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Low‐molecular weight (MW) solvent‐borne functional (meth)acrylic polymers find an important use in coating resins. However, when preparing such polymers through copper‐mediated reversible‐deactivation radical polymerization (RDRP), contamination with colored copper species and the use of expensive ligands represent significant obstacles from the industrial application viewpoint. Here, we investigated the possibilities of diminishing the catalyst levels in metallic coper‐mediated RDRP (Cu(0)‐RDRP) and atom transfer radical polymerization (ATRP) of a widely used functional monomer, glycidyl methacrylate (GMA), targeting a low MW of approximately 3000. Both Cu wire‐ and powder‐catalyzed Cu(0)‐RDRP provided well‐defined, low‐MW poly(GMA) at quantitative conversions when using an inexpensive PMDETA ligand in DMSO. However, only with Cu powder, the contamination of the final polymerization mixture with Cu species could be efficiently diminished to ≤66 ppm while maintaining the polymerization control. Additionally, the in situ block copolymerization was successfully demonstrated, furnishing a poly(GMA)‐b‐poly(MMA) mixture containing only 39 ppm of Cu in a process facilitated by the intrinsic reductive properties of the GMA's epoxide groups. Significantly, the targeted low‐MW poly(GMA) could also be synthesized by low‐catalyst‐concentration ATRP (CuBr/PMDETA system), obtaining well‐defined polymers with quantitative conversions at ca 50 ppm of Cu in the final mixture, both at r.t. and 50 °C.

The LancetCommission on pollution and health reported that pollution was responsible for 9 million premature deaths in 2015, making it the world's largest environmental risk factor for disease and premature death. We have now updated this estimate using data from the Global Burden of Diseases, Injuriaes, and Risk Factors Study 2019. We find that pollution remains responsible for approximately 9 million deaths per year, corresponding to one in six deaths worldwide. Reductions have occurred in the number of deaths attributable to the types of pollution associated with extreme poverty. However, these reductions in deaths from household air pollution and water pollution are offset by increased deaths attributable to ambient air pollution and toxic chemical pollution (ie, lead). Deaths from these modern pollution risk factors, which are the unintended consequence of industrialisation and urbanisation, have risen by 7% since 2015 and by over 66% since 2000. Despite ongoing efforts by UN agencies, committed groups, committed individuals, and some national governments (mostly in high-income countries), little real progress against pollution can be identified overall, particularly in the low-income and middle-income countries, where pollution is most severe. Urgent attention is needed to control pollution and prevent pollution-related disease, with an emphasis on air pollution and lead poisoning, and a stronger focus on hazardous chemical pollution. Pollution, climate change, and biodiversity loss are closely linked. Successful control of these conjoined threats requires a globally supported, formal science–policy interface to inform intervention, influence research, and guide funding. Pollution has typically been viewed as a local issue to be addressed through subnational and national regulation or, occasionally, using regional policy in higher-income countries. Now, however, it is increasingly clear that pollution is a planetary threat, and that its drivers, its dispersion, and its effects on health transcend local boundaries and demand a global response. Global action on all major modern pollutants is needed. Global efforts can synergise with other global environmental policy programmes, especially as a large-scale, rapid transition away from all fossil fuels to clean, renewable energy is an effective strategy for preventing pollution while also slowing down climate change, and thus achieves a double benefit for planetary health.

Parameters of epoxy can be effectively improved using polymer-grafted GO. This study reveals so far unknown structure-directing performance of single- and bimodally-grafted GO in impact-modified epoxy. Bimodal grafting leads to formation of lamellae with less ordered more distant GO and fair mobility of grafted dissimilar chains due to their repulsive interactions, resulting in favourable effect on mechanical properties of epoxy.Unlike single-grafted GO with aligned plates, this ordering is not disturbed by added rubber which is more markedly incorporated even as layered domains into lamellae. Formation of more complex structures controlled by grafting geometry was also found. Structure–properties relationships indicate low contribution of added rubber, both as single inclusions or incorporated into ordered GO domains, which confirms high effectivity of lamellar structure with linked polymer chains of relatively high mobility.

