The cellulose pyrolysis processes under the individual and synergistic effects of CaO and K2HPO4∙3H2O were studied by the thermogravimetric-mass spectrometric analysis (TG-MS) technique, mainly focusing on the changes of some important products such as CH4 during the pyrolysis process under different conditions. The experimental results showed that after the addition of CaO, the amounts of CO, CH4, and other species decreased. CaO could fix the “CO2-like reactive intermediate” produced during the cellulose pyrolysis process, thus reducing the evolution of CO2 in the temperature range of 300–440°C and continuing the CO2 evolution in the temperature range of 520–710°C. When K2HPO4∙3H2O was added, the amounts of CO, CH4, CO2, and other gaseous species increased, indicating that K2HPO4∙3H2O could significantly change the pyrolysis reaction process, such as promoting the benzene ring formation reactions involving small molecules such as toluene. When the mixture of CaO and K2HPO4∙3H2O was added, the weight loss at the initial stage of pyrolysis was relatively moderate compared to that adding K2HPO4∙3H2O alone. At the same time, an obvious weight loss appears in the pyrolysis process in the temperature range of 600–770°C, and the amounts of various species generated increased compared to those generated in the single catalytic pyrolysis. Therefore, CaO and K2HPO4∙3H2O exhibited a strong synergistic effect in the pyrolysis process.
The direct deoxygenation effect of CaO on bio-oil from cellulose pyrolysis was studied in a series of drop tube experiments together with gas chromatography-mass spectrometry analysis. The oxygen contents of the bio-oils were found to decrease from 44.4% for CaO-free cellulose to 40.7% when the CaO/cellulose mass ratio (R) was 2. The relative variation of the oxygen content of the bio-oils reached –8.4% for this mass ratio. The relative abundance of levoglucosan decreased sharply from 85.72 to 42.75% with an increase of R from 0 to 2. The decrease of the relative abundance of levoglucosan and an increase of the relative abundance of acetol and other small molecule products indicated a dominant shift of the parallel competitive reactions from the glycosidic bond rupture pathway to the decomposition and reforming route. The direct fixation of active quasi-CO2 intermediates, functioning as a ‘chemical sink’ in the decomposition and reforming route, caused this shift.
GP135 is an apical membrane protein expressed in polarized MDCK epithelial cells. When cultured in three-dimensional collagen gel, MDCK cells form branching tubules in response to hepatocyte growth factor stimulation in a manner that simulates the embryonic renal development. During this process, GP135 displays transient loss of membranous localization but reappears at the cell surface when nascent lumen emerges from the developing tubules. Despite being used for decades as the canonical hallmark of apical surface, the molecular identity and the significance of the dynamic expression of GP135 during the tubulogenic process remain elusive. For exploring the function of GP135, the full-length cDNA encoding GP135 was obtained. Sequence alignments and features analysis confirm GP135 as a canine homolog of podocalyxin, confirming the finding of an earlier independent study. Immunohistochemical assays on canine kidney sections identified both glomerular and tubular distribution of GP135 along the nephron. Mutant MDCK cells expressing siRNA targeted at two regions of GP135 show defects in hepatocyte growth factor-induced tubulogenesis. Re-expression of full-length and an O-linked glycosylation abbreviated construct of GP135 could recapitulate the tubulogenesis process lacking in siRNA knockdown cells; however, a deletion construct devoid of the cytoplasmic domain failed to rescue the phenotype. In summary, the data identify the MDCK apical domain marker GP135 as a tubular form of podocalyxin and provide evidence for its importance in renal tubulogenesis.
Abstract Evaporation deposition of a spilt sugary drop on the supporting surface can attract ants to surround it. People have a long history of using this phenomenon as an implication of sugar in the drop. Unfortunately, it is hard to detect sugar concentration and has to depend exclusively on ants. Here, we show a facile strategy for the eye‐naked detection on sugar concentrations in common liquid mixtures, based on their evaporation depositions. Our experiments show that evaporation drops without any sugar form clear ring‐like depositions, and the width of the ring area enlarges with the increase in sugar concentration. We demonstrate that the increase in sugar concentration can increase the liquid viscosity and decrease the capillary flow velocity, thus weakening the “coffee ring” effect. Our further experiments indicate that the temperature has insignificant effects on the correlation between sugar concentrations and ring‐like depositions, but the substrate wettability impacts on the correlation by promoting the formation of ring‐like depositions. Based on the mechanism study, we develop a strategy for detecting sugar concentrations via quantitatively correlating them with the width of the ring area, and demonstrate that it is valid for various liquid mixtures, for example, carbonate beverage, liquid medicine, and plant nutrient. Our findings not only present new insights into the understanding of the sugary drop evaporation, but also provide a facile strategy of detecting sugar concentration that promises great applications in food safety, pharmaceutical detection, and agricultural product measurements.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)
'/%3e%3cuse xlink:href='%23a' transform='rotate(60)'/%3e%3ccircle r='17' fill='%23000095'/%3e%3ccircle r='15' fill='%23fff'/%3e%3c/svg%3e)