Study of Tribological Properties of Fullerenol and Nanodiamonds as Additives in Water-Based Lubricants for Amorphous Carbon (a-C) Coatings

The tribological performances of fullerenol and nanodiamonds (NDs) as additives in water-based lubricants for amorphous carbon (a-C) coatings are investigated to avoid disadvantage factors, such as chemical reactions and deformation of particles. The effects of size and additive amount on tribological properties of nanoparticles are studied by rigid nanoparticles within the dot size range. The results show that owing to its small particle size (1–2 nm), fullerenol cannot prevent direct contact of the friction pair at low concentration conditions. Only when the quantity of fullerenol increased to support the asperity contact loads in sufficient concentration did nano-bearings perform well in anti-friction and anti-wear effects. Unlike fullerenol, nanodiamond particles with a diameter of about 5–10 nm show friction-reducing effect based on the nano-bearing effects at ultra-low concentration (0.01 wt.%), whereas particles at higher concentration block the rolling movement, hence increasing the coefficient of friction (COF) and wear. As a result of the effect of difference in size, fullerenol provides a better overall lubrication, but it is hard to reach a friction coefficient as low as NDs even under the optimal conditions.

Simple Serum Pancreatic Ductal Adenocarcinoma (PDAC) Protein Biomarkers—Is There Anything in Sight?

A poor PDAC prognosis is due to a lack of effective treatment and late diagnosis. The early detection of PDAC could significantly decrease mortality and save lives. Idealbiomarkers for PDAC should be cost-effective, detectable in easily accessible biological material, and present in sufficient concentration in the earliest possible phase of the disease. This review addresses newly selected, simple protein biomarkers—new ones such as thrombospondin-2, insulin-linked binding protein 2, lysophosphatidic acid, and autotaxin and conventional ones such as Ca19-9, inflammatory factors, and coagulation factors. Their possible use in the early detection of PDAC, differentiation from benign diseases, prognosis, and treatment response prediction is discussed. We also address the usefulness of possible combinations of biomarkers in diagnostic panels.

DETECTION OF SOMATIC MUTATIONS IN THE BRAF GENE BY PYROSEQUENCING

Introduction. Detection of somatic mutations in the BRAF gene can be used in clinical oncology to clarify the diagnosis, select therapy and assess the prognosis of the disease. Pyrosequencing technology makes it possible to identify both already known and new mutations, as well as to determine the mutant allele ratio in the sample.The aim of the study was to develop the pyrosequencing-based method for detecting mutations in 592–601 codons of the BRAF gene.Material and Methods. The nucleotide sequences were obtained using «PyroMark Q24» instrument. The sensitivity and specificity of the method were estimated using dilutions of plasmid DNA samples containing the intact BRAF gene fragment mixed with sequence containing one of the mutations V600E, V600R, V600K, V600M, and K601E. The clinical testing was performed on 200 samples from thyroid nodules.Results. The developed method makes it possible to determine samples containing 2 % of the mutant allele for mutations V600K and V600R, 3 % for V600E and V600M, and 10 % for K601E. The pyrogram signal values for samples without mutations ranged from 0 to 19.5 % for different mutations. An analysis algorithm was developed to confirm the presence and differentiation of mutations in the 600 codon at a low proportion of the mutant allele based on the signals ratio on the pyrogram. The 47 clinical samples with mutations were found, 45 with V600E and 1 with V600_K601>E, for one sample, the type of mutation in the 600 codon could not be determined. The proportion of the mutant allele was 3.5–45 %. The concentration of extracted DNA less than 10 copies per mkl was obtained in 47 samples, of which 8 samples were found to have the mutations.Conclusion. The pyrosequencing-based method was developed for the detection of somatic mutations in 592–601 codons of the BRAF gene. The technique provided sufficient sensitivity to detect frequent mutations in the 600 codon and allowed the detection of rare mutations. Extraction of DNA from clinical samples obtained by fine-needle aspiration biopsy in most cases provided a sufficient concentration of DNA, which made it possible to use the technique in combination with cytological analysis without additional sampling. This approach can be applied to determine somatic mutations in DNA fragments of same length for other oncogenes.