Lincosamides are clinically important antibiotics originally produced as microbial specialized metabolites. The complex biosynthesis of lincosamides is coupled to the metabolism of mycothiol as a sulfur donor. Here, we elucidated the N-deacetylation of the mycothiol-derived N-acetyl-l-cysteine residue of a lincosamide intermediate, which is comprised of an amino acid and an aminooctose connected via an amide bond. We purified this intermediate from the culture broth of a deletion mutant strain and tested it as a substrate of recombinant lincosamide biosynthetic proteins in the in vitroassays that were monitored via liquid chromatography–mass spectrometry. Our findings showed that the N-deacetylation reaction is catalyzed by CcbIH/CcbQ or LmbIH/LmbQ proteins in celesticetin and lincomycin biosynthesis, respectively. These are the first N-deacetylases from the TldD/PmbA protein family, from which otherwise only several proteases and peptidases were functionally characterized. Furthermore, we present a sequence similarity network of TldD/PmbA proteins, which suggests that the lincosamide N-deacetylases are unique among these widely distributed proteins.

Fatigue behavior of A356 aluminum alloy for motorcycle rim was experimentally investigated based on T6 heat treatment and artificial aging. The high speed of 1,100 rpm from centrifugal casting was used in this study. The pouring temperature at 750 °C was employed and the preheated temperature at 250 °C was applied on the mold. The solution heat treatment of the sample was conducted for 4 hours at 540 o C before it immersed into the water for rapid cooling at room temperature. This step followed by natural aging treatment at 30 °C and artificial aging treatment at 150 °C, 175 °C, and 200 °C for 2 hours, respectively. It is found that increasing centrifugal casting speed into 1,100 rpm combined with heat treatment and artificial aging temperature can significantly increase not only its mechanical properties but also the fatigue life of motorcycle wheel made of A356 aluminum alloy. This experiment proved that the lowest fatigue crack growth rate obtained with this method was at temperature of 175°C.

Antitumor pyrrolobenzodiazepines (PBDs), lincosamide antibiotics, quorum-sensing molecule hormaomycin, and antimicrobial griselimycin are structurally and functionally diverse groups of actinobacterial metabolites. The common feature of these compounds is the incorporation of l-tyrosine- or l-leucine-derived 4-alkyl-l-proline derivatives (APDs) in their structures. Here, we report that the last reaction in the biosynthetic pathway of APDs, catalyzed by F420H2-dependent Apd6 reductases, contributes to the structural diversity of APD precursors. Specifically, the heterologous overproduction of six Apd6 enzymes demonstrated that Apd6 from the biosynthesis of PBDs and hormaomycin can reduce only an endocyclic imine double bond, whereas Apd6 LmbY and partially GriH from the biosyntheses of lincomycin and griselimycin, respectively, also reduce the more inert exocyclic double bond of the same 4-substituted Δ1-pyrroline-2-carboxylic acid substrate, making LmbY and GriH unusual, if not unique, among reductases. Furthermore, the differences in the reaction specificity of the Apd6 reductases determine the formation of the fully saturated APD moiety of lincomycin versus the unsaturated APD moiety of PBDs, providing molecules with optimal shapes to bind their distinct biological targets. Moreover, the Apd6 reductases establish the first F420H2-dependent enzymes from the luciferase-like hydride transferase protein superfamily in the biosynthesis of bioactive molecules. Finally, our bioinformatics analysis demonstrates that Apd6 and their homologues, widely distributed within several bacterial phyla, play a role in the formation of novel yet unknown natural products with incorporated l-proline-like precursors and likely in the microbial central metabolism.

The redox behavior and chemisorption of cysteamine (CA) at a charged mercury surface are described, with an emphasis on its acid–base properties supported by molecular dynamics and quantum mechanical calculations. It was found that CA forms chemisorbed layers on the surface of the mercury electrode. The formation of Hg-CA complexes is connected to mercury disproportionation, as reflected in peaks SII and SI at potentials higher than the electrode potential of zero charge (p.z.c.). Both the process of chemisorption of CA and its consequent redox transformation are proton-dependent. Also, depending on the protonation of CA, the formation of typical populations of chemisorbed conformers can be observed. In addition, cystamine (CA disulfide dimer) can be reduced on the mercury surface. Between the potentials of this reduction and peak SI, the p.z.c. of the electrode used can be found. Furthermore, CA can serve as an LMW catalyst for hydrogen evolution. The mechanistic insights presented here can be used for follow-up research on CA chemisorption and targeted modification of other metallic surfaces.

