W1 W2 Research Articles

W2: Practical considerations when using oral fluid as toxicological matrix

Introduction Over the last decades, the possibilities for monitoring the presence of drugs of abuse in oral fluid (OF) has increased enormously. Especially in the domain of testing drivers under influence of drugs (DUID), OF has gained popularity due to its non-invasive collected, directly on-site without hampering privacy. Several on-site immunosorbent tests (OIT) were developed over the years. For confirmatory analysis, the use of OF has been hampered by the influence of the salivary composition on the final drug concentrations. The OF collection protocol, the degree of stimulation of salivary flow, the physicochemical properties of drugs of abuse, and the type of drug administration are some of the parameters that influence the OF drug concentrations. Moreover, the final analytical result will be influenced by the OF collection. As a result, toxicological analysis of OF samples and the final interpretation is not always straightforward. Methods Laboratory and roadside studies, as well as double-blind placebo-controlled studies are used to evaluate the problems encountered using OF as confirmation matrix. The focus is put on Δ 9 -tetrahydrocannabinol (THC) analysis. The placebo-controlled study involves 10 test subjects smoking two subsequent doses of THC; 300 μg/kg and 150 μg/kg with a pause of 75 minutes using a Volcano vaporizer. Using the above mentioned studies, OIT (Drug-Test ® , Drager and Drugwipe ® , Securetec) and several OF collection devices (StatSure ® , Diagnostic Systems Inc; Quantisal ® , Immunalysis and Certus ® , Concateno) will be evaluated via UPLC-MS/MS analysis. Results Sensitivity of OIT seem to increase. The DrugTest 5000 and Drugwipe demonstrated respectively a sensitivity of 93% and 72% for Δ 9 -tetrahydrocannabinol during roadside studies. The Drugwipe is very sensitive just after smoking, but it rapidly decreases within 1.5 hours. The type of OF collection has to be specified when using OF as confirmation matrix, as THC recovery ranged from 50 to 70% and is dependent on the storage conditions. While matrix effects due to the collector buffers are observed, stability is often guaranteed via the stabilizing buffers. In a roadside study, we observed that after 5 minutes collection time, about 0.11–1.15 mL of OF was collected. Therefore, the final drug concentrations in neat OF have to be calculated via the following formula: C = [C UPLC/MS · (V1 + (W1–W2))] / [V2 x (W1–W2)] with C being the drug concentration in neat OF, C UPLC/MS the concentration obtained via the calibration curve, V1 the buffer volume, V2 the theoretical total collected volume and W1 and W2 respectively the weight of the collection device after and before OF collection. Neat OF THC concentrations in the placebo controlled study ranged from 12,361 ng/g 5 minutes after smoking down to 34 ng/g 80 minutes after 2 smoking sessions. Under placebo conditions, a median of 8 ng/g THC in OF was observed. The impact of all these observations on DUID legislations will be discussed. Conclusion OF has its limitations as a toxicological matrix. However, in situations where ‘recent’ drug use in combination with analytical cut-offs for interpretations are used, OF combines an easy collection of samples with a quick analysis of large batches.

Double emulsion template suspension polymerisation: towards the synthesis of polyelectrolyte core porous hydrophobic shell particles for environmental applications

Herein we report a novel synthetic strategy for the synthesis of micrometre sized core–shell particles comprising a polyelectrolyte core and a porous hydrophobic shell. A water-in-oil-in-water (W1/O/W2) double-emulsion was used as the template for the simultaneous polymerisation of both the internal aqueous and the intermediate oil phase leading to the formation of a cross-linked poly(acrylic acid) (PAAc) core contained in a poly(4-tert-butylstyrene-co-divinylbenzene) (poly(4-tBSty-co-DVB)) shell. The mass transport process from the internal aqueous phase to the external phase was reduced by means of an “oil phase locking” mechanism in which a rapid gel point transition of the oil phase ensured stability against internal aqueous–external aqueous phase (W1–W2) coalescence. The formation of core–shell particles was favoured by the effect of acrylic acid monomer which was responsible for the selective destabilization of the internal aqueous/oil interface (W1/O) allowing rapid internal aqueous phase coarsening. The particles thus obtained were investigated as potential sorbent materials for the simultaneous removal and encapsulation of organic and inorganic cationic species from aqueous solutions.

