Polymer micelles with cross-linked ionic cores are shown here to improve the therapeutic performance of the platinum-containing anticancer compound cisplatin. Biodistribution, antitumor efficacy, and toxicity of cisplatin-loaded core cross-linked micelles of poly(ethylene glycol)-b-poly(methacrylic acid) were evaluated in a mouse ovarian cancer xenograft model. Cisplatin-loaded micelles demonstrated prolonged blood circulation, increased tumor accumulation, and reduced renal exposure. Improved antitumor response relative to free drug was seen in a mouse model. Toxicity studies with cisplatin-loaded micelles indicate a significantly improved safety profile and lack of renal abnormalities typical of free cisplatin treatment. Overall, the study supports the fundamental possibility of improving the potential of platinum therapy using polymer micelle-based drug delivery.

Benefits of the frequently prescribed platinum (II) chemotherapy drugs are compromised by undesirable side effects, poor pharmacokinetics and development of drug resistance. Polymer micelles derived from amphiphillic block copolymers, offer a novel macromolecular platform for carrier based delivery of such compounds. Soft polymeric nanocarriers were synthesized by template-assisted method involving condensation of the poly(ethylene oxide)-b-polymethacrylate anions by metal ions into core–shell block ionomer complex micelles followed by chemical cross-linking of the polyion chains in the micelle cores. The resulting micelles can efficiently incorporate cisplatin with a high loading capacity (up to 42% w/w). Core cross-linking stabilized the micelles against structural disintegration and prevented premature drug release. The reversible cisplatin entrapment involved the carboxylate groups of the micellar core. The drug was released in a pH-responsive manner, without loss of its biological activity. The stable cross-linked polymer micelles can potentially improve platinum (II) drug disposition with improved therapeutic potential.

The integration of student research into a general chemistry laboratory and an environmental geology course has been evaluated for its effectiveness to improve (i) student attitudes about science and chemistry, (ii) student understanding of the nature of experimental science and the scientific method, and (iii) student perceptions of the application of science and the interdisciplinary nature of science. Students in introductory science courses frequently devote all or most of their time and effort to learning basic laboratory techniques by following predefined procedures that have intentionally predictable outcomes. Though this longstanding model of laboratory structure is an important means of effectively preparing students for future chemical study, it often neglects items i−iii. Students were guided through a research experience by an interdisciplinary team of faculty so that students could begin the research and bring it to an appropriate conclusion, including formal presentations, within a single semester. Evaluation of this instructional strategy indicated that students believed they were doing work similar to a research scientist, that they appreciated this opportunity to do research, that it increased how much they like science in general, and that they were more likely to consider majoring in chemistry. The advanced instrumentation, personal relevance of the research, and collaborations (within and outside the department) contributed significantly to the overall success of the project.

Based on new U.S. Environmental Protection Agency rules, many metal finishing and plating facilities have switched, or are evaluating switching, from solvent-based metal cleaning systems to aqueous (or alkaline)-based cleaning systems. Some of the constituents in the aqueous cleaners may inhibit metals removal in wastewater treatment processes. This study was conducted to evaluate the effects of sodium xylenesulfonate (SXS), a constituent of a common aqueous cleaner, on zinc removal from industrial wastewater using hydroxide precipitation. In addition, the effects of polyaluminum chloride (PAC) dosages used in the treatment plant were also evaluated. It was found that low levels of SXS did not significantly affect zinc removal. However, higher concentrations of SXS, especially when combined with greater than optimum levels of PAC, did significantly inhibit zinc removal through hydroxide precipitation.

This report compares two precipitation intensity or volume weighted rainwater collection methods. A continuous flow measurement of conductivity and pH is compared to the corresponding data for samples collected by a fraction collection system. Conductivity data from summer thunderstorms in Omaha, Nebraska, collected by the two systems are comparable to each other and with integrated collection by a wet-only, event collector. The flow system pH measurement exhibits bias with respect to the fraction collection system due to insufficient electrode equilibration time, especially when the precipitation conductivity is low, < 10 μS cm−1.

This report reviews the literature of sequential or within-event precipitation sampler construction and includes a limited survey of their applications. Collection apparatus have been classified as manually segmenting samplers, linked collection vessels, automatically segmenting samplers and continuous monitors (Robertson et. al., U.S. EPA Report, 1980). Design criteria for an ideal collector are discussed.

ADVERTISEMENT RETURN TO ISSUEPREVBook and Media Revie...Book and Media ReviewNEXTLab Automation using the IBM PC (Becker, Jordan; Gates, Stephen C.)Frederic C. Laquer and Henry L. Laquer Cite this: J. Chem. Educ. 1990, 67, 5, A146Publication Date (Print):May 1, 1990Publication History Received3 August 2009Published online1 May 1990Published inissue 1 May 1990https://doi.org/10.1021/ed067pA146Request reuse permissions This publication is free to access through this site. Learn MoreArticle Views211Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (1 MB) Get e-Alertsclose Get e-Alerts

Phenolic compounds are a major pollution by-product of the underground coal gasification process. The adsorption of phenol onto a siltstone was studied using batch techniques and 1:1 crushed siltstone to solution slurries. The siltstone used was associated with a Wyoming coal deposit of a type similar to that which could be gasified in situ. The pH of the solution was found to be the major factor controlling the adsorption of phenol onto the siltstone. Phenol was adsorbed when the solution pH was less than the pKa while no sorption was observed at higher pH. Since in situ gasification sites have an elevated pH post gasification, phenolic compounds may be transported by groundwater in these regions. Significant differences were also found for the adsorption of phenol onto initially wet or dry adsorbate. Desorption studies were also performed. Langmuir and Freundlich adsorption isotherms were used to model the data.

A wastewater-treatment system, particularly useful for treating chemical leachates, was developed on a laboratory scale. Subbituminous coal, 20-60-mesh, was pyrolyzed. A synthetic wastewater containing 3520 ppm total organic carbon was contacted with nonactivated char, char activated in water-saturated nitrogen at 850/sup 0/C, and coal ash. During a contact time of 0.5 hour, organic removals from the wastewater were 13.3% by nonactivated char, 38.8% by activated char, and 46.5% by ash. For a contact time of 72 hours, organic removals were about 25% for nonactivated char, 58.8% for activated char, and 53.4% for ash. This treatment system is applicable where large amounts of waste carbonaceous material (coal, wood, crop residues) are available. The spent char can be incinerated. Heat from incineration can be used in the pyrolysis step, and the coal ash can be recycled to the water-purification step.