There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

: The unpolarized absorption and circular dichroism spectra of the fundamental vibrational transitions of the chiral molecule, 4-methyl-2-oxetanone, are calculated ab initio. Harmonic force fields are obtained using Density Functional Theory (DFT), MP2, and SCF methodologies and a 5S4P2D/3S2P (TZ2P) basis set. DFT calculations use the Local Spin Density Approximation (LSDA), BLYP, and Becke3LYP (B3LYP) density functionals. Mid-IR spectra predicted using LSDA, BLYP, and B3LYP force fields are of significantly different quality, the B3LYP force field yielding spectra in clearly superior, and overall excellent, agreement with experiment. The MP2 force field yields spectra in slightly worse agreement with experiment than the B3LYP force field. The SCF force field yields spectra in poor agreement with experiment.The basis set dependence of B3LYP force fields is also explored: the 6-31G* and TZ2P basis sets give very similar results while the 3-21G basis set yields spectra in substantially worse agreements with experiment. jg

Ab initio calculation of vibrational absorption and circular dichroism spectra using density functional force fields

Discovered in 2005, cyclic (alkyl)(amino)carbenes (CAACs) are among the most nucleophilic (σ donating) and also electrophilic (π-accepting) stable carbenes known to date. These properties allow them to activate a variety of small molecules and enthalpically strong bonds, to stabilize highly reactive main-group and transition-metal diamagnetic and paramagnetic species, and to bind strongly to metal centers, which gives rise to very robust catalysts. The most important results published up to the end of 2013 are briefly summarized, while the majority of this Review focuses on findings reported within the last three years.

Cyclic (Alkyl)(amino)carbenes (CAACs): Recent Developments

Nanocellulose-assisted 3D-printable, transparent, bio-adhesive, conductive, and biocompatible hydrogels as sensors and moist electric generators.

Naturally derived polymer hydrogels are extensively used in tissue engineering applications due to their excellent biocompatibility, electroconductivity, and biodegradability. The conductive hydrogels have great applications in the fields of biosensing, drug delivery, and skin-tissue regeneration, behavior that can be easily tuned by the external stimuli. Collagen-containing electronic skin has the potential to regenerate the skin surrounding the wound site with minimum secondary infection. However, this area is still unexplored due to limited information as well as applications. Herein, we elaborate the biomedical as well as agroecosystem applications of bioprinted hydrogels by considering some common examples. In addition, the source and nature of the different biopolymers used in this field are also discussed.

Naturally derived 3D printed hydrogel scaffolds for agroecosystem and biomedical applications

Coupled flexural and torsional vibration attenuation with locally resonant metamaterials

354Fabrication of multifunctional hemostats is indispensable against chronic blood loss and accelerated wound healing. Various hemostatic materials that aid wound repair or rapid tissue regeneration has been developed in the last 5 years. This review provides an overview of the three-dimensional (3D) hemostatic platforms designed through the latest technologies like electrospinning, 3D printing, and lithography, solely or in combination, for application in rapid wound healing. We critically discuss the pivotal role of micro/nano-3D topography and biomaterial properties in mediating rapid blood clots and healing at the hemostat-biointerface. We also highlight the advantages and limitations of the designed 3D hemostats. We anticipate that this review will guide the fabrication of smart hemostats of the future for tissue engineering applications.

Multifunctional 3D platforms for rapid hemostasis and wound healing: Structural and functional prospects at biointerfaces

One of the significant challenges in bone tissue engineering (BTE) is the healing of traumatic tissue defects which requires longer time to recover owing to the recruitment of local infection and delayed angiogenesis. Various strategies, such as hydrogel dressings, growth factors delivery, and stem cell therapy has been shown potential alternative to the traumatic tissue repair; however, limited their actual clinical application due to the socio-economic burden. Herein, we reported a 3D printable multi-functional hydrogel scaffold composing polyphenolic carbon quantum dots (CQDs, 100 ug mL-1 ) and gelatin methacryloyl (GelMA, 12 wt.%) for bone regeneration and anti-tumor therapy. The CQDs was synthesized from a plant-inspired bioactive molecule, 1, 3, 5-trihydroxybenzene (a polyphenol) via facile wet chemistry method. The 3D printed GelMA-CQDs hydrogels displayed typical shear-thinning behavior with excellent printability. Our results demonstrated that the nanocomposite 3D hydrogel promoted M2 polarization of macrophage (Raw 264.7) cells via upregulation of anti-inflammatory genes (e.g., IL-4 and IL10), and induced angiogenesis and osteogenesis of human bone mesenchymal stem cells (hBMSCs). The bioprinted hBMSCs were able to produced vessel-like structures in the presence of GelMA-CQDs hydrogel after 14 days of incubation. Furthermore, the 3D printed scaffolds also showed remarkable near infra-red (NIR) responsive properties under 808 nm NIR light (1.0 W cm-2 ) irradiation and showed controlled release of antitumor drugs (∼49%) at pH 6.5, and thereby killing the osteosarcoma cells. Therefore, we anticipate that the tissue regeneration and healing ability with therapeutic potential of the 3D printed GelMA-CQDs scaffolds may provide a promising alternative for traumatic tissue regeneration via augmenting angiogenesis and accelerated immunomodulation. This article is protected by copyright. All rights reserved.

A 3D Bioprinted Nanoengineered Hydrogel with Photo-activated Drug Delivery for Tumor Apoptosis and Simultaneous Bone Regeneration via Macrophage Immunomodulation.

Sayan Dutta

Papers

Nanocellulose-assisted 3D-printable, transparent, bio-adhesive, conductive, and biocompatible hydrogels as sensors and moist electric generators.

Naturally derived 3D printed hydrogel scaffolds for agroecosystem and biomedical applications

Coupled flexural and torsional vibration attenuation with locally resonant metamaterials

Multifunctional 3D platforms for rapid hemostasis and wound healing: Structural and functional prospects at biointerfaces

A 3D Bioprinted Nanoengineered Hydrogel with Photo-activated Drug Delivery for Tumor Apoptosis and Simultaneous Bone Regeneration via Macrophage Immunomodulation.