THE INFRARED COLORS OF THE SUN

Solar infrared colors provide powerful constraints on the stellar effective temperature scale, but to this purpose they must be measured with both accuracy and precision. We achieve this requirement by using line-depth ratios to derive in a model independent way the infrared colors of the Sun, and use the latter to test the zero-point of the Casagrande et al. (2010) effective temperature scale, confirming its accuracy. Solar colors in the widely used 2MASS -J H K- and WISE -W1 W2 W3 W4- systems are provided. A cross check of the effective temperatures derived implementing 2MASS or WISE magnitudes in the infrared flux method confirms that the absolute calibration of the two systems agree within the errors, possibly suggesting a 1% offset between the two, thus validating extant near and mid infrared absolute calibrations. While 2MASS magnitudes are usually well suited to derive effective temperatures, we find that a number of bright, solar-like stars exhibit anomalous WISE colors. In most cases this effect is spurious and traceable to lower quality measurements, although for a couple of objects (3 +/- 2 % of the total sample) it might be real and hints towards the presence of warm/hot debris disks.

Left ventricular thrombus formation after acute myocardial infarction

Cardiovascular disease remains the leading cause of death in western society. Mortality from acute myocardial infarction (AMI) has decreased since the introduction of primary percutaneous coronary intervention (PCI), which has...

APPLICATION OF WAVE INTENSITY AND ECHO-TRACKING TO EVALUATE CARDIOVASCULAR FUNCTION CHANGES IN PATIENTS WITH MYOCARDIAL INFARCTION

Objectivesto evaluate the changes of cardiovascular function and its clinical significance in patients of myocardial infarction (MI) with Wave intensity (WI) and Echo-tracking (ET) techniqueMethods59 patients with coronary artery disease...

Metal complexes of a new class of polydentate Mannich bases: Synthesis and spectroscopic characterisation

A new class of polydentate Mannich bases featuring an N 2S 2 donor system, bis((2-mercapto- N-phenylacetamido)methyl)phosphinic acid H 3L 1 and bis((2-mercapto- N-propylacetamido)methyl)phosphinic acid H 3L 2, has been synthesised from condensation of phosphinic acid and paraformaldehyde with 2-mercaptophenylacetamide W1 and 2-mercaptopropylacetamide W2, respectively. Monomeric complexes of these ligands, of general formula K 2[Cr III(L n )Cl 2], K 3[M′ II(L n )Cl 2] and K[M(L n )] (M′ = Mn(II) or Fe(II); M = Co(II), Ni(II), Cu(II), Zn(II), Cd(II) or Hg(II); n = 1, 2) are reported. The structures of new ligands, mode of bonding and overall geometry of the complexes were determined through IR, UV–Vis, NMR, and mass spectral studies, magnetic moment measurements, elemental analysis, metal content, and conductance. These studies revealed octahedral geometries for the Cr(III), Mn(II) and Fe(II) complexes, square planar for Ni(II) and Cu(II) complexes and tetrahedral for the Co(II), Zn(II), Cd(II) and Hg(II) complexes. Complex formation studies via molar ratio in DMF solution were consistent to those found in the solid complexes with a ratio of (M:L) as (1:1).

