Surface Unit Research Articles

A novel neuropilin-1–binding sequence in the human T-cell lymphotropic virus type 1 envelope glycoprotein

Entry of human T-cell lymphotropic virus type 1 (HTLV-1) into host cells is mainly mediated by interactions between the viral envelope glycoprotein surface unit (SU) and three host receptors: glucose transporter type 1, heparin/heparan sulfate proteoglycan, and neuropilin-1 (Nrp1). Here, we analyzed the interaction between HTLV-1 SU and Nrp1 using nuclear magnetic resonance and isothermal titration calorimetry. We found that two SU peptides, residues 85–94 and residues 304–312, bound directly to the Nrp1 b1 domain with affinities of 7.4 and 17.7 μM, respectively. The binding modes of both peptides were almost identical to those observed for Tuftsin and vascular endothelial growth factor A binding to the Nrp1 b1 domain. These results suggest that the C-terminal region of HTLV-1 SU contains a novel site for direct binding of virus to the Nrp1 b1 domain. Our biophysical characterization of the SU peptides may help in developing inhibitors of HTLV-1 entry.

C70 increases the plasmonic signal of gold-atom chains on Si(553)

Infrared plasmonic excitations of the quasi-one dimensional gold-atom induced superstructures on silicon surfaces are particularly sensitive to doping effects. Such effects, here related to C70 adsorption, can be clearly measured as we show for gold atom chains on the Si(553) surface at room temperature. The strong plasmonic signal that is exclusively present for polarization along the chain direction does not disappear under C70 exposure. In contrast, it increases for adsorption of the first monolayer. The rising intensity corresponds to an increase of the one-dimensional plasma frequency. This process saturates at a coverage corresponding to ca. one C70 per 1 × 2 surface unit cell. The observed plasmonic behaviour upon C70 adsorption is opposite to the consequences of electron donating gold ad-atoms on the plasmonic response. The increase of the one-dimensional plasma frequency upon C70 adsorption is accompanied by an increase of the electronic scattering rate, which is in accord to the theory on adsorbate induced surface resistivity.

Synthesis and DSSC application of donor-acceptor stilbenoid dendrimers with triphenylamine as core and benzothiazole as surface unit

Abstract The π-conjugated donor-acceptor stilbenoid dendrimers are successfully synthesized in high yields by either Aldol-type condensation or Wittig reaction with triphenylamine as donor and benzothiazole as acceptor. The molar extinction coefficient increases with increase in the number of the conjugated π-bridges. All the stilbenoid dendrimers exhibit quasi-reversible oxidation reduction signal in cyclic voltammetry. The highly π-conjugated stilbenoid dendrimers exhibit better current generating capacity and light energy harvesting efficiency than the other dendrimers, when used as additives in dye-sensitized solar cells. Stilbenoid dendrimer 7 shows the maximum power conversion efficiency (ɳ) of 5.08%.

Effect of Climate Change on Pedological Modifications and Soil Aridity Process in Vineyards

The general warming of climate disturbed the evolution of natural factors: water and soil, climate changes in the vineyard ecosystems and the summers became hotter and drier, the autumns are longer, the winters are shorter and seldom excessive, droughts are common and wet periods are excessively rainy. Soil contains plant nutrients, minerals, organic matter and seeds. It can also contain pesticides and toxic heavy metals. Building disturbs and loosens soil and can create large volumes of dust and debris. We consider that the results of these researches will have a special utility for both private farmers and companies, because in this area of NE region of Romania the viticulture has tradition and brings important income to growers. The goal of this paperwork was to analyses the influence of some factors such as variety of grapes and applied agro techniques on the growth and development of the grapevine and especially the impact of the applied technology on the productive potential of the surface unit, in order to improve some maintenance technologies of this species and the choosing of the best varieties which respond the best to the climate changes. The suitability of the grapevine culture results from the interference of the main ecological requirements of the species: light (light energy), temperature (solar energy), water (soil and air humidity), soil (root culture medium), nutrients and the air (the composition) for growth and development and the natural setting, which the area can offer to the studied species. The crop yield depends primarily on variety, on the interaction with the pedo - climatic factors and the applied technology. The necessity of the chosen topic is justified by the importance of the technological factors on the grapevine culture.

