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Here, we present a new route to dyes of the BODIPY family. We first built up a N-Boc-protected dipyrromethene scaffold via an aminopalladation cascade. Subsequentially, the pyrrole moiety was deprotected and the BF2 unit inserted. Depending on the terminating reaction, BODIPYs with either aryl or alkynyl moieties were accessible. [ABSTRACT FROM AUTHOR]

A 1,3‐carbocarbonation of 2‐substituted cyclopropane 1,1‐dicarboxylates introduces various saturated or unsaturated carbon residues at the 1‐ and 3‐ position of the former three‐membered ring. Under copper catalysis, ring‐opening attack with a Grignard reagent proceeded smoothly; the intermediate was converted to the final product by reaction with appropriate carbon‐based electrophiles under basic conditions. As nucleophiles, Grignard reagents derived from sp3‐, sp2‐, and sp‐hybridized carbon residues were successfully employed, whereas various aliphatic bromides and EBX derivatives (for sp moieties) served as electrophiles. [ABSTRACT FROM AUTHOR]

Focuses on a study that presented an energy analysis of neutral atoms in broad oxygen ion beams by Doppler-shift measurements. Description of the experimental setup; Process of the charge exchange collisions with thermal oxygen molecules in the process chamber; Discussion of the excitation mechanisms used.

Presents a study which analyzed the behavior of carbon fluoride radicals in carbon fluorine[sub4]/dioxide plasmas as a function of the oxygen partial pressure in a radio frequency reactor. Experimental details; Results and discussion; Conclusions.

Abasic sites can occur in DNA for different reasons, and thus the detection of this special molecular structure has turned into the focus of research. Here we have investigated the hybridization of abasic ssDNA to immobilized ssDNA probes by impedance spectroscopy. For this purpose three different abasic 25mer ssDNA (abasic site near the electrode; in the middle and near the solution) are studied in comparison to fully complementary 25mer ssDNA. For all abasic strands the surface binding can be followed concentration dependent via impedance spectroscopy; however, the concentration range and the maximum impedance change are found to be different compared to fullmatch ssDNA. Here, the position of the abasic site within the DNA strand significantly determines the signal behavior, and thus, even allows a partial discrimination between the different abasic DNA strands. By investigating the binding in parallel by SPR, only slightly smaller surface concentrations are detected for the abasic strands in comparison to the fullmatch strand. This points to the formation of different DNA structures when abasic sites are contained. [ABSTRACT FROM AUTHOR]

Abstract: The petrographic analysis and crystallographic analysis of concretionary carbonate cements (“coal balls”) from Carboniferous paralic swamp deposits reveal the presence of (length fast) radiaxial fibrous dolomite (RFD), a fabric not previously reported from the Phanerozoic. This finding is of significance as earlier reports of Phanerozoic radiaxial fibrous carbonates are exclusively of calcite mineralogy. Dolomite concretions described here formed beneath marine transgressive intervals within palustrine coal seams. This is of significance as seawater was arguably the main source of Mg2+ ions for dolomite formation. Here, data from optical microscopy, cathodoluminescence, electron backscattered diffraction, X-ray diffraction and geochemical analyses are presented to characterize three paragenetic dolomite phases and one calcite phase in these concretions. The main focus is on the earliest diagenetic, non-stoichiometric (degree of order: 0.41–0.46) phase I, characterized by botryoidal dolomite constructed of fibres up to 110μm wide with a systematic undulatory extinction and converging crystal axes. Petrographic and crystallographic evidence clearly qualifies phase I dolomite as radiaxial fibrous. Conversely, fascicular optical fabrics were not found. Carbon-isotope ratios (δ13C) are depleted (between −11.8 and −22.1‰) as expected for carbonate precipitation from marine pore-fluids in organic-matter-rich, paralic sediment. Oxygen isotope (δ18O) ratios range between −1.3 and −6.0‰. The earliest diagenetic nature of these cements is documented by the presence of ubiquitous, non-compacted fossil plant remains encased in phase I dolomite as well as by the complex zoned luminescence patterns in the crystals and is supported by crystallographic and thermodynamic considerations. It is argued that organic matter, and specifically carboxyl groups, reduced thermodynamic barriers for dolomite formation and facilitated Mg/CaCO3 precipitation. The data shown here reveal a hitherto unknown level of complexity with respect to radiaxial fibrous carbonates and are of importance for those concerned with dolomite and carbonate petrography in general. [Copyright &y& Elsevier]

Abstract: Chaetoceros calcitrans is a small, fast-growing diatom with a high nutritional value for filter feeders. It is often used in hatcheries, particularly in the production of bivalve spat. It is widely produced in batch culture systems ranging from carboys to plastic bags to high volume tanks. Continuous culture of C. calcitrans has generally not been successful due to frequent crashes of the culture. We report the continuous culture of C. calcitrans in a hanging plastic bag system that is suitable for use in commercial hatcheries. Runs of continuous production lasted up to 125d, with an average bag life of 24.4d. Crashes occurred at irregular intervals in individual bags and caused the cell concentration to drop by up to three orders of magnitude. Cultures recovered over a few days following a crash. The temporary reduction of production due to crashes in individual bags was compensated by a 30% higher production than required. At dilution rates of 1.0–1.3volume exchangesd−1 the system produced 7–13×106 cellsmL−1 d−1. The cell diameter mode as determined by a Coulter Counter was 2.8–3.0μm. The cells had the typical flat rectangular box shape with well-developed setae. The culturable bacterial population of the algae culture was 105–107 colony forming unitsmL−1. Genetic integrity of C. calcitrans and monospecific status of the continuous culture were maintained over 7 sequential bag-to-bag transfers during a 125-day run. The fatty acid profiles of continuous and batch cultures of C. calcitrans were similar. Growth and survival of Greenshell™ mussel (Perna canaliculus) larvae were identical when fed with C. calcitrans batch culture or continuous culture delivered directly from the harvest line. When continuous culture was first collected over 24h, diluted and then delivered to the rearing tanks over 24h, larval growth was markedly slower (24d to reach settlement competency compared to 21d for the other two treatments); however the subsequent settlement success of competent larvae was not statistically different between the three diets (‘Carboy’, ‘Continuous/Harvest line’, ‘Continuous/Feed-out bin’; 33.9–35.5% settled). Concomitant to the differences in larval performance we observed a difference in larval fatty acid profile: lower-performing larvae had a markedly lower proportion of mono-unsaturated fatty acids and a markedly higher proportion of poly-unsaturated fatty acids. Lower performance and different fatty acid profiles of larvae fed the ‘Continuous/Feed-out bin’ diet appeared to be caused by unidentified changes that occurred during storage of the C. calcitrans culture. [Copyright &y& Elsevier]

