Dairy products discrimination according to the milk type using an electrochemical multisensor device coupled with chemometric tools

This study shows the potential application of a potentiometric electronic tongue coupled with a lab-made DataLogger device for the classification of dairy products according to the type of milk used in their production, i.e., natural, fermented and UHT milk. The electronic tongue device merged a commercial pH electrode and 15 lipid/polymeric membranes, which were obtained by a drop-by-drop technique. The potentiometric signal profiles gathered from the 16 sensors, during the analysis of the 11 dairy products (with ten replicate samples), together with principal component analysis showed that dairy samples could be naturally grouped according to the three types of milk evaluated. To further investigate and verify this capability, a linear discriminant analysis together with a simulated annealing variable selection algorithm was also applied to the electrochemical data, which were randomly split into two datasets, one used for model training and internal-validation using a repeated K-fold cross-validation procedure (with 64% of the data); and the other for external validation purposes (containing the remaining 36% of the data). The multivariate supervised strategy used allowed establishing a classification model, based on the potentiometric information of four sensor lipid membranes, which enabled achieving a successful discrimination rate of 100% for both internal- and external-validation processes. The demonstrated versatility of the built electronic tongue for discriminating dairy products according to the type of milk used in their production combined with its simplicity, low-cost and fast time analysis may envisage a possible future application in dairy industry.     

Continuous SiC-based model monofilaments with a low free carbon content: Part I: From the pyrolysis of a polycarbosilane precursor under an atmosphere of hydrogen

Pyrolysis of a Yajima-type polycarbosilane (PCS) has been performed under an atmosphere of hydrogen on both bulk samples and model monofilaments up to 1000°C, in order to reduce the free carbon content of the resulting ceramics. The organic/inorganic transition occurs within the 400–800°C temperature range, with mainly an evolution of CH₄. At 1000°C, it yields an hydrogenated amorphous ceramic with a C/Si atomic ratio and a free carbon content significantly lower than for its counterpart obtained under inert atmosphere (namely, 1.18 and 9 at% versus 1.72 and 27 at%). Hydrogen is thought to favour the release of the pendent methyl groups of the PCS via demethanation radical reactions. Continuous model filaments were produced via the melt spinning of the PCS, electron beam curing, pyrolysis under hydrogen up to 1000°C, and a final heat treatment under argon up to 1600°C. The ceramic fibres exhibit a C/Si atomic ratio of 1.10, a free carbon content of ≈8 at%, a Young's modulus of 260–300 GPa and a tensile failure stress of 2100 MPa. Their thermal stability is limited to 1400°C due to some oxygen contamination during the process. This revised version was published online in November 2006 with corrections to the Cover Date.     

Mass screening of colorectal cancer: where are we up to?

BACKGROUND AND STUDY AIMS: Conventionally, acute cholangitis is managed by placing a nasobiliary drainage catheter. We have attempted to place a biliary endoprosthesis in such patients as an alternative to using nasobiliary catheter drainage. PATIENTS AND METHODS: Twenty-seven patients with acute cholangitis were managed by placement of 7-Fr straight biliary endoprostheses instead of using nasobiliary drainage catheters to decompress the biliary system. The procedure was carried out without sphincterotomy and without image intensification. RESULTS: Biliary endoprosthesis placement was successfully carried out in all the patients. Definitive treatment was then provided to all but four patients, who either had inoperable cancer or were at high risk for surgery. Early stent occlusion occurred in one patient, and in another patient the Dormia basket became entrapped while stones were being removed from the common bile duct. There were no mortalities. CONCLUSIONS: Biliary endoprosthesis placement is safe, easy to perform, and is a cheaper alternative to endoscopic nasobiliary drainage.     

Informative value of Hemoccult test according to the number of positive slides in mass screening of colorectal cancer]

Desmoid tumors develop in the muscle or aponeurosis, but rarely in the chest wall. We report a patient with desmoid tumor in the chest wall. A 30-year-old female visited our hospital due to an abnormal shadow in the chest detected at a health examination. No definite diagnosis could be made by chest CT, MRI, or Ga scintigraphy, and finally a biopsy demonstrated desmoid tumor. The left anterior chest and posterolateral chest (lung apex) were opened, and tumors were resected together with the chest wall. No radiotherapy was performed. No recurrence has been observed for 1.5 years after operation. This tumor does not yield distant metastasis, but its recurrence rate is very high. Therefore, we intend to follow this patient for a long period.     

Data mining for text categorization with semi‐supervised agglomerative hierarchical clustering

In this paper we study the use of a semi‐supervised agglomerative hierarchical clustering (ssAHC) algorithm to text categorization, which consists of assigning text documents to predefined categories. ssAHC is (i) a clustering algorithm that (ii) uses a finite design set of labeled data to (iii) help agglomerative hierarchical clustering (AHC) algorithms partition a finite set of unlabeled data and then (iv) terminates without the capability to label other objects. We first describe the text representation method we use in this work; we then present a feature selection method that is used to reduce the dimensionality of the feature space. Finally, we apply the ssAHC algorithm to the Reuters database of documents and show that its performance is superior to the Bayes classifier and to the Expectation‐Maximization algorithm combined with Bayes classifier. We showed also that ssAHC helps AHC techniques to improve their performance. © 2000 John Wiley & Sons, Inc.     