Synthesis, photophysical, and electrochemical properties of triazolyl dendrimers with thiazolylchalcone surface unit

ABSTRACTSynthesis of novel triazolyl dendrimers with thiazolylchalcone surface group and triazole as bridging unit has been achieved in good yields by click chemistry through convergent approach. All the triazolyl dendrimers showed an absorption band between 293 and 336 nm and an emission band between 430 and 435 nm. The intensity of absorption and emission bands increases on increasing the number of dendritic wedges and triazole units. Triazolyl dendrimers exhibited quasi-reversible behavior in cyclic voltammetry. A shift in the reversible potential was observed in cyclic voltammetry on increasing the dendritic wedges in the triazolyl dendrimers.

Occator crater in color at highest spatial resolution

The geology of the outstanding crater Occator on Ceres has been studied by combining highest resolution color images and other information from the DAWN mission. Thus, surface and sub-surface layers and geologic processes can be understood and interpreted in a consistent manner. In order to achieve this, morphometry, absolute surface unit ages, color, and the distribution of foci of activity were the key data. These data show that the ascent of brine from reservoir(s) at depth and deposition of its salts on the surface persisted much longer than initially thought possible as an immediate result of the primary impact. The youngest depositional processes of bright material occurred less than 2 Ma ago. Also, the bright Cerealia and Vinalia Faculae are not the only traces of this activity; updoming is present on the southwestern crater floor. Faculae coincide with fractures and vents and indicate complex mechanisms of the deposition of bright carbonate-rich material. Due to the large age difference between the Occator impact itself, modeled cooling times of heated crater material, and the recent activity at the faculae we conclude that endogenic forces were lately acting. The distribution and thickness of surface and sub-surface brine layers are far from homogeneous in the upper crust beneath Occator. Further evidence regarding the distribution of materials has been derived from the distribution of the ejecta and the transition of ejecta to background material outside the crater.

Single atomic layer allotrope of bismuth with rectangular symmetry

We report the observation of a new allotrope of two-dimensional bismuth. Our scanning tunneling microscopy experiments show that the structure is clearly different than the previously synthesized allotropes $\ensuremath{\beta}$- and $\ensuremath{\alpha}$-bismuthene. It has a rectangular symmetry similar to that of $\ensuremath{\alpha}$-bismuthene, but is composed of a puckered single monolayer of Bi atoms ($\ensuremath{\alpha}$-bismuthene is intrisincally a paired layer material similar to black phosphorous). Atomic resolution images and an observed moir\'e pattern show that the new allotrope has a significantly contracted surface unit cell. The electronic structure is dominated by high density of states at the Fermi level as measured using scanning tunneling spectroscopy (STS) and confirmed by calculations based on density functional theory (DFT) which reveal Dirac cones at three different points in the Brillouin zone.

Micropatterned surface electrode for massive selective stimulation of intraepidermal nociceptive fibres

BackgroundNo satisfactory neurophysiological test for nociceptive afferents is available to date. Laser stimuli present risks of skin damage, whilst electrical stimulation through specially designed electrodes is not selective enough. New methodWe present a new electrode designed according to critical issues identified in preliminary computer simulations concerning electric field gradient through the skin. To provide selective stimulation the activating electric field must be limited to intraepidermal free nerve endings. To this end, a new interdigitated electrode (IDE) was made of conductive rails arranged in a comb-like micropattern, situated only 150μm apart from each other (150 IDE) and alternately connected to the opposite poles of the stimulator. ResultsEvoked potentials recorded from the scalp were obtained after stimulation with the 150 IDE and with a similarly designed, but more widely spaced electrode (1000μm, or 1000 IDE). Small amplitude early and medium latency components were recorded with the 1000 IDE, suggesting activation of Aβ fibres. On the other hand, the 150 IDE only evoked late responses, confirming sufficient selectivity in small fibre activation. Comparison with existing method(s)The main differences with existing electrodes are: 1) Microspaced interdigitated conductive rails. 2) The potentially unlimited surface of stimulation and high efficiency per surface unit, resulting in large numbers of activated nociceptors. ConclusionsA new electrode providing selective stimulation of nociceptive nerve free endings is presented. It is non-invasive, and its surface can be enlarged at will. It is expected that it may greatly help in neurophysiological assessment of conditions affecting the nociceptive pathway.

