The partial testing design: a less costly way to test equivalence for sensitivity and specificity

We propose a new, less costly, design to test the equivalence of digital versus analogue mammography in terms of sensitivity and specificity. Because breast cancer is a rare event among asymptomatic women, the sample size for testing equivalence of sensitivity is larger than that for testing equivalence of specificity. Hence calculations of sample size are based on sensitivity. With the proposed design it is possible to achieve the same power as a completely paired design by increasing the number of less costly analogue mammograms and not giving the more expensive digital mammograms to some randomly selected subjects who are negative on the analogue mammogram. The key idea is that subjects who are negative on the analogue mammogram are unlikely to have cancer and hence contribute less information for estimating sensitivity than subjects who are positive on the analogue mammogram. To ascertain disease state among subjects not biopsied, we propose another analogue mammogram at a later time determined by a natural history model. The design differs from a double sampling design because it compares two imperfect tests instead of combining information from a perfect and imperfect test.     

A new epitope presenting system displays a HIV-1 V3 loop sequence and induces neutralizing antibodies

The principal neutralizing domain, IGPGRAF sequence, from the V3-loop of HIV-1 was inserted in two positions on the surface of the protein that makes up the capside shell of the insect Flock House Virus. The hybrid proteins were expressed in insect cells via recombinant baculoviruses. Three different hybrids were used as immunogens: two with a single copy of the insert in different positions of the carrier protein and a third with two copies of the insert at the same positions as before. All hybrid proteins induced strong and broad specific immune response in guinea pigs against different V3-loop sequences. However, only one of the hybrid proteins was able to induce a strong neutralizing response against MN and IIIB HIV-1 isolates. Our results demonstrate that a very short peptide sequence of HIV-1 can constitute a valuable immunogen able to induce a neutralizing response if presented to the immune system in the context of the FHV capsomer structure.     

Comparison of production of choriogonadotropin inhibitory protein, prolactin and insulin-like growth factor binding protein-1 by human decidua in vitro

BACKGROUND: Tissue plasminogen activator (tPA) is elevated in cancer patients and is thought to promote tumor angiogenesis by facilitating endothelial cell migration through plasmin-mediated degradation of extracellular matrix. Due to the presence of an epidermal growth factor (EGF)-finger domain in the tPA A-chain and the existence of an endothelial cell (EC) receptor that binds this domain, it was hypothesized that tPA has a direct receptor-mediated effect on EC proliferation, independent of plasmin. METHODS AND RESULTS: Using cultured canine ECs, tPA (7.25 microg/ml, approximately 107 nM) increased proliferation as much as 50 and 170% in the absence and presence of growth factors, respectively. tPA-induced increases in EC proliferation occurred independent of plasmin generation, as the plasmin inhibitor, aprotinin (10 microg/ml) did not inhibit tPA-induced proliferation. However, tPA-induced proliferation was inhibited dose-dependently to a maximum of 78% using a monoclonal antibody against the tPA EGF-finger domain. This antibody, known to inhibit tPA binding to its receptor, did not inhibit tPA-induced plasmin generation. To investigate the role of potential signal transduction pathways, ECs were exposed to lavendustin A, a tyrosine kinase inhibitor, at 33.5 microM (IC50 for basic fibroblast growth factor). Lavendustin A did not inhibit tPA-induced EC proliferation. However, Rp-cAMP, an inhibitor of cAMP-dependent kinases, specifically inhibited tPA-induced EC proliferation in a dose-dependent manner (IC50 = 50.5 microM). Pertussis toxin at maximal concentrations for this system (0.5 ng/ml) did not inhibit tPA-induced EC proliferation. CONCLUSION: These results lend support to the hypothesis that tPA may have a direct receptor-mediated effect on EC proliferation and that this effect occurs independent of plasmin and may be dependent upon protein kinase A activity.     

Determination of assimilable organic carbon (aoc) in ozonated water with acinetobacter calcoaceticus

The effect of ozone application in drinking water on the production of assimilable organic carbon (AOC) was evaluated. The typical procedure to determine AOC is suggested by van der Kooij, which is the method of bacterial growth measurement by colony‐forming units using the strain P17 and/or NOX. The bacterial indicator species used for this study is Acinetobacter calcoaceticus which was isolated and identified while ozonating Nakdong river water. This strain could never be isolated from the raw water, but this strain was the predominant isolate in the ozonated water. Within a short incubation time, this organism was found to replicate well on acetate and oxalate as the sole carbon sources. The yield coefficients of this organism for acetate and oxalate are the same order of magnitude as the value of P17 and NOX. With full‐scale experiments, A. calcoaceticus concentration was found to increase after ozonation, but did not decrease upon chlorination. In laboratory‐scale experiments with Yongsan river water, aldehyes were found to be produced in proportion to the ozone dose. The raw water contains low concentrations of aldehydes, but has a high AOC concentration. A correlation between aldehyde production and AOC production was observed in the tested water with ozonation.     

