Organic and Inorganic Template Assisted Synthesis of Silica Nanotubes and Evaluation of Its Properties for Drug Targeting

Mesoporous silica network nanotubes were fabricated using both organic and inorganic templates such as citric acid (CA), cetyltrimethylammonium bromide (CTAB), and sodium bicarbonate (SBC). The phase analysis of synthesized silica network was confirmed by X-ray diffractometer (XRD) analysis, and the present functional groups were revealed by Fourier Transformer Infrared Spectroscopy (FTIR) and the formation of tubular morphology was analyzed by Transmission Electron Microscopy (TEM). The mesoporous nature of each template sample was studied using Brunauer–Emmett–Teller (BET) instrument. The surface area and porous size were calculated successfully for fabricated silica network nanotubes.

Nickel-phosphorus-boron amorphous alloy nanotubes improves the selective hydrogenation of furfural to furfuryl alcohol

Ni–P–B (NPB) amorphous alloy nanotubes were prepared for the selective liquid-phase hydrogenation of furfural to furfuryl alcohol. The content of P in NPB amorphous alloy nanotubes was adjusted by the initial NaH2PO2-containing liquid crystal system of non-ionic/anionic mixed surfactants. The promotion effect of an appropriate amount of P was mainly characterized by its large active surface area, ability for greater absorption of H, strong synergistic interaction, better stability, high conversion and catalytic selectivity. The NPB nanotubes exhibited higher hydrogenation activity when compared with the corresponding NPB nanoparticles, which might be dependent on the specific surface area, uniform active sites and tubular morphology of the catalysts.

Outstanding fuel cell performance of a fully platinum-free electrocatalysts using a cost-effective catalyst support material

One of the effective ways to increase the electrocatalytic activity of carbon based electrocatalyst in a fuel cell is by in-situ incorporation of heteroatom into the carbon nanostructure. Herein, a cost effective catalyst support material, nitrogen rich carbon nanostructure (NCNS) with high surface area and tubular morphology was synthesized. NCNS supported palladium-alloy based electrocatalyst (Pd3Co/NCNS) was successfully prepared and used on both sides of a fuel cell as potential alternative to expensive Pt-based electrocatalysts. The large number of nitrogen-carbon moieties present in NCNS served as anchoring sites for catalyst nanoparticles. Moreover, the tubular morphology and high surface area plays an important role in enhanced electrochemical activity of the prepared nanocomposite. The Pd-based bimetallic alloy dispersed on NCNS exhibited high activity towards both oxidation of hydrogen and reduction of oxygen in acidic medium. Thus, a fully Pt-free electrocatalyst was constructed using a cost effective electrocatalyst. The peak power density achieved using Pd3Co/NCNS at both anode and cathode simultaneously was found to be almost 25 % of the maximum power density attained using commercial Pt/C on both sides, which is the maximum value reported so far in PEMFC without using Pt on either side.

REEP3 and REEP4 determine the tubular morphology of the endoplasmic reticulum during mitosis

The endoplasmic reticulum (ER) is extensively remodeled during metazoan open mitosis. However, whether the ER becomes more tubular or more cisternal during mitosis is controversial, and dedicated factors governing the morphology of the mitotic ER have remained elusive. Here, we describe the ER membrane proteins REEP3 and REEP4 as major determinants of ER morphology in metaphase cells. REEP3/4 are specifically required for generating the high-curvature morphology of mitotic ER and promote ER tubulation through their reticulon homology domains (RHDs). This ER-shaping activity of REEP3/4 is distinct from their previously described function to clear ER from metaphase chromatin. We further show that related REEP proteins do not contribute to mitotic ER shaping and provide evidence that the REEP3/4 carboxyterminus mediates regulation of the proteins. These findings confirm that ER converts to higher curvature during mitosis, identify REEP3/4 as specific and crucial morphogenic factors mediating ER tubulation during mitosis, and define the first cell cycle-specific role for RHD proteins.

Myo-inositol oxygenase accentuates renal tubular injury initiated by endoplasmic reticulum stress

Besides oxidant stress, endoplasmic reticulum (ER) stress has been implicated in the pathogenesis of various metabolic disorders affecting the kidney. These two forms of stresses are not mutually exclusive to each other and may operate by a feedback loop in worsening the cellular injury. To attest to this contention, studies were performed to assess whether in such a setting, there is worsening of tubulointerstitial injury. We employed tunicamycin as a model of ER stress and used tubular cells and mice overexpressing myo-inositol oxygenase (MIOX), an enzyme involved in glycolytic events with excessive generation of ROS. Concomitant treatment of tunicamycin and transfection of cells with MIOX-pcDNA led to a marked generation of ROS, which was reduced by MIOX-siRNA. Likewise, an accentuated expression of ER stress sensors, GRP78, XBP1, and CHOP, was observed, which was reduced with MIOX-siRNA. These sensors were markedly elevated in MIOX-TG mice compared with WT treated with tunicamycin. This was accompanied with marked deterioration of tubular morphology, along with impairment of renal functions. Interestingly, minimal damage and elevation of ER stressors was observed in MIOX-KO mice. Downstream events that were more adversely affected in MIOX-TG mice included accentuated expression of proapoptogenic proteins, proinflammatory cytokines, and extracellular matrix constituents, although expression of these molecules was unaffected in MIOX-KO mice. Also, their tunicamycin-induced accentuated expression in tubular cells was notably reduced with MIOX-siRNA. These studies suggest that the biology of MIOX-induced oxidant stress and tunicamycin-induced ER stress are interlinked, and both of the events may feed into each other to amplify the tubulointerstitial injury.

Tubular morphology preservation and doping engineering of Sn/P-codoped hematite for photoelectrochemical water oxidation

Sn/P codoped nanotubular hematite is reported as an anode for improved and robust solar-assisted water oxidation.

Characterization of Seminiferous Epithelium Stages in the Wild Javan Muntjac (Muntiacus muntjak muntjak) Using the Tubular Morphology Method

Stages of the seminiferous epithelium of the testis of the wild Javan muntjac (Muntiacus muntjak muntjak) in hard antler period were characterized based on the tubular morphology method. The number and the relative frequencies of seminiferous epithelium stages and the morphometry of germinal cell nuclei were identified microscopically. We identified eight stages of seminiferous epithelium in testicular tissue of the Javan muntjac and found that the relative frequencies of stages I to VIII were 14.87, 15.12, 17.75, 6.87, 7.37, 12.37, 13, and 12.62%, respectively. The diameter of the nuclei of germinal cells varied in each stage of seminiferous epithelium. Diplotene-stage primary spermatocytes had prominent and large nuclei ~8.97 ± 1.0 μm in stages III and IV. Pachytene primary spermatocytes appeared in most stages, except stage IV, whereas leptotene- and diplotene-stage primary spermatocytes were found in stages I and II, and III and IV, respectively. Round spermatids were observed in stages IV to VIII and in stage I but were absent in stages II and III, while elongated spermatids were observed in all stages except stage I. Our findings show that the stages of seminiferous epithelium in the Javan muntjac are similar to those found in neotropical cervids, small ruminants, and other domestic animals.