Gold Bead Research Articles

The Production of Thin‐Walled Jointless Gold Beads from the Maykop Culture Megalithic Tomb of the Early Bronze Age at Tsarskaya in the North Caucasus: Results of Analytical and Experimental Research

This study, the first of this kind, reconstructs the technical chaîne operatoire of thin‐walled jointless gold bead production in the Maykop culture on the basis of trace‐wear analysis, experimental research and comparative analysis, using gold beads from the Early Bronze Age dolmen (c. 3200–2900 bc) in kurgan 2 at Tsarskaya (discovered in 1898). The results of the study demonstrate that such beads were produced from a perforated disc‐shaped blank by pressure (with intermittent annealing) within a hemispherical depression in a shaping block (presumably made from stone or bone) and subsequent abrasive treatment of the surface. Most probably, this technique was a regional expression of Near Eastern jewellery traditions that emerged within the urbanized centres of Upper Mesopotamia in the early fourth millennium bc and spread out, through the Caucasus, into the southern boundaries of the Eurasian steppe.

Optimizing Surface Modifications for Quantum Dot Labelled DNA SAMs Using Electrochemistry Coupled Fluorescence Imaging

Electrochemical biosensors are being developed for detecting specific sequences of nucleic acids using DNA modified gold surfaces[1]. A single crystal gold bead electrode was used to study the arrangement on DNA on different gold surfaces[2]. The gold surface was prepared with a mercaptoundecanol (MUDOL) self-assembled monolayer (SAM). Using a specific desorption potential of -0.850 V/SCE, the MUDOL was reductively desorbed from the Au(111) facet. The defects in the SAM were passivated with a shorter alkylthiol, mercaptohexanol. Thiol modified DNA which is also labeled with a fluorophore was allowed to populate the 111 facet specifically. This was studied using fluorescence microscopy coupled with electrochemical control. A fluorescence image of the gold bead (Figure a) showed that only the 111 facets were modified. The density of the DNA modification was also evaluated using the reorientation of DNA based on the electrode charge density. At positive potentials the DNA was positioned close to the electrode and the fluorescence was quenched. At negative potentials the DNA was repelled and the fluorescence increased. This change in fluorescence is indicative of the density of DNA on the surface. The same approach will be used to assemble DNA modified Quantum Dots (QDs) onto the Au(111) facets. A complementary ssDNA was attached to a glutathione capped quantum dot vis a his-tag peptide. The QD labelled ssDNA was allowed to hybridize with the ssDNA on the gold electrode. Figure (b) is the cartoon depiction of such a layer. Recent research results will be described on the characterization of QD labelled DNA SAMs. The QDs due to their broad absorption and narrow emission spectrum also offer the advantage of building more complicated multiplexed systems in future. (1) Hsieh, K.; Ferguson, B. S.; Eisenstein, M.; Plaxco, K. W.; Soh, H. T. Integrated Electrochemical Microsystems for Genetic Detection of Pathogens at the Point of Care. Acc. Chem. Res. 2015, 48, 911–920. (2) Yu, Z. L.; Casanova-Moreno, J.; Guryanov, I.; Maran, F.; Bizzotto, D. Influence of Surface Structure on Single or Mixed Component Self-Assembled Monolayers via in Situ Spectroelectrochemical Fluorescence Imaging of the Complete Stereographic Triangle on a Single Crystal Au Bead Electrode. J. Am. Chem. Soc 2015, 137, 276–288. Figure 1

Tailoring the DNA SAM surface density on different surface crystallographic features using potential assisted thiol exchange

The influence of surface crystallography and applied potential on the thiol-exchange procedure to create mixed alkylthiol DNA SAMs is detailed. A single crystal gold bead and fluorophore labeled thiol modified DNA were used to characterize the resulting surface modifications. The thiol-exchange occurs with different efficiencies on the low index planes (111,100,110) as compared to 311 and 210. Positive applied potentials (>0/SCE) result in 10 × higher coverage than when compared to deposition at the open circuit potential (OCP) over the same 60 min time period. Negative potentials (<0/SCE) resulted in less uniform coverage with the 111 facet being significantly modified. The electrolyte used during the deposition was a 10 mM TRIS Buffer with 100 mM NaCl 500 mM MgCl2. The influence of [Cl−] was studied showing it had a significant impact on the thiol-exchange at the positive potentials, where higher [Cl−] resulted in higher DNA coverages and a more uniform coverage across the multi-crystalline surface. The local environment of the thiol-exchanged DNA SAMs were compared for different regions on the surface using potential driven DNA reorientation modulating the fluorescence intensity. These results showed a common behaviour from all surfaces suggesting that the DNA SAMs prepared by thiol-exchange were consistently prepared with a variable surface concentration controlled by potential and time.

