Atmospheric outflow of anthropogenic semivolatile organic compounds from East Asia in spring 2004

To estimate the emissions of anthropogenic semivolatile organic compounds (SOCs) from East Asia and to identify unique SOC molecular markers in Asian air masses, high-volume air samples were collected on the island of Okinawa, Japan between 22 March and 2 May 2004. Contributions from different source regions (China, Japan, the Koreas, Russia, and ocean/local) were estimated by use of source region impact factors (SRIFs). Elevated concentrations of hexachlorobenzene (HCB), hexachlorcyclohexanes (HCHs), dichlorodiphenyltrichloroethanes (DDTs), and particulate-phase polycyclic aromatic hydrocarbons (PAHs) were attributed to air masses from China. A large proportion of the variation in the current-use pesticides, gas-phase PAHs, and polychlorinated biphenyl (PCB) concentrations was explained by meteorology. Chlordanes showed a technical mixture profile and similar concentrations regardless of source region. alpha/gamma HCH and trans/cis chlordane ratios did not vary significantly with different source regions and had regional averages of 2.5 +/- 1.0 and 1.2 +/- 0.3, respectively. Particulate-phase PAH concentrations were significantly correlated (p value < 0.05) with other incomplete combustion byproduct concentrations, including elemental mercury (Hg0), CO, NOx, black carbon, submicrometer aerosols, and SO2. By use of measured PAH, CO, and black carbon concentrations and estimated CO and black carbon emission inventories, the emission of six carcinogenic particulate-phase PAHs was estimated to be 1518-4179 metric tons/year for Asia and 778-1728 metric tons/year for China, respectively. These results confirm that East Asian outflow contains significant emissions of carcinogenic particulate-phase PAHs.     

Chemical Ecology of the Defense of Two Nymphalid Butterfly Larvae Against Ants

We analyzed the behavioral responses of the ants Camponotus rufipes and Solenopsis geminata towards all instars of Dione junio and Abananote hylonome. We also analyzed ant behavior towards hexane extracts of larvae and extracts of the spines and neck glands of the fifth instars of both species and identified the chemical compounds present. Larvae of both species were repellent to ants from the first instar onward. Later instars survived ant attacks better than earlier instars. The spines and neck glands of the larvae influenced the behavior of C. rufipes. The chemical compounds contained in the hexane extracts of whole first and fifth instars and in the spines and neck glands of fifth instars were principally carboxylic acids and terpenes. Further bioassays confirmed the repellent effect of some of these acids toward ants.     

Reproducible,biocompatible medical materials from biologically derived polysaccharides: Processing and Characterization

Natural polysaccharides like chitosan and dextran have garnered considerable interest in biomedical applications due to their biocompatibility, biodegradability, and nontoxicity. Nonetheless, the development of a reproducible class of medical devices from these materials is challenging and has had limited success. Chitosan and dextran are inherently variable and synthesis using these materials is prone to inconsistencies. In this study, we put forward a robust product development regimen that allows these natural materials to be developed into a reproducible class of biomaterials. First, an array of validated characterization methods (Proton Nuclear Magnetic Resonance, titrations, Ultraviolet spectroscopy, Size Exclusion Chromatography—Multi-Angle Light Scattering, Size Exclusion Chromatography—Refractive Index, and proprietary methods) were developed that allowed rigorous specifications to be set for unprocessed chitosan and dextran, chitosan and dextran intermediates, and chemically modified materials—acrylated chitosan (aCHN) and oxidized dextran (oDEX). Second, a robust and reproducible synthesis scheme involving various in-process controls was developed to chemically modify the unprocessed polysaccharides. Third, purification methods to remove byproducts and low-molecular-weight impurities for both aCHN and oDEX were developed. The study presents a viable strategy for converting variable, natural materials into a reproducible class of biomaterials that can be applied in various biomedical applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48454.     

Distributed deadlock resolution in store-and-forward networks

We present a simple distributed algorithm that resolves store-and-forward deadlocks in data communication networks. The basic idea of the algorithm is to detect cycles of nodes that may cause store-and-forward deadlocks, and to rotate packets along these cycles. The algorithm uses a fixed amount of storage in each node for its execution, and, under reasonable assumptions upon the routing and packet handling, it ensures that packets that enter the network arrive at their destinations in finite time.     

