Energy balance and global warming potential of corn straw-based bioethanol in China from a life cycle perspective

<p>As the second largest corn producer in this world, China has abundant corn straw resources. The study assessed the energy balance and global warming potential of corn straw-based bioethanol production and utilization in China from a life cycle perspective. The results revealed that bioethanol used as gasoline and diesel blend fuel could reduce global warming potential by 10%–97% and 4%–96%, respectively, as compared to gasoline and diesel for transport. The total global warming potential, net global warming potential, net energy, and Net Energy Ratio per MJ ethanol generated from corn straw-based bioethanol system are estimated to be 0.20 kg CO₂-eq, 0.012 kg CO₂-eq, 0.60 MJ, and 1.87, respectively. By using sensitivity analysis, we found that the collected coefficient and compressing density of straw have a more obvious influence on energy balance; transportation distance has a more obvious influence on global warming potential emission factor. The by-products may be utilized as fertilizer, animal feed, cement replacement, or high-value lignin chemicals, which make a contribution to offsetting 0.28 MJ per MJ ethanol of energy consumption.</p

What Governs Friction of Silicon Oxide in Humid Environment: Contact Area between Solids, Water Meniscus around the Contact, or Water Layer Structure?

In order to understand the interfacial parameters governing the friction force (<i>F</i>_t) between silicon oxide surfaces in humid environment, the sliding speed (<i>v</i>) and relative humidity (RH) dependences of <i>F</i>_t were measured for a silica sphere (1 μm radius) sliding on a silicon oxide (SiO_<i>x</i>) surface, using atomic force microscopy (AFM), and analyzed with a mathematical model describing interfacial contacts under a dynamic condition. Generally, <i>F</i>_t decreases logarithmically with increasing <i>v</i> to a cutoff value below which its dependence on interfacial chemistry and sliding condition is relatively weak. Above the cutoff value, the logarithmic <i>v</i> dependence could be divided into two regimes: (i) when RH is lower than 50%, <i>F</i>_t is a function of both <i>v</i> and RH; (ii) in contrast, at RH ≥ 50%, <i>F</i>_t is a function of <i>v</i> only, but not RH. These complicated <i>v</i> and RH dependences were hypothesized to originate from the structure of the water layer adsorbed on the surface and the water meniscus around the annulus of the contact area. This hypothesis was tested by analyzing <i>F</i>_t as a function of the water meniscus area (<i>A</i>_m) and volume (<i>V</i>_m) estimated from a thermally activated water-bridge formation model. Surprisingly, it was found that <i>F</i>_t varies linearly with <i>V</i>_m and correlates poorly with <i>A</i>_m at RH < 50%; and then its <i>V</i>_m dependence becomes weaker as RH increases above 50%. Comparing the friction data with the attenuated total reflection infrared (ATR-IR) spectroscopy analysis result of the adsorbed water layer, it appeared that the solidlike water layer structure formed on the silica surface plays a critical role in friction at RH < 50% and its contribution diminishes at RH ≥ 50%. These findings give a deeper insight into the role of water condensation in friction of the silicon oxide single asperity contact under ambient conditions

Fabrication of a Homogeneous, Integrated, and Compact Film of Organic–Inorganic Hybrid Ni(en)₃Ag₂I₄ with Near-Infrared Absorbance and Semiconducting Features

The organic–inorganic hybrid crystal Ni­(en)₃Ag₂I₄ (where en represents 1,2-ethylenediamine) crystallizes in hexagonal space group <i>P</i>6₃, in which the AgI₄^3– tetrahedra connect into a diamondlike inorganic framework via sharing of the vertex and the Ni­(en)₃²⁺ octahedra fill in the pores of the framework. UV–vis–near-IR (NIR) spectroscopy disclosed that this hybrid shows intense NIR absorbance centered at ca. 870 nm, and the variable-temperature conductivity measurement revealed that the hybrid is a semiconductor with <i>E</i>_a = 0.46 eV. The electronic band structure of Ni­(en)₃Ag₂I₄ was calculated using the density functional theory method, indicating that the NIR absorbance arises from d-d transition within the Ni²⁺ cation of Ni­(en)₃²⁺. The homogeneous, compact, and transparent crystalline film of Ni­(en)₃Ag₂I₄ was fabricated via a secondary seed growth strategy, which has promising application in NIR devices

Graphene Failure under MPa: Nanowear of Step Edges Initiated by Interfacial Mechanochemical Reactions

The low wear resistance of macroscale graphene coatings does not match the ultrahigh mechanical strength and chemical inertness of the graphene layer itself; however, the wear mechanism responsible for this issue at low mechanical stress is still unclear. Here, we demonstrate that the susceptibility of the graphene monolayer to wear at its atomic step edges is governed by the mechanochemistry of frictional interfaces. The mechanochemical reactions activated by chemically active SiO2 microspheres result in atomic attrition rather than mechanical damage such as surface fracture and folding by chemically inert diamond tools. Correspondingly, the threshold contact stress for graphene edge wear decreases more than 30 times to the MPa level, and mechanochemical wear can be described well with the mechanically assisted Arrhenius-type kinetic model, i.e., exponential dependence of the removal rate on the contact stress. These findings provide a strategy for improving the antiwear of graphene-based materials by reducing the mechanochemical interactions at tribological interfaces