A simple and efficient automated microvolume radiosynthesis of [18F]Florbetaben

Background Current automated radiosynthesizers are generally optimized for producing large batches of PET tracers. Preclinical imaging studies, however, often require only a small portion of a regular batch, which cannot be economically produced on a conventional synthesizer. Alternative approaches are desired to produce small to moderate batches to reduce cost and the amount of reagents and radioisotope needed to produce PET tracers with high molar activity. In this work we describe the first reported microvolume method for production of [18F]Florbetaben for use in imaging of Alzheimer’s disease. Procedures The microscale synthesis of [18F]Florbetaben was adapted from conventional-scale synthesis methods. Aqueous [18F]fluoride was azeotropically dried with K2CO3/K222 (275/383 nmol) complex prior to radiofluorination of the Boc-protected precursor (80 nmol) in 10 μL DMSO at 130 °C for 5 min. The resulting intermediate was deprotected with HCl at 90 °C for 3 min and recovered from the chip in aqueous acetonitrile solution. The crude product was purified via analytical scale HPLC and the collected fraction reformulated via solid-phase extraction using a miniature C18 cartridge. Results Starting with 270 ± 100 MBq (n = 3) of [18F]Fluoride, the method affords formulated product with 49 ± 3% (decay-corrected) yield,> 98% radiochemical purity and a molar activity of 338 ± 55 GBq/μmol. The miniature C18 cartridge enables efficient elution with only 150 μL of ethanol which is diluted to a final volume of 1.0 mL, thus providing a sufficient concentration for in vivo imaging. The whole procedure can be completed in 55 min. Conclusions This work describes an efficient and reliable procedure to produce [18F]Florbetaben in quantities sufficient for large-scale preclinical applications. This method provides very high yields and molar activities compared to reported literature methods. This method can be applied to higher starting activities with special consideration given to automation and radiolysis prevention.

A Simple and Efficient Automated Microvolume Radiosynthesis of [18F]Florbetaben

Background: Current automated radiosynthesizers are generally optimized for producing large batches of PET tracers. Preclinical imaging studies, however, often require only a small portion of a regular batch, which cannot be economically produced on a conventional synthesizer. Alternative approaches are desired to produce small to moderate batches to reduce cost and the amount of reagents and radioisotope needed to produce PET tracers with high molar activity. In this work we describe the first reported microvolume method for production of [18F]Florbetaben for use in imaging of Alzheimer’s disease.Procedures: The microscale synthesis of [18F]Florbetaben was adapted from conventional-scale synthesis methods. Aqueous [18F]fluoride was azeotropically dried with K2CO3/K222 (275/383 nmol) complex prior to radiofluorination of the Boc-protected precursor (80 nmol) in 10 μL DMSO at 130°C for 5 min. The resulting intermediate was deprotected with HCl at 90°C for 3 min and recovered from the chip in aqueous acetonitrile solution. The crude product was purified via analytical scale HPLC and the collected fraction reformulated via solid-phase extraction using a miniature C18 cartridge.Results: Starting with 270 ± 100 MBq (n=3) of [18F]Fluoride, the method affords formulated product with 49 ± 3% (decay-corrected) yield,> 98% radiochemical purity and a molar activity of 338 ± 55 GBq/μmol. The miniature C18 cartridge enables efficient elution with only 150 μL of ethanol which is diluted to a final volume of 1.0 mL, thus providing a sufficient concentration for in vivo imaging. The whole procedure can be completed in 55 min.Conclusions: This work describes an efficient and reliable procedure to produce [18F]Florbetaben in quantities sufficient for large-scale preclinical applications. This method provides very high yields and molar activities compared to reported literature methods. This method can be applied to higher starting activities with special consideration given to automation and radiolysis prevention.

Stability and robustness of asymptotic autocatalytic systems

Here, we address the consequences of the extension in the space of a simple model of a system that is closed to efficient causation: the (M,R)-system model. To do so, we use a diffusion term to describe the collective motion of the nutrients’ concentration across the compartmentalized space that defines the organism. We show that the non-trivial stable steady state remains despite such generalization, as long as the system is small enough to deal with the transport of the precursors to feed the entire protocell and dispose of a sufficient concentration of it in its surroundings. Such consideration explains the emergence of a bifurcation with two parameters that we characterize. Finally, we show that the robustness of the system under catastrophic losses of catalysts also remains, preserving the original’s model character.

Versatile TIM Solution with Chain Network Solder Composite

ABSTRACT A novel epoxy-based SAC solder paste TIM system has been developed with the use of non-volatile epoxy flux. Cu filler was added to the solder paste, with Cu volume % of metal ranged from 17 to 60 volume % of metal. Formation of semi-continuous high melting Cu chain network was achieved, with Cu particles bridged by the CuSn IMC. This chain network, at sufficient concentration, serves as skeleton and maintains the shape of the sandwiched solder paste layer, thus prevents further spread out at subsequent SMT reflow process, and also allowed formation of TIM joint even in the absence of solderable metallization on flip chip and packaging housing. This chain network hampered the flow of liquid solder, thus restrained the expansion of outgassing, and consequently resulted in low voiding. Existence of crevices was attributed to excessive oxide brought in by Cu particles, and appeared to increase with increasing Cu filler content. Presence of ductile solder within TIM joint promises high resistance against brittle cracking under stress. The Cu content could be further optimized between 17 and 33 volume % of metal to avoid flux bleeding and maintain good epoxy adhesion between TIM phase and parts. The 20°C thermal conductivity achieved was 6.1 W/mK, and could be up to about 13 W/mK with further epoxy flux optimization.

