Infrared emission from interstellar dust cloud with two embedded sources: IRAS 19181+1349

Mid and far infrared maps of many Galactic star forming regions show multiple peaks in close proximity, implying more than one embedded energy sources. With the aim of understanding such interstellar clouds better, the present study models the case of two embedded sources. A radiative transfer scheme has been developed to deal with an uniform density dust cloud in a cylindrical geometry, which includes isotropic scattering in addition to the emission and absorption processes. This scheme has been applied to the Galactic star forming region associated with IRAS 19181+1349, which shows observational evidence for two embedded energy sources. Two independent modelling approaches have been adopted, viz., to fit the observed spectral energy distribution (SED) best; or to fit the various radial profiles best, as a function of wavelength. Both the models imply remarkably similar physical parameters.Comment: 17 pages, 6 Figures, uses epsf.sty. To appear in Journal of Astronophysics & Astronom

A cell rolling cytometer reveals the correlation between mesenchymal stem cell dynamic adhesion and differentiation state

This communication presents quantitative studies of the dynamic adhesion behavior of mesenchymal stem cells (MSCs) enabled by the combination of cell-surface receptor–ligand interactions and three-dimensional hydrodynamic control by microtopography.National Institutes of Health (U.S.) (Grant HL-095722)National Institutes of Health (U.S.) (Grant HL-097172)National Science Foundation (U.S.) (CAREER Award 0952493)Korea (South). Ministry of Science, ICT and Future Planning (National Research Foundation of Korea. Pioneer Research Center Program 2013M3C1A3064777)National Research Foundation of Korea (Framework of International Cooperation Program 2013K2A1A2053078

Dysfunctional stem and progenitor cells impair fracture healing with age

Successful fracture healing requires the simultaneous regeneration of both the bone and vasculature; mesenchymal stem cells (MSCs) are directed to replace the bone tissue, while endothelial progenitor cells (EPCs) form the new vasculature that supplies blood to the fracture site. In the elderly, the healing process is slowed, partly due to decreased regenerative function of these stem and progenitor cells. MSCs from older individuals are impaired with regard to cell number, proliferative capacity, ability to migrate, and osteochondrogenic differentiation potential. The proliferation, migration and function of EPCs are also compromised with advanced age. Although the reasons for cellular dysfunction with age are complex and multidimensional, reduced expression of growth factors, accumulation of oxidative damage from reactive oxygen species, and altered signaling of the Sirtuin-1 pathway are contributing factors to aging at the cellular level of both MSCs and EPCs. Because of these geriatric-specific issues, effective treatment for fracture repair may require new therapeutic techniques to restore cellular function. Some suggested directions for potential treatments include cellular therapies, pharmacological agents, treatments targeting age-related molecular mechanisms, and physical therapeutics. Advanced age is the primary risk factor for a fracture, due to the low bone mass and inferior bone quality associated with aging; a better understanding of the dysfunctional behavior of the aging cell will provide a foundation for new treatments to decrease healing time and reduce the development of complications during the extended recovery from fracture healing in the elderly

Interval type-2 fuzzy modelling and stochastic search for real-world inventory management

Real-world systems present a variety of challenges to the modeller, not least of which is the problem of uncertainty inherent in their operation. In this research, an interval type-2 fuzzy model is applied to a real-world problem, the goal being to discover a suitable optimisation configuration to enable a search for an inventory plan using the model. To this end, a series of simulated annealing configurations and the interval type-2 fuzzy model were used to search for appropriate inventory plans for a large-scale real-world problem. A further set of tests were conducted in which the performance of the interval type-2 fuzzy model was compared with a corresponding type-1 fuzzy model. In these tests the results were inconclusive, though, as will be discussed there are many ways in which type-2 fuzzy logic can be exploited to demonstrate its advantages over a type-1 approach. To conclude, in this research we have shown that a combination of interval type-2 fuzzy logic and simulated annealing is a logical choice for inventory management modelling and inventory plan search, and propose that the benefits that a type-2 model offers, can make it preferable to a corresponding type-1 system

