Harnessing Normal and Engineered Mesenchymal Stem Cells Derived Exosomes for Cancer Therapy: Opportunity and Challenges

There remains a vital necessity for new therapeutic approaches to combat metastatic cancers, which cause globally over 8 million deaths per year. Mesenchymal stem cells (MSCs) display aptitude as new therapeutic choices for cancer treatment. Exosomes, the most important mediator of MSCs, regulate tumor progression. The potential of harnessing exosomes from MSCs (MSCs-Exo) in cancer therapy is now being documented. MSCs-Exo can promote tumor progression by affecting tumor growth, metastasis, immunity, angiogenesis, and drug resistance. However, contradictory evidence has suggested that MSCs-Exo suppress tumors through several mechanisms. Therefore, the exact association between MSCs-Exo and tumors remains controversial. Accordingly, the applications of MSCs-Exo as novel drug delivery systems and standalone therapeutics are being extensively explored. In addition, engineering MSCs-Exo for targeting tumor cells has opened a new avenue for improving the efficiency of antitumor therapy. However, effective implementation in the clinical trials will need the establishment of standards for MSCs-Exo isolation and characterization as well as loading and engineering methods. The studies outlined in this review highlight the pivotal roles of MSCs-Exo in tumor progression and the promising potential of MSCs-Exo as therapeutic drug delivery vehicles for cancer treatment.     

Continuous Application of Polyglycerol‐Supported Salen in a Membrane Reactor: Asymmetric Epoxidation of 6‐Cyano‐2,2‐dimethylchromene

In the current work, suitability of hyperbranched polyglycerol as a high loading catalyst support is demonstrated. A polyglycerol‐supported manganese‐salen complex (chemzyme) is applied as a homogeneous catalyst in the epoxidation of 6‐cyano‐2,2‐dimethylchromene. The recyclability of the corresponding catalyst was investigated in repetitive batch experiments as well as a continuous operation of the reaction in an ultrafiltration membrane reactor. An enhanced stability of the catalyst in repetitive batches was observed as a result of immobilization whereby the total turnover number increased from 23 in a single batch to 80 in four repetitive batches. To enable continuous operation, a continuously operated, stirred tanked reactor (CSTR) was equipped with an ultrafiltration membrane (MPF‐50) and a retention of 98% was determined. The continuous chemzyme membrane reactor was operated over the course of 20 residence times. After approximately 12 residence times, the steady state was reached yielding 70% conversion as well as an enantiomeric excess up to 92%. A space‐time yield (sty) of 458 g L ⁻¹ d⁻¹ and a turnover frequency (TOF_reaction) of up to 18 h⁻¹ was reached in the steady state. It was determined that the total turnover number (TTN) was enhanced by a factor of 10 from 24 (batch) up to 240 for 20 residence times in CSTR operation.     

Effects of H<Subscript>2</Subscript> Atmospheres on Sintering of Low Alloy Steels Containing Oxygen-Sensitive Masteralloys

Processing of novel sintered steels with compositions including oxygen-sensitive elements requires deep understanding of the chemistry of sintering. The use of H₂ atmospheres alleviates the oxygen transference from the base powder to the oxygen-sensitive particles. However, in H₂, methane formation at 700–1200°C causes dramatic homogeneous decarburization of the part that affects both mechanical behavior and dimensional stability. The intensity and the critical temperatures of this effect depend strongly on the alloying elements, being significantly enhanced in presence of Si. When combining the alloying elements as Fe-Mn-Si masteralloys, methane formation is enhanced around 760°C due to the high Mn content (40 wt.%) in the masteralloys. Nevertheless, the benefits of H₂ towards oxide reduction can still be advantageously used if diluting it in the form of N₂-H₂ atmospheres, or if limiting the use of H₂ to temperatures below 500°C. Thus, decarburization due to methane formation can be successfully controlled.     

Adsorption of divalent heavy metal ions from water using carbon nanotube sheets

Removal of some divalent heavy metal ions (Cu(2+), Zn(2+), Pb(2+), Cd(2+), Co(2+)) from aqueous solutions using carbon nanotube (CNT) sheets was performed. CNT sheets were synthesized by chemical vapor deposition of cyclohexanol and ferrocene in nitrogen atmosphere at 750°C, and oxidized with concentrated nitric acid at room temperature and then employed as adsorbent for water treatment. Langmuir and Freundlich isotherms were used to describe the adsorption behavior of heavy metal ions by oxidized CNT sheets. The obtained results demonstrated that the oxidized CNT sheets can be used as an effective adsorbent for heavy metal ions removal from water. It was found out that kinetics of adsorption varies with initial concentration of heavy metal ions. Preference of adsorption onto the oxidized CNT sheets can be ordered as Pb(2+)>Cd(2+)>Co(2+)>Zn(2+)>Cu(2+). Using the oxidized CNT sheets, waste water treatment without CNT leakage into water is economically feasible. Therefore, CNT sheets have good potential application in environmental protection.     

