palliative care service use by patients with haematological malignancies. None.

Time-Dependent Density Functional Theory Investigation of the Electronic Structure and Chiroptical Properties of Curved and Helical Silver Nanowires.

Time-dependent density functional theory methods are employed to examine the evolution of the absorption and circular dichroism (CD) spectra of neutral bare silver helical nanostructures as a function of their geometrical parameters. Calculations of excited states to determine optical absorption and CD spectra were performed using the SAOP/TZP level of theory. In our model, the geometry of the helical silver chain is dependent on the Ag-Ag-Ag bond angle and the Ag-Ag-Ag-Ag dihedral angle. The influence of different geometrical structures on the optical absorption and CD spectra were studied for helical and planar Ag8. Silver nanowires Agn (n = 4, 6, 8, 10, 12) were examined to determine the effect of the helical chain length on the electronic properties. The results show that when the metal atomic chain loses planarity, strong CD signals arise; the intensities of the CD peaks for these structures are strongly affected by the shape and length of the silver nanowires. The theoretically predicted CD spectra of the nonplanar Ag4 and Ag6 model systems show good agreement in spectral shapes and reasonable agreement in peak locations compared to experimental data for silver-DNA clusters. However, the theoretical and experimental results for the longer Ag12 wire show larger differences in the peak locations, which could potentially be caused by effects such as the presence of DNA and cationic silver atoms in the experimental system.

Syntheses, structures and anion exchange properties of accommodative silver chains using a positively charged and flexible ligand

Eight silver(I) coordination polymers were synthesized and structurally characterized. Direct reaction of various Ag(I) starting materials with a positively charged and flexible ligand, 1,3-di(2-picolyl)imidazolium (L) in different salts, including L-Cl, L-ClO4 and L-PF6, gave compounds [AgL(NO3)2] (1), [AgL(CH3CN)](BF4)2 (2), [Ag2L2(NO3)2](NO3)Cl (3), [AgL(CH3CN)](PF6)2·0.5CH3CN (4), [AgL(NO3)](PF6) (5), [AgL](NO3)(PF6) (6), [AgL(CH3CN)2](ClO4)(PF6)·CH3CN (7), and [AgL](ClO4)2·CH3CN (8). Structural analysis revealed that ligand L has three kinds of conformations in these structures. As benefited by the flexible feature of L, the silver chains in 1–8 are different and are depended on the shape and the size of counter anions. Anion exchange studies showed that crystals of 4, 6 and 8 had anion exchange properties, and the channel size in the corresponding solid state structures played a crucial role. These results highlighted the significance of positively charged and flexible ligand L in the construction of various silver chain structures with different conformations and thus packing diagrams for anion exchange studies.