Optimal Solutions for Mixed Bundling of Two Independently-Valued Goods

This paper develops analytical results and insights for the mixed bundling problem of pricing a product line consisting of two component goods and a bundle of the two goods. Consumer valuations for the two goods follow a symmetric bivariate uniform distribution, a setting which has previously been considered analytically intractable. Prior analytical work has demonstrated the superiority of mixed bundling, but failed to provide an explicit specification of the optimal solution or prices. Alternately, researchers have employed numerical solution techniques to solve instances of the mixed bundling problem. I reduce the multi-product pricing problem to a univariate nonlinear optimization problem in the bundle price with a global maximum that can be identified uniquely. I derive tight lower and upper bound functions for the optimal bundle price. The average of these two functions can be used as an alternate, and extremely simple, analytical expression for the optimal bundle price. Another alternative formula for the optimal bundle price is obtained by applying statistical estimation over solutions for a large space of problem instances. Both approximations are highly accurate, producing a pro t that is within half percent of the exact optimal pro t. The optimal bundle price has an elegant analytical expression (a linear function of the marginal costs of the two goods) and prices for component goods are an algebraic function of the bundle price. With a bivariate distribution in the unit square and constant unit marginal costs w1 and w2, the optimal bundle price can be written as 0:86032 0:55929(w1 w2)/2.

Separation of the maxima in samples of geometric random variables

We consider samples of n geometric random variables W1 W2 ... Wn where P{W) = i} = pqi-l, for 1 ? j ? n, with p + q = 1. For each fixed integer d > 0, we study the probability that the distance between the consecutive maxima in these samples is at least d. We derive a probability generating function for such samples and from it we obtain an exact formula for the probability as a double sum. Using Rice's method we obtain asymptotic estimates for these probabilities. As a consequence of these results, we determine the average minimum separation of the maxima, in a sample of n geometric random variables with at least two maxima.

Atypical MRI Findings of Wernicke Encephalopathy in Alcoholic Patients

Atypical MRI Findings of Wernicke Encephalopathy in Alcoholic PatientsAkihiro Sugai and Koki KikugawaAudio Available | Share

The spectral decomposition of shifted convolution sums

Let π1, π2 be cuspidal automorphic representations of PGL2(R) of conductor 1 and Hecke eigenvalues λπ1,2(n), and let h>0 be an integer. For any smooth compactly supported weight functions W1,2:R×→C and any Y>0, a spectral decomposition of the shifted convolution sum ∑m±n=hλπ1(|m|)λπ2(|n|)|mn|W1(mY)W2(nY) is obtained. As an application, a spectral decomposition of the Dirichlet series ∑m,n≥1m−n=hλπ1(m)λπ2(n)(m+n)s(mnm+n)100 is proved for Rs>1/2 with polynomial growth on vertical lines in the s-aspect and uniformity in the h-aspect

Transposition of the great arteries: from fetus to adult

This article provides a review of trends in modern practice in the management and outcome of transposition of the great arteries (TGA) from fetal until adult life. It focuses on...

Management of diabetes in cardiovascular patients

Type 2 diabetes mellitus (T2DM) is a common disease affecting ∼3–5% of people living in the western world. Cardiovascular disease (CVD) (coronary heart disease (CHD), stroke and peripheral vascular disease)...

Cone-beam filtered backprojection image reconstruction using a factorized weighting function

We present several new families of mathematically exact cone-beam image reconstruction algorithms for a general source trajectory that fulfills Tuy's data sufficiency condition. The basic structure of the new algorithms is to reconstruct images via filtered backprojection (FBP) with a 1-D shift-invariant filter. Specifically, the general weighting function w(x,;t) for redundant data was decomposed into three components w1(x,), w2(x,t), and sgn[·y(t)], viz. w(x,;t)=[w1(x,)w2(x,t)sgn(·y(t))]. Based upon the normalization condition of the weighting function, the first component w1(x,) may be calculated using the second component w2(x,t) Thus, the design of the weighting function was reduced to the selection of the second component w2(x,t). Using this scheme, it has been demonstrated that, for a given scanning configuration, one may develop infinitely many different, exact cone-beam FBP image reconstruction algorithms. To demonstrate how this general procedure may be used to develop FBP image reconstruction algorithms, a two-concentric-circle scanning configuration is discussed in detail. Numerical simulations have been conducted to validate several of the derived image reconstruction algorithms. Several possible scan strategies are presented, and the possibility of performing multiple reconstructions with different scan configurations to reduce image noise is described. Noise properties also have been numerically studied for the implemented image reconstruction algorithms, then compared with two other shift-invariant FBP reconstruction algorithms.