Data_Sheet_1_The improvement of Hovenia acerba-sorghum co-fermentation in terms of microbial diversity, functional ingredients, and volatile flavor components during Baijiu fermentation.pdf

The quality of Baijiu was largely affected by raw materials, which determine the flavor and taste. In the present study, organic acids, polyphenols, volatile flavor components and microbial community in Hovenia acerba-sorghum co-fermented Baijiu (JP1) and pure sorghum-fermented Baijiu (JP2) were comprehensively analyzed. Organic acids, polyphenols and volatile flavor components in JP1 were more abundant than JP2. The abundance and diversity of bacteria and fungi in JP1 was higher than that in JP2 in the early stage of fermentation, but presented opposite trend in the middle and late stages. Leuconostoc, Lentilactobacillus and Issatchenkia were dominant genera in JP1. Whereas, Cronobacter, Pediococcus and Saccharomyces occupied the main position in JP2. Lentilactobacillus and Issatchenkia were positively related to most of organic acids and polyphenols. Pseudomonas, Rhodococcus, Cronobacter, Pediococcus, Brucella, Lentilactobacillus, Lactobacillus, Saccharomycopsis, Wickerhamomyces, Aspergillus, Thermomyces and unclassified_f—Dipodascaccae were associated with the main volatile flavor components. The main metabolic pathways in two JPs exhibited the variation trend of first decreasing and then increasing, and the metabolism activity in JP1 were higher than that in JP2. The results demonstrated the introduction of Hovenia acerba improved the functional ingredients and volatile flavor components, which is helpful for the quality promotion of Baijiu. This study identified the key microorganisms and discussed their effect on organic acids, polyphenols and volatile flavor components during the fermentation of Baijiu with different raw materials, providing a scientific basis for the development and production of high-quality Baijiu.</p

Nanocolloidosomes with Selective Drug Release for Active Tumor-Targeted Imaging-Guided Photothermal/Chemo Combination Therapy

Selective drug release is highly desirable for photothermal/chemo combination therapy when two or even more theranostic agents are encapsulated together within the same nanocarrier. A conventional nanocarrier can hardly achieve this goal. Herein, doxorubicin and indocyanine green (DOX/ICG)-loaded nanocolloidosomes (NCs), with selective drug release, were fabricated as a novel multifunctional theranostic nanoplatform for photothermal/chemo combination therapy. Templating from galactose-functionalized hydroxyethyl starch-polycaprolactone (Gal-HES-PCL) nanoparticles-stabilized Pickering emulsions, the resultant DOX/ICG@Gal-HES-PCL NCs had a diameter of around 140 nm and showed an outstanding tumor-targeting ability, preferable tumor penetration capability, and promotion of photothermal effect. Moreover, these NCs can be used for NIR fluorescence imaging and thus render real-time imaging of solid tumors with high contrast. Collectively, such NCs achieved the best in vivo antitumor efficacy combined with laser irradiation compared with DOX/ICG@HES-PCL NCs and DOX/ICG mixture. These NCs are valuable for active tumor-targeted imaging-guided combination therapy against liver cancer and potentially other diseases

α‑Amylase- and Redox-Responsive Nanoparticles for Tumor-Targeted Drug Delivery

Paclitaxel (PTX) is an effective antineoplastic agent and shows potent antitumor activity against a wide spectrum of cancers. Yet, the wide clinical use of PTX is limited by its poor aqueous solubility and the side effects associated with its current therapeutic formulation. To tackle these obstacles, we report, for the first time, α-amylase- and redox-responsive nanoparticles based on hydroxyethyl starch (HES) for the tumor-targeted delivery of PTX. PTX is conjugated onto HES by a redox-sensitive disulfide bond to form HES–SS-PTX, which was confirmed by results from NMR, high-performance liquid chromatography-mass spectrometry, and Fourier transform infrared spectrometry. The HES–SS-PTX conjugates assemble into stable and monodispersed nanoparticles (NPs), as characterized with Dynamic light scattering, transmission electron microscopy, and atomic force microscopy. In blood, α-amylase will degrade the HES shell and thus decrease the size of the HES–SS-PTX NPs, facilitating NP extravasation and penetration into the tumor. A pharmacokinetic study demonstrated that the HES–SS-PTX NPs have a longer half-life than that of the commercial PTX formulation (Taxol). As a consequence, HES–SS-PTX NPs accumulate more in the tumor compared with the extent of Taxol, as shown in an in vivo imaging study. Under reductive conditions, the HES–SS-PTX NPs could disassemble quickly as evidenced by their triggered collapse, burst drug release, and enhanced cytotoxicity against 4T1 tumor cells in the presence of a reducing agent. Collectively, the HES–SS-PTX NPs show improved in vivo antitumor efficacy (63.6 vs 52.4%) and reduced toxicity in 4T1 tumor-bearing mice compared with those of Taxol. These results highlight the advantages of HES-based α-amylase- and redox-responsive NPs, showing their great clinical translation potential for cancer chemotherapy