Search

Imaging the visual systems of bumblebees and other pollinating insects may increase understanding of their dependence on specific habitats and how they will be affected by climate change. Current high-resolution imaging methods are either limited to two dimensions (light- and electron microscopy) or have limited access (synchrotron radiation x-ray tomography). For x-ray imaging, heavy metal stains are often used to increase contrast. Here, we present micron-resolution imaging of compound eyes of buff-tailed bumblebees (Bombus terrestris) using a table-top x-ray nanotomography (nano-CT) system. By propagation-based phase-contrast imaging, the use of stains was avoided and the microanatomy could more accurately be reconstructed than in samples stained with phosphotungstic acid or osmium tetroxide. The findings in the nano-CT images of the compound eye were confirmed by comparisons with light- and transmission electron microscopy of the same sample and finally, comparisons to synchrotron radiation tomography as well as to a commercial micro-CT system were done., QC 20220301

For ensuring the operation of the mechanisms at high temperatures and pressures, it is necessary to use both stable base oils and effective additives in the composition of the lubricants. In the research, antioxidative and anticorrosive properties were identified in the oils of the condensation products of the alkylphenols with paraformaldehyde and thiocyanic acid polymer. The condensation products of the 5­amino­1,2,4­dithiazole­3­thione (Xanthane Hydride) with the 2,6­di­tert­Butylphenol and paraformaldehyde were investigated. A mixture of the products was obtained in the solution of the glacial acetic acid where the ratio of the 5­amino­1,2,4­dithiazole­3­thione and 2,6­di­tert­Butylphenol fragments is 1:1 and 1:3, respectively.An assumption about the structure of the substances was set up on the basis of the chemical and spectral data. For the compound with the empirical formula C19H27N2O(3–5)S3 the structure containing a residue of the 2,6­di­tert­Butylphenol and one heterocyclic fragment was proposed. For the compound with the empirical formula C43H65N2O(3–5)S3 the structure containing three residues of the 2,6­di­tert­Butylphenol was proposed. It was found that the products with a high content of the 2,6­di­tert­Butyphenol residues dissolve in the oils best of all. It was also found that alkylphenol derivatives of the thiocyanic acid and Xanthane Hydride are promising inhibitors of the corrosion and oxidation of the fuels and lubricants. The technique of the 5­amino­1,2,4­dithiazole­3­thione synthesis was improved. It was determined that it is better to synthesize it by treating an aqueous solution of the ammonium thiocyanate with the concentrated hydrochloric acid (instead of the sulfuric acid) in equimolar proportions at the temperature of 5–15 C. At the same time, the output of the aim product does not decrease and it can be easier purified., Визначені антиокиснювальні та протикорозійні властивості в оливах продуктів конденсації алкілфенолів з параформом і полімером тіоціанової кислоти. Досліджено продукти конденсації 5-аміно-1,2,4-дитіазол-3-тіону (ксантангідриду) з 2,6-ди-третбутилфенолом і параформом. Зокрема, у розчині льодяної оцтової кислоти утворюється суміш продуктів, у яких співвідношення фрагментів ксантангідриду і 2,6-ди-третбутилфенолу становить 1:1 та 1:3. На основі хімічних і спектральних даних зроблено припущення щодо будови речовин. Встановлено, що найлегше розчиняються в оливах продукти з високим умістом 2,6-ди-третбутильних залишків., Определены антиокислительные и антикоррозионные свойства в маслах продуктов конденсации алкилфенолов с параформом и полимером тиоциановой кислоты. Исследованы продукты конденсации 5-амино-1,2,4-дитиазол-3-тиона (ксантангидрида) с 2,6-ди-третбутилфенолом и параформом. В частности, в растворе ледяной уксусной кислоты образуется смесь продуктов, в которых соотношение фрагментов ксантангидрида и 2,6-ди-третбутилфенола составляет 1:1 и 1:3. Основываясь на химических и спектральных данных, высказано предположение о строении веществ. Установлено, что лучше всего в маслах растворяются продукты с высоким содержанием 2,6-ди-третбутильных остатков.