Abstract: Quite diverse concepts for targets have been proposed for ESS. While there is no doubt that different approaches are possible in principle, here it is argued that a large new neutron production facility, prepared for operation at an unprecedented power level, should rely as much as possible on proven technology. The neutron spallation sources SINQ and UCN at PSI feature as their standard a solid state target consisting of Zircaloy tubes filled with lead (“cannelloni”). These targets are cooled with heavy water. SINQ is currently being operated for the second decade at a power level of about 1MW. A first quick assessment of the suitability of this target type for ESS conditions gives encouraging results but a wide variety of technical questions has still to be addressed in more detail. Possible paths for optimization as well as proposals for promising configurations are sketched. [Copyright &y& Elsevier]

Several questions concerning the survival of isolated neurons and neuronal stem and progenitor cells (NPCs) have not been answered in the past: (1) If lactate is discussed as a major physiological substrate of neurons, do neurons and NPCs survive in a glucose-free lactate environment? (2) If elevated levels of glucose are detrimental to neuronal survival during ischemia, do high concentrations of glucose (up to 40 mmol/L) damage neurons and NPCs? (3) Which is the detrimental factor in oxygen glucose deprivation (OGD), lack of oxygen, lack of glucose, or the combination of both? Therefore, in the present study, we exposed rat cortical neurons and NPCs to different concentrations of d-glucose ranging from 0 to 40 mmol/L, or 10 and 20 mmol/L l-lactate under normoxic and anoxic conditions, as well as in OGD. After 24 h, we measured cellular viability by biochemical assays and automated cytochemical morphometry, pH values, bicarbonate, lactate and glucose concentrations in the cell culture media, and caspases activities. We found that (1) neurons and NPCs survived in a glucose-free lactate environment at least up to 24 h, (2) high glucose concentrations >5 mmol/L had no effect on cell viability, and (3) cell viability was reduced in normoxic glucose deprivation to 50% compared to 10 mmol/L glucose, whereas cell viability in OGD did not differ from that in anoxia with lactate which reduced cell viability to 30%. Total caspases activities were increased in the anoxic glucose groups only. Our data indicate that (1) neurons and NPCs can survive with lactate as exclusive metabolic substrate, (2) the viability of isolated neurons and NPCs is not impaired by high glucose concentrations during normoxia or anoxia, and (3) in OGD, low glucose concentrations, but not low oxygen levels are detrimental for neurons and NPCs. [ABSTRACT FROM AUTHOR]

Blood–brain barrier (BBB) disruption, resulting from loss of tight junctions (TJ) and activation of matrix metalloproteinases (MMPs), is associated with edema formation in ischemic stroke. Cerebral edema develops in a phasic manner and consists of both vasogenic and cytotoxic components. Although it is contingent on several independent mechanisms, involving hypoxic and inflammatory responses, the single effect of prolonged hypoxia on BBB integrity in vivo was not addressed so far. Exposing mice to normobaric hypoxia (8% oxygen for 48 h) led to a significant increase in vascular permeability associated with diminished expression of the TJ protein occludin. Immunofluorescence studies revealed that hypoxia resulted in disrupted continuity of occludin and zonula occludens-1 (Zo-1) staining with significant gap formation. Hypoxia increased gelatinolytic activity specifically in vascular structures and gel zymography identified MMP-9 as enzymatic source. Treatment with an MMP inhibitor reduced vascular leakage and attenuated disorganization of TJ. Inhibition of vascular endothelial growth factor (VEGF) attenuated vascular leakage and MMP-9 activation induced by hypoxia. In conclusion, our data suggest that hypoxia-induced edema formation is mediated by MMP-9-dependent TJ rearrangement by a mechanism involving VEGF. Therefore, inhibition of MMP-9 might provide the basis for therapeutic strategies to treat brain edema. [ABSTRACT FROM AUTHOR]

Abstract: Cationization of molecular substances results often in the emission of characteristic peak patterns of secondary ions (SI) of these molecular species and is accompanied by matrix-enhanced SI yields. Besides the cationization of molecular overlayers on substrates of periodic table group IB elements, recent especially matrix-enhanced SIMS by physical vapor deposition (PVD) processes of Ag and Au was in the focus of investigations. In this work, selected lubricants components were investigated by ToF-SIMS, using different methods for cationization: (i) substrate cationization with periodic table group IA and IB elements (Cu, Ag, Cs, Au), (ii) cationization by dissolved salts of group IA and IB elements (Li, K, Na, Cu, Ag), and (iii) the in situ PVD by sputtering of group IB element targets (Cu, Ag, Au) by using the pulsed dual source column (DSC) of a ToF-SIMS instrument and thick lubricant layers on silicon wafers positioned in the immediate vicinity of the sputter crater. The Cu- and Ag-cationization of the investigated trimethylol-propane esters TMP(C8/C10) and poly-alpha-olefins (PAO) were possible with all specified methods, whereas only the esters were cationized also by alkaline elements (Li, Na, K, Cs). Au-cationization products were only observed for volatile PAO components that have deposited on the fresh cleaned surface of the sputter crater bottom of the Au-target. [Copyright &y& Elsevier]

