This study conducted an investigation of the effect of lignosulfonate (LS) on enzymatic saccharification of lignocelluloses. Two commercial LSs and one laboratory sulfonated kraft lignin were applied ...to Whatman paper, dilute acid and SPORL (sulfite pretreatment to overcome recalcitrance of lignocelluloses) pretreated aspen, and kraft alkaline and SPORL pretreated lodgepole pine. All three lignin samples inhibited cellulose saccharification of Whatman paper, but enhanced the saccharification of the four lignocellulosic substrates. The level of enhancement was related to the molecular weight and degree of sulfonation of the lignin as well as the substrate lignin structure. When different molecular weight (MW) fractions of one commercial LS (SXP), generated from sulfite pulping of hardwood, were applied to the Whatman paper, the large MW fraction (SXP1) with the lowest degree of sulfonation inhibited cellulose saccharification while the intermediate (SXP2) and smallest (SXP3) MW fractions enhanced saccharification. All MW fractions enhanced saccharification of the four lignocellulosic substrates with maximal enhancement by the smallest MW fraction, SXP3. The enhancement was most significant for the kraft lodgepole pine substrate and least significant for the SPORL pretreated lodgepole pine using all three LS and SXP fractions. The results suggest that LS acts as a surfactant to enhance pure cellullose saccharification. When LS is applied to lignocelluloses, it acts as a surfactant to block bound lignin from binding cellulase nonproductively leading to enhanced saccharification.
The amygdala, one of the most studied brain structures, integrates brain-wide heterogeneous inputs and governs multidimensional outputs to control diverse behaviors central to survival, yet how ...amygdalar input-output neuronal circuits are organized remains unclear. Using a simplified cell-type- and projection-specific retrograde transsynaptic tracing technique, we scrutinized brain-wide afferent inputs of four major output neuronal groups in the amygdalar basolateral complex (BLA) that project to the bed nucleus of the stria terminals (BNST), ventral hippocampus (vHPC), medial prefrontal cortex (mPFC) and nucleus accumbens (NAc), respectively. Brain-wide input-output quantitative analysis unveils that BLA efferent neurons receive a diverse array of afferents with varied input weights and predominant contextual representation. Notably, the afferents received by BNST-, vHPC-, mPFC- and NAc-projecting BLA neurons exhibit virtually identical origins and input weights. These results indicate that the organization of amygdalar BLA input-output neuronal circuits follows the input-dependent and output-independent principles, ideal for integrating brain-wide diverse afferent stimuli to control parallel efferent actions. The data provide the objective basis for improving the virtual reality exposure therapy for anxiety disorders and validate the simplified cell-type- and projection-specific retrograde transsynaptic tracing method.
Norepinephrine (NE) is a key biogenic monoamine neurotransmitter involved in a wide range of physiological processes. However, its precise dynamics and regulation remain poorly characterized, in ...part due to limitations of available techniques for measuring NE in vivo. Here, we developed a family of GPCR activation-based NE (GRABNE) sensors with a 230% peak ΔF/F0 response to NE, good photostability, nanomolar-to-micromolar sensitivities, sub-second kinetics, and high specificity. Viral- or transgenic-mediated expression of GRABNE sensors was able to detect electrical-stimulation-evoked NE release in the locus coeruleus (LC) of mouse brain slices, looming-evoked NE release in the midbrain of live zebrafish, as well as optogenetically and behaviorally triggered NE release in the LC and hypothalamus of freely moving mice. Thus, GRABNE sensors are robust tools for rapid and specific monitoring of in vivo NE transmission in both physiological and pathological processes.
Display omitted
Display omitted
•GRABNE sensors are genetically encoded GPCR activation-based norepinephrine sensors•GRABNE distinguishes norepinephrine from dopamine with 1,000-fold specificity•The norepinephrine measurements are sensitive, with high spatiotemporal resolution•Norepinephrine dynamics are observed during stressful behaviors in zebrafish and mice
Feng et al. develop and validate a pair of genetically encoded GPCR-activation-based norepinephrine sensors, which, for the first time, enable specific in vivo measurement of norepinephrine dynamics during stressful behaviors with high spatiotemporal resolution in zebrafish and mice.
