Comparison of piracetam measured with HPLC-DAD, HPLC-ESI-MS, DIP-APCI-MS, and a newly developed and optimized DIP-ESI-MS.

The direct inlet probe-electrospray ionization (DIP-ESI) presented here was based on the direct inlet probe-atmospheric pressure chemical ionization (DIP-APCI) developed by our group. It was coupled to an ion trap mass spectrometer (MS) for the detection of more polar compounds such as degradation products from pharmaceuticals. First, the position of the ESI tip, the gas and solvent flow rates, as well as the gas temperature were optimized with the help of the statistic program Minitab® 17 and a caffeine standard. The ability to perform quantitative analyses was also tested by using different concentrations of caffeine and camphor. Calibration curves with a quadratic calibration regression of R (2) = 0.9997 and 0.9998 for caffeine and camphor, respectively, were obtained. The limit of detection of 2.5 and 1.7 ng per injection for caffeine and camphor were determined, respectively. Furthermore, a solution of piracetam was used to compare established analytical methods for this drug and its impurities such as HPLC-diode array detector (DAD) and HPLC-ESI-MS with the DIP-APCI and the developed DIP-ESI. With HPLC-DAD and 10 µg piracetam on column, no impurity could be detected. With HPLC-ESI-MS, two impurities (A and B) were identified with only 4.6 µg piracetam on column, while with DIP-ESI, an amount of 1.6 µg piracetam was sufficient. In the case of the DIP-ESI measurements, all detected impurities could be identified by MS/MS studies. Graphical Abstract Scheme of the DIP-ESI principle.

Impact of recycling filter backwash water on organic removal in coagulation-sedimentation processes.

The overall purpose of this research was to examine the impacts of filter backwash water (FBWW) and membrane backwash water (MBWW) recycles on water quality in coagulation-sedimentation processes. Specifically, the impact of recycling 5 or 10% by volume of FBWW and MBWW with surface water on the removal of natural organic matter (NOM) was evaluated at bench-scale using a standard jar-test apparatus and measurement of specific water quality parameters including total organic carbon (TOC), dissolved organic carbon (DOC), UV254, turbidity, total aluminum and zeta potential. The results of jar test conducted on a source water with a specific UV absorbance (SUVA) value within the range of 2-4 mg/Lm showed a significantly higher removal of DOC from the raw water that was blended with 5 and 10% by volume of FBWW as compared to control trials where backwash water was not added. Increasing rates of MBWW that did not contain destabilized hydroxide precipitates did not significantly change DOC concentrations in the settled water samples as compared to the control trials. For source waters that are characterized as having low turbidity with medium SUVA values, these results could hold particular significance for plants that have reached treatment ceilings in terms of dissolved NOM removal using conventional coagulation designs.

Glycal glycosylation and 2-nitroglycal concatenation, a powerful combination for mucin core structure synthesis.

A 3,4-O-unprotected galactal derivative having bulky 6-O-TIPS protection (compound 2) could be regioselectively 3-O-glycosylated with O-(galactopyranosyl) trichloroacetimidates; depending on the protecting group pattern stereoselectively alpha- and beta-linked disaccharides were obtained. With O-(2-azido-2-deoxyglucopyransyl) trichloroacetimidate as donor (compound 10A), glycosylation of 2 and of a 6-O-unprotected galactal derivative led in acetonitrile as solvent exclusively to a beta(1-3)- and a beta(1-6)-linked disaccharide, respectively. Nitration of the galactal moieties of the saccharides followed by Michael-type addition of serine and threonine derivatives (7a,b) installed the alpha-galacto-configuration, thus readily furnishing O-glycosyl amino acid building blocks for the incorporation of core 1, core 2, core 3, core 6, and core 8 structures into glycopeptides. 2-Nitrogalactal and 2-nitroglucal derivatives could be also successfully employed in glycoside bond formation via Michael-type addition in a reiterative manner, affording the corresponding core 5, core 7, and core 6 building blocks. In this approach, highly stereoselective glycoside bond formations were based exclusively on Michael-type addition to the nitro-enol ether moiety of the 2-nitroglycals. Hence, 2-nitroglycals are versatile intermediates for base-catalyzed glycoside bond formation.

Fluorimetric analysis of hydrogen peroxide with automated measurement.