Abstract: We have applied time-of-flight secondary ion mass spectrometry (ToF-SIMS) and laser post-ionization secondary neutral mass spectrometry (laser-SNMS) to examine the immobilization process of PNA and its hybridization capability to unlabeled complementary DNA fragments, to characterize immobilized proteins, and to image intrinsic elements and molecules with subcellular spatial resolution in different types of frozen non-dehydrated biological samples. The possibilities and limitations of ToF-SIMS and laser-SNMS for imaging elements and molecules in biological samples are discussed. Furthermore possibilities for enhancing the detection sensitivity by using polyatomic and cluster primary ions and different laser post-ionization schemes, as well as ways of obtaining 3D molecular images from biological samples are described. The data shows that both ToF-SIMS and laser-SNMS are capable of imaging elements and molecules in complex biological samples and that they are very valuable tools in advancing applications in life sciences. It was found that cluster-ion bombardment is very useful for enhancing the molecular yield, while laser-SNMS resulted in much higher detection sensitivity for elements and specific molecules and is particularly well suited for imaging ultra-trace element concentrations in biological samples. [Copyright &y& Elsevier]

Hypoxic-ischemic damage is a major challenge for neuronal tissue. In the present study, we investigated the effects of anoxia and glucose deprivation on adult neural stem cells (NSCs) in vitro. We assessed glucose deprivation, anoxia and the combination of the latter separately. After 24 h of anoxia, cell numbers increased up to 60% compared to normoxic controls. Whereas nearly all normoxic cells incorporated the mitotic marker BrdU (99%), only 85% of the anoxic cells were BrdU-positive. Counting of interphase chromosomes showed 8-fold higher cell division activity after anoxia. The number of necrotic cells doubled after anoxia (14% compared to 7% after normoxia). Apoptosis was measured by two distinct caspases assays. Whereas the total caspase activity was reduced after anoxia, caspase 3/7 showed no alterations. Glucose deprivation and oxygen glucose deprivation both reduced cell viability by 56 and 53%, respectively. Under these conditions, total caspases activity doubled, but caspase 3/7 activity remained unchanged. Erythropoietin, which was reported as neuroprotective, did not increase cell viability in normoxia, but moderately under oxygen glucose deprivation by up to 6%. Erythropoietin reduced total caspase activity by nearly 30% under all the conditions, whereas caspase 3/7 activity was not affected. Our results show that anoxia increases proliferation and viability of adult NSCs, although a fraction of NSCs does not divide during anoxia. In conclusion, anoxia increased cell viability, cell number and proliferation in NSCs from the rat brain. Anoxia turned out to be a highly stimulating environmental for NSCs and NSCs died only when deprived of glucose. We conclude that the availability of glucose but not of oxygen is a crucial factor for NSC survival, regulating apoptotic pathways via caspases activity other than the caspases 3/7 pathway. Therefore, we conclude that NSCs are dying from glucose deprivation, not from hypoxic-ischemic damage. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: The aim was to assess in vitro the resistance to corrosion of eight commercial dental alloys by two quantitative methods, electrochemical and immersion tests, then to statistically test the hypothesis of possible correlation between the polarization resistance (R p) and the elemental release. Methods: Two quantitative methods; electrochemical and immersion test, were used. From the first, after recording the OCP during 24h immersion in acidified artificial saliva (pH 2.3), R p was obtained using the linear polarization in anodic path and applying the Mansfeld''s method. From the static immersion test, using the same test solution, the elemental release from was analysed and determined using the ICP-AES. Thereafter, the two measurements were used to plot the regression line and to determine the correlation coefficient. The significance of the correlation was tested using F-test at a confidence interval of 0.99. Results: : The resistance to corrosion results obtained from the two methods were ranked and compared; an inverse relation between them was evident. Then, the obtained coefficient of correlation (R 2) was 0.886. With the F-test at 0.99 confidence interval, the hypothesis was accepted as the calculated F was about 44 against critical F =13.7. Conclusion: The correlation between the two measurements, R p and mass loss, was proved statistically significant. This result may provide a new approach to predict the corrosion behaviour of dental alloys by firstly using the easier methods. [Copyright &y& Elsevier]

Abstract: A nuclear quadrupole interaction (NQI) study using the time differential perturbed angular correlation (TDPAC) technique on ammonium paramolybdate (APM) has shown three inequivalent molybdenum sites in this compound which consists of seven MoO6 polyhedra connected through edges. In this study the nuclear probe 99Mo was used to measure the γ–γ perturbed angular correlation of 99Tc on Mo-sites to obtain the quadrupole interaction parameters. The quadrupole interaction frequencies (ω Q ) for the three sites are 0.0224, 0.0386 and 0.0434rad/ns and the asymmetry parameters (η) of the electric field gradient (EFG) are 0.45, 0.18, and 0.58, respectively. The site assignment is based on the population ratios 4:2:1. The Mo atoms with the highest population show the lowest ω Q indicating that this set of polyhedra is “least” distorted or condensed. Besides the least squares fit, a cross-correlation algorithm has been used to analyze the experimental data to corroborate the fitted parameters and quoted errors. The derived NQI-parameters can be used for site assignments in other compounds built from condensed Mo–O octahedra. [Copyright &y& Elsevier]

Abstract: New on-line analytical system coupling thin layer chromatography (TLC) and high selective identification unit—time of flight secondary ion mass spectrometry (TOF–SIMS) is introduced in this article. Chromatographic mixture separation and analyte surface deposition followed with surface TOF–SIMS analysis on-line allows to identify the analytes at trace and ultratrace levels. The selected analytes with different detectability and identification possibility were analysed in this hyphenated unit (Methyl Red indicator, Terpinolen and Giberrelic acid). Here, the chromatographic thin layer plays a universal role: separation unit, analyte depositing surface and TOF–SIMS interface, finally. Two depositing substrates and TOF–SIMS compatible interfaces were tested in above-mentioned interfacing unit: modified aluminium backed chromatographic thin layer and monolithic silica thin layer. The sets of positive and negative ions TOF–SIMS spectra obtained from different SIMS modes of analysis were used for analyte identification purposes. SIMS enables analyte detection with high mass resolution at the concentration level that is not achieved by other methods. [Copyright &y& Elsevier]

