Hypoxic Culture Conditions as a Solution for Mesenchymal Stem Cell Based Regenerative Therapy

Cell-based regenerative therapies, based on in vitro propagation of stem cells, offer tremendous hope to many individuals suffering from degenerative diseases that were previously deemed untreatable. Due to the self-renewal capacity, multilineage potential, and immunosuppressive property, mesenchymal stem cells (MSCs) are considered as an attractive source of stem cells for regenerative therapies. However, poor growth kinetics, early senescence, and genetic instability during in vitro expansion and poor engraftment after transplantation are considered to be among the major disadvantages of MSC-based regenerative therapies. A number of complex inter-and intracellular interactive signaling systems control growth, multiplication, and differentiation of MSCs in their niche. Common laboratory conditions for stem cell culture involve ambient O-2 concentration (20%) in contrast to their niche where they usually reside in 2-9% O-2. Notably, O-2 plays an important role in maintaining stem cell fate in terms of proliferation and differentiation, by regulating hypoxia-inducible factor-1 (HIF-1) mediated expression of different genes. This paper aims to describe and compare the role of normoxia (20% O-2) and hypoxia (2-9% O-2) on the biology of MSCs. Finally it is concluded that a hypoxic environment can greatly improve growth kinetics, genetic stability, and expression of chemokine receptors during in vitro expansion and eventually can increase efficiency of MSC-based regenerative therapies.Article Link: http://www.hindawi.com/journals/tswj/2013/632972

Multiphoton excitations in vibrational rotational states of diatomic molecules in intense electromagnetic field

A theory is presented and a calculational procedure is outlined for evaluating transition amplitudes of multiphoton excitations of vibrational-rotational levels in diatomic molecules. This theory can be utilized in studying behavior of molecules in intense electromagnetic fields

Numerical analysis of second harmonic generation in soft glass equiangular spiral photonic crystal fibers

In this paper, the accurate and numerically efficient finite element (FE)-based beam propagation method (BPM) has been employed to investigate second harmonic generation (SHG) in highly nonlinear soft glass (SF57) equiangular spiral photonic crystal fibers (ES-PCFs) for the first time. It is shown here that the SHG output power in highly nonlinear SF57 soft glass PCF exploiting the ES design is significantly higher compared with that of silica PCF with hexagonal air-hole arrangements. The effects of fabrication tolerances on the coherence length and the modal properties of ES-PCF are also illustrated. Moreover, phase matching between the fundamental and the second harmonic modes is discussed through the use of the quasi-phase matching technique. Furthermore, the ultralow bending loss in the SF57 ES-PCF design has been successfully analyzed

Contributing Factors to Under-Five Child Malnutrition in Rural Bangladesh

Background and objectives: Bangladesh has the highest malnutrition rates in the world. The main objective of this study is to identify and determine the main factors for child malnutrition among children under the age 5 years in rural Bangladesh. Material and methods: This research was conducted in rural areas at Meherpur district in Bangladesh. Convenience sampling method is used and 85 under 5 child information is collected through a structured questionnaire. The information’s of child’s are gathered from the mothers of the child. Malnourished children is measured by using APLS method and WHO Child Growth Standard Median Index. Binary logistic regression model is used to find out the key factors of malnutrition. Results: It is found that family income, maintain proper diet during pregnancy period, proper diet maintain for children have negative significant (p\u3c0.05) effect on child malnutrition. Conclusion: The magnitude of the child’s malnutrition still is of great concern in Bangladesh. Since, poverty, imbalanced diet during pregnancy period and imbalanced diet for under 5 children influences to malnutrition are significantly associated with high prevalence of malnutrition, so government and people should reduce these factor to reduce malnutrition in rural area of Bangladesh

Soft Glass Equiangular Spiral Photonic Crystal Fiber for Supercontinuum Generation

An equiangular spiral photonic crystal fiber (ES-PCF) design in soft glass is presented that has high nonlinearity ( gamma > 5250 W-1 middot km-1 at 1064 nm and gamma > 2150 W-1 middot km-1 at 1550 nm) with a low and flat dispersion (D ~ 0.8 ps/kmmiddotnm and dispersion slope ~ -0.7 ps/km middot nm2 at 1060 nm). The design inspired by nature is characterized by a full-vectorial finite element method. The ES-PCF presented improves over the mode confinement of triangular core designs and dispersion control of conventional hexagonal PCF, combining the advantages of both designs; it can be an excellent candidate for generating supercontinuum pumped at 1.06 mum