Experimental Replication of a Granulated Gold Bead from an Ancient Tomb at Bat, Oman

During excavation of a tomb at Bat, Oman, an unusual gold bead entirely composed of 96 granules was discovered. The bead comes from an unstratified context in the bottom of the fill of the tomb, which means that it could date anywhere during the use-life of the tomb between the 3rd and 1st Millennium BC. The technical problems surrounding the manufacture of this bead are discussed and an experimental approach is used to explore a possible method of fabrication. The results of the experiments show that a combination of autogenous welding and brazing with copper salts to construct and join the individual units of the bead was successful to produce a visual replica of the bead. The method of bead construction based on the serial production of units and sub-units also has implications on the practice and organization of goldsmithing during this era.

A non-linear harmonic analysis of potential induced fluorescence modulation of a DNA self assembled monolayer

The characterization of a mixed mercaptohexanol - fluorophore labeled DNA self-assembled monolayer (SAM) on a single crystal gold bead electrode is demonstrated using an electrochemical perturbation and optical harmonic analysis scheme. This approach relies on the non-linear characteristics of the fluorescence intensity response towards a single frequency sinusoidal potential perturbation (163Hz) which causes the DNA SAM to reorient, changing the efficiency of fluorescence quenching by the gold electrode. This results in a modulated fluorescence intensity that is composed of first, second and third harmonic signals which were found to strongly depend on the hybrization state of the DNA SAM, the DNA packing density on the surface, and the surface crystallography. Comparing the results between the different surface crystallographies on the same electrode and between different electrodes was simplified with a self-consistent normalization method reducing the influence of the raw fluorescence intensity. A significant difference in the second harmonic response was observed for single and double stranded DNA SAMs especially on the lower coverage (100) region and surfaces with related crystallographies. The third harmonic signal was weaker, but also showed a distinction between the hybridization states. Higher coverage (311) surface regions showed no significant fluorescence modulation nor any difference based on state of hybridization. Within a limited potential range, the electrochemical response (current) from the modified electrode did not show significant non-linearity revealing that the source of the harmonic signals was due to the non-linear relationship between the fluorescence quenching and fluorophore separation from the electrode surface. Increasing the amplitude of the potential perturbation increased the harmonic signal magnitudes further differentiating the DNA hybridization state.

A protocol for registration and correction of multicolour STED superresolution images.

Multicolour fluorescence imaging by STimulated Emission Depletion (STED) superresolution microscopy with doughnut-shaped STED laser beams based on different wavelengths for each colour channel requires precise image registration. This is especially important when STED imaging is used for co-localisation studies of two or more native proteins in biological specimens to analyse nanometric subcellular spatial arrangements. We developed a robust postprocessing image registration protocol, with the aim to verify and ultimately optimise multicolour STED image quality. Importantly, this protocol will support any subsequent quantitative localisation analysis at nanometric scales. Henceforth, using an approach that registers each colour channel present during STED imaging individually, this protocol reliably corrects for optical aberrations and inadvertent sample drift. To achieve the latter goal, the protocol combines the experimental sample information, from corresponding STED and confocal images using the same optical beam path and setup, with that of an independent calibration sample. As a result, image registration is based on a strategy that maximises the cross-correlation between sequentially acquired images of the experimental sample, which are strategically combined by the protocol. We demonstrate the general applicability of the image registration protocol by co-staining of the ryanodine receptor calcium release channel in primary mouse cardiomyocytes. To validate this new approach, we identify user-friendly criteria, which - if fulfilled - support optimal image registration. In summary, we introduce a new method for image registration and rationally based postprocessing steps through a highly standardised protocol for multicolour STED imaging, which directly supports the reproducibility of protein co-localisation analyses. Although the reference protocol is discussed exemplarily for two-colour STED imaging, it can be readily expanded to three or more colours and STED channels.

