Sudoite, ordered illite/smectite and illite from some K-bentonite beds in the Middle and Upper Visean of Belgium

Conference (1995, August)

A Sudoku Submatrix Study

E-print/Working paper (2010)

In our last article, we gave some properties of Sudoku matrices. We here investigate some properties of the Sudoku submatrices. We first deal with their eigenvalues and try to find an upper bound on them ... [more ▼]

In our last article, we gave some properties of Sudoku matrices. We here investigate some properties of the Sudoku submatrices. We first deal with their eigenvalues and try to find an upper bound on them, and then follow exactly the same structure as in our last article to establish a connection between Sudoku matrices’ properties and sudoku submatrices’ properties. [less ▲]

Sudokus' ranks

E-print/Working paper (2011)

A Latin square of order n^2 is a Sudoku matrix if subdividing its entries into n^2 disjoint n-by-n subblocks causes each symbol to appear once in each subblock. Symbols are taken from {1, ..., n^2}, and n ... [more ▼]

A Latin square of order n^2 is a Sudoku matrix if subdividing its entries into n^2 disjoint n-by-n subblocks causes each symbol to appear once in each subblock. Symbols are taken from {1, ..., n^2}, and n^2 = 9 then corresponds to the familiar recreation. A construction of cyclic latin squares (see Shiu, W.C. and Fang, K.T. and Ma, S. L., On the Rank of Cyclic Latin Squares, Linear and Multilinear Algebra, Vol. 40, pp. 183-188) determines their minimum rank and shows they can attain full rank. It follows that Sudoku matrices can also be full rank. The present authors initially thought that the minimum ranks of Sudoku matrices would equal the minimum ranks of cyclic latin squares of the same order, i.e. 1 + \sum_{i=1}^{s} \varphi\left((p_i)^{t_i}\right) where n=\prod_{i=1}^{s} (p_i)^{t_i} is the prime factorization (of n), and \varphi is Euler's totient function. However, a block-cyclic latin square construction is found that attains a smaller rank. For the case n^2 = 9, one gets a rank 5 matrix rather than rank 7. Some generalizations such as taking symbols from {0, ..., n^2 -1} are discussed, and comparisons made to ranks of more general kinds of latin squares. We also discuss the possibility of finding a rank inferior to 5 for a 9*9 Sudoku matrix. (Until here, no test revealed such a possibility, but tests are not finished yet.) [less ▲]

Sufasalazine unveils a contact-independent HSV-TK/ganciclovir gene therapy bystander effect in malignant gliomas

in International Journal of Oncology (2007), 30(1), 283-290

The efficacy of HSV-TK/ganciclovir-based gene therapy on malignant gliomas largely relies on the amplitude of the bystander effect. In these experiments, the anti-inflammatory drug Sulfasalazine increased ... [more ▼]

The efficacy of HSV-TK/ganciclovir-based gene therapy on malignant gliomas largely relies on the amplitude of the bystander effect. In these experiments, the anti-inflammatory drug Sulfasalazine increased the HSV-TK/ganciclovir bystander effect in C6, 9L and LN18 cells but not in U87 glioma cells. Using bi-compartmental culture devices and conditioned medium transfer experiments, we showed that in C6, 9L and LN18 cells but not in U87 cells, Sulfasalazine also unveiled a new, contact-independent mechanism of HSV-TK/ganciclovir bystander effect. Upon treatment with ganciclovir, human LN18-TK but not U87-TK cells synthetized and released TNF-alpha in the culture medium. Sulfasalazine sensitized glioma cells to the toxic effect of TNF-alpha. and enhanced its secretion in LN18-TK cells in response to GCV treatment. The caspase-8 inhibitor Z-IETD-FMK and a blocking antibody to TNF-alpha both inhibited the contact-independent bystander effect in LN18 cells. Taken together, these results suggest that TNF-alpha mediates the contact-independent bystander effect in LN18 cells. The treatment with GCV and/or Sulfasalazine of tumor xenografts consisting of a mix of 98% C6 and 2% C6-TK cells shows that Sulfasalazine is also a potent adjunct to the in vivo treatment of gliomas. [less ▲]

Sugar beet leaves as new source of hydroperoxide lyase in a bioprocess producing green-note aldehydes.

in Biotechnology Letters (2008), 30(6), 1115-9

Hydroperoxide lyase activity was found in sugar beet leaves. Its optimum pH and temperature were, respectively, 6.7 and 22 degrees C. Under these conditions, conversion of linolenic acid 13-hydroperoxide ... [more ▼]

Hydroperoxide lyase activity was found in sugar beet leaves. Its optimum pH and temperature were, respectively, 6.7 and 22 degrees C. Under these conditions, conversion of linolenic acid 13-hydroperoxide to cis-3-hexenal with a maximum yield of 80% was reached after only 2 min. The stability of cis-3-hexenal was improved by acidifying the reaction medium. Based on these studies, a bioprocess producing green-note aldehydes in a laboratory-scale was achieved. [less ▲]

Sugar beet leaves as source of lyase in bioprocess producing green note aldehydes

Poster (2007)

Sugar beet leaves were used as source of lyase in a biocatalytic process for the production of C6-aldehydes. Their hydroperoxide lyase activity was revealed important. The optimum values of pH and ... [more ▼]

Sugar beet leaves were used as source of lyase in a biocatalytic process for the production of C6-aldehydes. Their hydroperoxide lyase activity was revealed important. The optimum values of pH and temperature for reactions were respectively 6.7 and 22 °C. A simple and fast process providing high molar conversion of hydroperoxides to aldehydes is proposed. The yield of the main product cis-3-hexenal reached 80% after only 2 min and was stabilised by acidifying the reaction medium to pH 2. [less ▲]

Sugar esters lipase mediated synthesis from vegetable oils

Scientific conference (2005, September 19)

Sugar esters: ways of synthesis and potential applications.