Anticancer pyrrolobenzodiazepines (PBDs) are one of several groups of natural products that contain unusual 4-alkyl-l-proline derivatives (APDs) in their structure. APD moieties of PBDs are characterized by high structural diversity achieved through unknown biosynthetic machinery. Based on LC-MS analysis of culture broths, feeding experiments, and protein assays, we show that APDs are not incorporated into PBDs in their final form as was previously hypothesized. Instead, a uniform building block, 4-propylidene-l-proline or 4-ethylidene-l-proline, enters the condensation reaction. The subsequent postcondensation steps are initiated by the introduction of an additional double bond catalyzed by a FAD-dependent oxidoreductase, which we demonstrated with Orf7 from anthramycin biosynthesis. The resulting double bond arrangement presumably represents a prerequisite for further modifications of the APD moieties. Our study gives general insight into the diversification of APD moieties of natural PBDs and provides proof-of-principle for precursor directed and combinatorial biosynthesis of new PBD-based antitumor compounds.

The interaction between a double-hydrophilic comb copolymer with the polyanionic backbone poly[methacrylic acid-stat-poly(ethylene glycol) methyl ether methacrylate] (PMAA–PEGMA) and the cationic surfactant N-dodecylpyridinium chloride (DPCl) was studied in alkaline aqueous solutions by using a combination of light and X-ray scattering techniques, covering 5 orders of magnitude in space (the qvector range from 10–5to 5 nm–1) and time (from milliseconds to several hours). The results showed that the polyelectrolyte–surfactant (PE–S) complex of PMAA–PEGMA and DPCl forms micrometer-sized coacervate particles containing collapsed PMAA–PEGMA chains with attached and densely packed DPCl micelles. Time-resolved SAXS measurements coupled with a stopped-flow apparatus revealed that the phase separation of the PE–S complex into a coacervate phase occurred in <25 ms after mixing the polyelectrolyte and the surfactant. Thus, microphase separation was faster than the self-assembly of DPCl into densely packed micelles. The terminal stages of polyelectrolyte–surfactant coacervation were dictated by the Ostwald ripening of the droplets in the time range of hours.

What are the factors that determine how long a person chooses to listen to an unfamiliar piece of music? We examined this question across three experiments in which we played participants novel repeating multi-instrument stimuli and recorded their listening times and reasons for their decisions to either continue or stop listening. To influence the habituating effects of repeating musical material drawn from a large stimulus library (> 450 items), we manipulated novelty along several musical dimensions. In Experiment 1, all instruments entered simultaneously. In Experiment 2, instrument entrances were also offset in time. In Experiment 3, we composed core multi-instrument loops and manipulated them to further minimize harmonic variability, minimize rhythmic variability, introduce spatialization, or change timbral characteristics. Novelty introduced by instrument entrances was the strongest determinant of listening times, though harmonic variability and timbral features were also important. Subjective enjoyment was the best predictor of listening times, mediating the effects of the degree of perceived groove in a stimulus, the urge to move, interest in a stimulus, perceived complexity, and congruency with current mood. We conclude that naturalistic looping musical stimuli serve well to examine the diverse psychological and musical determinants of choice behavior underlying music consumption.

Background: Pulmonary embolism (PE) is a possible noncardiac cause of cardiac arrest. Mortality is very high, and often diagnosis is established only by autopsy. Methods: In a retrospective study, we analyzed clinical presentation, diagnosis, therapy, and outcome of patients with cardiac arrest after PE admitted to the emergency department of an urban tertiary care hospital. Results: Within 8 years, PE was found as the cause in 60 (4.8%) of 1246 cardiac arrest victims. The initial rhythm diagnosis was pulseless electrical activity in 38 (63%), asystole in 19 (32%), and ventricular fibrillation in 3 (5%) of the patients. Pronounced metabolic acidosis (median pH, 6.95, and lactate level, 16 mmol/L) was found in most patients. In 18 patients (30%), the diagnosis of PE was established only postmortem. In 42 (70%) it was diagnosed clinically, in 24 of them the diagnosis of PE was confirmed by echocardiography. In 21 patients, 100 mg of recombinant tissue-type plasminogen activator was administered as thrombolytic treatment, and 2 (10%) of these patients survived to hospital discharge. Comparison of patients of the thrombolysis group (n=21) with those of the nonthrombolysis group (n=21) showed a significantly higher rate of return of spontaneous circulation (81% vs 43%) in the thrombolysis group (P=.03). Conclusions: Mortality related to cardiac arrest caused by PE is high. Echocardiography is supportive in determining PE as the cause of cardiac arrest. In view of the poor prognosis, thrombolysis should be attempted to achieve return of spontaneous circulation and probably better outcome. Arch Intern Med. 2000;160:1529-1535

Pulmonary embolism is a great masquerader. It presents with numerous non-specific signs and symptoms that may mimic a variety of other clinical conditions. Once pulmonary embolism is suspected diagnostic and [...]

