Organocatalytic enantioselective decarboxylative aldol reaction of malonic acid half thioesters with aldehydes

Copycat: A highly enantioselective biomimetic aldol reaction of malonic acid half thioesters with a variety of aldehydes affords optically active ??-hydroxy thioesters by employing the cinchona-derived sulfonamide organocatalyst 1. The synthetic utility of this protocol was demonstrated by performing formal syntheses of the antidepressants (R)-fluoxetine, (R)-tomoxetine, (-)-paroxetine, and (R)-duloxetine

Two-dimensional Peierls instability via zone-boundary Dirac line nodes in layered perovskite oxides

Interplay of Fermi surface topology and electron correlation is the quintessential ingredient underlying spontaneous symmetry breaking in itinerant electronic systems. In one-dimensional (1D) systems at half filling, the inherent Fermi surface nesting makes the translationally invariant metallic state unstable, which is known as Peierls instability. Extending the scope of Peierls instability to two (2D) or three dimensions (3D), however, is not straightforward, since the Fermi surface in higher dimensions is generally not nested. In this work, we show that a perfectly nested Fermi surface can be realized in a class of 2D perovskite oxides, giving rise to 2D Peierls instability. Here the central role is played by the zone-boundary Dirac line node (DLN) protected by two orthogonal glide mirrors induced by the rotation of oxygen octahedra. Especially at a critical angle of the octahedron rotation, the zone-boundary DLN flattens, leading to logarithmically diverging susceptibility. We propose the 2D Peierls instability driven by dispersionless DLN as a principle mechanism for spontaneous symmetry breaking in various layered perovskite oxides including the antiferromagnetism of Sr2IrO4. As a clear signature of the 2D Peierls instability, we predict that the magnetic domain wall in Sr2IrO4 hosts localized soliton modes

Gravity-oriented microfluidic device for uniform and massive cell spheroid formation

We propose a simple method for forming massive and uniform three-dimensional (3-D) cell spheroids in a multi-level structured microfluidic device by gravitational force. The concept of orienting the device vertically has allowed spheroid formation, long-term perfusion, and retrieval of the cultured spheroids by user-friendly standard pipetting. We have successfully formed, perfused, and retrieved uniform, size-controllable, well-conditioned spheroids of human embryonic kidney 293 cells (HEK 293) in the gravity-oriented microfluidic device. We expect the proposed method will be a useful tool to study in-vitro 3-D cell models for the proliferation, differentiation, and metabolism of embryoid bodies or tumours

Systems-level mechanisms of action of Panax ginseng: a network pharmacological approach

Panax ginseng has been used since ancient times based on the traditional Asian medicine theory and clinical experiences, and currently, is one of the most popular herbs in the world. To date, most of the studies concerning P. ginseng have focused on specific mechanisms of action of individual constituents. However, in spite of many studies on the molecular mechanisms of P. ginseng, it still remains unclear how multiple active ingredients of P. ginseng interact with multiple targets simultaneously, giving the multidimensional effects on various conditions and diseases. In order to decipher the systems-level mechanism of multiple ingredients of P. ginseng, a novel approach is needed beyond conventional reductive analysis. We aim to review the systems-level mechanism of P. ginseng by adopting novel analytical framework–network pharmacology. Here, we constructed a compound-target network of P. ginseng using experimentally validated and machine learning-based prediction results. The targets of the network were analyzed in terms of related biological process, pathways, and diseases. The majority of targets were found to be related with primary metabolic process, signal transduction, nitrogen compound metabolic process, blood circulation, immune system process, cell-cell signaling, biosynthetic process, and neurological system process. In pathway enrichment analysis of targets, mainly the terms related with neural activity showed significant enrichment and formed a cluster. Finally, relative degrees analysis for the target-disease association of P. ginseng revealed several categories of related diseases, including respiratory, psychiatric, and cardiovascular diseases

PPV ????????? ??? ?????????????????? ?????? ???????????? ?????? EL ????????? ?????? ??? ??????