Manganese-calcium intermixing facilitates heteroepitaxial growth at the [formula omitted] calcite-water interface

Abstract In situ atomic force microscopy (AFM) measurements were performed to probe surface precipitates that formed on the 10 1 ¯ 4 surface of calcite (CaCO3) single crystals following reaction with Mn2+-bearing aqueous solutions. Three-dimensional epitaxial islands were observed to precipitate and grow on the surfaces. In situ time-sequenced measurements demonstrated that the growth rates were commensurate with those obtained for epitaxial islands formed on calcite crystals reacted with Cd2+-bearing aqueous solutions of the same range in supersaturation with respect to the pure metal carbonate phase. This finding was unexpected as rhodochrosite (MnCO3) and calcite display a 10% lattice mismatch, based on the area of their 10 1 ¯ 4 surface unit cells, whereas the lattice mismatch is only 4% for otavite (CdCO3) and calcite. Coatings of varying thicknesses were therefore synthesized by reacting calcite single crystals in calcite-equilibrated aqueous solutions with up to 250 μM MnCl2. Ex situ X-ray photoelectron spectroscopy (XPS), scanning transmission electron microscopy (STEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), X-ray reflectivity (XRR), and AFM measurements of the reacted crystals demonstrated the formation of an epitaxial (Mn,Ca)CO3 solid solution. The epitaxial solid solution had a spatially complex composition, whereby the first few nanometers were rich in Ca and the Mn content increased with distance from the original calcite surface, culminating in a topmost region of almost pure MnCO3 for the thickest coatings. The effective lattice mismatch was therefore much smaller than the nominal mismatch thus explaining the measured growth rates. These findings highlight the strong influence played by the substrate on the composition of surface precipitates in aqueous conditions.

Structural heat-resistant β-NiAl + γ′-Ni3Al alloys of the Ni–Al–Co system: II. Oxidation

The heat resistance of the β + γ′ alloys with 28–29 at % Al, 10 at % Co, and 0.25–0.4 at % Re in air at 1300°C is studied. The structures of the scale and the subscale layers that form during oxidation for 2 and 100 h due to the interdiffusion of aluminum and oxygen are investigated. Alloying with 10 at % Co is shown to increase the heat resistance in the absence of chromium and a low content of the elements tht are active to oxygen (La). The heat resistance of the β + γ′ NIAL1 and NIAL2 alloys at 1300°C, which was estimated from the surface unit mass increment in 100 h, is at level of the heat resistance of the γ′ + γ VKNA (VIN) alloys at 1200–1250°C.

Contact lens and ocular surface ‐ After all, its still a foreign body

SummaryContact lenses, as indicated by the name, are in direct contact with the ocular surface. CL are swimming within the tear film, between eye ball & palpebral conjunctiva ‐ in the middle of the Ocular Surface Unit. Interactions thus have direct impact on tear film & tissues with the risk of potential side effects (for details please see: WWW.OSCB‐BERLIN.ORG).One main impact is increased mechanical friction by the ′additional structure′. Friction increases during eye movements and blinks when the lid border moves over the contact lens rim and along its anterior lens surface. Limited diffusion of nutritients can occur through the lens, particularly the supply with oxygen is critical for the cornea that depends on gas diffusion – Modern materials have meanwhile decreased this risk. Chemical impacts occur by the lens material or by solutions for lens cleaning & storing.

