Mcclanahanowen3590

Quantum simulations can provide new insights into the physics of strongly correlated electronic systems. check details A well-studied system, but still open in many regards, is the Hubbard-Holstein Hamiltonian, where electronic repulsion is in competition with attraction generated by the electron-phonon coupling. In this context, we study the behavior of four quantum dots in a suspended carbon nanotube and coupled to its flexural degrees of freedom. The system is described by a Hamiltonian of the Hubbard-Holstein class, where electrons on different sites interact with the same phonon. We find that the system presents a transition from the Mott insulating state to a polaronic state, with the appearance of pairing correlations and the breaking of the translational symmetry. These findings will motivate further theoretical and experimental efforts to employ nanoelectromechanical systems to simulate strongly correlated systems with electron-phonon interactions.Herein, we report a photoinduced dehydrogenation/(3+2) cycloaddition reaction by merging organic photoredox and Lewis acid catalysis, providing a straightforward and efficient approach for directly installing a benzofuran skeleton on the saturated aza-heterocycles. In this protocol, we also describe a novel organic photocatalyst (t-Bu-DCQ) with the advantages of a wider redox potential, easy synthesis, and a low price. Furthermore, the stepwise activation mechanism of dual C(sp3)-H bonds was demonstrated by a series of experimental and computational studies.Modulation of fuel selection is critical in skeletal muscle function. Hydroxysafflor yellow A (HSYA) is the major bioactive component in safflower (Carthamus tinctorius L.) and, in our previous study, has been demonstrated to promote a shift from fast to slow myofiber. However, the effects of HSYA on fuel selection in skeletal muscle and its underlying mechanisms remain unclear. In this study, the in vitro experiments found that water extracts of safflower, rich in HSYA, significantly suppressed the expressions of the genes related to glucose utilization and activated the expressions of the lipolysis genes. Furthermore, HSYA resulted in a shift in substrate utilization toward fat relative to carbohydrates in C2C12 myotubes. Animal tests showed HSYA could significantly reduce the respiratory exchange ratio and prolonge endurance performance in mice and also trigger a switch in intramuscular fuel selection preference from carbohydrates to fat at rest and during exercise. Mechanistic studies revealed that HSYA converted this fuel selection by activating peroxisome proliferator activated receptor δ (PPARδ), and these effects of HSYA could be reversed by specific suppression of PPARδ by PPARδ siRNA. Collectively, our study demonstrated that HSYA can switch substrate utilization from glucose to fat in myocytes by activating PPARδ signaling, resulting in prolonged endurance performance. These findings provided direct evidence for the endurance performance enhancement effect of HSYA and explored new perspectives for the innovation and application of HSYA in the health care industry.Bio-based propionate is widely welcome in the food additive industry. The current anaerobic process by Propionibacteria endures low titers and a long fermentation time. In this study, a new route for propionate production from l-threonine was designed. 2-Ketobutyrate, deaminated from l-threonine, is cleaved into propionaldehyde and CO2 and then be oxidized into propionic acid, which is neutralized by ammonia released from the first deamination step. This CoA-independent pathway with only CO2 as a byproduct boosts propionate production from l-threonine with high productivity and purity. The key enzyme for 2-ketobutyrate decarboxylation was selected, and its expression was optimized. The engineered Pseudomonas putida strain, harboring 2-ketoisovalerate decarboxylase from Lactococcus lactis could produce 580 mM (43 g/L) pure propionic acid from 600 mM l-threonine in 24 h in the batch biotransformation process. link2 Furthermore, a high titer of 62 g/L propionic acid with a productivity of 1.07 g/L/h and a molar yield of >0.98 was achieved in the fed-batch pattern. Finally, an efficient sequential fermentation-biotransformation process was demonstrated to produce propionate directly from the fermentation broth containing l-threonine, which further reduces the costs since no l-threonine purification step is required.We develop a nonequilibrium response theory for macroscopic quantum systems that separates the contributions of ensemble heterogeneity and intrinsic quantum uncertainty. To accomplish this, we describe systems with a quantum P-ensemble, which goes beyond the standard density matrix description by explicitly specifying the classical heterogeneity between individual quantum systems in an ensemble. We use the P-ensemble formalism to present quantum generalizations of linear response theory and the Jarzynski nonequilibrium work relation. We derive these generalizations from a Bochkov-Kuzovlev generating functional for quantum P-ensembles, which can be further utilized to derive all orders of response theory that apply to ensemble quantum systems. We contrast these developments with their ρ-ensemble analogs, and we discuss how these P-ensemble theories provide a guide for an effective application of single molecule experiments.Human epidermal growth factor receptor 2 (HER2) is overexpressed in breast, gastric, esophageal, ovarian, and endometrial cancer. Combination therapy using trastuzumab and pertuzumab antibodies targeting HER2 has shown better survival outcomes in breast cancer patients. In the quest to understand the synergistic effect observed due to combination therapy, trastuzumab, pertuzumab, and their F(ab')2 fragments were labeled with radioisotope and fluorescent