Poly(p-phenylene vinylene), PPV??? ??????????????? ?????? ???????????????(electron transport layer, ETL)??? ????????? ?????? ???????????? ?????? ??????????????????(electroluminescence device, ELD)??? ???????????? ?????? ?????? ????????? ???????????????. ?????? ??????????????? 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole(PBD)??? ???????????? ?????? ???????????? ?????? ?????????(matrix polymer)?????? stilbene??? ??????????????? ???????????? poly(styrene-co-p-vinyl-trans-stilbene (PVTS)), poly(styrene-co-MeO-PVTS) ??? poly(styrene-co-MeO-ST)??? ???????????????. ?????? ????????? ???????????? ?????? ???????????? ELD??? ?????????????????? poly(styrene-co-PVTS)??? ?????? ???????????? ??? EL ????????? ????????? ????????? ???????????? ???????????????. Poly(styrene-co-MeO-PVTS) ??? poly(styrene-co-MeO-ST) ??? ?????? ?????? ????????? ?????? methoxy?????? ???????????? ?????? ???????????? ??? EL ????????? ?????? ???????????? ?????? ITO/PPV/Mg ?????? ????????? ????????? ?????? ?????? ?????? ????????????. Poly(styrene-co-PVTS)??? ETL??? ??? EL ????????? ????????? styrene?????? ??? conjugation ????????? ????????? EL ?????? ??????????????? ????????? ????????? ?????? ?????? ?????? ????????? PPV??? ?????? ?????? ???????????? ???????????????. Organic eletroluminescence devices (ELD) with hetero-junction structure were fabricated utilizing poly(p-phenylne vinylene) (PPV) as emitting layer and electron transport layer (ETL). 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD) was used as an electron transport agent. Copolymers with stilbene type comonomers, such as poly(styrene-co-PVTS), poly(styrene-co-MeO-PVTS) and poly(styrene-co-MeO-ST) were synthesized to be used as a matrix polymer to disperse electron transport agent (PBD). Among the hetero-junction EL devices fabricated with the above materials, the device with poly(styrene-co-PVTS) as matrix polymer for ETL gave the highest luminance (120.7 cd/m(2), 13 V). EL devices made with poly(styrene-co-MeO-PVTS) or poly(styrene-co-MeO-ST) matrix exhibited lower luminance than the one with polystyrene matrix and the single layer EL (ITO/PPV/Mg) device.clos

Inhibition of Biofilm Formation in <i>Cutibacterium acnes</i>, <i>Staphylococcus aureus</i>, and <i>Candida albicans</i> by the Phytopigment Shikonin

Skin microbiota, such as acne-related Cutibacterium acnes, Staphylococcus aureus, and fungal Candida albicans, can form polymicrobial biofilms with greater antimicrobial tolerance to traditional antimicrobial agents and host immune systems. In this study, the phytopigment shikonin was investigated against single-species and multispecies biofilms under aerobic and anaerobic conditions. Minimum inhibitory concentrations of shikonin were 10 µg/mL against C. acnes, S. aureus, and C. albicans, and at 1–5 µg/mL, shikonin efficiently inhibited single biofilm formation and multispecies biofilm development by these three microbes. Shikonin increased porphyrin production in C. acnes, inhibited cell aggregation and hyphal formation by C. albicans, decreased lipase production, and increased hydrophilicity in S. aureus. In addition, shikonin at 5 or 10 µg/mL repressed the transcription of various biofilm-related genes and virulence-related genes in C. acnes and downregulated the gene expression levels of the quorum-sensing agrA and RNAIII, α-hemolysin hla, and nuclease nuc1 in S. aureus, supporting biofilm inhibition. In addition, shikonin prevented multispecies biofilm development on porcine skin, and the antimicrobial efficacy of shikonin was recapitulated in a mouse infection model, in which it promoted skin regeneration. The study shows that shikonin inhibits multispecies biofilm development by acne-related skin microbes and might be useful for controlling bacterial infections