A perception study of syntactic disambiguation using resynthesized speech

It is already well known that when a preceding word (W1) is accented, the following word (W2) is likely to undergo a postaccent downstep. Such a downstep is especially evident in a left‐branching structure (henceforth LB) as in [[W1 W2] W3], while it is mitigated in a right‐branching structure (henceforth RB) as in [W1 [W2 W3]]. That is, ups and downs of the F0 peak of W2 disambiguate the RB and the LB structure when a postaccent downstep is available (Selkirk and Tateishi, 1991; Kubozono, 1993, Hirose, 2005). Two questions, however, emerge. One is whether or not the magnitude of W3’s downstep would ever contribute to the branching disambiguation. The other is what would happen when all words are unaccented, i.e., when no postaccent downstep is available. We carried out a perception study using resynthesized speech as stimuli, to examine those questions. Our results show that neither the W3 peak values of a postaccent environment nor the W2 peak values of an unaccented environment had significant effect on the LB vs. RB disambiguation. Such results will be compared with Hirose’s (2005) production and perception study on spontaneous speech.

Assessment of arterio-ventricular coupling by tissue Doppler and wave intensity in type 2 diabetes

Aim To evaluate ventricular-arterial coupling in preclinical cardiovascular disease, we used a new wave intensity approach and tissue Doppler in patients with and without type 2 diabetes mellitus (DM). Methods Sixty-five type 2 diabetes patients and 57 control individuals with normal systolic left ventricular function and without overt coronary or peripheral artery disease were assessed by tissue Doppler for myocardial velocities and by a combined Doppler and echo-tracking system (Aloka SSD-5500, Tokyo) for local arterial stiffness (epsilon, pulse wave velocity) and the characteristic peaks W1 and W2 of pulse wave intensity. Results Diabetes patients had significantly higher systolic blood pressure and pressure derivates (p<0.002). Diastolic myocardial velocity (Ve) was decreased (p<0.001). Epsilon and pulse wave velocity (p<0.001) were higher and so was W1 (11785±7491 vs. 9191±4299, p<0.04) but not W2. In the pooled data, independent predictors for Ve were age, septal wall thickness, Vs and HbA1C (R2 duration of diabetes (R2 0.479). 0.426) and for W1 systolic blood pressure, Vs, W2 and duration of diabetes (R2 0.479). Conclusion In type 2 diabetes pump function is preserved and maintained against increased arterial stiffness and impedance at the expense of increased myocardial oxygen requirements. Tissue Doppler and wave intensity measurements may be useful for therapeutic monitoring.

Neural correlates of Chinese word-appropriateness judgment: An MEG study

To study the neural correlates of Chinese word-appropriateness judgment, we used 2-word phrases and corresponding meaningless pairs produced by replacing the second words (W2) with homophones. Fourteen right-handed healthy adults viewed word pairs randomly presented one word at a time, and judged the lexical appropriateness of the W2 for combining its preceding first word (W1) into a meaningful phrase. We measured magnetoencephalographic (MEG) responses to W1, appropriate W2, and inappropriate W2 stimuli. For each subject, multi-dipole analyses revealed sequential neuromagnetic activations which involved the bilateral visual cortices at ∼ 100 milliseconds (ms), the bilateral occipitotemporal regions at ∼ 190 ms, and the left temporal lobe at ∼ 350 ms (M350) following stimuli. We found that the word appropriateness had no clear effect on the occipitotemporal activation to W2 stimuli, whereas the M350 activation to inappropriate W2 was greater than that to W1 or appropriate W2. In 8 of our subjects, we found an additional activation in the right temporal region, with a smaller amplitude as compared with the left M350. Our results suggest that the M350 activity reflects both lexical and semantic appropriateness assessment. The lateralized M350 strengths may be used to determine the language dominance hemisphere; and additionally, our 2-word contexture judgment paradigm can be applied in further research on the cortical processing of lexicon-semantic information in Chinese speakers.

