Nanocellulose-based fibres derived from palm oil by-products and their in vitro biocompatibility analysis

Abstract

Fibres with nanocellulose isolated from oil palm empty fruit bunches (OPEFBs) were produced. Nanocellulose and PVA-nanocellulose fibres were prepared by wet spinning in an acetone coagulation bath without drawing. The addition of nanocellulose was varied from 10% to 30%, to reveal the beneficial effects of nanocellulose content on the properties of produced spun-fibres. Higher concentration of nanocellulose increased the stiffness of spun-fibres. PVA and PVA-bacterial cellulose fibres were also produced as a control and for comparison, respectively. The nanocellulose fibre formed a compact structure, while PVA fibres had hollow structures. The effect of the produced spun-fibres on the biocompatibility of calf pulmonary artery endothelial cells was assayed by an MTT test. Based on the MTT assay the addition of nanocellulose increased the percentage of cell viability of the obtained spun-fibres slightly. These results point towards the use of sustainable sources of nanocellulose as a beneficial and biocompatible fibre material.     

Carcinosarcoma of the esophagus: three cases with immunohistological examination

Carcinosarcoma of the esophagus is a rare malignant tumor with both carcinomatous and sarcomatous components. We present 3 cases of carcinosarcoma of the esophagus and discuss the histogenesis of the tumors. We performed immunohistochemical studies using various antibodies: anti-cytokeratin, anti-vimentin, anti-smooth muscle actin, anti-p53, and MIB 1 reacting with Ki-67 nuclear antigen.     

Structural and electrical properties of HfO2 with topnitrogen incorporated layer

A novel technique to control the nitrogen profile in HfO₂ gate dielectric was developed using a reactive sputtering method. The incorporation of nitrogen in the upper layer of HfO₂ was achieved by sputter depositing a thin Hf_xN_y layer on HfO₂, followed by reoxidation. This technique resulted in an improved output characteristics compared to the control sample. Leakage current density was significantly reduced by two orders of magnitude. The thermal stability in terms of structural and electrical properties was also enhanced, indicating that the nitrogen-doped process is effective in preventing oxygen diffusion through HfO₂. Boron penetration immunity was also improved by nitrogen-incorporation. It is concluded that the nitrogen-incorporation process is a promising technique to obtain high-k dielectric with thin equivalent oxide thickness and good interfacial quality     

Novel cinnamyl hydroxyamides and 2-aminoanilides as histone deacetylase inhibitors: apoptotic induction and cytodifferentiation activity

Four novel series of cinnamyl-containing histone deacetylase (HDAC) inhibitors 1-4 are described, containing hydroxamate (1 and 3) or 2-aminoanilide (2 and 4) derivatives. When screened against class?I (maize HD1-B and human HDAC1) and class?II (maize HD1-A and human HDAC4) HDACs, most hydroxamates and 2-aminoanilides displayed potent and selective inhibition toward class?I enzymes. Immunoblotting analyses performed in U937 leukemia cells generally revealed high acetyl-H3 and low acetyl-α-tubulin levels. Exceptions are compounds 3?f-i, 3?m-o, and 4?k, which showed higher tubulin acetylation than SAHA. In U937 cells, cell-cycle blockade in either the G?/M or G?/S phase was observed with 1-4. Five hydroxamates (compounds 1?h-l) effected a two- to greater than threefold greater percent apoptosis than SAHA, and in the CD11c cytodifferentiation test some 2-aminoanilides belonging to both series 2 and 4 were more active than MS-275. The highest-scoring derivatives in terms of apoptosis (1?k, 1?l) or cytodifferentiation (2?c, 4?n) also showed antiproliferative activity in U937 cells, thus representing valuable tools for study in other cancer contexts.     