Characteristics of a Spherical-Seat TPJB With Four Methods of Directed Lubrication—Part I: Thermal and Static Performance

Static and thermal characteristics (measured and predicted) are presented for a four-pad, spherical-seat, tilting-pad journal bearing (TPJB) with 0.5 pivot offset, 0.6 L/D, 101.6 mm nominal diameter, and 0.3 preload in the load-between-pivots orientation. One bearing is tested four separate times in the following four different lubrication configurations: (1) flooded single-orifice (SO) at the bearing shell, (2) evacuated leading edge groove (LEG), (3) evacuated spray-bar blocker (SBB), and (4) evacuated spray-bar (SB). The LEG, SBB, and SB are all considered methods of “directed lubrication.” These methods rely on lubrication injected directly to the pad/rotor interface. The same set of pads is used for every test to maintain clearance and preload; each method of lubrication is added as an assembly to the bearing. Test conditions include surface speeds and unit loads up to 85 m/s and 2.9 MPa, respectively. Static data include rotor–bearing eccentricities and attitude angles. Thermal data include measured temperatures from 16 bearing thermocouples. Twelve of the bearing thermocouples are embedded in the babbitt layer of the pads, while the remaining four are oriented at the leading and trailing edge of the loaded pads exposed to the lubricant. Bearing thermocouples provide a circumferential and axial temperature gradient. The pivot stiffness (pad and pivot in series) is measured and incorporated into predictions.

Characteristics of a Spherical Seat TPJB With Four Methods of Directed Lubrication—Part II: Rotordynamic Performance

Measured and predicted rotordynamic characteristics are presented for a four-pad, spherical-seat, tilting-pad journal bearing (TPJB) with 0.5 pivot offset, 0.6 L/D, 101.6 mm nominal diameter, and 0.3 preload in the load-between-pivots orientation. One bearing is tested four separate times in the following four different lubrication configurations: (1) flooded single-orifice (SO) at the bearing shell, (2) evacuated leading edge groove (LEG), (3) evacuated spray-bar blocker (SBB), and (4) evacuated spray-bar (SB). The same set of pads is used for every test to maintain clearance and preload; each method of lubrication is added as an assembly to the bearing. Test conditions include surface speeds and unit loads up to 85 m/s and 2.9 MPa, respectively. Dynamic data includes four sets (one set for each bearing configuration) of direct and cross-coupled rotordynamic coefficients derived from measurements and fit to a frequency-independent stiffness-damping-mass (KCM) matrix model. The pivot stiffness (pad and pivot in series) is measured and incorporated into predictions.

Effect of the interfacial O and Mg vacancies on electronic structure and transport properties of the FeRh/MgO/FeRh (0 0 1) magnetic tunnel junction: DFT calculations

The electronic, magnetic and transport properties of oxygen or magnesium vacancies at the FeRh/MgO/FeRh (001) magnetic tunnel junction are studied within first principles. Configurations with one O or Mg vacancy per C(2×2) surface unit cell, which is located in the MgO interfacial layers, are investigated. We observed that the O and Mg vacancies defect have a very little influence on the magnetic state of the spacer. Very interestingly, the Fe atoms exhibit an enhanced magnetic moment in the case of Mg-vacancy, this latter was found to decrease in the case of O-vacancy. The variations in the spin polarization and magnetic moment values for Fe and Rh atoms at the interface were found to be larger in presence of Mg vacancy. An analysis of the charge densities of our systems was also performed; large variations in the Mg-vacancy system were observed. This affects more the t2g states of the interfacial Fe atom. Moreover, we present an ab initio calculated transmission and I-V characteristics for FeRh/MgO/FeRh (001) magnetic tunnel junction and we compare results to those of O and Mg-vacancy at the interface using the TRANSIESTA code, which combines the DFT electronic structure calculations with the non-equilibrium Green function formalism (NEGF) for transport properties. The results show that the zero-bias minority spin transmission is much larger than the majority spin transmission for all structures. In all systems and for all magnetic configurations, minority spin currents are higher than majority spin ones, this means that transport properties are, mainly, determined by minority spin channel.

