Assessment of DMSP turnover reveals a non-bioavailable pool of dissolved DMSP in coastal waters of the Gulf of Mexico

Environmental context DMSP is one of the most important substrates for marine bacteria and its cycling contributes substantially to fluxes of carbon and sulfur in the ocean. Accurate determination of the concentration of DMSP available to bacteria is essential to quantifying DMSP consumption rates, and this work improves those determinations by identifying non-bioavailable pools of DMSP that have previously gone unrecognised. Improved estimates of DMSP consumption rates will lead to better understanding of its role in ocean food web and biogeochemical dynamics. Abstract Dissolved dimethylsulfoniopropionate (DMSPd) is an important substrate for marine microbes and a precursor of sulfur gases. We compared DMSPd turnover flux rates in coastal seawater measured with a 35S-DMSPd tracer to those obtained with the DMSP-uptake inhibitor glycine betaine (GBT). The 35S-DMSP tracer method yielded DMSPd turnover fluxes (35.7–215nM day–1) that were 1.7 to 152 times higher than those obtained in parallel samples with the GBT inhibitor method (0.34–21.6nM day–1). Tests confirmed that GBT functioned as planned by strongly inhibiting DMSPd degradation and that 35S-DMSPd gave accurate estimates of DMSPd loss rate constants. This left the initial DMSPd concentrations, determined by small volume drip filtration (SVDF) through Whatman GF/F filters (0.7-μm nominal retention) ([DMSPd]SVDF), as a potential cause of the discrepancy in rate estimates. Indeed, GF/F filtrate incubations showed that the initial [DMSPd]SVDF overestimated the bioavailable DMSPd concentrations for at least two reasons: (1) a significant fraction (10–37%) of DMSP passing through GF/F filters was in particles >0.2μm (likely bacteria) and therefore not dissolved, and (2) a significant pool (0.44–1.0nM) of operationally dissolved, non-particle DMSP ([DMSPd]<0.2μm), comprising 40–99% of [DMSPd]SVDF, was refractory to degradation on a time scale of days. The nature of this refractory DMSP is currently unknown. Accounting for DMSP-containing particles and the refractory DMSP pool in GF/F filtrates is necessary to obtain the true bioavailable DMSPd concentrations, which we estimate to be very low (0.006–1.0nM; mean of 0.41nM) in the coastal waters examined, and to avoid overestimation of DMSPd turnover fluxes when using the 35S-DMSP tracer technique.

Analysis on Primary Recrystallization Characteristics of High Permeability Grain-Oriented Silicon Steel by Inherent Inhibitor Method and Acquired Inhibitor Method

Contrastive analysis on recrystallized strips of high permeability grain-oriented silicon steel by inherent and acquired inhibitor method has been done, including structure, grain size, coincidence site lattice（CSL） and texture. Results show that the mean primary grain sizes of high permeability grain-oriented silicon steel by inherent inhibitor method and acquired inhibitor method of this experiment are 12.66μm and 27.95μm, respectively. The former is homogeneous structure while the latter is coarsened to some extent. Both primary recrystallized strips have equivalent percentage of ∑9 boundary, but the strip by acquired inhibitor method has higher percentage of ∑3 boundary than that by inherent inhibitor method. Both primary recrystallized strips have {111}<112> as the main texture component, however, the strip by acquired inhibitor method has（113）[5，-11，2] texture component, which is not desirable for ideal secondary recrystallization texture.

Delivery of Antiangiogenic Agents for Cancer Gene Therapy

The understanding that tumor growth and metastasis are angiogenesis dependent processes has led to interest in targeting tumor vasculature in anticancer therapy. Furthermore, recent insights into the molecular interactions that orchestrate physiologic and pathologic angiogenesis have resulted in a variety of antiangiogenic strategies. A gene therapy-mediated approach for the delivery of antiangiogenic agents has several advantages, including the potential for sustained expression. However, the choice of angiogenesis inhibitor, method of gene delivery, and target/site for transgene expression are important variables to be considered when designing this approach. Here we review the major alternatives within each of these categories and provide illustrative examples of their use in preclinical models.

Multicenter evaluation of a specific pancreatic isoamylase assay based on a double monoclonal-antibody technique.

Eleven evaluators from nine laboratories in five countries evaluated a new immunoinhibition method for pancreatic isoamylase determination that is as simple to perform as that for total amylase. The precision at low and intermediate activity concentrations was superior, and at high concentrations it equalled that of the wheat-germ inhibitor method. The test was linear to approximately 2000 U/L, depending on the instrumentation used. The percentage salivary isoamylase activities remaining in specimens after reaction with two monoclonal antibodies ranged from 2 to 4.4%. Comparative studies showed good correlation with the wheat-germ inhibitor (r greater than 0.978) and electrophoresis methods (r = 0.920). Hemolysis, lipemia, and bilirubinemia have no effect on results. Interlaboratory studies demonstrated excellent transferability of the method, if instruments are calibrated with the same calibrator. Reference intervals for pancreatic isoamylase are 13 to 64 U/L (25 degrees C), 13 to 83 U/L (30 degrees C), and 17 to 115 U/L (37 degrees C). A clinical evaluation of patients with acute pancreatitis showed that pancreatic isoamylase has a greater clinical sensitivity than total amylase.