Identification of small-molecule inhibitors of the XendoU endoribonucleases family

The XendoU family of enzymes includes several proteins displaying high sequence homology. The members characterized so far are endoribonucleases sharing similar biochemical properties and a common architecture in their active sites. Despite their similarities, these proteins are involved in distinct RNA-processing pathways in different organisms. The amphibian XendoU participates in the biosynthesis of small nucleolar RNAs, the human PP11 is supposed to play specialized roles in placental tissue, and NendoU has critical function in coronavirus replication. Notably, XendoU family members have been implicated in human pathologies such as cancer and respiratory diseases: PP11 is aberrantly expressed in various tumors, while NendoU activity has been associated with respiratory infections by pathogenic coronaviruses. The present study is aimed at identifying small molecules that may selectively interfere with these enzymatic activities. Combining structure-based virtual screening and experimental approaches, we identified four molecules that specifically inhibited the catalytic activity of XendoU and PP11 in the low micromolar range. Moreover, docking experiments strongly suggested that these compounds might also bind to the active site of NendoU, thus impairing the catalytic activity essential for the coronavirus life cycle. The identified compounds, while allowing deep investigation of the molecular functions of this enzyme family, may also represent leads for the development of new therapeutic tools.     

The Influence of Pre‐Electrospinning Plasma Treatment on Physicochemical Characteristics of PLA Nanofibers

Morphology, crystallinity, thermal, and mechanical properties of nanofibrous mats are known to highly affect the behavior of these materials in desired applications. In this study, multiple characteristics of poly(lactic acid) (PLA) nanofibrous mats prepared from plasma‐treated pre‐electrospinning solutions are studied as a function of various plasma operational parameters. X‐ray diffraction, differential scanning calorimetry, thermogravimetric analysis, X‐ray photoelectron spectroscopy, scanning electron microscopy, and tensile tests are performed. In addition, the pristine and plasma‐treated PLA solutions are examined with size exclusion chromatography to study the effect of the conducted pre‐electrospinning plasma treatments (PEPT) on the molecular weight of PLA. Aging analysis of the pristine and plasma‐treated solutions is also performed by evaluating the viscosity, conductivity, surface tension, and pH during an aging period of 10 days. To investigate if the results are only affected by the plasma treatment or also affected by the electrospinning, pristine and plasma‐treated PLA cast layers are also analyzed. The results reveal that PEPT preserved the surface chemical composition of the nanofibers and the molecular weight distribution of PLA, while morphology and mechanical properties of the nanofibers are considerably enhanced. Moreover, plasma‐treated polymer solutions resulted in the formation of nicely elongated nanofibers up to 4 days after plasma treatment.     

Performance of polysilicon gate HfO/sub 2/ MOSFETs on [100] and [111] silicon substrates

Mobility dependence on Si substrate orientations was investigated for HfO/sub 2/ MOSFETs for the first time. High-temperature (600 /spl deg/C) forming gas (FG) annealing (HT-FGA) was applied on the devices on both [100] and [111] substrates to evaluate the mobility for optimal interfacial quality. Using HT-FGA, D/sub it/ of the [111] devices was reduced down below 1 /spl times/ 10/sup 12/ cm/sup -2/V/sup -1/. Similar to SiO/sub 2/ devices, NMOS mobility of the [111] devices was lower than that of the [100] devices at higher effective fields, while it was reversed for PMOSFETs.     

Electrical characterization and analysis techniques for the high-κ era

Various conventional and novel electrical characterization techniques have been combined with careful, robust analysis to properly evaluate high-κ gate dielectric stack structures. These measurement methodologies and analysis techniques have enhanced the ability to separate pre-existing defects that serve as fast transient charging and discharging sites from defects generated with stress. In addition, the differentiation of electrically active bulk high-κ traps, silicon substrate interface traps, and interfacial layer traps has been effectively demonstrated.     

Involvement of actin and polarisome in morphological change during spore germination of Saccharomyces cerevisiae

We studied the morphological changes of Saccharomyces cerevisiae ascospores during germination. Initiation of germination is followed by polarization of actin patches, maintaining their localization to the site of cell surface growth. Loss of polarisome components, Spa2p, Pea2p, Bud6p or Bni1p, results in depolarization of actin patches. Green fluorescent protein-fused polarisome components exhibit the polarized localization, implying that polarisome is involved in the polarized outgrowth during germination. At the late stage of germination, we found that actin patches temporally depolarize before bud emergence. The observation that loss of Cla4p extends the polarized growth period suggests that Cla4p is involved in the actin-depolization step. Actin polarization in the initial stage is accelerated by overexpression of Ras2p, whereas hyperpolarization is continuously observed by overexpression of Rho1p. Thus, yeast spore germination is a morphological event that is regulated by a number of factors implicated in mitotic bud morphogenesis.