Ultimate Capacity of Battered Pile Groups Subjected to Oblique Pullout Loads in Sand

A testing program comprising 250 oblique pullout tests was conducted to study the effect of variable parameter on pullout capacity of batter pile groups in sand. Test was conducted in laboratory on five pile groups. Model piles consist of aluminium having three length 0.40, 0.60, 0.90 m at two unit weights 16.28 and 15.79 kN/m3. Two pile surfaces were tested and angle of oblique load was kept at 0°, 10°, 20°, 30°,45o. Analysis of results indicates that increasing value of pile length, sand unit weight, and surface roughness increases the the pullout capacity of oblique piles. Increasing angle of oblique load from horizontal also increases the oblique pullout capacity for batter pile group but have no significant difference at lower angle of oblique load. Difference in oblique load caring capacity for each pile length, unit weight and surface roughness became significant at higher angle of oblique load. ANOVA single factor test indicate except pile surface other parameter viz length, unit weight and angle of oblique load significantly affect oblique load caring capacity.

Zn vacancies creation via (2 × 2) surface reconstruction

Zinc vacancies have been incorporated in ZnO via (2 × 2) surface reconstruction during the epitaxy growth. Evolution of in situ reflection high-energy electron diffraction (RHEED) patterns indicate Zn-polar surface (2 × 2) reconstruction was realized under extreme O-rich conditions. Atom sized triangular pits and islands were presented by the high resolution scanning tunneling microscopy (STM) images, which stand for a single Zn vacancy per (2 × 2) surface unit cell. The neutral acceptor-bound exciton (A0,X), peak located at 3.344 eV, and red luminescence (RL), maximum emission intensity at ~1.76 eV, which related to Zn vacancy, have been studied by variable-temperature/power steady-state photoluminescence (PL) spectroscopy.

Tear Film Steroid Profiling in Dry Eye Disease by Liquid Chromatography Tandem Mass Spectrometry.

Dry eye disease (DED) is a multifactorial disorder of the ocular surface unit resulting in eye discomfort, visual disturbance, and ocular surface damage; the risk of DED increases with age in both sexes, while its incidence is higher among females caused by an overall hormonal imbalance. The role of androgens has recently investigated and these hormones were considered to have a protective function on the ocular surface. In order to correlate DED to tear steroid levels, a robust, specific, and selective method for the simultaneous quantification of cortisol (CORT), corticosterone (CCONE), 11-deoxycortisol (11-DECOL), 4-androstene-3,17-dione (ADIONE), testosterone (TESTO), 17α-hydroxyprogesterone (17-OHP), and progesterone (PROG) was developed and applied for the analysis of tear samples. The method involves a simple extraction procedure of steroids from tears collected on Schirmer strips, followed by a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) analysis. In total, tear samples from 14 DED female patients and 13 healthy female controls were analysed and, CORT, ADIONE, and 17-OHP response levels resulted significantly decreased in dry eye patients respect to controls. The receiver operating characteristic (ROC) curve obtained by the combination of these three steroids (AUC = 0.964) demonstrated the good diagnostic power of the differential tear steroids in identifying DED. In conclusion, the present method made it possible, for the first time, to study steroid profiling directly in tear fluid.

Synthesis, Cell Viability, and Flow Cytometric Fluorescence Pulse Width Analysis of Dendrimers with Indazoles Surface Unit

Dendrimers with indazole surface units were synthesized up to second generation in good yields, and the MTT cell proliferation assay was carried out with A549 lung adenocarcinoma cell lines. The cell viability and the flow cytometry analysis shows that increased mitochondrial activity was concomitant with increased mitochondrial biomass with no loss of mitochondrial membrane potential or cell death.

