Elbow Sites Research Articles

Stable Au(111) Hexagonal Reconstruction Induced by Perchlorinated Nanographene Molecules.

Surface reconstructions play a crucial role in surface science because of their influence on the adsorption and arrangement of molecules or nanoparticles. On the Au(111) surface, the herringbone reconstruction presents favorable anchoring at the elbow sites, where the highest reactivity is found. In this work, we deposited large organic perchlorinated molecules on a Au(111) surface via high-vacuum electrospray deposition. With noncontact atomic force microscopy measurements at room temperature, we studied the molecular structures formed on the surface before and after annealing at different temperatures. We found that a supramolecular layer is formed and that a hexagonal reconstruction of the Au(111) surface is induced. After high-temperature annealing, the molecules are removed, but the hexagonal Au(111) surface reconstruction is preserved. With the hexagonal Au(111) surface reconstruction, a periodic lattice of anchoring sites is formed.

Whole-Genome Shotgun Metagenomic Sequencing Reveals Shifts in the Skin Microbiome and Bacteriophages of Psoriasis: An Extended Analysis of Published Data

Background Psoriasis is an immune-mediated cutaneous disease that may have shifts in the skin microbiome. Prior research on the skin microbiome in psoriasis has been limited to rRNA based approaches that lack resolution of taxonomic and functional level assessment. Objective To further illuminate strain and sub-strain level analysis of psoriatic lesions using the CosmosID-HUB Microbiome pipeline. Methods A previous study completed by Tett et al recruited patients with psoriasis who had skin microbiome samples taken from psoriatic plaques on the ear and the elbow as well as sites on the skin unaffected by psoriasis. They performed whole genome shotgun sequencing and made their dataset publicly available. We analyzed the dataset using the CosmosID-HUB Microbiome pipeline to evaluate the strain and sub-strain taxonomic analysis as well as functional gene profiling. Results When analyzed with the CosmosID pipeline, both ear and elbow sites in affected areas had decreased alpha diversity compared to unaffected areas. There was an increased relative abundance of Staphylococcus and Corynebacteria at affected sites. We identified distinguishing species and strains of the yeast Malassezia, including M. restricta. that were significantly enriched in healthy elbow samples. Vitamin B12 production genes were not present in psoriatic skin whereas it was present in healthy samples, supporting the notion of relative vitamin B12 deficiency in psoriatic plaques. Phage analysis revealed a greater diversity of Staphylococcus-related phages in unaffected elbow samples. Conclusion A greater diversity of microbial strains and their functional roles identified in this study may help to tailor treatment for psoriasis.

Cubital fossa defect- our reconstructive experience with pedicle flaps

IntroductionCubital fossa wounds can be complicated by the non-availability of reliable, well-vascularized donor tissue. Closure with pliable and readily available donor tissue for cubital defect and early mobilization of the elbow joint is essential for better results. The authors did this study to see how best the results of cubital fossa defect cover can be achieved by pedicle flaps in a single stage without compromising the donor areas. Material and methodPatients having deep elbow wounds in which vital structures were lying exposed in the cubital region were included in this study. The patients were assessed for the availability of tissue for cover, reliability of flaps, flap pliability, the functional outcome of the elbow and donor site morbidity. ResultsA total of 17 cases of cubital region defects are presented wherein closure of the wound by means of primary closure was not possible. Out of these, eight were covered with Pedicled Thoracodorsal Artery Perforator (TDAP) flaps, five with Pedicled split Latissimus Dorsi Muscle (SLDM) flaps and four with reversed lateral arm flaps (RLA). Post-operatively all the flaps were healthy, patients attained a good range of elbow joint movements with no clinically evident morbidity of the donor site. ConclusionCubital fossa defect coverage needs dedicated planning to obtain a sturdy tissue for cover. In the presence of local tissue damage or scarring, we have looked elsewhere to bring pliable and well-vascularized tissue which is reliable. The flaps we used have allowed single-stage reconstruction and early mobilization of the elbow joint with good functional recovery.

Prevalence of Martin-Gruber Anastomosis in Healthy Subjects: An Electrophysiological Study from Raigarh, Chhattisgarh.