We report the experimental generation of highly energetic carbon ions up to 48 MeV per nucleon by shooting double-layer targets composed of well-controlled slightly underdense plasma and ultrathin ...foils with ultraintense femtosecond laser pulses. Particle-in-cell simulations reveal that carbon ions are ejected from the ultrathin foils due to radiation pressure and then accelerated in an enhanced sheath field established by the superponderomotive electron flow. Such a cascaded acceleration is especially suited for heavy ion acceleration with femtosecond laser pulses. The breakthrough of heavy ion energy up to many tens of MeV/u at a high repetition rate would be able to trigger significant advances in nuclear physics, high energy density physics, and medical physics.
A new method to prepare nanolignin using a simple high shear homogenizer is presented. The kraft lignin particles with a broad distribution ranging from large micron‐ to nano‐sized particles were ...completely homogenized to nanolignin particles with sizes less than 100 nm after 4 h of mechanical shearing. The 13C nuclear magnetic resonance (NMR) and 31P NMR analysis showed that there were no major changes in the chemical composition between the starting kraft lignin particles and the nanolignin obtained after 4 h of mechanical treatment. The nanolignin particles did not show any change in molecular weight distribution and polydispersity compared to the original lignin particles. The nanolignin particles when used with polyvinyl alcohol (PVA) increased the thermal stability of nanolignin/PVA blends more effectively compared to the original lignin/PVA blends.
Lignin to nanolignin: Nanolignin particles are obtained by homogenizing kraft lignin particles using a high shear homogenizer. The nanolignin particles show no change in chemical structure, molecular weight distribution, and polydispersity compared to the kraft lignin particles. The nanolignin particles are well dispersed within the polyvinyl alcohol (PVA) matrix (see image) with minimal agglomeration to enhance the composite performance.
Acquisition of neuronal circuit architectures, central to understanding brain function and dysfunction, remains prohibitively challenging. Here I report the development of a simultaneous and ...sequential octuple-sexdecuple whole-cell patch-clamp recording system that enables architectural reconstruction of complex cortical circuits. The method unveils the canonical layer 1 single bouquet cell (SBC)-led disinhibitory neuronal circuits across the mouse somatosensory, motor, prefrontal, and medial entorhinal cortices. The ∼1,500-neuron modular circuits feature the translaminar, unidirectional, minicolumnar, and independent disinhibition and optimize cortical complexity, subtlety, plasticity, variation, and redundancy. Moreover, architectural reconstruction uncovers age-dependent deficits at SBC-disinhibited synapses in the senescence-accelerated mouse prone 8, an animal model of Alzheimer’s disease. The deficits exhibit the characteristic Alzheimer’s-like cortical spread and correlation with cognitive impairments. These findings decrypt operations of the elementary processing units in healthy and Alzheimer’s mouse cortices and validate the efficacy of octuple-sexdecuple patch-clamp recordings for architectural reconstruction of complex neuronal circuits.
Display omitted
•Octuple-sexdecuple patch recordings enable architectonics of complex cortical circuits•Architectonics identifies modular L1 SBC-led disinhibitory circuits across cortices•Architectures of L1 SBC-led disinhibitory circuits construe principles of cortical operation•Architectonics reveals specific deficits at SBC-disinhibited synapses in an AD mouse model
Zhu introduced an octuple-sexdecuple patch-clamp recording technique, allowing for the architectural reconstruction of cortical L1 SBC-led modular circuits featuring translaminar, unidirectional, minicolumnar, and independent disinhibition. The architectures construe cortical operational principles and circuit- and connection-specific deficits at SBC-disinhibited synapses in the SAMP8 mouse, an Alzheimer’s disease model.
Alkaline pretreatment of spruce at low temperature in both presence and absence of urea was studied. It was found that the enzymatic hydrolysis rate and efficiency can be significantly improved by ...the pretreatment. At low temperature, the pretreatment chemicals, either NaOH alone or NaOH-urea mixture solution, can slightly remove lignin, hemicelluloses, and cellulose in the lignocellulosic materials, disrupt the connections between hemicelluloses, cellulose, and lignin, and alter the structure of treated biomass to make cellulose more accessible to hydrolysis enzymes. Moreover, the wood fiber bundles could be broken down to small and loose lignocellulosic particles by the chemical treatment. Therefore, the enzymatic hydrolysis efficiency of untreated mechanical fibers can also be remarkably enhanced by NaOH or NaOH/urea solution treatment. The results indicated that, for spruce, up to 70% glucose yield could be obtained for the cold temperature pretreatment (-15°C) using 7% NaOH/12% urea solution, but only 20% and 24% glucose yields were obtained at temperatures of 23°C and 60°C, respectively, when other conditions remained the same. The best condition for the chemical pretreatment regarding this study was 3% NaOH/12% urea, and -15°C. Over 60% glucose conversion was achieved upon this condition. Biotechnol. Bioeng. 2008;99: 1320-1328.