Ferro-Self-Assembly: Magnetic and Electrochemical Adaptation of a Multiresponsive Zwitterionic Metalloamphiphile Showing a Shape-Hysteresis Effect

We report on a novel multi-stimuli-responsive amphiphile, 1-(<i>Z</i>)-heptenyl-1’-dimethylammonium-methyl-(3-sulfopropyl)ferrocene<b> </b>(<b>6</b>), whose self-assembly properties can be altered by three different stimuli, namely: (i) the addition of external salts which serve to unfold the sultone headgroup, thus triggering self-assembly of <b>6</b> into vesicles; (ii) oxidation to <b>6⁺</b>, which changes the lipophilic ferrocene to a hydrophilic ferrocenium entity, thereby broadening the size-distribution of the aggregates; and (iii) exposition of <b>6⁺ </b>to an external magnetic field of 0.8 T. Under thease conditions and at sufficient concentration, <b>6</b>^<b>+</b>forms large, tubular aggregates with lengths of up to 15 µm, which persist for over 5 min after the field is switched off again. <b>6⁺</b> is thus the first amphiphile to exhibit a shape-hysteresis effect. The self-assembly/disassembly processes and their dynamics were studied live and in situ by optical birefringence measurements coupled to light scattering. <br>

Ferro-Self-Assembly: Magnetic and Electrochemical Adaptation of a Multiresponsive Zwitterionic Metalloamphiphile Showing a Shape-Hysteresis Effect

We report on a novel multi-stimuli-responsive amphiphile, 1-(<i>Z</i>)-heptenyl-1’-dimethylammonium-methyl-(3-sulfopropyl)ferrocene<b> </b>(<b>6</b>), whose self-assembly properties can be altered by three different stimuli, namely: (i) the addition of external salts which serve to unfold the sultone headgroup, thus triggering self-assembly of <b>6</b> into vesicles; (ii) oxidation to <b>6⁺</b>, which changes the lipophilic ferrocene to a hydrophilic ferrocenium entity, thereby broadening the size-distribution of the aggregates; and (iii) exposition of <b>6⁺ </b>to an external magnetic field of 0.8 T. Under thease conditions and at sufficient concentration, <b>6</b>^<b>+</b>forms large, tubular aggregates with lengths of up to 15 µm, which persist for over 5 min after the field is switched off again. <b>6⁺</b> is thus the first amphiphile to exhibit a shape-hysteresis effect. The self-assembly/disassembly processes and their dynamics were studied live and in situ by optical birefringence measurements coupled to light scattering. <br>

Ozone Gas: Scientific Justification and Practical Guidelines for Improvised Disinfection using Consumer-Grade Ozone Generators and Plastic Storage Boxes.

We describe direct measurements of ozone concentration achievable in small enclosed containers (plastic storage boxes) for use as improvised decontamination systems for small articles such as disposable PPE (N95 masks, nitrile gloves, etc.), clothing, mail and small packages, food, and other miscellaneous articles. The emphasis is on the reliable and sustained generation of ozone gas concentrations of sufficient concentration and duration to create an effective virucidal environment to achieve more than 95% to 99% viral inactivation, based upon the data already published in the peer-review literature on this topic. The suggestion that ozone be used to inactivate virus is certainly not a new idea. Our objective in this report is to make clear that the necessary levels of ozone can be improvised using simple, easy-to-use, inexpensive, and widely available supplies, and that there is every theoretical and experimental reason to believe that this approach is as highly effective in viral inactivation by ozone as are the far more expensive, complex, cumbersome, and less available equivalent ozone (and other) disinfectant systems that have themselves become unavailable during times of pandemic crisis. Using multiple types of readily available commercial ozone generators, concentration in the tested improvised enclosure is tracked over time to assess ozone charging and decay rates, and the ozone quenching effects of items placed in the box. Generator performance is compared against published ozone dosage values for virucidal and antimicrobial activity. Bubbler and box-fan-type ozone generators were found to be effective at achieving and maintaining target concentrations of 10ppm ozone or higher, whereas automotive cigarette lighter and universal serial bus type plug in “air freshener” ozone generators could not achieve the target concentrations in these experiments. Calculations and practical guidelines for assembly and effective use of an ozone box for improvised decontamination are offered. The majority of this report is directed toward the scientific justification and rationale for this approach. The end of the document summarizes the findings and offers simplified designs for the construction and use of ozone boxes as an improvised method of disinfection.