probes. Detailed in vitro studies to understand binding synergism in HER2 overexpressing cell lines were done. Antibodies and their F(ab')2 fragments prepared by enzyme digestion with pepsin were radiolabeled with iodine-125. In vitro binding studies to evaluate immunoreactivity, specificity, affinity, and binding synergism between radiolabeled trastuzumab, pertuzumab, and their F(ab')2 fragments were carried out. Synergism was observed by 20-30% enhanced uptake of radiolabeled pertuzumab and its F(ab')2 fragments in the presence of excess of unlabeled trastuzumab or F(ab')2-trastuzumab. However, uptake of radiolabeled trastuzumab was not enhanced in the presence of excess pertuzumab or its fragments; rather inhibition or competition in binding to HER2 was observed. Studies using fluorescent antibodies by flow cytometry confirmed enhanced binding of pertuzumab in the presence of trastuzumab. Live cell tracking was done to give insights into the binding synergy and fate of fluorescent antibodies . Colocalization of antibodies on HER2 followed by internalization in the cells was observed. The radiolabeled immunoconjugates served as an important tool for experimental characterization of interaction between pertuzumab and trastuzumab to HER2. link3 Studies with fluorescent antibodies corroborated the binding data and provided evidence of colocalization and internalization of both the antibodies in HER2-positive cells.Much progress has been made in developing tools to generate component-based design representations of biological systems from standard libraries of parts. Most biological designs, however, are still specified at the sequence level. Consequently, there exists a need for a tool that can be used to automatically infer component-based design representations from sequences, particularly in cases when those sequences have minimal levels of annotation. Such a tool would assist computational synthetic biologists in bridging the gap between the outputs of sequence editors and the inputs to more sophisticated design tools, and it would facilitate their development of automated workflows for design curation and quality control. Accordingly, we introduce Synthetic Biology Curation Tools (SYNBICT), a Python tool suite for automation-assisted annotation, curation, and functional inference for genetic designs. We have validated SYNBICT by applying it to genetic designs in the DARPA Synergistic Discovery & Design (SD2) program and the International Genetically Engineered Machines (iGEM) 2018 distribution. Most notably, SYNBICT is more automated and parallelizable than manual design editors, and it can be applied to interpret existing designs instead of only generating new ones.Bimetallic active sites in enzymes catalyze small-molecule conversions that are among the top 10 challenges in chemistry. As different metal cofactors are typically incorporated in varying protein scaffolds, it is demanding to disentangle the individual contributions of the metal and the protein matrix to the activity. Here, we compared the structure, properties, and hydrogen peroxide reactivity of four homobimetallic cofactors (Mn(II)2, Fe(II)2, Co(II)2, Ni(II)2) that were reconstituted into a four-helix bundle protein. Reconstituted proteins were studied in solution and in crystals. All metals bind with high affinity and yield similar cofactor structures. Cofactor variants react with H2O2 but differ in their turnover rates, accumulated oxidation states, and trapped peroxide-bound intermediates. Varying the metal composition thus creates opportunities to tune the reactivity of the bimetallic cofactor and to study and functionalize reactive species.Due to the current global SARS-CoV-2 pandemic, rapid and accurate diagnostic tools are needed to prevent the spread of COVID-19 across the globe. An electrochemical sensing platform was constructed using CNTs/WO3-screen printed electrodes for imprinting the complete virus particles (SARS-CoV-2 particles) within the polymeric matrix to create viral complementary binding sites. The sensor provided high selectivity toward the target virus over other tested human corona and influenza respiratory interference viruses. The sensitivity performance of the sensor chips was evaluated using different viral concentrations, while the limits of detection and quantification were 57 and 175 pg/mL, respectively. Reaching this satisfied low detection limit (almost 27-fold more sensitive than the RT-PCR), the sensor was applied in clinical specimens obtained from SARS-CoV-2 suspected cases. Thus, dealing directly with clinical samples on the chip could be provided as a portable device for instantaneous and simple point of care in hospitals, airports, and hotspots.With the development of technology, adjuvant immunotherapy has become a promising strategy for prevention of postoperative tumor regression and metastasis by stimulating the host immune response. However, the therapeutic effects are still unsatisfactory due to the lack of synergy between different methods. In this study, an efficient synergistic immunotherapy system based on injectable sodium alginate hydrogels was designed to inhibit in situ recurrence and metastasis at the same time. On the one hand, an injectable sodium alginate (SA) hydrogel microsystem loaded with toll-like receptor (TLR) agonists (CpG ODNs) was synthesized for inhibiting in situ recurrence, and then carcinoembryonic antigen (CEA) probe was also added to detect CEA based on fluorescence resonance energy transfer (FRET) technology to monitor the occurrence and development of tumor recurrence. On the other hand, an anti-programmed cell death 1 ligand 1 antibody (anti-PD-L1)-modified SA nanogel loaded with indocyanine green (ICG@SA-anti-PD-L1 nanogel) was prepared for diagnosing and inhibiting lung metastasis by assisting orthotopic tumor therapy.