BackgroundCharacterising the correlates of HIV persistence improves understanding of disease pathogenesis and guides the design of curative strategies. This study investigated factors associated with integrated HIV-1 DNA load during consistently suppressive first-line antiretroviral therapy (ART).MethodTotal, integrated, and 2-long terminal repeats (LTR) circular HIV-1 DNA, residual plasma HIV-1 RNA, T-cell activation markers, and soluble CD14 (sCD14) were measured in peripheral blood of 50 patients that had received 1-14 years of efavirenz-based or nevirapine-based therapy.ResultsIntegrated HIV-1 DNA load (per 10(6) peripheral blood mononuclear cells) was median 1.9 log10 copies (interquartile range 1.7-2.2) and showed a mean difference of 0.2 log10 copies per 10 years of suppressive ART (95% confidence interval - 0.2, 0.6; p = 0.28). It was positively correlated with total HIV-1 DNA load and frequency of CD8(+)HLA-DR/DP/DQ(+) cells, and was also higher in subjects with higher sCD14 levels, but showed no correlation with levels of 2-LTR circular HIV-1 DNA and residual plasma HIV-1 RNA, or the frequency of CD4(+)CD38(+) and CD8(+)CD38(+) cells. Adjusting for pre-ART viral load, duration of suppressive ART, CD4 cell counts, residual plasma HIV-1 RNA levels, and sCD14 levels, integrated HIV-1 DNA load was mean 0.5 log10 copies higher for each 50% higher frequency of CD8(+)HLA-DR/DP/DQ(+) cells (95% confidence interval 0.2, 0.9; p = 0.01).ConclusionsThe observed positive association between integrated HIV-1 DNA load and frequency of CD8(+)DR/DP/DQ(+) cells indicates that a close correlation between HIV persistence and immune activation continues during consistently suppressive therapy. The inducers of the distinct activation profile warrant further investigation.

BackgroundCharacterising the correlates of HIV persistence improves understanding of disease pathogenesis and guides the design of curative strategies. This study investigated factors associated with integrated HIV-1 DNA load during consistently suppressive first-line antiretroviral therapy (ART).MethodTotal, integrated, and 2-long terminal repeats (LTR) circular HIV-1 DNA, residual plasma HIV-1 RNA, T-cell activation markers, and soluble CD14 (sCD14) were measured in peripheral blood of 50 patients that had received 1-14 years of efavirenz-based or nevirapine-based therapy.ResultsIntegrated HIV-1 DNA load (per 10(6) peripheral blood mononuclear cells) was median 1.9 log10 copies (interquartile range 1.7-2.2) and showed a mean difference of 0.2 log10 copies per 10 years of suppressive ART (95% confidence interval - 0.2, 0.6; p = 0.28). It was positively correlated with total HIV-1 DNA load and frequency of CD8(+)HLA-DR/DP/DQ(+) cells, and was also higher in subjects with higher sCD14 levels, but showed no correlation with levels of 2-LTR circular HIV-1 DNA and residual plasma HIV-1 RNA, or the frequency of CD4(+)CD38(+) and CD8(+)CD38(+) cells. Adjusting for pre-ART viral load, duration of suppressive ART, CD4 cell counts, residual plasma HIV-1 RNA levels, and sCD14 levels, integrated HIV-1 DNA load was mean 0.5 log10 copies higher for each 50% higher frequency of CD8(+)HLA-DR/DP/DQ(+) cells (95% confidence interval 0.2, 0.9; p = 0.01).ConclusionsThe observed positive association between integrated HIV-1 DNA load and frequency of CD8(+)DR/DP/DQ(+) cells indicates that a close correlation between HIV persistence and immune activation continues during consistently suppressive therapy. The inducers of the distinct activation profile warrant further investigation.

Protocols for characterizing cellular phenotypes commonly use chemical fixatives to preserve anatomical features, mechanically stabilize tissue, and stop physiological responses. Formaldehyde, diluted in either phosphate-buffered saline or phosphate buffer, has been widely used in studies of neurons, especially in conjunction with dyes and antibodies. However, previous studies have found that these fixatives induce the formation of bead-like varicosities in the dendrites and axons of brain and spinal cord neurons. We report here that these formaldehyde formulations can induce bead formation in the dendrites and axons of adult rat and rabbit retinal ganglion cells, and that retinal ganglion cells differ from hippocampal, cortical, cerebellar, and spinal cord neurons in that bead formation is not blocked by glutamate receptor antagonists, a voltage-gated Na(+) channel toxin, extracellular Ca(2+) ion exclusion, or temperature shifts. Moreover, we describe a modification of formaldehyde-based fixatives that prevents bead formation in retinal ganglion cells visualized by green fluorescent protein expression and by immunohistochemistry.

Reactions of 3-nitro-2-trifluoro(trichloro)methyl-2H-chromenes, including 2-unsubstituted derivatives, with N-alkyl-α-amino acids (sarcosine, proline) and paraformaldehyde proceed diastereoselectively to give 1-benzopyrano[3,4-c]pyrrolidines in good yields as a result of a 1,3-dipolar cycloaddition of the intermediate nonstabilized azomethine ylide at the Δ3-bond of the chromene system. © 2013 Elsevier Ltd. All rights reserved.