Topological superconductivity is one of most fascinating properties of topological quantum matters that was theoretically proposed and can support Majorana Fermions at the edge state. ...Superconductivity was previously realized in a Cu-intercalated Bi2Se3 topological compound or a Bi2Te3 topological compound at high pressure. Here we report the discovery of superconductivity in the topological compound Sb2Te3 when pressure was applied. The crystal structure analysis results reveal that superconductivity at a low-pressure range occurs at the ambient phase. The Hall coefficient measurements indicate the change of p-type carriers at a low-pressure range within the ambient phase, into n-type at higher pressures, showing intimate relation to superconducting transition temperature. The first principle calculations based on experimental measurements of the crystal lattice show that Sb2Te3 retains its Dirac surface states within the low-pressure ambient phase where superconductivity was observed, which indicates a strong relationship between superconductivity and topology nature.
•We successfully produced resin-based artificial rock specimens with 3D internal flaws with the SLA 3DP technique.•The flaw geometry greatly affects volumetric and mechanical properties of samples ...with 3D internal flaws.•Wing and anti-wing cracks could only propagate for approximately 1–1.5times the length of the initial flaw.•The ratio of initial cracking stress to uniaxial compressive strength is independent on the number of pre-existing flaws.
In nature, rock discontinuities, e.g., cracks, voids and joints, are usually three-dimensional, which to a large extent control the volumetric fracturing behaviors of rock masses. Understanding their growth behaviors and effects on rock volumetric fracturing properties is crucial for the stability assessment of rock engineering. In this study, three-dimensional printing (3DP) method was adopted to fabricate resin-based artificial rocks containing single flaw and double pre-existing penny-shaped 3D internal flaws. Static uniaxial compression tests were, subsequently, conducted on these samples to investigate the influence of flaw number, flaw angle (α) and ligament angle (β) on the volumetric fracturing behaviors of the 3DP artificial rocks. The results indicate that flaw geometry has remarkable influence on the mechanical and fracture behaviors of the flawed samples. The single flawed sample with α equal to 60° has the lowest compressive strength (σc) and axial strain at the peak stress (εa). σc and εa of the double flawed sample generally increase when β changes from 45° to 105°. When the flaw number increases from one to two, the initiation stress of the first wing crack, σc and εa decrease. With the aid of high-speed cameras, we studied 3D crack growth inside the transparent 3DP resin samples in real-time for the first time. Wing and anti-wing cracks wrapped around the flaw edge could only propagate for approximately 1–1.5 times the length of the initial flaw. Wing cracks generated at the inner tips of the flaws cannot coalesce, except for the sample with β of 105°. The maximum crack propagation velocity in single flawed specimens is higher than that in double flawed samples. The continuous propagation of the secondary cracks developed after the peak stress lead to the burst-like failure of the flawed samples. This study could enhance our understanding of volumetric fracturing behaviors of rocks.
Cellulose nanocrystals (CNC) have recently received much attention in the global scientific community for their unique mechanical and optical properties. Here, we conducted the first detailed ...exploration of the basic properties of CNC, such as morphology, crystallinity, degree of sulfation and yield, as a function of production condition variables. The rapid cellulose depolymerization and sulfation reactions under concentrated acid concentrations of around 60 wt% resulted in a very narrow operating window for CNC production. We found that CNC yields as high as 70 wt% from a bleached eucalyptus kraft pulp with glucan content of 78 wt% can be achieved under a tight range of reaction conditions and that a weighted average length of over 200 nm and sulfur content (a measure of CNC surface charge) between 3 and 10 mg/g can be produced. This study provided critical knowledge for the production of CNC with characteristics tailored for different specific applications, significant to commercialization.
PDF