Martin Gruber anastomosis is a common anomaly in forearm between median and ulnar nerve. It may lead to technical pitfall or misinterpretation of nerve conduction studies of these nerves. The aim of this studywasto determine the prevalence of Martin-Gruber Anastomosis (MGA) in healthy Raigarh subjects by electrophysiological evaluation. A cross-sectional study was conducted in both forearms of 140 healthy subjects. Electrophysiological studies were performed to measure compound muscle action potentials of abductor pollicis brevis, abductor digiti minimi and first dorsal interosseous muscles when stimulated from distal (wrist) and proximal (elbow) site. Descriptive and analytic statistics were performed using SPSS software. MGA was found in 44 (15.71%) out of the 280 forearms in 30 (21.4%) out of 140 subjects. It was present in 14 males and 16 females. Most frequent type of MGA was of Type II in both genders. The MGA was found bilaterally in 14 subjects. In unilateral cases 8 subjects had MGA in right forearm and 8 subjects had MGA in left forearm. The high prevalence of MGA in the Raigarh population suggest that the orthopedics and neurosurgeons should also take in account this anatomic anomaly while analyzing median and ulnar nerve conduction studies or needle electromyography.

Stable π-radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) adsorbed at the elbows of [formula omitted] reconstructed Au(111)

Stable organic radicals serve as model systems for investigating metal-free magnetic phenomena at (sub)nanometer length scales. We have investigated at the single-molecule level the stable π-radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) adsorbed at the elbow sites of the 22×3 reconstructed Au(111) surface. Low-temperature scanning tunneling microscopy (STM) and -spectroscopy under ultrahigh vacuum conditions at 8 K reveal structural as well as frontier-orbital related electronic details of DPPH/Au(111). A Kondo-like spectroscopic signature indicates preservation of the unpaired electron spin state.

Adlayer growth vs spontaneous (near-) surface alloy formation: Zn growth on Au(111).

As part of an extensive effort to explore the function of Au/ZnO catalysts in the synthesis of methanol from CO2 and H2, we have systematically investigated the temperature dependent growth, structure formation, and surface intermixing of Zn on the herringbone reconstructed Au(111) surface and the thermal stability of the resulting surfaces by scanning tunneling microscopy (STM) and x-ray photoelectron spectroscopy (XPS). After Zn deposition at low temperatures, at about 105 K (STM) or below (XPS), we observed nucleation and two-dimensional growth of Zn islands mainly at the elbow sites of the Au(111) herringbone reconstruction. This results in local perturbations of the reconstruction pattern of the Au(111) substrate, which can create additional nucleation sites. XPS data indicate that Zn dissolution into deeper layers is kinetically hindered under these conditions, while local exchange with the Au surface layer, in particular at the elbow sites during nucleation, cannot be excluded. Zn deposition at room temperature, in contrast, results in near-surface alloy formation with a strongly distorted pattern of the herringbone reconstruction and condensation of the Zn and exchanged Au adatoms at ascending steps, together with some loss of Zn into deeper layers. Upon annealing, Zn atoms diffuse to lower layers and eventually to the Au bulk, and the surface successively regains its original Au(111) herringbone structure, which is almost reached after 500 K annealing. Compared with previous reports on the growth of other metals on Au(111), Zn shows a rather high tendency for intermixing and near-surface alloy formation.

Growth and structural studies of In/Au(111) alloys and InOx/Au(111) inverse oxide/metal model catalysts.

Indium oxide has received attention as an exciting candidate for catalyzing the CO2 hydrogenation to methanol due to its high selectivity (>80%). Compared to the extent of research on the activity of indium oxide-based powder catalysts, very little is known about the phenomena associated with the formation of surface alloys involving indium or the growth mechanism for indium oxide nanoparticles. In this report, scanning tunneling microscopy and X-ray photoelectron spectroscopy (XPS) were employed to elucidate the growth mode, structure, and chemical state of In/Au(111) alloys and InOx/Au(111) inverse model catalysts. Our study reveals distinct morphological differences between In/Au(111) and InOx/Au(111), and the InOx structure also depends strongly on the preparation conditions. In/Au surface alloy systems with extremely low coverage (0.02 ML) form islands preferentially on the elbow sites of reconstructed Au(111) herringbone, regardless of hexagonally closed packed and face centered cubic stacking. At higher coverage (0.1 ML), the In islands expand over the herringbone in the ⟨110⟩ direction and create two dimensional domain structures over the entire surfaces. Moreover, this 2D domain structure is disturbed by temperature with high dispersion of indium atoms observed during the annealing process. Oxidation of the In/Au(111) surface alloys with O2 at 550 K produces InOx/Au(111) systems which contain various sizes of InOx aggregates (from 0.7 nm to 10 nm). On the other hand, InOx/Au(111) surfaces prepared by vapor deposition of In at 550 K in an O2 background exhibit highly dispersed and uniformly small InOx particles (∼1 nm). Both InOx systems were confirmed to be partially oxidized by XPS.