A Review of Research Trends in Gold Implantation Therapy Focused on Gold Thread, Gold Needle and Gold Bead

A Review of Research Trends in Gold Implantation Therapy Focused on Gold Thread, Gold Needle and Gold Bead

Influence of surface structure on single or mixed component self-assembled monolayers via in situ spectroelectrochemical fluorescence imaging of the complete stereographic triangle on a single crystal Au bead electrode.

The use of a single crystal gold bead electrode is demonstrated for characterization of self-assembled monolayers (SAM)s formed on the bead surface expressing a complete set of face centered cubic (fcc) surface structures represented by a stereographic projection. Simultaneous analysis of many crystallographic orientations was accomplished through the use of an in situ fluorescence microscopic imaging technique coupled with electrochemical measurements. SAMs were prepared from different classes of molecules, which were modified with a fluorescent tag enabling characterization of the influence of electrical potential and a direct comparison of the influence of surface structure on SAMs adsorbed onto low index, vicinal and chiral surfaces. The assembly of alkylthiol, Aib peptide and DNA SAMs are studied as a function of the electrical potential of the interface revealing how the organization of these SAMs depend on the surface crystallographic orientation, all in one measurement. This approach allows for a simultaneous determination of SAMs assembled onto an electrode surface onto which the whole fcc stereographic triangle can be mapped, revealing the influence of intermolecular interactions as well as the atomic arrangement of the substrate. Moreover, this method enables study of the influence of the Au surface atom arrangement on SAMs that were created and analyzed, both under identical conditions, something that can be challenging for the typical studies of this kind using individual gold single crystal electrodes. Also demonstrated is the analysis of a SAM containing two components prepared using thiol exchange. The two component SAM shows remarkable differences in the surface coverage, which strongly depends on the surface crystallography enabling estimates of the thiol exchange energetics. In addition, these electrode surfaces enable studies of molecular adsorption onto the symmetry related chiral surfaces since more than one stereographic triangle can be imaged at the same time. The ability to observe a SAM modified surface that contains many complete fcc stereographic triangles will facilitate the study of the single and multicomponent SAMs, identifying interesting surfaces for further analysis.

Development of Computer-Aided Manufacturing System for a Jewelry-Making CNC Machine

Abstract. This paper designs a CAM system for a jewelry-making CNC machine. The CAM system not only provides a human-computer interface for setting machining parameters, but also can generate special NC programs automatically and realize the simulation for the machining process. In addition, the paper gives an efficient application for machining an ellipsoidal gold bead. The basic design of the jewelry-making CAM system and the experimental results are presented.

Elastic rotation of Escherichia coli FOF1 having ε subunit fused with cytochrome b562 or flavodoxin reductase

Intra-molecular rotation of FOF1 ATP synthase enables cooperative synthesis and hydrolysis of ATP. In this study, using a small gold bead probe, we observed fast rotation close to the real rate that would be exhibited without probes. Using this experimental system, we tested the rotation of FOF1 with the ε subunit connected to a globular protein [cytochrome b562 (ε-Cyt) or flavodoxin reductase (ε-FlavR)], which is apparently larger than the space between the central and the peripheral stalks. The enzymes containing ε-Cyt and ε-FlavR showed continual rotations with average rates of 185 and 148rps, respectively, similar to the wild type (172rps). However, the enzymes with ε-Cyt or ε-FlavR showed a reduced proton transport. These results indicate that the intra-molecular rotation is elastic but proton transport requires more strict subunit/subunit interaction.

Gold rotor bead tracking for high-speed measurements of DNA twist, torque and extension

Simultaneous measurements of DNA twist and extension have been used to measure physical properties of the double helix and to characterize structural dynamics and mechanochemistry in nucleoprotein complexes. However, the spatiotemporal resolution of twist measurements has been limited by the use of angular probes with large rotational drags, preventing the detection of short-lived intermediates or small angular steps. Here we introduce AuRBT, demonstrating a >100X improvement in time resolution over previous techniques. AuRBT employs gold nanoparticles as bright low-drag rotational and extensional probes, relying on instrumentation that combines magnetic tweezers with objective-side evanescent darkfield microscopy. In an initial application to molecular motor mechanism, we have examined the high-speed structural dynamics of DNA gyrase, revealing an unanticipated transient intermediate. AuRBT also enables direct measurements of DNA torque with >50X shorter integration times than previous techniques; here we demonstrate high-resolution torque spectroscopy by mapping the conformational landscape of a Z-forming DNA sequence.