Poisoning of topoisomerase I by an antitumor indolocarbazole drug: stabilization of topoisomerase I-DNA covalent complexes and specific inhibition of the protein kinase activity

The authors describe an eye with a central retinal vein occlusion that developed chorioretinal anastomoses following transvitreal venipuncture, a vitreoretinal surgical technique.     

A novel phosphorylation-dependent RNase activity of GAP-SH3 binding protein: a potential link between signal transduction and RNA stability

A potential p120 GTPase-activating protein (RasGAP) effector, G3BP (RasGAP Src homology 3 [SH3] binding protein), was previously identified based on its ability to bind the SH3 domain of RasGAP. Here we show that G3BP colocalizes and physically interacts with RasGAP at the plasma membrane of serum-stimulated but not quiescent Chinese hamster lung fibroblasts. In quiescent cells, G3BP was hyperphosphorylated on serine residues, and this modification was essential for its activity. Indeed, G3BP harbors a phosphorylation-dependent RNase activity which specifically cleaves the 3'-untranslated region of human c-myc mRNA. The endoribonuclease activity of G3BP can initiate mRNA degradation and therefore represents a link between a RasGAP-mediated signaling pathway and RNA turnover.     

High density polyethylene-g-maleic anhydride preparation in presence of electron donors

The reaction of molten HDPE with MAH at 215 and 250°C using di-t-amyl peroxide and t-butyl cumyl peroxide as catalysts yielded HDPE-g-MAH accompanied by crosslinked polymer. The formation of the latter, increased by the presence of MAH and insoluble in refluxing xylene, was prevented by the presence of electron donor additives, i.e., dimethylacetamide (DMAC), dimethyl sulfoxide (DMSO), and tri(nonylphenyl) phosphite (TNPP). A charge containing 0.0625–0.125% catalyst, 5% MAH and 0.5% additive, all based on HDPE and added to the molten HDPE in four portions, resulted in gel-free polymer with an MAH content of 0.7–1.7%. HDPE-g-MAH with the least color was obtained with TNPP, followed by DMAC and DMSO. Notwithstanding the absence of gel in the HDPE-g-MAH prepared from HDPE with a melt flow of 17 g/10 min, the carboxylated HDPE had a melt flow of 0.0–1 g/10 min, indicative of an increase in the molecular weight of the product. This is attributed to a coupling reaction between MAH radicals appended to the HDPE backbone (HDPE–MAH·) and HDPE radicals formed as a result of hydrogen abstraction from HDPE by radicals from the catalyst and/or excited MAH.     

Endothelium-dependent blunted membrane potential responses to ATP-sensitive K+ channel modulators in aortae from rats with cirrhosis

Gemcitabine, 2'2'-difluoro-2'-deoxycytidine, is an inhibitor of DNA synthesis and has been shown previously in vitro and in vivo to enhance the cytotoxic activity of radiation as well as some chemotherapeutic agents. Because gemcitabine has shown clinical activity on its own in several solid tumors traditionally treated with radiotherapy, it was of interest to optimize the combination of gemcitabine and radiation. To determine the optimal gemcitabine dose to combine with irradiation and to determine the effect of gemcitabine on tumor growth, mice bearing SA-NH tumors were treated with 2.5 to 600 mg/kg gemcitabine, and subsequent tumor growth was determined. At low doses, gemcitabine induced transient growth delay, whereas higher doses showed both cytotoxic and cytostatic activity. Flow cytometric, histological, and mitotic analyses of irradiated tumors showed that gemcitabine induced a dose-dependent inhibition of DNA synthesis and induction of apoptosis of cells in S phase. DNA synthesis recovered in cells at the G1-S boundary of the cell cycle in a dose-dependent manner, and a parasynchronous movement of cells through the cell cycle ensued. To determine the optimal schedule for gemcitabine administration in relation to irradiation, tumor-bearing mice were given a single 50 mg/kg dose of gemcitabine at various times before or after irradiation. Gemcitabine enhanced radioresponse in a time-dependent fashion. The highest enhancement factors for tumor growth delay (1.68-2.03) were observed when gemcitabine was administered 24-60 h before irradiation. Although gemcitabine reduced the radiation tumor control dose at all administration times used, the greatest enhancement of tumor radiocurability occurred when gemcitabine was administered 24 h before irradiation (dose modification factor of 1.54). Moreover, gemcitabine decreased the lung metastatic rate in mice with local tumor control from 73% in mice receiving radiation alone to 40% in mice receiving the combination (all combination times included). These results suggest that gemcitabine has strong radioenhancing properties and that the greatest interaction occurs when gemcitabine administration precedes irradiation by 24-72 h. Preliminary studies indicate that normal tissues recover more quickly than tumor tissues from gemcitabine treatment; thus, optimized scheduling of gemcitabine and irradiation may serve to improve the therapeutic ratio of the combination.