Prioritizing Long-term Watershed Management Strategies Using Group Decision Analysis

There is a growing consensus that an effective way of enhancing long-term water resources management and environmental sustainability is through locally based planning at the watershed scale. Managing watershed resources for particular uses requires interactive dialogue among all stakeholders who have different objectives. Therefore, the resolution of inter-group conflict should be an acknowledged task of the planning process. In this paper, an integrated framework for prioritizing watershed management strategies is proposed. A case study is employed to highlight the challenges of using group decision analysis in strategic planning and to illustrate the interaction between different stakeholders on watershed issues. In particular, two group decision-making approaches are used to assess and analyse different stakeholders' preferences for various strategies and alternatives. Professional experts, government agencies and community leaders constitute the different parties included in the framework. The main focus is on the application of group decision analysis in the long-term watershed planning process. The results of the overall preference analysis show that water resources development is the most important strategy followed by agricultural and range management.     

Additional cassettes for epitope and fluorescent fusion proteins in Candida albicans

Epitope tags that confer specific properties, including affinity for resins or antibodies or detection by fluorescence microscopy, are highly useful for biochemical and cell biological investigations. In Candida albicans and several other related yeasts, the CUG codon specifies serine instead of leucine, requiring that molecular tools be customized for use in this important human fungal pathogen. Here we report the construction of a set of plasmids containing 13‐Myc, 3HA, GST, V5 or His9 epitope cassettes that facilitate PCR‐mediated construction of epitope‐tagged proteins. Common primer sets amplify the different tags with two different selectable markers. In addition, we report construction of a codon‐optimized Discosoma red fluorescent protein (DsRFP) gene. Like mCherryRFP, this DsRFP signal is detectable in transformants at the colony level and is useful in double‐labelling experiments with green fluorescent protein (GFP). Finally, we describe a construct that directs PCR‐mediated two‐step insertion of GFP internal to a coding sequence, which facilitates tagging of secreted proteins, including GPI‐anchor cell wall proteins that require endogenous N‐ and C‐termini for function. These reagents expand the repertoire of molecular tools available for working with C. albicans and other members of the CUG clade of pathogenic yeasts. Copyright © 2009 John Wiley & Sons, Ltd.     

Post Recognition Speech Localization

How much does knowledge regarding a certain spoken word or phrase help with its localization? This is a very fundamental question for speech processing, and will be partially addressed in this paper. In particular, this work will utilize prior information regarding the contents of a speech signal in order to improve the artificial localization of it using Time delay of arrival (TDOA) between two microphones. The prior information, which is used to develop a very simple frequency-selective phase transform (FPT), increases the effective SNR by only using a subset of the highest SNR frequencies in the Phase Transform. Simulations in a reverberant environment show that the proposed approach can more robustly and accurately localize speech sources. For 20 ms signal segments, it is shown that using a subset of 45 percent of available speech frequency bins is superior to using 30, 60, or 100, where using 100 corresponds to the standard Phase Transform.     

A single-period inventory model with inventory update decision: the newsboy problem extension

Inventory models use a set of parameters to establish their respected optimal policy. Such parameters are information items that have to be generated (obtained) and, therefore, there is a cost for obtaining them. Traditional inventory models simply ignore the existence of this cost and, therefore, the established optimal policies by these models may not be necessarily optimal in practice. In this paper, based on the requirements dictated by a real-world project, we analyze the impact of information update decisions for a specific class of inventory model (a single-period inventory model). The main difference between the presented model in this paper and newsboy problem is the presence of an inventory update decision and its effect on other inventory decisions. That is to decide when inventory-related information should be updated, how much should be ordered, and what is the maximum level of demand that can be promised to the customers. We formulate these decisions and develop mathematical methods to find the corresponding optimal policies.     

Application of membrane separation processes in petrochemical industry: a review

In this paper a general review on different membrane processes and membrane reactors was done. As the main aim of this paper is to review the application of membrane processes in petrochemical industry, processes such as olefin/paraffin separation, light solvent separation, solvent dewaxing, phenol and aromatic recovery, dehydrogenation, oxidative coupling of methane and steam reforming of methane were discussed in detail. Besides, separation using polymer-inorganic nano composite membranes and wastewater treatment using membrane bio-reactors were reviewed.