Effect of Immobilization on Gold on the Temperature Dependence of Photochromic Switching of Dithienylethenes

We report the properties and switching characteristics of a series of dithienylethene photochromic switches immobilized on gold. Self-assembled monolayers (SAMs) of three structurally related dithienylethenes were formed on roughened gold bead substrates and studied by surface-enhanced Raman spectroscopy (SERS). These data were compared to SERS spectra obtained by aggregation of colloidal gold, solid state Raman spectra, and Raman spectra calculated using density functional theory (DFT). Two of the dithienylethenes studied have an “asymmetric” design, which was demonstrated earlier to lower the thermal barrier for photochemical ring opening in solution. Herein, we show that, when immobilized on a gold surface, the asymmetric dithienylethenes in fact display a higher thermal barrier than that of their symmetric counterparts. In addition, we show that photochemical ring closing of asymmetric dithienylethenes is inhibited when immobilized on gold.

Egyptian faience and rose gold at Mochlos, Crete

The Mycenaean necklace found in a tomb in the Limenaria cemetery at Mochlos, Crete, consists of a row of faience beads and a central gold bead, and it is dated to the LM IIIA period (about 1400–1300 BC). Studies on faience have shown that different production technologies were used in this period: efflorescence, cementation and direct application methods. The efflorescence method was used in Egypt. The manufacture of the faience from Mochlos indicates an Egyptian origin, but the shape and the style are Aegean. The gold bead shows a deliberately applied rose patination on one side and a normal golden colour on the other. The analyses showed that the composition of the pink film is very similar to that on Tutankhamun’s sequins. The technique of colouring gold is known from objects found in royal tombs in Egypt. This piece of jewelry shows, like the faience, a strong Egyptian technological influence.

아산 명암리 밖지므레 유적 출토 유리구슬의 화학적 특성

아산 밖지므레 유적 마한 분묘에서 출토된 유리 65점은 포타쉬유리군이 13점, 소다유리군이 52점으로 소다유리군이 우세하게 나타났다. 색상별로 세분하면, 감청색 유리는 포타쉬유리군과 소다유리군이 공반되는 반면 자색 유리는 포타쉬유리군이고 적색, 벽색, 녹색, 금박유리는 소다유리군으로 나타났다. 감청색 유리는 안정제의 함량이 낮은 LCA계이고 이중에 소다유리는 MgO와 <TEX>$K_2O$</TEX> 함량이 낮은 LMK형으로 천연탄산소다가 원료로 사용된 것으로 판단된다. 적색 유리는 균질한 유리가 LCA-B계/HMK형이고 불균질한 유리가 HCLA계/LMK형으로 각각 해양 식물 재와 천연탄산소다가 사용되었을 가능성이 있다. 벽색과 녹색 유리는 환옥이 LCA-A계/LMHK형이고 연주옥이 LCA-B계/HMK형으로 형태에 따라 차이를 보인다. 금박구슬은 19.9~22.6K의 순도를 갖는 금박과 HCLA계/LMK형의 소다유리로 제작되었다. 즉, 아산 밖지므레 유적 유리구슬 대부분은 백제시대 타 유적에서 확인되는 유리 조성과 유사성이 높은 편이나 벽색 및 녹색 연주옥과 일부 적색 환옥은 다른 화학 조성을 보이므로 원료에 차이가 있음을 알 수 있다. 이와 같은 특성은 고대유리의 교역 체계 이해를 위한 중요한 단서를 제공할 것으로 기대된다. 65 samples of glass bead excavated from Mahan tombs of Asan Bakjimeure site consists of 13 of potash glass group and 52 of soda glass group and soda glass is superior in numbers. When classified according to color, purple blue glass bead is accompanied potash and soda glass group whereas purple glass bead is potash glass group and red, greenish blue, green and gold foil glass bead is soda glass group. Purple blue glass bead is classified as LCA type in which the content of the stabilizer is low. Of this, the soda glass categorized as LMK type with low content of MgO and <TEX>$K_2O$</TEX> is determined that natron is used as the raw material. As to red glass, the homogeneous glass is LCA-B/HMK type and the heterogeneous glass is HCLA/LMK type. Thus, each of these two types are likely to be used plant ash and natron respectively. Greenish blue and green glass depends of the type that round glass is LCA-A/LMHK type and the segmented glass is LCA-B/HMK type. The gold foil glass bead is manufactured by the purity of 19.9~22.6K gold foil and the soda glass of HCLA/LMK type. In other words, the most of the glass bead of Asan Bakjimeure site is similar to the composition of the glass confirmed in other sites of the Baekche period. On the other hand, the greenish blue and green segmented bead and some red round bead is a different chemical composition is considered that the difference in raw materials. These characteristics is expected to be an important evidence for the understanding of the trade system of the ancient glass.