The digestion of fixed tissue sections is a critical step in the optimization of any in situ hybridization protocol. We describe a novel application of microwave oven heating to optimize mRNA detection in paraformaldehyde-fixed tissues by in situ hybridization using digoxigenin- labeled probes. This technique replaces protease digestion of fixed tissue sections with 10 min of microwave pretreatment, followed by either conventional hybridization or hybridization involving microwave incubation. This new technique has several advantages over the standard protease treatment-based methods presently in use. (a) Microwave oven heating is a simple, rapid, and highly reproducible technique. (b) Microwave pretreatment significantly increased the hybridization signal and reduced the background compared to conventional protease digestion. Consequently, the hybridization time required to obtain optimal mRNA detection was reduced to 30 min. (c) Ten minutes of microwave pretreatment produced an optimal hybridization signal in six different tissues using a variety of probes, demonstrating the general applicability of this technique. (d) Microwave heating of the probe during the hybridization step itself further reduced the hybridization time and substantially enhanced the hybridization signal obtained from proteinase K- digested tissue. (e) Microwave pretreatment caused no discernible loss of free cell structure and tissue morphology compared to untreated tissue sections. In conclusion, microwave oven heating can replace the complicated strategies and poor reproducibility of protease treatment of tissue sections, resulting in a simple, rapid, more reliable and sensitive method that has general applicability for in situ hybridization.

The digestion of fixed tissue sections is a critical step in the optimization of any in situ hybridization protocol. We describe a novel application of microwave oven heating to optimize mRNA detection in paraformaldehyde-fixed tissues by in situ hybridization using digoxigenin- labeled probes. This technique replaces protease digestion of fixed tissue sections with 10 min of microwave pretreatment, followed by either conventional hybridization or hybridization involving microwave incubation. This new technique has several advantages over the standard protease treatment-based methods presently in use. (a) Microwave oven heating is a simple, rapid, and highly reproducible technique. (b) Microwave pretreatment significantly increased the hybridization signal and reduced the background compared to conventional protease digestion. Consequently, the hybridization time required to obtain optimal mRNA detection was reduced to 30 min. (c) Ten minutes of microwave pretreatment produced an optimal hybridization signal in six different tissues using a variety of probes, demonstrating the general applicability of this technique. (d) Microwave heating of the probe during the hybridization step itself further reduced the hybridization time and substantially enhanced the hybridization signal obtained from proteinase K- digested tissue. (e) Microwave pretreatment caused no discernible loss of free cell structure and tissue morphology compared to untreated tissue sections. In conclusion, microwave oven heating can replace the complicated strategies and poor reproducibility of protease treatment of tissue sections, resulting in a simple, rapid, more reliable and sensitive method that has general applicability for in situ hybridization.

Leishmania donovani promastigotes, the causative agent of visceral leishmaniasis, survive inside macrophages by inhibiting phagosomal maturation. The main surface glycoconjugate on promastigotes, lipophosphoglycan (LPG), is crucial for parasite survival. LPG has several detrimental effects on macrophage function, including inhibition of periphagosomal filamentous actin (F-actin) breakdown during phagosomal maturation. However, in RAW 264.7 macrophages pre-stimulated with lipopolysaccharide (LPS) and interferon ? (IFN?), known to up-regulate inducible nitric oxide synthase (iNOS) and nitric oxide (NO) production, L. donovani promastigotes are unable to inhibit periphagosomal F-actin breakdown and phagosomal maturation proceeds normally. Moreover, the iNOS inhibitor aminoguanidine, blocked the positive effects of LPS/IFN? suggesting that NO is a key player in F-actin remodeling. In conclusion, production of NO by stimulated macrophages seems to allow phagosomal maturation following uptake of L. donovani promastigotes, suggesting a novel mechanism whereby NO facilitates killing of an intracellular pathogen. © 2007 Elsevier Inc. All rights reserved.