Right ventricular function is an important prognostic factor for pulmonary embolism. (1) Massive pulmonary embolism may lead to right ventricular failure, reduced left ventricular output, and even death. (2) Cardiac [...]

Carbon has unique and desirable properties for use in applications such as fuel cells and batteries. The properties can vary widely depending on its structure and surface characteristics. Two types of carbon, a synthetic graphite produced from petroleum coke and an extruded graphite rod, were characterized using Raman spectroscopy and X-ray Photoelectron spectroscopy and the features were correlated with electrochemical properties of the material. The graphite rod was found to have a more disordered structure, greater sp3 character, and a greater surface oxygen content as compared to the synthetic graphite from coke. Our results show that the characteristics of electrodeposited platinum and polyaniline depend on the type of substrate; the preferable carbon for producing composite materials for catalyst applications is the graphite from petroleum coke.

Our purpose was to analyze evidence related to timing of cooling from studies of targeted temperature management (TTM) after return of spontaneous circulation (ROSC) after cardiac arrest and to recommend directions for future therapy optimization. We conducted a preliminary review of studies of both animals and patients treated with post-ROSC TTM and hypothesized that a more rapid cooling strategy in the absence of volume-adding cold infusions would provide improved outcomes in comparison with slower cooling. We defined rapid cooling as the achievement of 34°C within 3.5 hours of ROSC without the use of volume-adding cold infusions, with a ≥3.0°C/hour rate of cooling. Using the PubMed database and a previously published systematic review, we identified clinical studies published from 2002 through 2014 related to TTM. Analysis included studies with time from collapse to ROSC of 20–30 minutes, reporting of time from ROSC to target temperature and rate of patients in ventricular tachycardia or ventricular fibrillation, and hypothermia maintained for 20–24 hours. The use of cardiopulmonary bypass as a cooling method was an exclusion criterion for this analysis. We compared all rapid cooling studies with all slower cooling studies of ≥100 patients. Eleven studies were initially identified for analysis, comprising 4091 patients. Two additional studies totaling 609 patients were added based on availability of unpublished data, bringing the total to 13 studies of 4700 patients. Outcomes for patients, dichotomized into faster and slower cooling approaches, were determined using weighted linear regression using IBM SPSS Statistics software. Rapid cooling without volume-adding cold infusions yielded a higher rate of good neurological recovery than slower cooling methods. Attainment of a temperature below 34°C within 3.5 hours of ROSC and using a cooling rate of more than 3°C/hour appear to be beneficial.

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The measurements of np-spin observables at $0^\circ$have been performed for the first time on the Delta-Sigma experimental facility of LHE JINR up to Pn=4.5 GeV/c using the monochromatic neutron beam. They include detailed measurements of the $\Delta\sigma_{\rm L}(np)$spin differences and the study of the $np\to pn$elastic charge-exchange process. In the $\Delta\sigma_{\rm L}(np)$and $-\Delta\sigma_{\rm L}({\rm I}=0)$energy dependencies over the energy region T$_{\rm kin}=1.2$–3.7 GeV the peculiarity at 1.8 GeV was observed. Such energy behavior was predicted by the QCD approach as a signal of the $NN\!\to 6q$phase transition. For the exhaustive investigation of this effect it is necessary to measure the energy dependence of the complete set of npobservables with both longitudinal (L) and transverse (T) polarizations of the neutron beam and proton target. This will allow Direct Reconstruction of all three NNforward Scattering Amplitudes (DRSA) to be performed, and the observed peculiarity to be checked around T$_{\rm kin}=1.8$GeV and at the higher energies using the Argand diagrams method.