The nuclear quadrupole interaction of 204mPb in lead oxides has been measured by γ– γ time differential perturbed angular correlation. Ab-initio calculations of the electric field gradients and X-ray diffraction allowed the assignment of the detected nuclear quadrupole interactions to the different Pb sites in the PbO phases litharge and massicote as well as in Pb3O4. The TDPAC probe 204mPb was produced with a 204Bi/204mPb-generator at the home laboratory at the University of Leipzig. The use of a high performance liquid chromatography system increased significantly the yield, the specific activity of 204mPb, and reduced the acidic concentration of the eluate. [ABSTRACT FROM AUTHOR]

In this tutorial paper we compare the ab-initio calculations of electronic charge densities and related electric field gradients in simple molecules like H2 as well as the triangular H3 with variable bond distance and bond angle using the Amsterdam Density Functional (ADF) code with calculations based on a simple linear combination of hydrogen 1s-orbitals. In order to gain more insight into ADF – or other ab-initio – calculations it is rather useful to vary structural parameters. In addition to geometry optimisations we propose to vary bond distances and bond angles over extended ranges in order to arrive at a better interpretation of the results. [ABSTRACT FROM AUTHOR]

We designed new primers that give shorter amplicons for Penta D and Penta E for easy separation on native polyacrylamide gels. 112 unrelated Northern Thai men were typed. A total of nine and eight-teen alleles was found for Penta D and Penta E, respectively. Both loci showed a high power of discrimination (Penta D: 0.927; Penta E: 0.966; both loci combined: 0.9975) as reported in other populations. Penta D met Hardy-Weinberg expectations, whereas Penta E did not, maybe because of the small sample size in relation to the large number of alleles of this locus. [Copyright &y& Elsevier]

The effects of freeze-thaw, freezing and sediment geochemistry on terminal anaerobic processes occurring in sediments taken from below cyanobacterial mats in meltwater ponds of the McMurdo Ice Shelf in Antarctica were investigated. Depending on the geochemical and physical status of the sediments (i.e., frozen or thawed), as well as passage of sediment through a freeze-thaw cycle, terminal carbon and electron flow shifted in which the proportions of hydrogen and acetate utilized for methanogenesis and sulfate reduction changed. Thus, in low-sulfate (or chloride) sediment which was thawed and incubated at 4°C, total carbon and electron flow were mediated by acetate-driven sulfate reduction and H[sub 2]-driven methanogenesis. When the same sediments were incubated frozen, both methanogenesis and sulfate reduction decreased. However, under these conditions methanogenesis was favored over sulfate reduction, and carbon flow from acetate to methane increased relative to sulfate reduction; > 70% of methane was contributed by acetate, and more than 80% of acetate was oxidized by pathways not coupled to sulfate reduction. In high-sulfate pond sediments, sulfate reduction was a major process mediating terminal carbon and electron flow in both unfrozen and frozen incubations. However, as with low-sulfate sediments, acetate oxidation became uncoupled from sulfate reduction with freezing. Geochemical and temperature effects could be expressed by linear models in which the log (methanogenesis to sulfate reduction) was negative log linear with respect to either temperature or the log of the sulfate (or chloride) concentration. From these relationships it was possible to predict the ratio for a given temperature (low-sulfate sediments) or sulfate (chloride) concentration. Small transitory changes, such as elevated sulfate reduction coupled to increased acetate turnover, resulted from application of a freeze-thaw cycle to low-salinity pond sediments. The results demonstrate... [ABSTRACT FROM AUTHOR]

Describes the major heterothrophic processes occurring in the sediments of a low-salinity melt-water pond in Antarctica. Effect of acetate addition on methanogenesis; Methane production stimulated by formate; Inhibition of methanogenesis by chloride.

Broad ion beams in the energy range of 0.2 to 1.5 keV originating from a filament source with argon as feed gas have been analyzed by high-resolution emission spectroscopy. The Doppler structure of Ar[sup +] emissions reveals the existence of different velocity classes. Besides slow ions and ions possessing the main beam energy, electronically excited Ar[sup +] ions with twice the main beam energy are detected which are attributed to a single-electron capture process in Ar[sup ++] /Ar collisions. As a preliminary result from a reactive beam extracted from a microwave CF[sub 4] source plasma fast F atoms are detected which are attributed to charge exchange and dissociative collisions in the process chamber. [ABSTRACT FROM AUTHOR]

