A new approximate evaluation method for two-echelon inventory systems with emergency shipments

We consider the control of repairable spare parts in a network consisting of a central warehouse, a central repair facility, and multiple local warehouses. Demands for spare parts occur at the local warehouses. If a local warehouse is out of stock, then an arriving demand is satisfied by an emergency delivery from the central warehouse or the central repair facility. Such emergency shipments are common practice for networks that support technical systems with high downtime costs, and it is important to take them into account when the inventory is optimized. Our main contribution consists of the development of a new approximate evaluation method. This method gives accurate approximations for the key performance measures, as we show via numerical analysis. The method is also fast and thus can easily be incorporated in existing (greedy) heuristic optimization methods. Our method outperforms the approximate evaluation method of Muckstadt and Thomas (1980), as we also show via the numerical analysis. Finally, we show that the performance of the system is rather insensitive to the leadtime distribution of the repairs at the central repair facility, which implies that our method works well for generally distributed repair leadtimes

Tree Growth Yield and Fruit Quality of Different Apple Cultivars Trained as Super Spindle

This study was carried out on Topaz, Cooper 39 and Muscat apple cultivars grafted on M27 rootstocks under Tokat ecological conditions during 2008 - 2010. The trees planted in 2.0 m x 0.5 m row spacing (10,000 trees ha-1) and trained to super spindle (SS) training system. The vegetative development, yield and fruit quality performances of the trees supported by wire – pole combination were observed for three years. At the end of the experiment, it was determined that Cooper 39 had a higher trunk cross sectional area (TCA) than Topaz and Muscat. While cumulative yield (CY) per tree and cumulative yield efficiency (CYE) were determined to be the highest in Cooper 39, these values were found to be the lowest in Topaz. CY per hectare over the first three crop year was found to be the highest in Cooper 39 and the yield reached to 142.9 t.ha1. The lowest CY per hectare (69.6 ton ha-1) was determined in Topa

Zeta potential: A surface electrical characteristic to probe the interaction of nanoparticles with normal and cancer human breast epithelial cells

We demonstrate the use of surface Zeta potential measurements as a new tool to investigate the interactions of iron oxide nanoparticles and cowpea mosaic virus (CPMV) nanoparticles with human normal breast epithelial cells (MCF10A) and cancer breast epithelial cells (MCF7) respectively. A substantial understanding in the interaction of nanoparticles with normal and cancer cells in vitro will enable the capabilities of improving diagnostic and treatment methods in cancer research, such as imaging and targeted drug delivery. A theoretical Zeta potential model is first established to show the effects of binding process and internalization process during the nanoparticle uptake by cells and the possible trends of Zeta potential change is predicted for different cell endocytosis capacities. The corresponding changes of total surface charge of cells in the form of Zeta potential measurements were then reported after incubated respectively with iron oxide nanoparticles and CPMV nanoparticles. As observed, after MCF7 and MCF10A cells were incubated respectively with two types of nanoparticles, the significant differences in their surface charge change indicate the potential role of Zeta potential as a valuable biological signature in studying the cellular interaction of nanoparticles, as well as specific cell functionality. © Springer Science+Business Media, LLC 2007

Transmission Near-Field Scanning Optical Microscopy Investigation on Cellular Uptake Behavior of Iron Oxide Nanoparticles

Cellular uptake behavior of iron oxide nanoparticles is investigated using a transmission near-field scanning optical microscopy (NSOM) without the need of fluorescent labeling. By using the transmission NSOM system, we could simultaneously explore the near-field optical analysis of the cell interior and record the topographic information of the cell surface. The cell endocytosis of iron oxide nanoparticles by normal breast MCF10A cells is first studied by this transmission NSOM system, and this dual functional nanoscale-resolution microscopy shows the capability of mapping the spatial localization of nanoparticles in/outside cell surface without the need of fluorescence labeling. Nanoscale optical signature patterns for iron oxide nanoparticle-loaded vesicles inside the cells were observed and analyzed. © Springer Science+Business Media, LLC 2012

Synthesis and characterization of iron oxide derivatized mutant cowpea mosaic virus hybrid nanoparticles