Reliability of Inclinometer-Derived Passive Range of Motion Measures in Youth with Cerebral Palsy

Aims: This study evaluated, for youth with cerebral palsy (CP), the reliability of passive range of motion (PROM) measures taken with an inclinometer, a device that may be simpler to use than a goniometer. Methods: The PROM for elbow and wrist extension, ankle dorsal flexion (knee flexed 90° and fully extended), and the knee popliteal angle of 30 youth with CP (18 boys, 12 girls, 7.0 ± 3.8 years old, classified in Gross Motor Function Classification levels I–V) was measured using an inclinometer. Two physical therapists took the measures during two different sessions, a maximum of 1 week apart. Results: Good mean intra-rater inter-session, inter-rater intra-session, and inter-rater inter-session reliability (ICC = 0.75–0.89), was found for the elbow, ankle, and knee sites. Absolute reliability for these sites and conditions was 7–14° (90% confident) and 10–16° (95% confident). Reliability values for wrist extension were comparable, albeit slight lower. Conclusions: Similar to published values for goniometry, inclinometery yields reliable upper and lower limb PROM measures from ambulatory and non-ambulatory youth with CP whether measures are carried out by different evaluators within or across sessions or whether measures are performed by the same evaluator across sessions.

Action of Ultrasound Therapy in Altering Motor Nerve Conduction Velocity of Ulnar Nerve

Ultrasound therapy is one of the commonest and most popular modality used for tissue healing, pain reduction, tissue extensibility and in inflammation by physiotherapists all around the globe. Various sensitivity tests on peripheral nerves are done with ultrasound therapy, yet conclusions are still skeptical, which makes it inconclusive in progressing the modality further into management of nerve disorders. This study aimed to analyze efficiency of therapeutic ultrasound in influencing ulnar nerve conduction velocity. To Analyze the effect of ultrasound therapy in altering motor nerve conduction velocity of ulnar nerve with two therapeutic frequencies. 40 healthy individuals were included according to the selection criteria and they were explained about safety and simplicity of procedure and informed consent was obtained. All the participants were randomly assigned into two groups as 20 in each group. Group-A was given ultrasound therapy at specific site of elbow to target the ulnar nerve with 1MHz frequency and Group–B followed the same procedure with 3MHz frequency. Pre and Post to ultrasound therapy application Motor Nerve Conduction Velocity (MNCV) of ulnar nerve were recorded for both the groups. The posttest mean of MNCV for forearm segment and arm segment for Group A and Group B showed statistically significant difference (P Value <0.001).The analysis done by the statistical data also revealed that the MNCV at forearm segment showed an increase in velocity compared to its pretest values, whereas the post MNCV values at arm component showed a decrease in velocity when compared to its pretest values. Among comparison the data within the groups it is evident that group A with 1 MHz of ultrasound sonification is more capable of altering the MNCV values in comparison with the 3MHz. frequency. Findings of this study conclude that ultrasound therapy can be used effectively in altering conduction velocity of a nerve and it has a potential ability to facilitate or inhibit a nerve physiological function.

Neuromuscular ultrasound in ulnar neuropathy at the elbow: correlation with electrodiagnostic studies

IntroductionUlnar nerve entrapment is the second most common entrapment neuropathy in the upper limb after carpal tunnel syndrome, and, if left untreated, it may lead to significant functional impairment and disability.ObjectiveThe aim of this study was to perform clinical, electrodiagnostic (EDX), and neuromuscular ultrasound assessment for patients with ulnar neuropathy at the elbow, to determine the possible roles of neuromuscular ultrasound in the localization of the neuropathy, in the detection of its possible etiologies and in the determination of its severity.Patients and methodsA sample of 15 (22 elbows) patients was recruited and subjected to full medical history, neurological assessment, EDX studies, and neuromuscular ultrasound examination. Ten (20 elbows) age-matched and sex-matched healthy volunteers were also recruited and served as a control group.ResultsThis study revealed significantly enlarged ulnar nerve cross-sectional area (CSA) at the ulnar groove and below the elbow and supracondylar sites in patients compared with the control group. receiver-operating characteristic curve analysis revealed high diagnostic accuracy of the absolute CSA at the ulnar groove, and below the elbow and supracondylar sites, with an area under the curve of 0.8, 0.8, and 0.9, respectively, and the cutoff values were >9, >8, and >8, respectively. The area under the curve for the ‘maximum CSA/midforearm CSA ratio’ was 0.9, with a cutoff value of more than 1.3.ConclusionOur study data suggest that neuromuscular ultrasound (NMUS) examination may play a potentially important role in the assessment of ulnar neuropathy at the elbow. It can localize the lesion and disease severity, and it can differentiate between patients and controls, given its high diagnostic ability. Abnormalities in ultrasonographic features of ulnar nerve entrapment with regard to CSA and ratio between ‘maximum CSA and midforearm CSA’ at the elbow was correlated with EDX findings.