Magnesium alloy AZ 91 is widely used as a structural material, but its use is limited at higher temperatures and high humidity. Plasma spraying technology allows to prepare protective metallic and nonmetallic coatings on magnesium and its alloys. In this study magnesium alloy AZ 91 was coated using plasma spraying method by AlSi30 wt. % and silicon. The Al-Si was applied to provide a bond-coat for topmost layer of silicon. This study focused on feeding distance (FD) on the quality of the prepared layers. The layers were prepared with a thickness of about 100 μm. The layers were observed with a scanning electron microscope with elemental map analysis. The layers were measured by Electrochemical impedance spectroscopy.

The experience of groove is associated with the urge to move to a musical rhythm. Here we focus on the relevance of audio features, obtained using music information retrieval (MIR) tools, for explaining the perception of groove and music-related movement. In Study 1 we extracted audio features from clips of real music previously rated on perceived groove. Measures of variability, such as the variance of the audio signal’s RMS curve and spectral flux (particularly in low frequencies), predicted groove ratings. Additionally, we dissociated two forms of event density, showing that an algorithm that emphasizes variability between beats predicted groove ratings better. In Study 2 we manipulated RMS levels and groove category (low, mid, and high groove) to confirm that perceived groove is not a function of loudness. In Study 3 we utilized novel music clips that manipulated the frequency of bass and bass drum (low vs. high) and attack time (short vs. long). Groove ratings and tapping velocities tended to be higher and tapping variability tended to be lower when the bass instruments had lower frequencies. The present findings emphasize the multifaceted nature of groove by linking audio and musical qualities to subjective experience and motor behavior.

Tungsten is currently considered as the most suitable plasma facing material for the first wall of a nuclear fusion reactor. First wall will be subjected to harsh conditions that will gradually deteriorate properties of the wall material. Some studies point out that fine-grained tungsten could be more resistant to the structure and property changes than coarse-grained tungsten. However, tailoring of tungsten microstructure is very laborious. Due to its high melting point, tungsten is very often processed mechanically and subsequently sintered into a compact body. In this study, preparation of ultrafine-grained tungsten by mechanical processing in a planetary ball mill was examined. Three types of tungsten samples were compared. One was made from coarse grained tungsten powder consolidated by SPS (spark plasma sintering). Other two samples were prepared from the powder processed in a planetary ball mill with and without addition of Y2O3. After ball milling, the powders were consolidated by SPS, i.e. fast sintering process that allows preserving fine-grained structure of the powder material. Properties of the samples such as hardness and thermal conductivity were examined and correlated with the processing history and microstructure.

The direct georeferencing technique in aerial photogrammetry using micro Unmanned Aerial Vehicles (UAV) is not commonly used against indirect approach due to high requirements of equipment and calibration. On the other hand this technique brings several advantages which can be beneficial in some applications. This paper deals with the development and testing of precise multi-sensor system for the direct georeferencing of aerial imagery. The system consist of dual-antenna Real Time Kinematic (RTK) Global Navigation Satellite System (GNSS) receiver with centimeter level accuracy and Inertial Navigation System (INS) which fuses inertial and position information to provide accurate navigation and orientation data in real time. Special attention is paid to the time synchronization of various sensor data and lever arm correction. 3D print technology was used to achieve low weight and high modularity of the system which can be easily modified and mounted to different types of UAVs. This paper also describes a test flight mission and the processing workflow from the data acquisition to the import of georeferenced orthophoto to a Geographic Information System (GIS).

ABSTRACTThe ABCF family protein Msr(A) confers high resistance to macrolides but only low resistance to ketolides in staphylococci. Mutations in conserved functional regions of ClpX as well as deletion of clpXsignificantly increased Msr(A)-mediated resistance to the ketolide antibiotic telithromycin. ClpX is the chaperone component of the ClpXP two-component proteolytic system. Nevertheless, no changes in resistance were observed in a clpPknockout strain expressing msr(A), demonstrating that ClpX affects Msr(A) independently of ClpP.

