The sustainable utilization of lignocellulosic biomass as a renewable and abundant source lies at the core of the emerging biobased economy for the production of fuels, materials, and platform chemicals. The first step in the implementation of many biomass valorization technologies is the “pretreatment” that aims at biomass fractionation and recovery of its main structural components, i.e., cellulose, hemicellulose, and lignin, which can be then converted by downstream (bio)­catalytic processes to targeted high added value intermediate chemicals or final products. In this respect, hydrothermal pretreatment in pure water (also called liquid hot water or autohydrolysis) offers a method with low operational costs, free of organic solvents and corrosive acids or bases, and with no use of “external” liquid or solid catalysts. In the present work, the hydrothermal pretreatment of three types of lignocellulosic forestry and agricultural residues/byproducts was studied. They are representative of hardwood (residual poplar branches from logging operations and grapevine pruning) and softwood (pine sawdust) biomass. The pretreatment experiments were conducted in a batch-mode, high-pressure reactor under autogenous pressure at varying temperature (170–220 °C) and time (15–180 min) regimes and at liquid-to-solid ratio (LSR) of 15. The intensification of the process was expressed by the severity factor, log Ro. The process was optimized for increasing the recovery of hemicellulose in the form of monomeric sugars (xylose, mannose, galactose) or the respective oligo-saccharides, as well as for improving the production of glucose in the subsequent enzymatic hydrolysis of the pretreated biomass. Maximum hemicellulose recovery for poplar, grapevine, and pine in the liquid products was around 60% at ∼70%–85% hemicellulose removal, based on initial hemicellulose content of each biomass type, and was achieved at relatively moderate treatment severities (log Ro = 3.8–4.1). Formation of major degradation products, such as acids (i.e., formic and levulinic acid) and furans (i.e., furfural and HMF) was relatively low and below ca. 1 mg/mL for the whole range of pretreatment severities. Enzymatic hydrolysis of the parent lignocellulosic materials toward glucose was very low (i.e., 10%) and remained low for the pretreated pine biomass (16%) but was substantially improved for poplar (49%) and especially for grapevine (77%) as a result of hydrothermal pretreatment at the highest severity (log Ro = 4.7). The significant improvement of enzymatic hydrolysis of grapevine was attributed to the nearly complete removal of hemicellulose and to the changes in the morphological and textural characteristics of biomass particles, with the most pronounced one being the 9-fold increase in surface and pore volume.

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The multifunctional role of oleylamine (OAm) as a versatile and flexible reagent in synthesis as well as a desired surface ligand for the synthesis of CoFe2O4 nanoparticles (NPs) is described. CoFe2O4 NPs were prepared by a facile, reproducible and scalable solvothermal approach in the presence of pure OAm. By monitoring the volume of OAm, different shapes of NPs, spherical and truncated, were formed. The syntheses led to high yields of monodispersed and considerably small (9-11 nm) CoFe2O4 NPs with enhanced magnetization (M(s) = 84.7-87.5 emu g(-1)). The resulting hydrophobic CoFe2O4 NPs were easily transferred to an aqueous phase through the formation of reverse micelles between the hydrophobic chains of OAm and cetyltrimethylammonium bromide (CTAB) and transverse relaxivities (r2) were measured. The spherical NPs had a greater effect on water proton relaxivity (r2 = 553 mM(-1) s(-1)) at an applied magnetic field of 11.7 T. The NPs became fluorescent probes by exploiting the presence of the double bond of OAm in the middle of the molecule; a thiol-ene "click" reaction with the fluorophore bovine serum albumin (FITC-BSA) was achieved. The labeled/biofunctionalized CoFe2O4 NPs interacted with cancer (HeLa and A549) and non-cancer cell lines (MRC5 and dental MSCS) and cell viability was estimated. A clear difference of toxicity between the cancer and non-cancer cells was observed while low cytotoxicity in living cells was supported. Confocal laser microscopy showed that NPs entered the cell membranes and were firstly localized close to them provoking a membrane expansion and were further accumulated perinuclearly without entering the nuclei.

Evidence now exists to indicate that some ribosomal proteins besides being structural components of the ribosomal subunits are involved in the regulation of cell differentiation and apoptosis. As we have shown earlier, initiation of erythroid differentiation of murine erythroleukemia (MEL) cells is associated with transcriptional inactivation of genes encoding ribosomal RNAs and ribosomal proteins S5 (RPS5) and L35a. In this study, we extended these observations and investigated whether transfection of MEL cells with RPS5 cDNA affects the onset of initiation of erythroid maturation and their entrance in cell cycle arrest. Stably transfected MEL cloned cells (MEL-C14 and MEL-C56) were established and assessed for their capacity to produce RPS5 RNA transcript and its translated product. The impact of RPS5 cDNA transfection on the RPS5 gene expression patterns and the accumulation of RPS5 protein in inducible transfected MEL cells were correlated with their ability to: (a) initiate differentiation, (b) enter cell cycle arrest at G(1)/G(0) phase, and (c) modulate the level of cyclin-dependent kinases CDK2, CDK4, and CDK6. The data presented indicate that deregulation of RPS5 gene expression (constitutive expression) affects RPS5 protein level and delays both the onset of initiation of erythroid maturation and entrance in cell cycle arrest in inducer-treated MEL cells.