Various aspects of self-motility of chemically active colloids in Newtonian fluids can be captured by simple models for their chemical activity plus a phoretic slip hydrodynamic boundary condition on their surface. For particles of simple shapes (e.g., spheres) -as employed in many experimental studies -which move at very low Reynolds numbers in an unbounded fluid, such models of chemically active particles effectively map onto the well studied so-called hydrodynamic squirmers [S. Michelin and E. Lauga, J. Fluid Mech. 747, 572 (2014)]. Accordingly, intuitively appealing analogies of "pusher/puller/neutral" squirmers arise naturally. Within the framework of self-diffusiophoresis we illustrate the above mentioned mapping and the corresponding flows in an unbounded fluid for a number of choices of the activity function (i.e., the spatial distribution and the type of chemical reactions across the surface of the particle). We use the central collision of two active particles as a simple, paradigmatic case for demonstrating that in the presence of other particles or boundaries the behavior of chemically active colloids may be qualitatively different, even in the far field, from the one exhibited by the corresponding "effective squirmer", obtained from the mapping in an unbounded fluid. This emphasizes that understanding the collective behavior and the dynamics under geometrical confinement of chemically active particles necessarily requires to explicitly account for the dependence of the hydrodynamic interactions on the distribution of chemical species resulting from the activity of the particles.I.

We investigate nematic wetting and filling transitions of crenellated surfaces (rectangular gratings) by numerical minimization of the Landau-de Gennes free energy as a function of the anchoring strength, for a wide range of the surface geometrical parameters: depth, width, and separation of the crenels. We have found a rich phase behavior that depends in detail on the combination of the surface parameters. By comparison to simple fluids, which undergo a continuous filling or unbending transition, where the surface changes from a dry to a filled state, followed by a wetting or unbinding transition, where the thickness of the adsorbed fluid becomes macroscopic and the interface unbinds from the surface, nematics at crenellated surfaces reveal an intriguingly rich behavior: in shallow crenels only wetting is observed, while in deep crenels, only filling transitions occur; for intermediate surface geometrical parameters, a new class of filled states is found, characterized by bent isotropic-nematic interfaces, which persist for surfaces structured on large scales, compared to the nematic correlation length. The global phase diagram displays two wet and four filled states, all separated by first-order transitions. For crenels in the intermediate regime re-entrant filling transitions driven by the anchoring strength are observed.

Traditional systemic chemotherapy involves the wide distribution of drug molecules in the body, causing toxic side effects in the healthy tissues and limiting the therapeutic dose required at the site of drug action. In order to decrease side effects and increase the drug efficacy, recent research on chemotherapy focuses on drug targeting. Targeted therapy can be achieved by several mechanisms including; 1) using an antibody as a drug that is specific to a disease biomarker, 2) using an antibody (or peptide) as a targeting agent conjugated to the drug molecule, 3) delivering the drug molecules to the target tissue in a nano-carrier with or without the targeting agent attached on its surface. The third approach involves the nanomedicines that can be targeted to diseased tissues by both passive (extravasating at diseased sites due to leaky vasculature) and active (specific interaction of the targeting agent with disease biomarker) targeting mechanisms. In this review we will cover the passively targeted nanomedicines prepared using nano drug carriers. Ideally the carrier particle should be in the right size (1-100nm), stable enough to prevent drug leakage during circulation, and safe not to cause any damage to healthy tissues. Competition for all these properties generated many different types of materials to be used as nanodrug delivery systems. After a brief review of most commonly used drug carriers, we discuss the clinical use of the targeted nanomedicines with regard to their pharmacokinetic and pharmacodynamics properties, and how these properties vary from conventional formulations providing free drugs in the circulation after administration.

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BackgroundFear of childbirth is a considerable mental, social, and physiological phenomenon among women as well as their families, which can be effective in choosing cesarean section for delivery.AimTo determine some factors contributing to the fear of childbirth among pregnant women.MethodThis cross-sectional study was conducted on 335 pregnant women referred to health centers in Toyserkan in 2016. Pregnant women with the gestational age of 16–40 weeks filled out Harman’s Childbirth Attitude Questionnaire (CAQ) as well as stating demographic and obstetrics characteristics. Data were analyzed by Software SPSS/19 through chi-square, ANOVA, and Pearson’s correlation tests.ResultsThe mean age and mean gestational age of the pregnant women were 26.5±4.9 years old and 26.52 weeks, respectively; 89.3% of the women reported fear of childbirth. There was a significant difference among the mean scores of the women’s fear of childbirth and education level, household income adequacy, gravidity, being familiar with the delivery process, and pre-pregnancy cares (p<0.05).ConclusionThe present study found the relationship between women’s fear of childbirth and their education level, household income, gravidity, familiarity with delivery process, and pre-pregnancy cares. It is necessary for health caregivers to take into consideration the vulnerable groups, especially nulliparous women during pre-pregnancy care as well as the social, and cultural status of women in order to identify the pregnant women exposed to fear of childbirth and reduce the chance of choosing cesarean section by providing appropriate services.

We propose the use of topographic modulation of surfaces to select and localize particles in nematic colloids. By considering convex and concave deformations of one of the confining surfaces we show that the colloid-flat surface repulsion may be enhanced or switched into an attraction. In particular, we find that when the colloidal particles have the same anchoring conditions as the patterned surfaces, they are strongly attracted to concave dimples, while if they exhibit different anchoring conditions they are pinned at the top of convex protrusions. Although dominated by elastic interactions the first mechanism is reminiscent of the depletion induced attraction or of the key-lock mechanism, while the second is specific to liquid crystal colloids. These long-ranged, highly tunable, surface-colloid interactions contribute for the development of template-assisted assembly of large colloidal crystals, with well defined symmetries, required for applications.

The division property method is a technique to determine integral distinguishers on block ciphers. While the complexity of finding these distinguishers is higher, it has recently been shown that MILP and SAT solvers can efficiently find such distinguishers. In this paper, we provide a framework to automatically find those distinguishers which solely requires a description of the cryptographic primitive. We demonstrate that by finding integral distinguishers for 30 primitives with different design strategies. We provide several new or improved bit-based division property distinguishers for ChaCha, Chaskey, DES, GIFT, LBlock, Mantis, Qarma, RoadRunner, Salsa and SM4. Furthermore, we present an algorithm to find distinguishers with lower data complexity more efficiently.

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