We previously showed that prolonged cardiac arrest (CA) produces neuronal death with microglial proliferation. Microglial proliferation, but not neuronal death, was attenuated by deeper hypothermia. Microglia are reportedly a major source of cytokines. In this study, we tested the hypotheses that (1) CA will result in highly specific regional and temporal increases in brain cytokines; and (2) these increases will be attenuated by deep hypothermia. Adult male Sprague-Dawley rats were subjected to rapid exsanguination. After 6 minutes of normothermic no-flow, different levels of hypothermia were induced by either ice-cold (IC) or room-temperature (RT) aortic flush. After 20 minutes CA, rats were resuscitated with cardiopulmonary bypass (CPB), and sacrificed at 6 or 24 hours. Rats subjected to CPB only (without CA) and shams (no CPB or CA) served as controls (n=6 per group). Cytokines were analyzed in cerebellum, cortex, hippocampus, and striatum. Immunofluorescence was used to identify cell types associated with individual cytokines. Intra-CA temperature was lower after IC versus RT flush (21°C vs. 28°C, p<0.05). At 6 hours, striatum showed a massive increase in interleukin (IL)-1α and tumor necrosis factor-alpha (TNF-α) (>100-fold higher than in hippocampus), which was attenuated by deeper hypothermia in the IC versus RT group. In contrast, IL-12 was 50-fold higher in hippocampus versus striatum. At 24 hours, cytokines decreased. In striatum, IL-1α colocalized with astrocytes while TNF-α colocalized with neurons. In hippocampus, IL-12 colocalized with hippocampal hilar neurons, the only region where neuronal degeneration was observed at 24 hours at both IC and RT groups. We report important temporo-spatial differences in the brain cytokine response to hypothermic CA, with a novel role of striatum. Astrocytes and neurons, but not microglia colocalized with individual cytokines. Hypothermia showed protective effects. These neuroinflammatory reactions precede neuronal death. New therapeutic strategies may need to target early regional neuroinflammation.

A low-cost, thin, graphitized carbon electrode with electrodeposited platinum and polyaniline has been characterized for electrochemical oxidation of aliphatic alcohols in alkaline medium and for possible further incorporation of atomic metals and alloys. Our previously developed atomic metal polyaniline composites used solid platinum as the electrode material. The replacement of this solid platinum with a small amount of electrochemically annealed Pt on a carbon support was optimized for alcohol oxidation. An HPLC procedure for analysis of oxidation products of 1-propanol has also been utilized for the characterization of the composite electrode.

ABSTRACTDetailed mutational analysis examines the roles of individual residues of the Vga(A) linker in determining the antibiotic resistance phenotype. It defines a narrowed region of residues 212 to 220 whose composition determines the resistance specificity to lincosamides, pleuromutilins, and/or streptogramins A. From the analogy with the recently described function of the homologous ABC-F protein EttA as a translational factor, we infer that the Vga(A) linker interacts with the ribosome and directly or indirectly affects the binding of the respective antibiotic.

Theoretically predicted effect of odd-even pattern of electron pairing on behavior of gold clusters in polyaniline/AuN (N = 0 to 8) has been confirmed experimentally. In these composites the atomic Au clusters with even number of atoms exhibit higher catalytic activity for electrochemical oxidation of n-propanol in 1 M NaOH than the odd-number atoms clusters. Also, infrared spectroscopy shows that even numbered PANI/AuN composites affect the N-H stretching vibration more strongly than the corresponding odd numbered ones. This behavior matches the theoretically predicted variations of HOMO-LUMO gap energy and the stability of the atomic Au clusters. It also agrees with the earlier experimental work in which the UPS spectra of isolated, mass-selected Au clusters have been reported.

AbstractA microirradiator is a radiation tool with a low amount of total activity but high flux density due to its small active area. The solid state calibrator is designed to be a bench-top detection device in conjunction with the microirradiator for ease of detection and calibration of the source. Results indicate that the device is more accurate and precise during longer measurements, and the addition of liquid scintillation cocktail with plastic scintillation increases the efficiency of detection. Ni-63 is commonly measured by a liquid scintillation cocktail due to the low energy (67 keV max.) beta electrons emitted. Here we report the assembly and calibration of a solid state scintillation device to detect and measure total activity vs.liquid scintillation of Ni-63.

Atom-by-atom deposition of gold into polyaniline (PANI) through a repeated cyclic pathway has been reported previously by us. It was noticed that the efficiency of the preparation was complicated by concurrent oxidative degradation of PANI in the course of the gold deposition process, resulting in the loss of the deposited matrix. The primary objective of this research was to minimize the loss of the matrix by separating the PANI degradation and the atomic gold deposition parts of the cycle. The overoxidation of PANI was performed as a preconditioning step, prior to the gold deposition cycles. The FTIR spectra obtained after preconditioning on the stabilized PANI film show that the imine attachment sites for the chloroaurate anion are still available" The presence of the deposited gold on the cyclic voltammograms of the PANI film could be easily observed. The work function of the prepared composite films increased linearly with the logarithm of number of gold deposition cycles.

