638 research outputs found
Computerized cyclic voltammetric detection after HPLC of the antineoplastic agents etoposide, teniposide, adriamycin and its metabolite adriamycinol in urine samples
A computerized electrochemical detection system for application
after HPLC, provided with a cyclic voltammetric oxidative and
reductive module, is described for the on-line qualitative determination
of electroactive antineoplastic agents and metabolites in urine
samples, collected from cancer patients, following intravenous
administration
Can yield gap analysis be used to inform R & D prioritisation?
The phrase “biggest bang for a buck” is associated with the policy making question that governments and development agencies face: “Where and which crops should receive highest priority for improving local and global food supply?”. A first step of prioritisation is to identify region x crop combinations for which high impact can be anticipated. We developed a new method for this prioritisation exercise and applied it to data from the Global Yield Gap and Water Productivity Atlas (GYGA). Our prioritisation distinguishes between two policy objectives (humanitarian and economic) and builds upon the relative yield gap and climate risk. Results of the prioritisation are presented and visualised in Google Earth
The Disk and Dark Halo Mass of the Barred Galaxy NGC 4123. II. Fluid-Dynamical Models
We report a dynamical determination of the separate contributions of disk and
dark halo masses to the rotation curve of a spiral galaxy. We use
fluid-dynamical models of gas flow in the barred galaxy NGC 4123 to constrain
the dynamical properties of the galaxy: disk M/L, bar pattern speed, and the
central density and scale radius of the dark halo. We derive a realistic barred
potential directly from the light distribution. For each model we assume a
value of the stellar M/L and a bar pattern speed Omega_p and add a dark halo to
fit the rotation curve. We then compute the gas flow velocities with a 2-D gas
dynamical code, and compare the model flow patterns to a 2-D velocity field
derived from Fabry-Perot observations. The strong shocks and non-circular
motions in the observed gas flow require a high stellar M/L and a fast-rotating
bar. Models with I-band disk M/L of 2.0 -- 2.5 h_75, or 80 -- 100% of the
maximum disk value, are highly favored. The corotation radius of the bar must
be <= 1.5 times the bar semi-major axis. These results contradict some recent
claimed ``universal'' galaxy disk/halo relations, since NGC 4123 is of modest
size (rotation curve maximum 145 km/sec, and V_flat = 130 km/sec) yet is quite
disk-dominated. The dark halo of NGC 4123 is less concentrated than favored by
current models of dark halos based on cosmological simulations. Since some 30%
of bright disk galaxies are strongly barred and have dust lanes indicating
shock morphology similar to that of NGC 4123, it is likely that they also have
high stellar M/L and low density halos. We suggest that luminous matter
dominates inside the optical radius R_25 of high surface brightness disk
galaxies.Comment: accepted by ApJ, 20 pages, 11 figures (2 color), uses emulateapj.sty,
onecolfloat.st
On Albanese torsors and the elementary obstruction
We show that the elementary obstruction to the existence of 0-cycles of
degree 1 on an arbitrary variety X (over an arbitrary field) can be expressed
in terms of the Albanese 1-motives associated with dense open subsets of X.
Arithmetic applications are given
Thermal unfolding and refolding of a lytic polysaccharide monooxygenase from <em>Thermoascus</em> aurantiacus
Lytic polysaccharide monooxygenases (LPMOs) are copper-containing enzymes which promote the degradation of recalcitrant polysaccharides like cellulose or chitin. Here, we have investigated the thermostability of an LPMO from Thermoascus aurantiacus (TaLPMO9A). TaLPMO9A was found to retain most of its initial activity after incubating at 100 °C while its apparent melting temperature (Tm) is 69 °C at neutral pH. Interestingly, our studies show that holoTaLPMO9A, apoTaLPMO9A and deglycosylated TaLPMO9A can fold back to their original conformation upon lowering the temperature. In the presence of β-mercaptoethanol the protein does not refold. Activity of TaLPMO9A and refolded TaLPMO9A was studied by an Amplex® Red assay as well as by TaLPMO9A catalysed oxidation of phosphoric acid swollen cellulose (PASC). These studies confirm the functional regain of TaLPMO9A activity upon going through one cycle of unfolding and refolding. The thermal unfolding and refolding of TaLPMO9A was measured spectroscopically. Utilizing the two-state model, detailed thermodynamic parameters were obtained for holoTaLPMO. Furthermore, we have investigated the kinetics of TaLPMO9A unfolding and refolding. Our results have implications in understanding LPMO stability, which is crucial for the efficient application of LPMOs as biocatalysts during biomass degradation
The dark matter halo shape of edge-on disk galaxies - I. HI observations
This is the first paper of a series in which we will attempt to put
constraints on the flattening of dark halos in disk galaxies. We observe for
this purpose the HI in edge-on galaxies, where it is in principle possible to
measure the force field in the halo vertically and radially from gas layer
flaring and rotation curve decomposition respectively. In this paper, we define
a sample of 8 HI-rich late-type galaxies suitable for this purpose and present
the HI observations.Comment: Accepted for publication by Astronomy & Astrophysics. For a higher
resolution version see
http://www.astro.rug.nl/~vdkruit/jea3/homepage/12565.pd
The effects of new life-prolonging drugs for metastatic castration-resistant prostate cancer (mCRPC) patients in a real-world population
Item does not contain fulltextBACKGROUND: In 2004 docetaxel was the first life-prolonging drug (LPD) registered for metastatic castration-resistant prostate cancer (mCRPC) patients. Between 2011 and 2014 new LPDs for mCRPC (cabazitaxel, abiraterone, enzalutamide, and radium-223) were introduced in the Netherlands. The objective of this study is to assess the impact of the introduction of new LPDs on treatment patterns and overall survival (OS) over time. PATIENTS AND METHODS: CRPC patients diagnosed in the years 2010-2016 in the observational, retrospective CAPRI registry (20 hospitals) were included and followed up to 2018. Two subgroups were analyzed: treatment-naïve patients (subgroup 1, n = 3600) and post-docetaxel patients (subgroup 2, n = 1355). RESULTS: In both subgroups, the use of any LPD increased: from 57% (2010-2011) to 69% (2014-2015) in subgroup 1 and from 65% (2011-2012) to 79% (2015-2016) in subgroup 2. Chemotherapy as first mCRPC-treatment (i.e., docetaxel) and first post-docetaxel treatment (i.e., cabazitaxel or docetaxel rechallenge) decreased (46-29% and 20-9% in subgroup 1 and 2, respectively), while the use of androgen-receptor targeting treatments (ART) increased from 11% to 39% and 46% to 64% in subgroup 1 and 2, respectively. In subgroup 1, median OS (mOS) from diagnosis CRPC increased from 28.5 months to 31.0 months (p = 0.196). In subgroup 2, mOS from progression on docetaxel increased from 7.9 months to 12.5 months (p < 0.001). After multiple imputations of missing values, in multivariable cox-regression analysis with known prognostic parameters, the treatment period was independent significant for OS in subgroup 1 (2014-2015 vs. 2010-2011 with HR 0.749, p < 0.001) and subgroup 2 (2015-2016 vs. 2011-2012 with HR 0.811, p = 0.037). CONCLUSION: Since 2010, a larger proportion of mCRPC patients was treated with LPDs, which was related to an increased mOS
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