Biased Ostwald Ripening in Site-Selective Growth of Two-Dimensional Gold Clusters

Nucleation, growth, and ripening of nanoscale Au islands formed on the Au(111) substrate have been investigated using variable temperature scanning tunneling microscopy. The Au(111) surface consists of two types of naturally occurring dislocations. After deposition of Au atoms at 115 K, a single nanometer-sized Au island is formed at each dislocation. Thermal annealing to 180 K causes gross mass transport in which Au atoms systematically move from one type of dislocation to the other. This leads to the preferential ripening of Au islands at one of the two types of dislocations, a phenomenon that has not been observed for any other metals deposited in Au(111). With repeated deposition and thermal annealing cycles, we have succeeded in obtaining two types of clusters with very different sizes: large clusters at the bulged elbow site and small clusters at the pinched elbow site.

Radiation Therapy Prophylaxis for Heterotopic Ossification in Non-Hip Sites

Background: Radiation therapy prophylaxis for heterotopic ossification is well-established for the hip, either pre or post-operatively. There is limited data for this treatment in non-hip sites. We report our institution’s experience. Methods: From October 2004 to August 2015, a total of 39 non-hip sites in 38 patients were treated with prophylactic radiation therapy for heterotopic ossification at our institution. An IRB approved retrospective review was performed. There were 15 patients who received treatments to the elbow, 13 to the knee (1 bilateral for a total of 14 knees), and 10 to other sites (leg stump (2), pubic symphysis (2), femur (1), foot (1), humerus stump (1), abdominal wall (1), shoulder (1), thigh (1)). All but 1 patient were treated with a single fraction treatment with 700 or 800 cGy. One patient received 2000 cGy in 10 fractions to the abdominal wall for heterotopic ossification extending from the xiphoid process. Results: Fifteen patients underwent treatment to the elbow with a median follow-up of 5 months (0 - 99). Median age for this group was 50 years (37 - 69). Nine (60.0%) patients had evidence of heterotopic ossification prior to surgery. All (100%) of the elbow patients were free from recurrence at last follow-up. There were no acute or late toxicities noted. For treatment to the knee, there were 4 (28.6%) recurrences, all in cases where there were pre-operative heterotopic ossification. There were two other recurrences in the non-hip, elbow or knee sites: one patient who received radiation therapy to the abdominal wall and one patient who underwent treatment to the thigh. Conclusions: Prophylactic radiation therapy with 700 cGy or 800 cGy in 1 fraction either before or after surgery remains a safe and effective treatment for both hip and most non-hip sites. Fractionated treatment may be used for larger treatment fields, however experience is limited.

An Unusual First Manifestation of Hodgkin Lymphoma: Epitrochlear Lymph Node İnvolvement-A Case Report and Brief Review of Literature.

Although epitrochlear lymph nodes may be enlarged as a part of generalized lymphadenopathy, isolated enlargement of epitrochlear lymph nodes is rarely seen. We describe Hodgkin’s lymphoma in a 55-year-old male who presented with isolated epitrochlear lymphadenopathy of his right arm. In the histopathological examination of the epitrochlear lymph node was a lymphocyte-rich Hodgkin lymphoma with a clinical grade (CS IA) diagnosed. The diagnosis was confirmed, via the bone marrow biopsy and positron emission tomography/computed tomography imaging, as pathological stage PS IA and clinical stage CS IA. Epitrochlear lymph node involvement, as a first presentation, is rarely seen in Hodgkin’s lymphoma. The aim of this study was to recapitulate the possible background diseases arising on the basis of an asymptomatic epitrochlear lymphadenopathy, to review the Hodgkin lymphoma presenting with primary epitrochlear lymphadenopathy in light of the literature, and to highlight the importance of a careful examination of the elbow site in routine physical examination.