P-269 - Correlation between the prognostic value of tumor-infiltrating lymphocytes (TILS) and sidedness in colorectal cancer (CC) patients (pts)

Introduction: Right-sided colon cancer (RCC) and left-sided colorectal cancer (LCRC) have a different biology and genomic pattern. Primary tumor location is emerging as an important prognostic factor in metastatic CC patients eligible to target therapy. In a previous work, we have reported that specific tumor-infiltrating lymphocytes (S-TILs) (CD3+, CD8+, CD45RO+) may represent a valuable prognostic tool to drive the decision making-process in stage II colon cancer (CC) disease. In this study we aim to evaluate the relationship and the prognostic impact between TILs and the anatomical subsite (RCC vs LCRC) in primary non metastatic CC, regardless the stage. Methods: We performed a retrospective analysis on 48 CC pts (17F/31M, median age 68.1 - range 52-91 years) underwent adjuvant therapy, of which 33 relapsed and 15 did not, subdivided according to the anatomical sidedness of their primary tumors. We analyzed, by immunohistochemical staining, the density of CD3+, CD8+ and CD45RO + (memory cells) in the center of the tumor (CT) and in its invasive margin (IM) within the surgical tissues samples after radical surgery, comparing them on their primary tumor location. Measurements were recorded by image analysis as the number of positive cells per tissue surface unit in square millimeters. For each marker, we identified two grading of staining, high density (HD) or low density (LD), where the cut-off was the median value observed. Kaplan-Meier analysis was applied to compare the effect of TILs, between HD and LD, on disease free survival (DFS) and overall survival (OS) in the subgroups pts of RCC and LCRC. Due to the small cohort of 48 pts we have not been able to combine the tumor stage II (N = 15) and III (N = 33) with anatomical sidedness, thus this analysis was conducted subdividing patients in 17 RCC and 31 LCRC. Results: When we stratified pts by TILs density for each specific marker (CD3+, CD8+ and CD45RO+) for the anatomical sidedness, HD TILs pts showed a trend in LCRC for a longer OS compared to RCC pts, which became statistically significant for CD45RO+ in CT (p = 0.0061). On the contrary, for the entire cohort of 48 pts no differences in OS and DFS were found between LCRC and RCC pts without stratification for TILs. DFS was significantly improved in LCRC at both IM and CT only in pts with HD CD3+. On the contrary RCC showed DFS benefit only in HD CD45RO+ at IM. OS was significantly improved in LCRC in pts showing HD CD3+ and CD45RO+ at CT. HD CD45RO+ was also significant at IM. No significant differences were observed among CD3+, CD45RO+, CD8+, HD vs LD, in RCC. Conclusion: Specific HD TILs is an important prognostic factor regardless of sidedness of CC tumour; furthermore, in our analysis, the presence of HD CD45RO+ in CT of LCRC is correlated to a better survival.

Rice sensitivity to saline irrigation in Southern Spain

Losses of productivity of flooded rice in Southern Spain may occur due to the use of saline water coming from the existent tidal regime in the marshes of Guadalquivir River, and the sensibility of the plants is variable according to its stage of development. The aim of this research was to evaluate the production of rice grains and its components, spikelet sterility and the phenological development of rice at different levels of salinity and in different periods of its cycle. In the conditions of the trial, the productive potential of rice based on the electrical conductivity (EC) of the irrigation water can be estimated by using the equation “Percentage of grain yield=100−12.0 (EC – 0.92)”. It was estimated that from 1.6–1.7dSm−1 salt content affects rice grain yield. Salinity also had a negative impact on a number of yield components including panicles per surface unit, tillers and spikelets per plant; floret sterility; and even delayed heading. Individual grain size was scarcely affected by salinity increase. The vegetative and reproductive phases were significantly more sensitive to salinity than grain filling and maturation phase. Irrigation management practices should be adopted to minimize salinity during these critical growth stages.