Amphiphile Adsorption on Rigid Polyelectrolytes

A theory is presented which quantitatively accounts for the cooperative adsorption of cationic surfactants to anionic polyelectrolytes. For high salt concentration we find that the critical adsorption concentration (CAC) is a bilinear function of the polyion monomer and salt concentrations, with the coefficients dependent only on the type of surfactant used. The results presented in the paper might be useful for designing more efficient gene delivery systems

Nonequilibrium stationary states of 3D self-gravitating systems

Three dimensional self-gravitating systems do not evolve to thermodynamic equilibrium, but become trapped in nonequilibrium quasistationary states. In this Letter we present a theory which allows us to a priori predict the particle distribution in a final quasistationary state to which a self-gravitating system will evolve from an initial condition which is isotropic in particle velocities and satisfies a virial constraint 2K=-U, where K is the total kinetic energy and U is the potential energy of the system

Gravitational Lensing and the Power Spectrum of Dark Matter Substructure: Insights from the ETHOS N-body Simulations

Strong gravitational lensing has been identified as a promising astrophysical probe to study the particle nature of dark matter. In this paper we present a detailed study of the power spectrum of the projected mass density (convergence) field of substructure in a Milky Way-sized halo. This power spectrum has been suggested as a key observable that can be extracted from strongly lensed images and yield important clues about the matter distribution within the lens galaxy. We use two different $N$-body simulations from the ETHOS framework: one with cold dark matter and another with self-interacting dark matter and a cutoff in the initial power spectrum. Despite earlier works that identified $k \gtrsim 100$ kpc$^{-1}$ as the most promising scales to learn about the particle nature of dark matter we find that even at lower wavenumbers - which are actually within reach of observations in the near future - we can gain important information about dark matter. Comparing the amplitude and slope of the power spectrum on scales $0.1 \lesssim k/$kpc$^{-1} \lesssim 10$ from lenses at different redshifts can help us distinguish between cold dark matter and other exotic dark matter scenarios that alter the abundance and central densities of subhalos. Furthermore, by considering the contribution of different mass bins to the power spectrum we find that subhalos in the mass range $10^7 - 10^8$ M$_{\odot}$ are on average the largest contributors to the power spectrum signal on scales $2 \lesssim k/$kpc$^{-1} \lesssim 15$, despite the numerous subhalos with masses $> 10^8$ M$_{\odot}$ in a typical lens galaxy. Finally, by comparing the power spectra obtained from the subhalo catalogs to those from the particle data in the simulation snapshots we find that the seemingly-too-simple halo model is in fact a fairly good approximation to the much more complex array of substructure in the lens.Comment: 13 pages + appendices, 7 figure

Current concepts and challenges in osteochondral tissue engineering and regenerative medicine

"Publication Date (Web): February 20, 2015"In the last few years, great progress has been made to validate tissue engineering strategies in preclinical studies and clinical trials on the regeneration of osteochondral defects. In the preclinical studies, one of the dominant strategies comprises the development of biomimetic/bioactive scaffolds, which are used alone or incorporated with growth factors and/or stem cells. Many new trends are emerging for modulation of stem cell fate towards osteogenic and chondrogenic differentiations, but bone/cartilage interface regeneration and physical stimulus have been showing great promise. Besides the matrix-associated autologous chondrocyte implantation (MACI) procedure, the matrix-associated stem cells implantation (MASI) and layered scaffolds in acellular or cellular strategy are also applied in clinic. This review outlines the progresses at preclinical and clinical levels, and identifies the new challenges in osteochondral tissue engineering. Future perspectives are provided, e.g., the applications of extracellular matrix-like biomaterials, computer-aided design/manufacture of osteochondral implant and reprogrammed cells for osteochondral regeneration.The authors thank the Portuguese Foundation for Science and Technology (FCT) through the projects TISSUE2TISSUE (PTDC/CTM/105703/2008) and OsteoCart (PTDC/CTM-BPC/115977/2009). We also acknowledge European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement REGPOT-CT2012-316331-POLARIS. L-P.Y. acknowledges the PhD scholarship from FCT (SFRH/BD/64717/2009). The FCT distinction attributed to J.M.O. and A.L.O. under the Investigator FCT program (IF/00423/2012) and (IF/00411/2013) are also greatly acknowledged

Menuju Perencanaan Lansekap Apartemen yang Berkelanjutan Setelah Covid-19: : Perencanaan Berdasarkan Fenomena atau Hanya Atas Faktor Landasan Kebutuhan Kapitalisme?

Perancangan lansekap akan senantiasa mengalami perkembangan mengikuti kebutuhan manusia yang dinamis dan tuntutan perubahan zaman. Dengan adanya fenomena Covid-19 juga menjadikan perencanaan kebutuhan lansekap apartemen menjadi pertanyaan besar ke mana akan mengalami perubahan, karena kota-kota besar akan senantiasa berkembang dan fenomena Covid-19 menjadikan disaster management perencanaan lansekap menjadi pertimbangan dasar yang perlu menjadi landasan dalam mem-breakdown ke arah mana konsep-konsep baru perlu dikembangkan. Analisis ini dilakukan secara kualitatif, berupaya menganalisis dan mengambil contoh-contoh kasus pula dan mengevaluasinya sehingga dapat diketahui elemen-elemen yang perlu diperhatikan dalam perancangan lansekap apartemen di masa mendatang. Hasil dari penelitian ini adalah berupa perbandingan antara ke-3 kasus apartemen yang dibangun pada periode berbeda antara tahun 2009-2016. Rekomendasi penelitian ini adalah berupa usulan ketetapan regulasi perbandingan prosentase antara fungsi perumahan dan sarana prasarana komersial, menerapkan regulasi yang ada mengenai sarana prasarana (dari Kementerian PU) secara lebih konsekuen, ketetapan regulasi mengenai aturan vegetasi yang sesuai kaidah lingkungan hidup dan degradasi yang terjadi, proporsi ruang bermain anak yang ramah anak, dan mengkaji serta menerapkan adaptasi adaptasi ruang yang terjadi sebagai adaptasi terhadap perencananaan ruang setelah pandemik yang berorientasi keberlanjutan kota dan masyarakat secara jangka panjang