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2001), 5(4), 209-219

Sugar esters are nonionic surfactants and exhibit relevant properties such as structural diversity and environmental and health safety. Their potential applications extend from human food to drug ... [more ▼]

Sugar esters are nonionic surfactants and exhibit relevant properties such as structural diversity and environmental and health safety. Their potential applications extend from human food to drug formulations and biochemical studies. Some sugar esters also exhibit interesting biological activities. Many papers on the subject have been submitted during the last 10 years. Those articles describe the various ways of synthesis of those compounds at the laboratory scale. During the last 10 years, the most studied method was the biotechnological one using catalysis by enzymes. Available knowledge on these molecules is reviewed. [less ▲]

SUGAR-1 Spectrometry in Ultraviolet of GAlaxies at Redshift-1

in Final Papers, 56th IAC 2005, Fukuoka, Japan (2005)

This paper describes the outcome of the work performed during the 28th Alpbach Summer School, focused on the theme The Birth, Life and Death of Stars. We propose a mission consisting of a large aperture ... [more ▼]

This paper describes the outcome of the work performed during the 28th Alpbach Summer School, focused on the theme The Birth, Life and Death of Stars. We propose a mission consisting of a large aperture (3.5m main mirror diameter) UV space telescope, with capabilities for imaging and low, medium and high resolution spectroscopy. Even though such a telescope can have multiple scientific applications, we suggest a survey-type mission (SUGAR-1), dedicated mainly to the spectroscopic study of starburst galaxies at redshift z ~ 1, which corresponds to an epoch of enhanced star formation density in the history of the Universe and, in particular, to the time when our Solar System was born. Stars are the fundamental building blocks of galaxies. A major aspect of understanding galaxy formation and evolution is to understand their star formation history. Starburst galaxies are galaxies experiencing intense star forming activity and exhibiting strong UV emission from a young, hot stellar population. The study of starbursts helps us to understand the star formation process, and its influence on the environment and processes in the interstellar gas. The study of the star formation rate (SFR) at various redshifts is possible from the intensities of the H, H, OII and OIII lines, and the luminosity of the UV continuum. These can be used to generate Madau plots, which are diagnostic. Madau plots indicate that a peak of star formation in the history of the Universe occurred at z ~ 1, which corresponds to -5 Gyr, i.e. the moment of the birth of our own Solar System. Observations of this era will enable us to investigate the initial conditions in galaxies like ours when the formation was triggered. By observing a large number of galaxies at 0.4 < z < 1.1, we can learn about the properties of the star formation processes and the conditions of the interstellar medium (ISM) and its chemical properties at this moment of enhanced star formation. Spectroscopy and imaging in the UV will have a great impact on galaxy evolution modeling, since they will provide insight on whether the time corresponding to z = 1 was a time of massive galaxy formation, or if the massive star formation of that time took place in already established galaxies, which were formed at a much earlier stage in the evolution of the Universe. Moreover, studies of the Universe at z ~ 1 are of cosmological relevance, because according to the Cosmological Standard Model, it is precisely at z ~ 1 when the Universe underwent a phase transition from ΩMatter being larger than ΩDarkEnergy, to the opposite. Therefore, to investigate this interesting time in the evolution of the Universe, we suggest the construction of a dedicated UV telescope with a pre-defined science mission to perform Spectrometry in Ultraviolet GAlaxies at Redshift-1 (SUGAR-1). In what follows, a more detailed description of the mission science goals is given. We will show how the science goals are transformed into science requirements for the mission, which are turned into telescope and instrument requirements. Then a brief description will be given of the main technical aspects of the mission (spacecraft structure, electronics, power and orbit). The spacecraft mass and cost budgets of the mission are addressed, ending with a final summary. [less ▲]

SUGAR: resultats d'une etude observationnelle belge concernant l'utilisation de la sitagliptine chez des patients diabetiques de type 2.

in Revue Médicale de Liège (2010), 65(3), 127-32

Sitagliptin (Januvia), the first selective inhibitor of dipeptidylpeptidase-4, has been assessed in a large Belgian prospective observational study. The aim of the SUGAR study was to evaluate the efficacy ... [more ▼]

Sitagliptin (Januvia), the first selective inhibitor of dipeptidylpeptidase-4, has been assessed in a large Belgian prospective observational study. The aim of the SUGAR study was to evaluate the efficacy of sitagliptin, at a dose of 100 mg once daily, when it was added in patients with uncontrolled type 2 diabetes followed in real life conditions. In the intent-to-treat population (n = 605), mean glycated haemoglobin level decreased from 8.41 +/- 1.18% to 7.29 +/- 0.86% after a follow up averaging 110 days (p < 0.0001). Similarly, mean fasting plasma glucose level decreased from 180 +/- 50 mg/dl to 141 +/- 37 mg/ dl (p < 0.0001). The improvement of these two parameters was observed independently of basal demographic characteristics, but was directly influenced by baseline initial corresponding values. The vast majority of patients included in SUGAR were initially treated by metformin as monotherapy (current criterion for sitagliptin reimbursement in Belgium); metformin daily dose slightly decreased when sitagliptin was added (from 1975 +/- 681 mg to 1919 +/- 667 mg; p = 0.033). Patients receiving other glucose-lowering agents, as single or combined therapies, had also a significant alleviation of their treatment when sitagliptin was added. After 3-6 months of follow up, more than 95% of patients still received sitagliptin, arguing for both the efficacy and the good tolerance of this new oral antidiabetic agent in clinical practice. [less ▲]