We report a simple and reliable method for detection of two or more antigens within tissue sections by indirect immunoenzyme staining using mouse monoclonal antibodies (MAbs). This technique involves treating sections with two 5-min microwave (MW) oven heatings between sequential rounds of three- layer immunoenzyme staining (mouse MAb, goat anti-mouse IgG, and mouse PAP or mouse APAAP) and color development. Discrete staining of cell surface, cytoplasmic, and nuclear antigens was evident within individual cells. This technique has a number of advantages over those currently available. First, MW treatment denatures bound antibody molecules, thereby completely blocking crossreactivity between sequential rounds of staining. This allows the use of primary (and other) antibodies raised in the same species and the use of a sensitive three-layer staining method. Second, antigen retrieval after MW treatment markedly increases the sensitivity of cytoplasmic and nuclear antigen detection. Third, inactivation of peroxidase and alkaline phosphatase enzymes present in PAP and APAAP complexes prevents inappropriate color development. Finally, this method can be used in both paraformaldehyde-fixed cryostat sections and formalin-fixed paraffin tissue sections. In conclusion, this is a simple, reliable, and sensitive technique that will be useful in many areas of diagnosis and research.

We report a simple and reliable method for detection of two or more antigens within tissue sections by indirect immunoenzyme staining using mouse monoclonal antibodies (MAbs). This technique involves treating sections with two 5-min microwave (MW) oven heatings between sequential rounds of three- layer immunoenzyme staining (mouse MAb, goat anti-mouse IgG, and mouse PAP or mouse APAAP) and color development. Discrete staining of cell surface, cytoplasmic, and nuclear antigens was evident within individual cells. This technique has a number of advantages over those currently available. First, MW treatment denatures bound antibody molecules, thereby completely blocking crossreactivity between sequential rounds of staining. This allows the use of primary (and other) antibodies raised in the same species and the use of a sensitive three-layer staining method. Second, antigen retrieval after MW treatment markedly increases the sensitivity of cytoplasmic and nuclear antigen detection. Third, inactivation of peroxidase and alkaline phosphatase enzymes present in PAP and APAAP complexes prevents inappropriate color development. Finally, this method can be used in both paraformaldehyde-fixed cryostat sections and formalin-fixed paraffin tissue sections. In conclusion, this is a simple, reliable, and sensitive technique that will be useful in many areas of diagnosis and research.

Our group has been exploring the synthesis of 1,1-disubstituted monomers and their polymers obtained via the DABCO catalyzed hydroxy-methylation of alkyl acrylates. Previous work in this area has involved complicated or low yield syntheses. We are using a simple, clean synthetic technique using paraformaldehyde and neat substrate to produce alkyl alpha(hydroxymethyl) acrylates, albeit in yields of only 25-30%. Conversion of the hydroxymethyl group with thionyl chloride gives a reactive allyl chloride which allows a wide range of ether forming reactions to be applied. The ether linkage is inherently more stable than the ester linkage and is much more flexible

A series of experiments was conducted to develop effective and economical resin systems to improve dimensional stability of southern hardwood flakeboards. First, boards 0.5 inch thick were made from 3-inch-long flakes of nine species of southern hardwoods. Dimensional stability was measured following 5-hour boil, vacuum-pressure soak, and 50 to 90 percent RH exposure test. Within the range of the experiment, all species except white oak and post oak yielded boards of acceptable dimensional stability at board density of 44.5 pounds per cubic foot or less. To improve dimensional stability, a resorcinol modified phenolic system was developed and tested. To produce a flakeboard of acceptably high durability from wood of high density species, a phenolic alloy of phenol-formaldehyde resin and polyisocyanate was developed., This article is from 'Proceedings of 1980 Symposium 'Wood Adhesives-Research, Application, and Needs' Held at Madison, Wisconsin on 23-25 September 1980', AD-A136 708, p31-41.

Paraformaldehyde powder, depolymerized by heat, produced formaldehyde gas that was effective in sterilizing laboratory rooms, a mobile laboratory trailer, various surfaces, fiberglass filter medium, and specialized laboratory equipment. A sporulating and nonsporulating strain of bacteria, a virus, and a bacterial toxin were used as test agents. The dissemination procedures and equipment, the assay techniques, and the facilities and equipment sterilized were described. (Author), Pub. in Applied Microbiology, v17 n4 p614-618, Apr 1969.

A developer for photographic materials is based on paraformaldehyde and hydroquinone. To increase the contrast of photographic images, P-containing polyalkylene glycols of the formula HO(CH2CH2O)n- (P(O)(OR)O(CH2CH2O)n) where R is alkyl or aryl, n is a whole even number, and x is a whole odd number, are added to the developer., Trans. of Patent (USSR) 253 574 1970.

The object of the invention is a method for obtaining combined mixtures of polyamide with polyformaldehyde which as the distinguishing feature that, for the purpose of obtaining uniform mixtures, the polyformaldehyde is dissolved in the monomer of polyamide and then the polymer is subjected to polymerization. (Author), Unedited rough draft trans. of Russian Patent 166 829, appl. no. 825008/23-5, 14 Mar 63.