Ultrasound-assisted production of bioethanol by simultaneous saccharification and fermentation of corn meal

An ultrasound-assisted liquefaction as a pretreatment for bioethanol production by simultaneous saccharification and fermentation (SSF) of corn meal using Saccharomyces cerevisiae var. ellipsoideus yeast in a batch system was studied. Ultrasound pretreatment (at a frequency of 40 kHz) was performed at different sonication times and temperatures, before addition of liquefying enzyme. An optimal duration of the treatment of 5 min and sonication temperature of 60 °C were selected, taking into account glucose concentration after the liquefaction step. Under the optimum conditions an increase of glucose concentration of 6.82% over untreated control sample was achieved. Furthermore, the SSF process kinetics was assessed and determined, and the effect of ultrasound pretreatment on an increase of ethanol productivity was investigated. The obtained results indicated that the ultrasound pretreatment could increase the ethanol concentration by 11.15% (compared to the control sample) as well as other significant process parameters. In this case, the maximum ethanol concentration of 9.67% w/w (which corresponded to percentage of the theoretical ethanol yield of 88.96%) was achieved after 32 h of the SSF process. A comparison of scanning electron micrographs of the ultrasound-pretreated and untreated samples of corn meal suspensions showed that the ultrasound stimulated degradation of starch granules and release of glucose, and thereby accelerated the starch hydrolysis due to the cavitation and acoustic streaming caused by the ultrasonic action.     

Innovative Design of Fire Doors: Computational Modeling and Experimental Validation

Usually the design of fire doors is carried out to fulfil thermal requirements only, whereas also thermal distortion could significantly affect the safety behavior of the door. Indeed, the door tends to bend away from its supporting frame due to a non-uniform temperature distribution, which could lead to flame and smoke propagation. In this work an innovative design scheme is proposed, where the mechanical response of the door is enhanced without affecting its insulating properties. This improvement is achieved by changing the disposition of the constitutive elements (insulating material and structural plates). The behavior of a conventional and of an innovative door during a fire test was simulated with three-dimensional (3D) finite element models. A non-linear thermo-mechanical transient analysis was performed as well. The numerical results were validated with an experimental campaign made on true scale specimens, where the doors were heated by a furnace reaching a maximum temperature of 950°C. The temperature distribution was measured with several thermocouples and an infrared camera, whereas displacements were monitored with a laser sensor. It was observed that, while temperatures on the unexposed surface were around 120°C in both cases, the maximum out-of-plane displacement measured in the innovative door was 3 times smaller than that of the conventional configuration.     

Exploring BODIPY-Based Sensor for Imaging of Intracellular Microviscosity in Human Breast Cancer Cells

BODIPY-based molecular rotors are highly attractive imaging tools for imaging intracellular microviscosity in living cells. In our study, we investigated the ability to detect the microviscosity of biological objects by using BDP-NO₂ and BDP-H molecular rotors. We describe in detail the optical properties of BDP-NO₂ and BDP-H molecular rotors in aqueous media with and without proteins, together with their accumulation dynamics and localization in live and fixed human breast cancer cells. Furthermore, we investigate the applicability of these molecules to monitor microviscosity in the organelles of human breast cancer cells by fluorescence lifetime imaging microscopy (FLIM). We demonstrate that the BDP-NO₂ molecular rotor aggregates in aqueous media and is incompatible with live cell imaging. The opposite effect is observed with BDP-H which preserves its stability in aqueous media, diffuses through the plasma membrane and accumulates in lipid droplets (LDs) and the cytosol of both live and fixed MCF-7 and MDA-MB-231 cancer cells. Finally, by utilizing BDP-H we demonstrate that LD microviscosity is significantly elevated in more malignant MDA-MB-231 human breast cancer cells, as compared to MCF-7 breast cancer cells. Our findings demonstrate that BDP-H is a water-compatible probe that can be successfully applied to measure microviscosity in the LDs of living cells.     