过共晶铝硅合金细化初晶硅的研究

研究了ZL8604过共晶铝硅合金初晶硅细化剂和加入方式与加入量以及影响细化效果的冶铸工艺因素,实验结果达到了技术指标要求。     

Femorodistal vein grafts: the utility of graft surveillance criteria

PURPOSE: This retrospective review of femorodistal vein grafts was analyzed to determine the usefulness of various graft surveillance criteria. METHOD: The surveillance schedule involved evaluations at 1 month, every 3 months the first year, and then every 6 months. Salvage intervention or graft occlusion occurring within the next follow-up interval defined surveillance end points. One hundred two grafts (329 surveillance visits) had an ankle/brachial index (ABI). A duplex scanning-determined midgraft peak systolic flow velocity (PSFV) was available for 81 grafts (262 visits). Forty-eight grafts (137 visits) had both a PSFV and entire graft duplex scanning (EGDS) to determine stenosis greater than 50%, whereas 40 grafts (91 visits) had simultaneous ABI and EGDS. RESULTS: When a greater than 15% decrease in ABI denoted an abnormal surveillance study result, a positive predictive value (PPV) of 24.3% and negative predictive value of 94.5% were noted. Similarly, a PSFV cutoff of less than 35 cm/sec demonstrated values of 26.3% and 94.2%, respectively. When an EGDS of greater than 50% stenosis or a PSFV of less than 35 cm/sec were the cutoff criteria, the PPV was 36.7% and negative predictive value 99.1%, whereas characterizing abnormal results further with ABI (> 15% decreases) increased the PPV to 83.3%. CONCLUSION: The combination of an EGDS, midgraft PSFV, and ABI provides optimal follow-up for our patients with a femorodistal vein graft.     

Structural studies of the putative O-specific polysaccharide of Acinetobacter baumannii O2 containing 3,6-dideoxy-3-N-(D-3-hydroxybutyryl)amino-D-galactose

A polysaccharide containing D-galactose, 2-deoxy-2-N-acetylamino-D-galactose and 3,6-dideoxy-3-N-(D-3-hydroxybutyryl)amino-D-galactose, probably corresponding to the lipopolysaccharide side chain, was obtained from an aqueous phenol extract of isolated cell walls from Acinetobacter baumannii strain O2. By means of NMR studies and chemical degradations, the repeating unit of the polymer was identified as a branched hexasaccharide of the structure shown, where Fuc3N represents 3-amino-3,6-dideoxygalactose and R represents D-3-hydroxybutyryl. Serological tests indicated that the polymer corresponded to the O2 antigen.     

旋波媒质基本参数的一种测试方法

本文提出了直接利用旋波材料板的Ｓ参数获得其基本参数的方法。通过自由空间测量旋波材料板的反射场和透射场，可以反演得到媒质的复介电常数、复磁导率、旋波量以及透射场的轴比和旋转角，测试程序简单，结果精度高。     

The cue-familiarity heuristic in metacognition

Four experiments contrasted the cue-familiarity hypothesis of feeling-of-knowing judgments (FKJs) and tip-of-the-tongue feelings (TOTs) to the target-retrievability hypothesis. Familiarity of the cues was contrasted to memorability of the targets in a paired-associate design (e.g., A-B A-B, A-B A-B', A-B A-D, A-B C-D), in which the number of repetitions of the cue A terms was dissociated from the memorability of the target B terms. Little support was found for the target-retrievability hypothesis, because in none of the 4 experiments were FKJs related to target memorability. In one experiment, an omnibus retrieval hypothesis (which implicates total retrieval rather than just correct retrieval) and the cue-familiarity hypothesis produced isomorphic predictions that were borne out by the FKJ and TOT results. All 4 experiments supported the cue-familiarity hypothesis, because FKJs and TOTs were directly related to the number of presentations (and thereby the familiarity) of the cues.     

Parallel BIST architecture for CAMs

A new parallel test algorithm and a built-in self test (BIST) architecture for efficient testing of various types of functional faults in content addressable memories (CAMs) are developed. The results show that efficient and practical testing with very low complexity and area overhead can be achieved