Gold Bead Implantation in Acupoints for Coxofemoral Arthrosis in Dogs: Method Description and Adverse Effects.

Simple SummaryTraditional acupuncture uses needles inserted at certain acupuncture points. Gold bead implantation at acupuncture points is used in acupuncture intended to relieve pain in certain diseases. The method of gold implantation is not well described in the literature. We describe the technique of implanting 24-karat gold beads around the joints of dogs with degenerative joint disease due to chronic hip dysplasia. The method is safe and fairly easy to perform under anesthesia. It has few serious side effects, as long as bead-deposition within the joint is avoided. There is some aggravation of discomfort during the first two weeks after treatment as well as bleeding and synovial leakage during treatment.Gold bead implantation has been used for years as an alternative method to improve function in chronic joint disease both in humans and dogs. The aims of the present study were to describe the technique of implanting 24-karat gold beads around the hip joints of dogs with chronic hip dysplasia, and to record any side effects or complications of such treatment. A prospective placebo-controlled double-blinded clinical trial was performed. Eighty dogs were randomly allocated to treatment or placebo, with 38 in the gold implantation group and 42 in the placebo group, and followed intensely for six months. The implantation technique was simple to perform, using fluoroscopy and with the dogs under inhalation anesthesia for about 30 minutes. Adverse effects, measured as pain or discomfort, were seen for a period of up to four weeks in 15 of the dogs in the gold implantation group, compared to six dogs in the placebo group. During implantation, a technical difficulty occurred as 82% of the dogs showed leakage of blood and/or synovia from the needles. The dogs in the gold implantation group were radiographed 18 months later. Of the 30 dogs that were radiographed at both inclusion and 24 months, 80% (24 dogs) showed a deterioration of the coxofemoral arthrosis, the other six had stable disease evaluated by radiography. Migration of gold beads was only observed in one dog.

Electrochemistry of a ferrocene-grafted cell-penetrating peptide

A cationic cell-penetrating peptide (CPP) labeled with both a ferrocenyl (Fc) moiety and a biotin (B) was successfully synthesized and investigated by electrochemistry. This original CPP derivative noted as Fc-CPP-B could be electrochemically detected, at a micromolar concentration, at a naked gold bead electrode. The presence of a biotin tag in the Fc-CPP-B complex allowed its complexation with avidin, which was itself tethered to a thiolated self-assembled monolayer. Such an avidin-modified gold surface, characterized by atomic force microscopy (AFM), allowed the immobilization of Fc-CPP-B onto the electrode surface, which greatly enhanced its electrochemical detection. Nevertheless, under these conditions the electrogenerated ferrocenium cation could not be reduced during the backward scan, indicating its unexpected reactivity when tethered within the avidin environment. In terms of detection and redox probe regeneration the best results were obtained at a glassy carbon electrode modified with a cation-exchange polymer. Ion-exchange voltammetry, performed under these conditions, allowed the pre-concentration of the peptide at the electrode surface thanks to the net positive charge of the CPP derivative. Interestingly, the anionic character of the polymer contributed to retain the electrogenerated cation Fc+ in the film so that it could be reduced back to its original neutral form during the reverse voltammetric scans.