Abstract TMP42: Safety and Efficacy of High-dose OnabotulinumtoxinA for Post-stroke Upper Limb Spasticity: Results of a Double-blind, Placebo-controlled Trial

Introduction: OnabotulinumtoxinA (onabotA) is approved for treatment of post-stroke upper limb spasticity (PSULS) at a maximum dose of 400U across elbow, wrist, and finger sites. Safety and efficacy of a higher dose for PSULS were evaluated in elbow and shoulder sites not previously assessed. Methods: A multicenter, double-blind, randomized, placebo-controlled study evaluated a single treatment of onabotA 300U (150U: elbow flexors; 150U: shoulder adductors) or 500U (250U; 250U) vs placebo in adults with PSULS (Modified Ashworth Scale [MAS] score ≥3). Safety and efficacy were assessed at weeks 2, 4, 6, 8, and 12. The study was terminated early for administrative reasons. Results: All 53 enrolled patients completed the study. Baseline characteristics were similar between groups, except the onabotA 500U group had more men. Most patients were Caucasian and had a cerebral ischemic stroke of moderate severity (mean=101.7 months before enrollment). Mean change from baseline in elbow MAS for onabotA 500U was significantly greater than placebo at all time points (300U at wks 2 and 4, Figure 1) . Significant tone reductions were also observed in the shoulder adductors with 500U (wks 2 and 4). The proportion of treatment responders (≥1-grade reduction in elbow MAS) was numerically greater for onabotA 500U and 300U than placebo at all time points (300U significant [ P <0.05] at wks 2, 4, and 8). CGI generally improved more with onabotA than placebo (not significant). AEs were typically mild/moderate, not related to treatment, and occurred in a similar proportion of both onabotA dose groups and a greater proportion of the placebo group (300U, 27.8%; 500U, 29.4%; placebo, 50%). Conclusions: Preliminary results from this randomized trial investigating the safety and efficacy of higher-dose onabotA for elbow and shoulder spasticity indicate a dose-related benefit. At the higher dose of 500U onabotA, no new safety signals were observed; AEs did not appear to be dose-related. Funding: Allergan

Oxygen-Driven Porous Film Formation of Single-Crystalline Ru Deposited on Au(111).

We examined the interaction of oxygen with ultrathin Ru layers deposited on a Au(111) substrate using scanning tunneling microscopy, X-ray photoelectron spectroscopy, and low-energy electron diffraction. The deposition of pure Ru below one monolayer (ML) at room temperature leads to the formation of clusters on the Au(111) surface, preferentially located at the elbow sites of the herringbone reconstruction. Subsequent exposure of molecular oxygen to such a Ru-covered Au(111) surface at 680 K results in the growth of two-layer-thick Ru islands that are embedded in the top Au(111) layer. This structural reorganization of Ru is driven by the minimization of surface energy and mediated by a mobile RuOx species. Deposition of an increasing amount of Ru at 620 K (0.5-10 ML, ML = monolayer) leads to a rough Ru film on Au(111). Subsequent oxygen treatment (10(-5) mbar) at 680 K creates either a porous Ru film (<4 ML) or a flat RuO2(110) film (>6 ML) depending on the thickness of the Ru film.

Physisorption versus chemisorption in inelastic electron tunneling spectroscopy: Mode position, intensity, and spatial distribution

Local vibrational spectra of meta-dichlorobenzene molecules adsorbed on different parts of the Au(111) reconstruction are investigated using a low-temperature scanning tunneling microscope. The spectra show substantial variations on subnanometer length scale. While for the molecule physisorbed on either the hcp or the fcc domain of the reconstruction only low-energy modes are beyond the detection limit, higher-energy modes are observed for the molecule chemisorbed at the elbow site. The different adsorption strengths of the molecules manifest themselves in an energy shift of the modes. These shifts are used to identify through which part the molecule is bonded to the surface.

