Aguilarlundgren2538

An automated, high-capacity, and high-throughput procedure for the rapid isolation and identification of biologically active natural products from a prefractionated library is presented. The semipreparative HPLC method uses 1 mg of the primary hit fraction and produces 22 subfractions in an assay-ready format. Following screening, all active fractions are analyzed by NMR, LCMS, and FTIR, and the active principle structural classes are elucidated. In the proof-of-concept study, we show the processes involved in generating the subfractions, the throughput of the structural elucidation work, as well as the ability to rapidly isolate and identify new and biologically active natural products. Overall, the rapid second-stage purification conserves extract mass, requires much less chemist time, and introduces knowledge of structure early in the isolation workflow.The neural differentiation of embryonic stem cells (ESCs) is of great value in the treatment of neurodegenerative diseases. Based on the two related signaling pathways that direct the neural differentiation of ESCs, we used gold nanoparticles (GNP) as a means of combining chemical and physical cues to trigger the neurogenic differentiation of stem cells. Neural differentiation-related functional units (glyco and sulfonate units on glycosaminoglycans, GAG) were anchored on the GNP surface and were then transferred to the cell membrane surface via GNP-membrane interactions. The functional units were able to activate the GAG-related signaling pathway, in turn promoting differentiation and maturation of stem cells into neuronal lineages. In addition, using the photothermal effect of GNP, the differentiation-inducing factor retinoic acid (RA), could be actively delivered into cells via laser irradiation. The RA-related intracellular signaling pathway was thereby further triggered, resulting in strong promotion of neurogenesis with a 300-fold increase in mature neural marker expression. The gold nanocomposites developed in this work provide the basis for a new strategy directing ESCs differentiation into nerve cells with high efficiency and high purity by acting on two related signaling pathways.Niobium oxide (NbOx) materials of various compositions are of interest for neuromorphic systems that rely on memristive device behavior. In this study, we vary the composition of NbOx thin films deposited via atomic layer deposition (ALD) by incorporating one or more in situ hydrogen plasma exposure steps during the ALD supercycle. Films with compositions ranging from Nb2O5 to NbO2 were deposited, with film composition dependent on the duration of the plasma exposure step, the number of plasma exposure steps per ALD supercycle, and the hydrogen content of the plasma. The chemical and optical properties of the ALD NbOx films were probed using spectral ellipsometry, X-ray photoelectron spectroscopy, and optical transmission spectroscopy. Two-terminal electrical devices fabricated from ALD Nb2O5 and NbO2 thin films exhibited memristive switching behavior, with switching in the NbO2 devices achieved without a high-field electroforming step. The ability to controllably tune the composition of ALD-grown NbOx films opens new opportunities for realizing a variety of device structures relevant for neuromorphic computing and other emerging electronic and optoelectronic applications.Mg3Sb2-based compounds by virtue of non-toxicity and low-cost become a promising class of candidates for mid-temperature thermoelectric power generation. Here, we successfully fabricated n-type Mg3Sb2-based materials using an inexpensive and efficient approach of one-step ball milling and spark plasma sintering, and demonstrate that complementary and favorable effect of multiple elements co-alloying/-doping leads to an excellent thermoelectric performance. The intrinsic p-type conducting behavior for Mg3Sb2 could be changed to n-type ones through Bi and Se co-alloying on Sb sublattices with excess Mg, resulting from the suppression of Mg vacancies and the formation of Mg interstitial. Inflammation inhibitor Furthermore, Mn doping on Mg sublattices could soften the chemical bonds, leading the increase of carrier mobility and concentration simultaneously. Additionally, multi-element co-alloying/-doping could significantly increase the lattice disorder, which undoubtedly strengthens the phonon scattering and readily results in a suppressed lattice thermal conductivity. As a result, a highest ZT value of 1.6 at 723 K, and an average ZT value up to 1.1 was obtained in the temperature range of 323-723 K in the Mg3.18Mn0.02Sb1.5Bi0.49Se0.01 sample, which is one of the highest value among the Te free Mg3Sb2. This work could give a guidance for improving the thermoelectric performance of Zintl phase materials or even others using the multi-element co-doping/-alloying strategy. Keywords Thermoelectric materials; Zintl compounds; ball milling; spark plasma sintering; n-type Mg3Sb2; (Mn, Se) codoping.Therapeutic efficacy of synergistic photodynamic therapy (PDT) and photothermal therapy (PTT) is limited by complex conjugation chemistry, absorption wavelength mismatch, and inadequate biodegradability of the PDT-PTT agents. Herein, we designed biocompatible copper sulfide nanodot anchored folic acid-modified black phosphorus nanosheets (BP-CuS-FA) to overcome these limitations, consequently enhancing the therapeutic efficiency of PDT-PTT. In vitro and in vivo assays reveal good biocompatibility and commendable tumor inhibition efficacy of the BP-CuS-FA nanoconjugate because of the synergistic PTT-PDT mediated by near-infrared laser irradiation. Importantly, folic acid unit could target folate receptor overexpressed cancer cells, leading to enhanced cellular uptake of BP-CuS-FA. BP-CuS-FA also exhibits significant contrast effect for photoacoustic imaging, permitting its in vivo tracking. The photodegradable character of BP-CuS-FA is associated with better renal clearance after the antitumor therapy in vivo. The present research may facilitate further development on straightforward approaches for targeted and imaging-guided synergistic PDT-PTT of cancer.The construction of β-d-fructofuranosidic linkages is one of the major challenges in carbohydrate chemistry. In this work, we developed an efficient method for the synthesis of β-d-fructofuranosides by using a 6-picoloyl-protected fructofuranosyl thioglycoside as the glycosyl donor. Subsequently, we applied the approach to a wide variety of donors and acceptors. Furthermore, the successful synthesis of levantetrose confirmed its applicability in the multistep synthesis of oligosaccharides.