Surface Topography and Biocompatibility of cp–Ti Grade2 Fabricated by Laser-Based Powder Bed Fusion: Influence of Printing Orientation and Surface Treatments

The selective laser melting process, commonly known as laser-based powder bed fusion (LB-PBF), enables the production of structures with unprecedented degrees of freedom that represents an excellent condition for development of metallic implants for biomedical applications. Herein, the effects of laser energy density on relative density and microstructure (presence of internal defects) of cp-TiGd2 fabricated by LB-PBF are studied. Additionally, the influence of printing orientation and different surface treatments on surface topography and biocompatibility are investigated. The aim of the research is to develop additive manufacturing process parameters that can achieve full density of cp-TiGd2 with satisfactory biocompatibility, as a low-cost alternative to biomedical materials such as Ti–6Al–4 V and Ti–6Al–7Nb. A wide range variation of process parameters leads to an optimized process with high density up to 99.97 ± 0.008%, improved surface roughness, and noncytotoxicity in horizontal and inclined as-built condition, as well as in Al₂O₃ (blasting angle 0°) condition.     

Relevance of corona virus in food industry: A literature review on risks,challenges, and potential preventive measures

Food industry is highly affected by COVID-19 pandemic; therefore, the preventive measures and precautions to be taken to reduce the risk of transmission of the SARS-CoV-2 virus and incidence of infection are necessary. This review integrate and analyze the available information and data on precautions of corona virus in food industry in pursuance of informing the public and the scientific community, as well as creating collective knowledge among food industry establishment and raising awareness of preventive measures during COVID-19 pandemic. In this study, the information and data have been reviewed about the transmitting routs of the SARS-CoV-2 virus and the preventive measures and precautions to be taken in food industry during COVID-19 pandemic in order to reduce the risk of transmission of the virus and incidence of the infection. The restriction of spreading corona virus through food industry in procedures, such as manufacturing, processing, packing, transporting. The transmitting routs of the SARS-CoV-2 virus are studied adequately in favor of suggesting strategies from the present scenarios. Limited number of publications has identified the risk factors for COVID-19 and preventive measures, especially in food industry. Findings from this review may contribute to promoting research and spreading knowledge among food industry establishment and raise awareness of preventive measures in food industry during COVID-19 pandemic.     

Programming Delayed Dissolution Into Sacrificial Bioinks For Dynamic Temporal Control of Architecture within 3D-Bioprinted Constructs

Sacrificial printing allows introduction of architectural cues within engineered tissue constructs. This strategy adopts the use of a 3D-printed sacrificial ink that is embedded within a bulk hydrogel which is subsequently dissolved to leave open-channels. However, current conventional sacrificial inks do not recapitulate the dynamic nature of tissue development, such as the temporal presentation of architectural cues matching cellular requirements during different stages of maturation. To address this limitation, a new class of sacrificial inks is developed that exhibits tailorable and programmable delayed dissolution profiles (1–17 days), by exploiting the unique ability of the ruthenium complex and sodium persulfate initiating system to crosslink native tyrosine groups present in non-chemically modified gelatin. These novel sacrificial inks are also shown to be compatible with a range of biofabrication technologies, including extrusion-based printing, digital-light processing, and volumetric bioprinting. Further embedding these sacrificial templates within cell-laden bulk hydrogels displays precise control over the spatial and temporal introduction of architectural features into cell-laden hydrogel constructs. This approach demonstrates the unique capacity of delaying dissolution of sacrificial inks to modulate cell behavior, improving the deposition of mineralized matrix and capillary-like network formation in osteogenic and vasculogenic culture, respectively.     

Insights into Phase Evolution and Mechanical Behavior of the Eutectoid Ti–6.4(wt%)Ni Alloy Modified with Fe and Cr

Titanium alloys gain increasing importance in industry due to the expansion of advanced manufacturing technologies such as additive manufacturing. Conventional titanium alloys processed by such technologies suffer from formation of large primary grains and anisotropy of mechanical properties. Therefore, novel alloys are required. Herein, the effect of ternary alloying elements Fe and Cr on the Ti–6.4(wt%)Ni eutectoid system is investigated. Both elements act as eutectoid formers. Fe and Cr show sluggish transformation behavior, whereas Ni is an active eutectoid-forming element. Thereby, sluggish refers to slow and active to fast transformation kinetics. The focus of this work is on the combined addition of such elements studied under different heat-treatment conditions. It is shown in the results that largely varying microstructures can be generated resulting in hardness values ranging from 239 to 556 HV_0.1. Moreover, the formation of a substructure within the α phase of direct aged alloys is observed. The formation mechanism of this substructure is investigated in detail. The mechanical properties are discussed based on the microstructural characteristics. The presence of intermetallic Ti₂Ni phase increases the Young's modulus, whereas the presence of ω phase results in embrittlement. The results shed light upon the complex phase formation and decomposition behavior of titanium alloys based on Ti–6.4Ni.