4,4′-Dithiodipyridine on Au(111): A Combined STM, STS, and DFT Study

We studied the adsorption of 4,4′-dithiodipyridine (PySSPy) on Au(111) under ultrahigh vacuum conditions and at low-temperature both experimentally by means of scanning tunneling microscopy and spectroscopy (STM and STS) and theoretically by density functional theory (DFT). We find PySSPy molecules, characterized by their elongated appearance in STM, assembled in islands that reside exclusively in fcc regions of the herringbone reconstructed Au (HB) terraces. A triangular structure motif dominates the local arrangement of the PySSPy. DFT calculations reveal a virtually planar adsorption geometry of the PySSPy with the S–S bond of the molecule almost parallel to the Au–Au bonds of the substrate underneath. Though van der Waals forces dominate the stability of the adsorbed PySSPy, there is also a covalent contribution to the PySSPy/Au interaction. As a consequence, the PySSPy structures are relatively unstable. As found by STS, the highest occupied molecular orbital (HOMO) is located at around −0.7 eV below the Fermi energy (Ef), in good agreement with the HOMO provided by DFT. The position of the lowest unoccupied molecular orbital (LUMO) is about 3.2 eV above Ef, leaving the HOMO–LUMO gap practically unchanged compared to a free molecule. The molecules exhibit a strong propensity to dissociate into monomers forming pyridine thiolates (PyS) at step edges or elbow sites of the HB. At room temperature, all PySSPy on the substrate dissociate resulting in linear chains of PyS characterized by a drop of the LUMO by about −0.9 eV.

Differential Joint-Specific Corticospinal Tract Projections within the Cervical Enlargement

The motor cortex represents muscle and joint control and projects to spinal cord interneurons and–in many primates, including humans–motoneurons, via the corticospinal tract (CST). To examine these spinal CST anatomical mechanisms, we determined if motor cortex sites controlling individual forelimb joints project differentially to distinct cervical spinal cord territories, defined regionally and by the locations of putative last-order interneurons that were transneuronally labeled by intramuscular injection of pseudorabies virus. Motor cortex joint-specific sites were identified using intracortical-microstimulation. CST segmental termination fields from joint-specific sites, determined using anterograde tracers, comprised a high density core of terminations that was consistent between animals and a surrounding lower density projection that was more variable. Core terminations from shoulder, elbow, and wrist control sites overlapped in the medial dorsal horn and intermediate zone at C5/C6 but were separated at C7/C8. Shoulder sites preferentially terminated dorsally, in the dorsal horn; wrist/digit sites, more ventrally in the intermediate zone; and elbow sites, medially in the dorsal horn and intermediate zone. Pseudorabies virus injected in shoulder, elbow, or wrist muscles labeled overlapping populations of predominantly muscle-specific putative premotor interneurons, at a survival time for disynaptic transfer from muscle. At C5/C6, CST core projections from all joint zones were located medial to regions of densely labeled last-order interneurons, irrespective of injected muscle. At C7/C8 wrist CST core projections overlapped the densest interneuron territory, which was located in the lateral intermediate zone. In contrast, elbow CST core projections were located medial to the densest interneuron territories, and shoulder CST core projections were located dorsally and only partially overlapped the densest interneuron territory. Our findings show a surprising fractionation of CST terminations in the caudal cervical enlargement that may be organized to engage different spinal premotor circuits for distal and proximal joint control.

Adsorption and Electron-Induced Dissociation of Ethanethiol on Au(111)

Dissociation of ethanethiol and the formation of Au-adatom-diethylthiolate rows on the Au(111) surface were investigated using scanning tunneling microscopy (STM) at low temperature. Ethanethiol molecules physisorb on Au(111) at 120 K by sequentially occupation of the elbow site, the fcc domain before covering the whole surface with a semiliquid layer without long-range order. Scanning the physisorbed layer with a sample bias higher than +1.2 V leads to dissociation via cleaving the H-S bond. One of the dissociation products, ethylthiolate, forms a double-row structure with the rows aligned in one of the [112(-)] directions. These double rows arise from the Au-adatom-dithiolate species: CH(3)CH(2)S-Au-SCH(2)CH(3).

Substrate Reconstruction Mediated Unidirectionally Aligned Molecular Dipole Dot Arrays

We report the fabrication of unidirectionally aligned molecular dipole dot arrays of vanadyl phthalocyanine (VOPc) on Au(111). Low-temperature scanning tunneling microscopy (LT-STM) studies reveal that isolated VOPc molecules adsorb predominantly at the elbow sites of the 22 × √3 herringbone reconstructed Au(111) surface, and adopt an O-down configuration with the phthalocyanine plane parallel to the substrate. It is proposed that the low-coordinated Au atom at the elbow sites on the reconstructed Au(111) can interact strongly with the O-down oriented VOPc molecule, and hence leads to the formation of the unidirectionally aligned VOPc molecular dipole dot arrays.