Transepithelial Transport of Fc-Targeted Nanoparticles by the Neonatal Fc Receptor for Oral Delivery

Nanoparticles are poised to have a tremendous impact on the treatment of many diseases, but their broad application is limited because currently they can only be administered by parenteral methods. Oral administration of nanoparticles is preferred but remains a challenge because transport across the intestinal epithelium is limited. We show that nanoparticles targeted to the neonatal Fc receptor (FcRn), which mediates the transport of immunoglobulin G antibodies across epithelial barriers, are efficiently transported across the intestinal epithelium using both in vitro and in vivo models. In mice, orally administered FcRn-targeted nanoparticles crossed the intestinal epithelium and reached systemic circulation with a mean absorption efficiency of 13.7%*hour compared with only 1.2%*hour for nontargeted nanoparticles. In addition, targeted nanoparticles containing insulin as a model nanoparticle-based therapy for diabetes were orally administered at a clinically relevant insulin dose of 1.1 U/kg and elicited a prolonged hypoglycemic response in wild-type mice. This effect was abolished in FcRn knockout mice, indicating that the enhanced nanoparticle transport was specifically due to FcRn. FcRn-targeted nanoparticles may have a major impact on the treatment of many diseases by enabling drugs currently limited by low bioavailability to be efficiently delivered though oral administration.Prostate Cancer Foundation (Award in Nanotherapeutics)National Cancer Institute (U.S.) (Center for Cancer Nanotechnology Excellence U54-CA151884)National Heart, Lung, and Blood Institute (Program of Excellence in Nanotechnology Award Contract HHSN268201000045C)National Institutes of Health (U.S.) (Grant EB000244)National Institutes of Health (U.S.) (R01 Grant EB015419-01)American Society for Engineering Education. National Defense Science and Engineering Graduate FellowshipNational Cancer Institute (U.S.) (Center for Cancer Nanotechnology Excellence Graduate Research Fellowship 5 U54 CA151884-02

Microfluidic technologies for accelerating the clinical translation of nanoparticles

Using nanoparticles for therapy and imaging holds tremendous promise for the treatment of major diseases such as cancer. However, their translation into the clinic has been slow because it remains difficult to produce nanoparticles that are consistent ‘batch-to-batch’, and in sufficient quantities for clinical research. Moreover, platforms for rapid screening of nanoparticles are still lacking. Recent microfluidic technologies can tackle some of these issues, and offer a way to accelerate the clinical translation of nanoparticles. In this Progress Article, we highlight the advances in microfluidic systems that can synthesize libraries of nanoparticles in a well-controlled, reproducible and high-throughput manner. We also discuss the use of microfluidics for rapidly evaluating nanoparticles in vitro under microenvironments that mimic the in vivo conditions. Furthermore, we highlight some systems that can manipulate small organisms, which could be used for evaluating the in vivo toxicity of nanoparticles or for drug screening. We conclude with a critical assessment of the near- and long-term impact of microfluidics in the field of nanomedicine

A new scheme of radiation transfer in H II regions including transient heating of grains

A new scheme of radiation transfer for understanding infrared spectra of H II regions, has been developed. This scheme considers non-equilibrium processes (e. g. transient heating of the very small grains, VSG; and the polycyclic aromatic hydrocarbon, PAH) also, in addition to the equilibrium thermal emission from normal dust grains (BG). The spherically symmetric interstellar dust cloud is segmented into a large number of "onion skin" shells in order to implement the non-equilibrium processes. The scheme attempts to fit the observed SED originating from the dust component, by exploring the following parameters : (i) geometrical details of the dust cloud, (ii) PAH size and abundance, (iii) composition of normal grains (BG), (iv) radial distribution of all dust (BG, VSG & PAH). The scheme has been applied to a set of five compact H II regions (IRAS 18116- 1646, 18162-2048, 19442+2427, 22308+5812 & 18434-0242) whose spectra are available with adequate spectral resolution. The best fit models and inferences about the parameters for these sources are presented.Comment: 16 pages total including 3 tables and 2 figure