Polyaniline (PANI) has been an effective matrix for hosting and preserving metal nanoclusters. In the case of gold, the tetrachloroaurate anion has a high affinity for the imine sites of PANI. Upon contact with PANI, is spontaneously reduced to metallic gold, but the size of the formed Au clusters cannot be precisely controlled. Herein, we report on the electrochemical method of controlled deposition of one atom by one atom of gold per imine site of PANI. By controlling the potential, we keep PANI in an oxidized state while exposing it to a solution of to form a complex, which is reduced to atomic gold by sweeping the potential negative. This frees up the imine sites of PANI again and makes them accessible for the next Au deposition cycle. The repeated deposition of Au atoms follows a cyclic pathway. The amount of gold deposited using this method is consistent for each repeated cycle.

See alsoLevi M. Disseminated intravascular coagulation or extended intravascular coagulation in massive pulmonary embolism. This issue, pp 1475–6; Thachil J. DIC score predicts mortality in massive clot coagulopathy as a result of extensive pulmonary embolism: a rebuttal. This issue, pp 1657–8; Leitner JM, Janata‐Schwatzek K, Spiel AO, Sterz F, Laggner AN, Jilma B. DIC score predicts mortality in massive clot coagulopathy as a result of extensive pulmonary embolism: reply to a rebuttal. This issue, pp 1658–9.

ABSTRACTThe lincomycin biosynthetic gene lmbXwas deleted in Streptomyces lincolnensisATCC 25466, and deletion of this gene led to abolition of lincomycin production. The results of complementation experiments proved the blockage in the biosynthesis of lincomycin precursor 4-propyl-l-proline. Feeding this mutant strain with precursor derivatives resulted in production of 4′-butyl-4′-depropyllincomycin and 4′-pentyl-4′-depropyllincomycin in high titers and without lincomycin contamination. Moreover, 4′-pentyl-4′-depropyllincomycin was found to be more active than lincomycin against clinical Staphylococcusisolates with genes determining low-level lincosamide resistance.

This tutorial article deals with work function, the thermodynamics of its chemical modulation and utilization of measuring work function as the analyte response in chemical sensors. Equilibrium potentiometry at zero current can be classified either as Nernstian or work function. In the Nernstian an integer charge is transferred between two phases and the interfacial potential is related to the activity of the principal transferring ion. In sensors that rely on modulation of the work function a charge transfer complex is formed as a result of the donor/acceptor interaction between the gas molecule and the electronic conductor. Although the governing equations are remarkably similar, their origin, their mechanism, and the operating principles are fundamentally different. The author suggests that the future of gas sensing lies in miniaturization and multisensor operation with sensing arrays made of work function-based field effect transistors.

Here we report the fabrication of two types microirradiators, consisting of recessed disk and protruding wire with low beta-energy radionuclide Ni-63 electrodeposited onto 25 um diameter Pt wire. Ni-63 is confined to a small surface area of the microelectrode; hence, this tool provides a means of delivery of localized, large dose density of beta radiation to the object, but a minimal dose exposure to the user. The activity levels of Ni-63 emitted from the recessed disk and protruding wire are of 0.25 and 1 Bq, respectively. The corresponding beta particles flux levels emitted from the recessed disk and protruding wire are of 51 and 11 kBq/cm2, respectively. These values, measured experimentally using liquid scintillation counting, fit very well the expected values of activity for each microirradiator, calculated considering the self-absorption effect, typical for low energy beta particles. In order to determine the optimal configuration the dose rates for varying distances from the object were calculated.

The electrochemical deposition of a novel N-substituted polypyrrole, 1-pyrrolyl-10-decanephosphonic acid, is presented. The properties of the film are found to be highly dependent on the potential range used during deposition. Self-terminated growth of a thin, non-conducting layer is observed when using anodic switching potentials of at least 1.8 V versus Ag/AgI. At anodic potentials between 1.5 V and 1.8 V, growth of a conducting polymer layer is possible, although, continued growth results in increased resistance of the film and gradual transition to a non-conducting state. A long-lived intermediate formed during the oxidation of the monomer is observed. Reduction of this intermediate, resulting in changes in the cyclic voltammogram, occurs at c.a. 400 mV. Fourier Transform Infrared Spectroscopy of the film confirms the presence of the tethered phosphonates in the film. In aqueous solution the insulating films are permeable to Ru(NH3)62+/ Ru(NH3)63+ but impermeable to Fe(CN)63-/ Fe(CN)64-.