Acupuncture and Wound Healing

Acupuncture has been used in the treatment of wounds, but there are few experimental or clinical studies in the veterinary literature of wound treatment with acupuncture. In an experimental burn wound study of mice, two needles were inserted around the burn wound daily for 30 minutes (similar to the “circle the dragon” wound treatment used in acupuncture) for 14 days. Wound healing was monitored and compared to wound healing associated with the use of a conventional collagen wound dressing. Acupuncture significantly reduced the inflammatory response, wound size and increased the local expression of extracellular matrix proteins similar to the collagen dressing. In a clinical study of closed surgical incisions, two local points at each end of the incision and other acupoints were stimulated once post-operatively and had no subjective effects on incision healing. Most veterinary acupuncturists treating wounds would do multiple treatments and usually treat more acupoints. In an equine case series, local and acupoint stimulation with gold bead implantation resulted in healing of difficult to heal wounds on the distal limbs. Well-designed, controlled studies of acupuncture for different wound types are needed. Acupuncture is often less expensive than surgery, requires less specialized equipment and can be used safely with other treatment techniques. Inserting acupuncture needles in the region around the wound moves Qi and Blood in the region to minimize Qi/Blood Stagnation in acute wounds or relieve long-term Stagnation in chronic wounds. Further investigation is warranted to clarify the benefits and mechanisms of action of acupuncture for wound healing.

Effects of Viscosity on Tethered Particle Motion (TPM) Experiments

Tethered Particle Motion (TPM) experiments are used to estimate the extension of a DNA molecule, attached at one end to a glass surface, and at the other (free) end to a microscopic bead. The DNA tether restricts the Brownian motion of the bead and the average amplitude of excursions of the bead from the anchor point indicates the DNA tether length. Excursions of the beads depend on the physical properties of the DNA-bead system, and the physical and chemical properties of the surrounding solution. Previously published TPM calibrations, for a range of DNA lengths and 200 to 970 nm diameter beads showed that larger beads increase excursions and comparatively more time is necessary for a bead to fully explore the available volume and report the maximum excursion for a longer as opposed to a shorter DNA molecule. Others have shown that magnesium ions reduce the excursions and increased viscosity slows the diffusion of an 80 nm gold bead tethered by a single length of DNA. New experiments with 320 and 480 nm diameter beads and DNA of several lengths show increasing viscosity increases the time required to report the maximum average excursion. Interpreting these results based on the dynamics of the viscous solvent-DNA-bead system highlights important experimental details for TPM measurements of DNA protein interactions and indicates how the kinetics of topological rearrangements might be impacted by increased viscosity environments such as cytoplasm.

Design of Gold Bead Chain Machine Based on Modern Design Methodology

This paper presents the design of a gold bead chain machine. The gold bead chain machine is designed for automatic gold chain process. Firstly, the gold bead chain’ structure and the design requirement are discussed. Then, based on the modern design methodology, the authors design the gold bead chain machine by using black-box to get the morphological matrix of the function and the function unit solutions. Lastly, the authors analyze and choose the optimal scheme and make an integration of the function unit solutions.

Double-Blinded, Placebo-Controlled Trial of the Pain-Relieving Effect of Gold Bead Implantation on Cervical Osteoarthritis

Abstract Background: Since the 1970s, veterinarians have treated animals with gold implantation at acupuncture points for different chronic joint pain conditions. Objective: The aim was to evaluate the effect of gold bead implantation on patients with cervical osteoarthritis (CO) in a randomized, double-blinded placebo-control study. Design, Setting, and Patients: Forty-six patients with X-ray verified CO with chronic pain (visual analogue scale [VAS] ≥6) were enrolled in the study. Intervention: The patients were randomly assigned to 2 groups: Group A (n = 24) was treated with gold implantations, and Group B (n = 22) received placebo treatment. Main Outcome Measure: A neurologist (blinded for the treatment modality) determined the VAS-scores and amount of analgesic treatment before and 1 year after the intervention. Results: In Group A, 16/24 and, in Group B, 2/22 patients stated a marked reduction of their symptoms (consumption of painkillers was reduced by 30% or more) 1 year after the treatment. The V...