Since no previous randomized comparison has been carried out between ultra-high and conventional dosage streptokinase therapy of fresh venous thromboses, the NBVL trial was carried out as a prospective, randomized, multicentre, phlebographically monitored comparison of the results and adverse effects of these two fibrinolytic treatment options. Using the normal exclusion criteria, 156 patients with a leg–pelvis venous thrombosis presumed to be a maximum of 14 days old were treated with 1.5 million U streptokinase/h for 6h daily ( n= 77, group A) or conventional dosage with 100 000 U streptokinase per hour ( n= 79, group B). There were 15 patients (eight in group A, seven in group B) who had to stop therapy prematurely, and eight patients (five in group A, three in group B) could not be evaluated because of incorrect monitoring times. The phlebograms were evaluated using IFP-C scores. These showed a reduction in the IFP score from 4.55 to 2.2 in the 64 patients in group A after a mean of 2.7 ± 0.6 therapy cycles with administration of 24.4 ± 5.7 million U streptokinase, i.e. 47% of the baseline value. The 69 patients in group B had a reduction in score from 4.2 to 2.93 after a mean of 3.7 ± 1.2 days of treatment with administration of 8.6 ± 3.3 million units, i.e. a fall of 30% in the baseline values ( p= 0.007). There were 132 out of 281 completely occluded venous segments in group A (47%) and 81 out of 279 segments in group B (29%) that showed complete patency. Eight out of 27 three-segment occlusions in group A and only one of 26 in group B showed complete patency. The IFP score improved by 55% in the 45 men in group A, compared with only 30% in the 47 men in group B ( p= 0.002). When both dosages are combined, men showed a greater improvement in IFP score than women (42 versus 29%; p= 0.02). The IFP score improved more in the 20 patients aged more than 60 years in group A than in the 19 patients aged over 60 years of age in group B (61 versus 20%; p= 0.003). No other significant differences in effect were seen on analysis of sub-groups and individual factors (sex, age, presumed age of thrombus and side of thrombosis). In the 77 patients in group A, haemorrhagic complications were less frequent than in the 79 patients in group B (22.1 versus 36.7%; p= 0.054), especially concerning urogenital haemorrhage (6.5 versus 22.8%; p= 0.004). Women were affected more frequently by haemorrhagic complications than men (35.2 versus 26.5%), and the 19 patients aged more than 65 years old were affected more than the 137 younger patients (21.1 versus 13.9%). There were no deaths, and clinically insignificant pulmonary emboli occurred three times. Ultra-high dosage streptokinase shows better and more rapid thrombolytic treatment for popliteal–femoral–iliac venous thromboses and causes fewer haemorrhagic complications than conventional dosage streptokinase. The better effect of ultra-high dosage can be observed particularly for three-segment occlusion as well as in male patients. In older patients, accurate diagnosis is required because of the higher rate of haemorrhagic complications. [ABSTRACT FROM AUTHOR]

Presents a description of two novel DNA-sequencing methods that use DNA hybridization biosensor chips. Study methodology and description of both techniques; Demonstration of how discrimination between complementary an noncomplementary sequences can be obtained during hybridization of DNA to oligodeoxynucleotides (ODNs) or peptide nucleic acid (PNA); Study findings; Concluding remarks.

Reports on the development of a DNA diagnostic and sequencing system that uses time-of-flight resonance ionization mass spectrometry (TOF-RIMS) to provide a rapid method of analyzing stable isotope-labeled oligonucleotides in form 1 sequencing by hybridization. Major advantage of TOF-RIMS; Determination of detection and hybridization parameters.

Reactions of dimethyl 2‐arylcyclopropane‐1,1‐dicarboxylates, used as representatives of D‐A cyclopropanes, with tropothione were carried out in the presence of scandium triflate as a catalyst, under mild conditions (CH2Cl2 solution, rt). The anticipated (8+3)‐cycloaddition products, cycloheptatriene fused thiopyrans, were obtained in good to excellent yields. Cycloadditions occurred with complete diastereoselectivity and in all cases single diastereomers were formed. Structures of isolated cycloadducts were established based on spectroscopic data and in two cases they were unambiguously confirmed by single crystal X‐ray diffraction analysis. In contrast to an analogous (8+3)‐cycloaddition reported for parent tropone, which was performed in the presence of Ni(ClO4)2, no 1,3‐H shift leading to products possessing a CH2 moiety located within the seven‐membered ring was observed. [ABSTRACT FROM AUTHOR]

Optical emission spectroscopy has been established as a simple method for simultaneous etch rate determination and endpoint detection in ion beam etching. During the sputtering of a thin layer with a refractive index different from the substrate interference is detected in the reflected light emitted by excited beam particles. This method will be very useful for other plasma and beam-assisted processes too, like deposition, reactive ion etching, and reactive ion beam etching. In contrast to the conventional methods, no additional light source is required. [ABSTRACT FROM AUTHOR]

Surface modification of indium tin oxide (ITO) electrodes with organic molecules is known to tune their work function which results in higher charge carrier selectivity in corresponding organic electronic devices and hence influences the performance of organic solar cells. In recent years, N‐heterocyclic carbenes (NHCs) have also been proven to be capable to modify the work function of metals and semimetals compared to the unfunctionalized surface via the formation of strong covalent bonds. In this report, we have designed and performed the modification of the ITO surface with NHC by using the zwitterionic bench stable IPr‐CO2 as the NHC precursor, applied via spin coating. Upon modification, the work function of ITO electrodes was reduced significantly which resulted in electron selective contacts in corresponding organic photovoltaic devices. In addition, various characterization techniques and analytical methods are used to elucidate the nature of the bound species and the corresponding binding mechanism of the material to the ITO surface. [ABSTRACT FROM AUTHOR]

Time-of-flight secondary ion mass spectrometry is one of the most promising techniques for label-free analysis of biomolecules with nanoscale spatial resolution. However, high-resolution imaging of larger biomolecules such as phospholipids and peptides is often hampered by low yields of molecular ions. Matrix-enhanced SIMS (ME-SIMS), in which an organic matrix is added to the sample, is one promising approach to enhancing the ion yield for biomolecules. Optimizing this approach has, however, been challenging because the processes involved in increasing the ion yield in ME-SIMS are not yet fully understood. In this work, the matrix α-cyano-4-hydroxycinnamic acid (HCCA) has been combined with cluster primary ion analysis to better understand the roles of proton donation and reduced fragmentation on lipid molecule ion yield. A model system consisting of 1:100 mol ratio dipalmitoylphosphatidylcholine (DPPC) in HCCA as well as an HCCA-coated mouse brain cryosection have been studied using a range of Bi and Ar cluster ions. Although the molecular ion yield increased with an increase in cluster ion size, the enhancement of the signals from intact lipid molecules decreased with an increase in cluster ion size for both the model system and the mouse brain. Additionally, in both systems, protonated molecular ions were significantly more enhanced than sodium and potassium cationized molecules for all of the primary ions utilized. For the model system, the DPPC molecular ion yield was increased by more than an order of magnitude for all of the primary ions studied, and fragmentation of DPPC was dramatically reduced. However, on the brain sample, even though the HCCA matrix reduced DPPC fragmentation for all of the primary ions studied, the matrix coating suppressed the ion yield for some lipids when the larger cluster primary ions were employed. This indicated insufficient migration of the lipids into the matrix coating, so that dilution by the matrix overpowered the enhancement effect. This study provides strong evidence that the HCCA matrix both enhances protonation and reduces fragmentation. For imaging applications, the ability of the analytes to migrate to the surface of the matrix coating is also a critical factor for useful signal enhancement. This work demonstrates that the HCCA matrix provides a softer desorption environment when using Bi cluster ions than that obtained using the large gas cluster ions studied alone, indicating the potential for improved high spatial resolution imaging with ME-SIMS. [ABSTRACT FROM AUTHOR]