SNA Networks of Small Systems

This paper discusses SNA/LEN, a possible extension of Systems Network Architecture intended to allow peer, dynamic, and easy to use networking functions for a variety of node sizes down to and including the new generation of personal computers. After reviewing the special requirements posed by small systems and the need for including them as equal partners in networks, the LEN architecture is described. This is done by following a sequence of steps that begin when a logical resource at some node that may not yet be part of the connectivity of an existing network requests a session with a remote logical resource of unknown location. After connectivity with the preexisiting network is established, directory services locates the remote object, route selection services determines the preferred path, a session is activated, and deadlock-free flow control assures a useful flow of data. Preliminary quantitative results from an LEN prototype are presented.     

Anthropogenic,Polyhalogenated, Organic Compounds in Sedentary Fish from Lake Huron and Lake Superior Tributaries and Embayments

Composite samples of fish taken from some of the major tributaries and embayments of Lake Superior and Lake Huron were analyzed for halogenated xenobiotics with the objective of detecting potential environmental problem areas, point source discharges of toxic materials, and previously unrecognized pollutants. The analyses were done by gas chromatographic, methane enhanced, negative ion, mass spectrometry. A variety of halogen-containing organic compounds and pesticides were identified. The highest concentration and variety of compounds were found in the fish from the highly industrialized Saginaw Bay drainage basin; fish from Lake Superior tributaries showed much lower concentrations.     

Dynamics of the emergence of genetic resistance to biocides among asexual and sexual organisms

The drugs cisplatin and gentamicin are used for treatment of various cancer patients suffering from infection. The authors report a detailed electron microscopic study of blood vessels in stria vascularis of guinea pigs after treatment with cisplatin alone and in combination with gentamicin. The most distinctive features expressing endothelial cellular injury were mitochondrial, including occasional paracrystalline inclusions; electron-lucent foci with depleted organelles; intracytoplasmic vacuole formations; lipid bodies; cytoplasmic extrusions located on the luminal surface; and severe luminal constriction of part of the vessels from animals treated with the combined drugs. The study suggests that the damage to strial capillaries due to treatment with cisplatin alone and in combination with gentamicin may contribute to the injurious effects of these drugs on the strial tissue. Furthermore, the results of this study may enlarge the awareness of the potential vascular damage and vascular complications in additional body systems after medical use of cisplatin alone or in combination with gentamicin.     

Management of posttransplant lymphoproliferative disease in pediatric liver transplant recipients receiving primary tacrolimus (FK506) therapy

BACKGROUND: Posttransplant lymphoproliferative disease (PTLD) after pediatric liver transplantation has been associated with high mortality rates. METHODS: The present study examined 282 consecutive pediatric liver transplant recipients from October 1989 to June 1996 who received primary tacrolimus immunosuppression. The aim was to determine the incidence of PTLD, management strategies, and patient outcome. RESULTS: The incidence of PTLD was 13% (361282) with a mean age of 5.5+/-0.7 years (range 0.6 to 15) at diagnosis. The average time from transplantation to PTLD was 10.1+/-2.1 months. Initial treatment of PTLD consisted of reduction (3 patients) or discontinuation (33 patients) of tacrolimus and initiation of antiviral therapy (intravenous ganciclovir, 14 patients; intravenous acyclovir, 22 patients; or both, 5 patients). Alpha-interferon was used in four patients (two successfully). One patient also received gamma-interferon, chemotherapy, and radiation for a central nervous system lesion. Chemotherapy was also used in one patient with Burkitt's, whereas one patient with a pulmonary lesion received additional radiation therapy. Three patients received supportive surgery for gastrointestinal involvement, and one patient had a splenectomy for hemolysis. Overall mortality was 22% (8/36) with 5 (14%) PTLD-related deaths (disseminated disease, 4 patients; bowel perforation, 1 patient). Of 31 survivors, 23 had acute rejection at a median time of 24 days after PTLD, with 2 patients developing chronic rejection. One patient required retransplantation. Present immunosuppression consists of tacrolimus monotherapy in 14 patients, tacrolimus/prednisone in 8 patients, and none in 6 patients. CONCLUSION: In summary, PTLD can be successfully treated with reduction of immunosuppression and administration of antiviral agents in most patients. The management of rejection after PTLD requires reassessment of disease status and judicious reintroduction of immunosuppression therapy.