The enhanced local magnetic field strength was qualitatively analyzed by magnetic force microscopy (MFM), demonstrating a characteristic advantage for attaching derivatized magnetic iron oxide (IO) nanoparticles in an organic medium. the synthesis of 11 nm size IO nanoparticles was carried out under nitrogen atmosphere using standard schlenk technique. The biocompatible γ-Fe2O3-COOH nanoparticles were synthesized by thermal decomposition of Fe(CO)5 and surface modified. Atomic force microscopy (AFM) was used to characterize structurally the as-synthesized IO nanoparticles on a silicon substrate. The histogram of the size distribution of the IO nanoparticles determined from 68 individual measurements on single IO nanoparticles exhibited a mean size of δ11 nm. MFM showed that the textured regions observed on each hybrid are indicative of IO nanoclusters decorating the surface of single virions

An improved method of supercharged transposed latissimus dorsi flap with the skin paddle for the management of a complicated lumbosacral defect

OBJECTIVE: Treatment of non-healing wounds of lower back often poses a powerful challenge. We present one of the first report of treatment of a lumbosacral defect with a supercharged latissimus dorsi flap with the skin paddle. CASE REPORT: We report a case of a 59 year-old man with myeloma of the sacral spine who underwent radiotherapy and chemotherapy and subsequently, laminectomies and placement of hardware for ongoing paresis and spine instability. Then, he developed an open wound and osteomyelitis of the spine with culture positive tuberculous granulomas. After multiple surgical debridement, he presented to our service and was treated with a single stage debridement followed by the performance of a latissimus dorsi musculocutaneous flap based on paraspinal perforators and supercharged. RESULTS: This solution, allowed for augmentation of blood flow to the muscle with the inferior gluteal artery, provided coverage of the defect resistant to the pressure, and simplified post-operative management of the patient. CONCLUSIONS: Alternative treatment options, including free tissue transfer, posed difficulties in finding suitable recipient vessels near the defect, in inserting the flap so as to restore its original length without compromising blood flow, and in postoperative care of the patient. Treatment of a lumbosacral defect with a supercharged latissimus dorsi flap with the skin paddle may represent a milestone procedure for complicated lower spine wounds

Investigation of NF-B1 and NF-BIA Gene Polymorphism in Non-Small Cell Lung Cancer

Lung cancer is a complex, multifactorial disease which is the leading cause of cancer death in both men and women. NF-B is a transcription factor which is known to affect the expression of more than 150 genes related to inflammation, lymphocyte activation, cell proliferation, differentiation, and apoptosis, as well as contributing to cell apoptosis and survival. However, NF-BIA (I B ) is the inhibitor of the transcription factor. The -94ins/delATTG polymorphism of the NF-B1 gene promoter region which causes a functional effect and NF-BIA 3 UTR A → G polymorphism has been shown to be related to various inflammatory diseases and cancer. Ninety-five NSCLC patients and 99 healthy controls were included in study. The NF-B1 -94ins/delATTG and NF-BIA 3 UTR A → G polymorphism have been studied by using PCR-RFLP method. It was found that the NF-B1 -94ins/delATTG DD genotype and D allele frequencies were higher in patients than healthy controls and the presence of the DD genotype has a 3.5-fold increased risk of the disease (P: 0.014). This study is the first to investigate the NF-B1 -94ins/delATTG and NF-BIA 3 UTR A → G polymorphism together in the Turkish population. According to the results, the NF-B1 -94ins/del ATTG promoter polymorphism may have a role in lung carcinogenesis and prognosis

Epitaxial growth in dislocation-free strained alloy films: Morphological and compositional instabilities

The mechanisms of stability or instability in the strained alloy film growth are of intense current interest to both theorists and experimentalists. We consider dislocation-free, coherent, growing alloy films which could exhibit a morphological instability without nucleation. We investigate such strained films by developing a nonequilibrium, continuum model and by performing a linear stability analysis. The couplings of film-substrate misfit strain, compositional stress, deposition rate, and growth temperature determine the stability of film morphology as well as the surface spinodal decomposition. We consider some realistic factors of epitaxial growth, in particular the composition dependence of elastic moduli and the coupling between top surface and underlying bulk of the film. The interplay of these factors leads to new stability results. In addition to the stability diagrams both above and below the coherent spinodal temperature, we also calculate the kinetic critical thickness for the onset of instability as well as its scaling behavior with respect to misfit strain and deposition rate. We apply our results to some real growth systems and discuss the implications related to some recent experimental observations.Comment: 26 pages, 13 eps figure