Presents information on a study which detected collision induced dissociation processes occurring in ion beams extracted from source plasmas. Methods; Results; Discussion.

High spatial resolution mass spectrometry imaging has been identified as a key technology needed to improve understanding of the chemical components that influence antibiotic resistance within biofilms, which are communities of micro-organisms that grow attached to a surface. Time-of-flight secondary ion mass spectrometry (ToF–SIMS) offers the unique ability for label-free 3D imaging of organic molecules with sub-micrometer spatial resolution and high sensitivity. Several studies of biofilms have been done with the help of ToF–SIMS, but none of those studies have shown 3D imaging of antibiotics in native-state hydrated biofilms with cell-level resolution. Because ToF–SIMS measurements must be performed in a high-vacuum environment, cryogenic preparation and analysis are necessary to preserve the native biofilm structure and antibiotic spatial distribution during ToF–SIMS measurements. In this study, we have investigated the penetration of the antibiotic ciprofloxacin into Bacillus subtilis biofilms using sub-micrometer resolution 3D imaging cryo-ToF–SIMS. B. subtilis biofilms were exposed to physiologically relevant levels of ciprofloxacin. The treated biofilms were then plunge-frozen in liquid propane and analyzed with ToF–SIMS under cryogenic conditions. Multivariate analysis techniques, including multivariate curve resolution (MCR) and inverse maximum signal factor (iMSF) denoising, were used to aid analysis of the data and facilitate high spatial resolution 3D imaging of the biofilm, providing individually resolved cells and spatially resolved ciprofloxacin intensity at "real world" concentrations. [ABSTRACT FROM AUTHOR]

Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is one of the most important techniques for chemical imaging of nanomaterials and biological samples with high lateral resolution. However, low ionization efficiency limits the detection of many molecules at low concentrations or in very small volumes. One promising approach to increasing the sensitivity of the technique is by the addition of a matrix that promotes ionization and desorption of important analyte molecules. This approach is known as matrix-enhanced secondary-ion mass spectrometry (ME-SIMS). We have investigated the effect of matrix acidity on molecular ion formation in three different biomolecules. A series of cinnamic acid based matrixes that vary in acidity was employed to systematically investigate the influence of matrix acidity on analyte ion formation. The positive ion signal for all three biomolecules showed a strong increase for more acidic matrixes. The most acidic matrix was then vapor-deposited onto mouse brain sections. This led to significant enhancement of lipid signals from the brain. This work indicates that proton donation plays an important role in the formation of molecular ions in ME-SIMS. [ABSTRACT FROM AUTHOR]

Mass mortalities of juvenile Pacific oysters ( Crassostrea gigas ) in aquaculture operations have been linked to the ostreid herpes virus 1 (OsHV-1) or its variants. This oyster has heritable resilience to the virus which can provide a basis for selective breeding for higher OsHV-1 resistance, however, controlled challenge methods for improving selection response towards increased OsHV-1 resistance are required. The objective of this study was to compare the survival of sibling juvenile oysters exposed to either a laboratory virus challenge or a heat shock challenge (as proxy for the virus challenge) and the survival of the same families on two oyster farms where they were exposed to natural field conditions including the presence of OsHV-1. A strong correlation between the family rankings was observed for the two farm sites. Estimated narrow sense heritabilities (h 2 ) on the underlying liability scale were 0.38 (on-farm survival), 0.45 (laboratory virus challenge survival) and 0.15 (heat shock challenge survival). Only on-farm survival and laboratory virus challenge had a high genetic correlation. The method for measuring heat shock resistance in juvenile oysters produced high variability in survival among families but low estimates of heritability. Overall, the results of this study indicate that the laboratory virus challenge is a simple and relatively effective tool for selective breeding specifically towards OsHV-1 resistance or as part of a controlled multi-trait program. Statement of relevance The OsHV-1 virus is a serious problem for commercial aquaculture of Pacific oysters in numerous countries. This paper tests two ways of evaluating oysters for resistance to OsHV-1 that can be incorporated into selective breeding programs. [ABSTRACT FROM AUTHOR]

Broad low-energy ion beams in the energy range of 0.2 to 1.5 kev originating from a filament source with argon as feed gas have been analyzed by high-resolution emission spectroscopy. The Doppler structure of Ar[sup +] emissions reveals the existence of different velocity classes. Besides slow ions and ions possessing the main beam energy, electronically excited Ar[sup +] ions with twice the main beam energy are detected which are attributed to a single-electron capture process in Ar[sup ++]/Ar collisions. As a preliminary result from a reactive beam extracted from a microwave CFa source, plasma fast F atoms are detected which are attributed to charge exchange and dissociative collisions in the process chamber. [ABSTRACT FROM AUTHOR]