Refinement of the crystal structures of three fluorine-bearing elbaites

The crystal structures of three Li-Al natural tourmalines (elbaites) containing 0.88–1.39 wt % F are refined to R= 0.0294, 0.0308, and 0.0417. It is revealed that the W threefold anion site is split into two sites, namely, the W1 threefold site and W2 ninefold site (W1–W2 ∼ 0.4 A, Y-W1 ≥ 1.94 A, Y-W2 ≥ 1.75 A). The following hypothesis is proposed and justified: the W1 and W2 sites are partially occupied by OH groups and fluorine anions, respectively. The ratio of the [YO4(OH)2] octahedra to the [YO4(OH)F] octahedra depends on the fluorine content and varies from structure to structure. The fact that the W site is more than 50% occupied by fluorine in the structures of two tourmalines under investigation allows the conclusion that fluor-elbaite with the ideal formula Na(Li1.5A11.5)A16(Si6O18)(BO3)3(OH)3F is a new mineral species and that elbaite can be considered a superspecies.

Internal Coalescence as a Mechanism of Instability in Water-in-Oil-in-Water Double-Emulsion Globules

Using capillary microscopy, internal coalescence between the internal aqueous compartments in a single water-in-oil-in-water (W1/O/W2) double-emulsion globule was investigated. Globules were prepared using either sodium dodecyl sulfate (SDS) (ionic) or Tween 80 (nonionic) as the water-soluble surfactants and Span 80 as the oil-soluble surfactant. Concentrations of both the hydrophobic and hydrophilic surfactants were varied until coalescence between the internal aqueous droplets was observed. Internal coalescence was observed when the concentration of SDS or Tween 80 in the internal aqueous phase was 1−3 CMC (critical micelle concentration) or 50−100 CMC, respectively, and occurred preferentially when the concentration in the internal phase was significantly greater than in the external phase. Internal coalescence always occurred in conjunction with coalescence between the internal W1 and external W2 aqueous phases (external coalescence). When W1 and W2 were not too dissimilar in their overall surfactant ...

Avoiding bias in calculations of relative growth rate.

In classical growth analysis, relative growth rate (RGR) is calculated as RGR = (ln W2 - ln W1)/(t2 - t1), where W1 and W2 are plant dry weights at times t1 and t2. Since RGR is usually calculated using destructive harvests of several individuals, an obvious approach is to substitute W1 and W2 with sample means W1 and W2. Here we demonstrate that this approach yields a biased estimate of RGR whenever the variance of the natural logarithm-transformed plant weight changes through time. This bias increases with an increase in the variance in RGR, in the length of the interval between harvests, or in sample size. The bias can be avoided by using the formula RGR = (ln W2 - ln W1)/(t2 - t1),where ln W1 and ln W2 are the means of the natural logarithm-transformed plant weights.

Plasma volume responses to consecutive anaerobic exercise tests.

This study examined the change in plasma volume (% delta PV) in response to consecutive Wingate tests (30 sec Anaerobic Power test). Twelve active men (21 +/- 1.6 yr, 81.3 +/- 6.6 kg) performed two Wingate tests (W1 and W2, separated by 10 min) on three occasions (T1-T3, tests were two weeks apart). Exercise resistance was maintained at 75 g.kg-1 body weight during testing. Blood samples were taken immediately before (Pre) and after (IP) W1 and W2. There were no significant differences in hematocrit, hemoglobin, mean power (MP) or peak power (PP) between T1-T3. There was a marked hemoconcentration in response to W1 (IP W1, -17.4 +/- 2.6% delta PV), with a further, but not significantly greater, hemoconcentration following W2 (IP W2, -8.2 +/- 1.1% delta PV). The % delta PV, between PRE W1 and IP W2 was-20.1 +/- 3.1%. These results suggest that an existing hemoconcentration (W1) may affect the magnitude of the % delta PV response to subsequent supramaximal exercise (W2).