A new technique for using quartz crystal microbalance (QCM) in magnetic field is described. This technique takes advantage of the sensitive nature of QCM to load changes. The idea is to perturb the oscillations of a QCM with deposited magnetic materials by applying magnetic field. A new instrument called magnetic QCM (MQCM) has been constructed to explore this technique. Past MQCM investigations have shown that QCM frequency and phase responds to magnetic nano-dispersions in elastic non-magnetic matrix and also to alternating layers of ferromagnetic and diamagnetic materials. We have found that this type of alternating multilayer structure on QCM is very sensitive to weak magnetic fields.

Properties of chemically sensitive field effect transistor (CHEMFET) sensor fabricated using variable proportion of room temperature ionic liquids (ILs) as an additive to polyaniline (PANI) doped with camphorsulphonic acid (CSA) have been examined as a gel-hybrid sensitive material. Almost 60 % increase in sensitivity to ammonia gas was observed after the addition of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide ([BMIM][Tf2N]) and tetrahexyl ammonium bis(trifluoromethane-sulfonyl)amide ([THA][Tf2N]). Also a considerable improvement in response time of CHEMFET to NH3 was observed with PANI[?]CSA gate material containing 0.68 or 0.76 mole fraction of [BMIM][Tf2N].

Chemical synthesis of 1-pyrrolyl-10-decanephosphonic acid (PyDPA) from pyrrole and the electrochemical polymerization of PyDPA in methylene chloride under potentiodynamic and potentiostatic conditions are reported. It is found that the electrochemical window used during polymerization affects the properties of the film. Potentiodynamic polymerization at anodic switching potentials of results in thin , overoxidized films, analogous to those obtained by overoxidation of polypyrrole. During potentiodynamic polymerization using anodic switching potentials between 1.55 and , the polymer undergoes a conducting-to-insulating transition. The amount of polymer deposited before the onset of passivation is shown to increase with decreasing anodic switching potential; therefore, film thickness, density, and electronic properties can be tuned. Both conducting and insulating films show cation permselectivity when cycling in but rejection of , regardless of thickness. Deposition at constant potential results in more reproducible film depositions and greater control over film properties.

Field‐effect transistors with mixed ionic‐electronic conductors have been prepared by varying the ratio of room temperature ionic liquid and emeraldine salt of polyaniline. Transistor with sufficiently high electronic conductivity (32 mol% ES‐PANI) and Au gate contact exhibited theoretical behavior of insulated gate field‐effect transistor. On the other hand the purely ionic gate behaved irreproducibly, indicating that a capacitive divider has been formed in the gate.

The product of spontaneous termination formed after addition of one or two tBuA units onto living PMMA chains in the MMAtBuA block copolymerization was isolated and characterized by SEC, UV, FTIR, Raman and NMR spectroscopy. It appears as a lowmolecularweight peak in SEC eluograms of the copolymers, absorbing at 260 nm; its retention time corresponds to that of the PMMA block. In its FTIR and Raman spectra, new bands appeared corresponding to the CC and CO vibrations of a conjugated and Hbonded ester group of the enol form of the cyclic oxoester composed of MMA and tBuA units. Experimental support of a backbiting reaction at the link between PMMA and PtBuA blocks is presented.

Abstract: The measurements of np-spin observables at 0° have been performed for the first time on the Delta-Sigma experimental facility of LHE JINR up to P n = 4.5 GeV/c using the monochromatic neutron beam. They include detailed measurements of the Δσ L(np) spin differences and the study of the np → pn elastic charge-exchange process. In the Δσ L(np) and −Δσ L(I = 0) energy dependencies over the energy region Tkin = 1.2–3.7 GeV the peculiarity at 1.8 GeV was observed. Such energy behavior was predicted by the QCD approach as a signal of the NN → 6q phase transition. For the exhaustive investigation of this effect it is necessary to measure the energy dependence of the complete set of np observables with both longitudinal (L) and transverse (T) polarizations of the neutron beam and proton target. This will allow Direct Reconstruction of all three NN forward Scattering Amplitudes (DRSA) to be performed, and the observed peculiarity to be checked around Tkin = 1.8 GeV and at the higher energies using the Argand diagrams method.