Aquaculture is a global-scale industry providing sustainable production of protein-rich foods required to feed the growing world population. Microalgae cultivation in aquaculture bioreactors can exude extracellular polymeric substances leading to biofouling of culture infrastructure and increased algal disease risk. A structure–behaviour relationship was developed by examining how the surface wettability of a range of functional nanocoatings impacts the extent of biofouling during exposure to continuous microalgae culture under normal hydrodynamic conditions. High-wetting (hydrophilic) surfaces were found to reduce biofouling better than water-repelling (hydrophobic) surfaces. Low toxicity in conjunction with antifouling behaviour was found for pulsed plasma poly(4-vinylpyridine) coated bioreactor surfaces (water contact angle = 38 ± 5°) towards the marine microalgal species Chaetoceros calcitrans, Chaetoceros mulleri , and Tisochrysis lutea (T- Iso), which are commonly grown as aquaculture food. [Display omitted] • Nanocoatings are fabricated with varying surface wetting. • A structure–behaviour relationship correlates surface wetting to extent of biofouling during microalgae culture exposure. • High wetting (hydrophilic) surfaces are better at reducing biofouling compared to water repelling (hydrophobic) surfaces. • Most effective are non-toxic pulsed plasma poly(4-vinylpyridine) nanocoatings. [ABSTRACT FROM AUTHOR]

Missions to planetary bodies require innovative techniques for the in situ investigation of their surfaces, especially when landings are planned. Therefore, Raman spectroscopy as an excellent laboratory tool for rapid mineralogical analysis of both terrestrial and extraterrestrial rocks has been successfully proposed for the investigation of planetary surfaces. Examples are the Raman laser spectrometer (RLS) of the joint ESA and Roscosmos mission ExoMars 2022 as well as Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals (SHERLOC) and SuperCam onboard NASA's Mars2020 Perseverance Rover; another is the Raman spectrometer for Martian Moons eXploration (MMX) (RAX), which is being developed for the in situ exploration of the Mars' moon Phobos. When preparing such space missions, it is essential to be prepared for all possible outcomes, such as samples exhibiting space weathering (SW). In this work, we study the influence of micrometeorite bombardment on bodies without atmosphere as one trigger of SW. This type of SW effect is simulated with an excimer laser irradiating the investigated samples with an energy density of ~2.5 J/cm2 for each pulse. As possible components on Phobos, we investigated the silicates olivine (Fo91) and pyroxene (En87) and their mixtures with Raman spectroscopy before and after laser irradiation. Surprisingly, the characteristic Raman bands of the individual minerals in the spectra are not influenced by this kind of SW. On the other hand, the fluorescence‐dominated background signal induced by laser irradiation is reduced, possibly due to the formation of nanophase Fe, which then facilitates a better interpretation of the individual mineral peaks. [ABSTRACT FROM AUTHOR]

Seven male Labrador retriever puppies from four different litters were identified with a brachycephalic-like face and skull, associated with low birth weight, severe growth retardation, and reduced abilities to crawl and suckle, which were not compatible with survival. Excessive doming of the cranium, brachygnathia superior and inferior, and an abnormally opened fontanelle were found in all affected puppies by computed tomography and at post-mortem examination. Pedigree analysis supported an X-linked recessive mode of inheritance. [ABSTRACT FROM AUTHOR]

A model alkane molecule, triacontane, is used to assess the effects of condensed gold and silver nanoparticles on the molecular ion yields upon atomic (Ga+ and In+) and polyatomic (C60+ and Bi3+) ion bombardment in metalassisted secondary ion mass spectrometry (MetA-SIMS). Molecular films spin-coated on silicon were metallized using a sputter-coater system, in order to deposit controlled quantities of gold and silver on the surface (from o to 15 nm equivalent thickness). The effects of gold and silver islets condensed on triacontane are also compared to the situation of thin triacontane overlayers on metallic subsirates (gold and silver). The results focus primarily on the measured yields of quasi-molecular ions, such as (M - H)+ and (2M -2H)+, and metal-cationized molecules, such as (M + Au)+ and (M + Ag)+, as a function of the quantity of metal on the surface. They confirm the absence of a simple rule to explain the secondary ion yield improvement in MetA-SIMS. The behavior is strongly dependent on the specific projectile/metal couple used for the experiment. Under atomic bombardment (Ga+, In+), the characteristic ion yields an increase with the gold dose up to ∼6 mn equivalent thickness. The yield enhancement factor between gold-metallized and pristine samples can be as large as ∼70 (for (M - H)+ under Ga+ bombardment; 10 nm of Au). In contrast, with cluster projectiles such as Bi3+ and C60+, the presence of gold and silver leads to a dramatic molecular ion yield decrease. Cluster projectiles prove to be beneficial for triacontane overlayers spin-coated on silicon or metal substrates (Au, Ag) but not in the situation of MetA-SIMS. The fundamental difference of behavior between atomic and cluster primary ions is tentatively explained by arguments involving the different energy deposition mechanisms of these projectiles. Our results also show that Au and Ag nanoparticles do not induce the same behavior in MetA-SIMS of Iriacontane. The microstructures of the metallized layers are also different. While metallic substrates provide higher yields than metal islet overlayers in the case of silver, whatever the projectile used, the situation is reversed with gold. [ABSTRACT FROM AUTHOR]

Abstract: The relationship between surface chemistry and morphology of flame treated low-density polyethylene (LDPE) was studied by various characterization techniques across different length scales. The chemical composition of the surface was determined on the micrometer scale by X-ray photoelectron spectroscopy (XPS) as well as with time of flight secondary ion mass spectrometry (ToF-SIMS), while surface wettability was obtained through contact angle (CA) measurements on the millimeter scale. The surface concentration of hydroxyl, carbonyl and carboxyl groups, as a function of the “number” of the flame treatment passes (which is proportional to the treatment time) was obtained. Moreover, a correlation was found with chemical composition and polarity, emphasizing the role of oxygen-containing functional groups introduced during the treatment. Carboxyl functional groups were specifically identified by fluorescent labeling and the results were compared with the ToF-SIMS data. In addition, atomic force microscopy (AFM) was used to evaluate changes in surface topography and roughness on the nanometer to micrometer length scales. After flame treatment, water-soluble low molecular weight oxidized materials (LMWOM), which were generated as products of oxidation and chain scission of the LDPE surface, agglomerated into small topographical mounds that were visible in the AFM micrographs. After rinsing the flame treated samples with water and ethanol, bead-like nodular surface structures were observed. The ionization state of flame treated LDPE surfaces was monitored by chemical force microscopy (CFM). The effective surface pK a values of carboxylic acid (–COOH) obtained by AFM were revealed by chemical force titration curves and the effective surface pK a values were found to be around 6. [Copyright &y& Elsevier]

Abstract: In the brain, glucose is transported by GLUT1 across the blood–brain barrier and into astrocytes, and by GLUT3 into neurons. In the present study, the expression of GLUT1 and GLUT3 mRNA and protein was determined in adult neural stem cells cultured from the subventricular zone of rats. Both mRNAs and proteins were coexpressed, GLUT1 protein being 5-fold higher than GLUT3. Stress induced by hypoxia and/or hyperglycemia increased the expression of GLUT1 and GLUT3 mRNA and of GLUT3 protein. It is concluded that adult neural stem cells can transport glucose by GLUT1 and GLUT3 and can regulate their glucose transporter densities. [Copyright &y& Elsevier]

Abstract: Porous lightweight materials have found increasing interest for various applications. Regular structured cellular materials might be accessible by sintering the hollow metallic particles. The properties of the final product depend to a large extent on the properties of original hollow metallic particles. Therefore, the preparation of reliable hollow spheres of defined parameters represents an important step towards the cellular solids production by means of powder metallurgy route. Electrochemical deposition of metallic coatings on the surface of hollow spherical particles facilitates the required modification of the surface corresponding to high mechanical quality. The copper hollow spheres were created on porous iron powder particles by electroless deposition. The suitable matrix for the preparation of relatively light but mechanically strong porous materials was obtained by electrochemical plating of copper hollow micro-particles by Ni layer. In this study ToF-SIMS depth profiling and SEM/EDX analysis with elements mapping are used to investigate the distribution of the coating components across the surface and subsurface layer of coated hollow particles. [Copyright &y& Elsevier]

Abstract: Microcolumn liquid chromatography (μHPLC) coupled on-line with time of flight secondary ion mass spectrometry (ToF-SIMS) was applied for mixture of diterpenoic acids (abietic, gibberellic and kaurenoic) analysis. Chromatographic effluent, with analytes separated, was carried out directly onto different, ToF-SIMS compatible surface substrates, for further ToF-SIMS analysis. Silica gel Si60, aluminium backplate modified Si60, monolithic silica gel and Raman spectroscopy chromatographic thin layers were used as the deposition substrates in this experiment. By ToF-SIMS surface imaging the deposition trace picture has been obtained. Effluent deposition surface area was scanned for diterpenoic acid fragment mass values based on mass spectrometric library. Measured ToF-SIMS dataset of fragment abundance and intensities were used for preliminary fragmentation schemes construction. The lowest substrate background activity has been established for monolithic silica gel thin layer and aluminium backplate modified Si60 thin layer. In the case of Raman spectroscopy pre-treated thin layer or conventional chromatographic thin layer Si60, the both, high background signal intensity and impossibility to construct negative ions surface image, were observed. Diterpenoic acids studied serve the similar mass spectrum but ToF-SIMS coupled with liquid chromatographic separation brings new impact to the positive identification of analytes studied. [Copyright &y& Elsevier]

Strongly confined NaVO+ segregation and its thermoresponsive functionality at the interface between simple sputter‐deposited amorphous vanadium oxide thin films and soda‐lime glass is substantiated in this work by in situ temperature‐controlled time‐of‐flight secondary‐ion mass spectrometry (ToF‐SIMS). The obtained ToF‐SIMS depth profiles provide unambiguous evidence for a reversible transformation that causes systematic switching of the NaVO+/Na+ and Na+/VO+ intensities upon cycling the temperature between 25 and 340 °C. Subsequently, NaVO complexes are found to be reversibly formed (at 300 °C) in vanadium oxide‐diffused glass, leading to thermoresponsive electrical behavior of the thin‐film glass system. This new segregation and diffusion‐dependent multifunctionality of NaVO+ point toward applications as an advanced material for thermoelectrical/optical switches, in smart windows or in thermal sensors. [ABSTRACT FROM AUTHOR]

Describes the identification of DYS385 allele variants by using shorter amplicons and haplotype data in Northern Thailand. Sequence of the locus; DYS385 haplotype frequencies in Northern Thais; Comparison of most frequent DYS385 haplotypes in various populations.

Introduction. – Necrobiotic xanthogranuloma is a rare cutaneous disorder usually associated with monoclonal gammapathy. We describe two new cases.Exegesis. – A 70-year-old patient was affected by a monoclonal gammopathy. She presented with a diplopia related to a retro-orbital tumor. The biopsy showed inflammatory lesions. Five years later, inflammatory xanthomatous skin lesions appeared. Biopsy specimens gave the diagnosis of necrobiotic xanthogranuloma. A 70-year-old woman was referred for inflammatory cutaneous lesions. Clinical, biological investigations and skin biopsies led to the diagnosis of cutaneous sarcoidosis associated with monoclonal gammopathy. Four years later, she developed a nephrotic syndrome. New skin biopsy specimens showed a necrobiotic xanthogranuloma.Conclusion. – Necrobiotic xanthogranuloma is a systemic disease. It is a rare non-Langerhans cell histiocytosis characterized by frequent cutaneous and ophthalmologic lesions and associated with monoclonal gammopathy. To our knowledge, retro-orbital involvement has never been reported in necrobiotic xanthogranuloma. Treatment is difficult. [ABSTRACT FROM AUTHOR]