UNLABELLED: In the pathophysiology of chronic obstructive pulmonary disease (COPD) oxidative stress plays an important role, which can be determined by measuring hydrogen peroxide. Hydrogen peroxide can be measured fluorimetrically in exhaled breath condensate (EBC), however, not standardized. The objective of this study was to investigate the sensitivity and reproducibility of measuring the hydrogen peroxide concentration in EBC of COPD patients using an automated flow injection device with varying flow rates and measurements. METHODS: 10 microl p-hydroxyphenylacetic acid (1.0 mmol/l) and 10 microl horseradish peroxidase (15 mU/l) were manually added to several hydrogen peroxide containing solutions and EBC of patients suffering from COPD. The fluorescence of the reaction product was measured with an automated sampler, flow injection and scanning fluorescence detector, excitation wave 295 nm, emission wave 405 nm, at different flow rates. The degree of fluorescence was expressed as either the area under the curve or the peak value. RESULTS: A flow rate of 1 ml/min gave the best results. There were no significant differences in calibration curves or detection limits using area under the curve or peak value (respectively 0.007 and 0.005 micromol/l) (flow rate 1.0 ml/min). The mean volume of EBC was 2.8 ml, the mean hydrogen peroxide concentration in the patient group was 0.2 micromol/l and the standard deviation of duplication 0.009 micromol/. CONCLUSIONS: The low detection limit may be explained by using flow injection, because it measures the fluorescence over a period of time. It is important to choose an appropriate flow rate. There is no difference in the detection limit between measuring the fluorescence as area under the curve or as peak value.

Impact of allogenic blood transfusions on temperature, platelet count and differential leukocyte count of patients after coronary artery bypass grafting.

We compared the median values of temperature, platelet count, white blood cell count and differential leukocyte count (neutrophils, eosinophils, basophils, lymphocytes and monocytes) just before and after coronary artery bypass grafting of patients transfused with packed red cell units (n = 119), and not transfused with packed red cell units (n = 98). Just before surgery and at 7 h, 13 h, 22 h, 46 h and 142 h after surgery, blood samples were taken. In the patient group undergoing transfusion lower median values at a significance level of alpha = 0.025 were found of their temperature postoperatively at 7 h, platelets at 22 h, 46 h and 142 h, white blood cell count at 13 h and 22 h, neutrophils at 7 h, 13 h and 22 h, lymphocytes at 46 h and 142 h, compared to the patients not transfused.

Nitroglycal Concatenation: A Broadly Applicable and Efficient Approach to the Synthesis of Complex O-Glycans.

Base-catalyzed glycosylations provide the basis for a new and general entry to the synthesis of mucin-type O-glycans. The desired α-linked 2-acetamidoglycosyl amino acids B are accessible selectively starting from glycals of type A. Fmoc=9-fluorenylmethoxycarbonyl.

Role of cognitively stimulating home environment in children's academic intrinsic motivation: a longitudinal study.

The short- and long-term, and direct and indirect, relations between cognitively stimulating home environment and academic intrinsic motivation were investigated in a longitudinal study from childhood through early adolescence. Structural equations modeling was used to test the hypothesis that home environment positively predicts academic intrinsic motivation over this period. It was also hypothesized that home environmental processes would positively predict motivation controlling for socioeconomic status (SES). When children were age 8, home environment (comprising both direct observations and parent report) and SES were measured. Academic intrinsic motivation was assessed at ages 9, 10, and 13. Results supported the hypotheses. Home environment had statistically positive and significant, direct and indirect paths to academic intrinsic motivation from childhood through early adolescence, indicating both short- and long-term effects across these ages. Moreover, home environment was significant above and beyond SES. The findings revealed that children whose homes had a greater emphasis on learning opportunities and activities were more academically intrinsically motivated.

Dyslexic subtypes and severity levels: are there gender differences?

The prevalence of dyslexia among 100 children participating in a longitudinal study was examined. At age 10 years, The Dyslexia Screener (TDS) test, a direct assessment of coding skills used in reading and spelling, was administered. The incidence of suspected dyslexia of borderline or worse severity among boys and girls was not significantly different, nor did males and females differ significantly in terms of TDS-suspected dyslexic types of severity levels. Results challenge the widely held belief of an increased incidence of reading disability among males and, in conjunction with findings from other recent studies, underscore the need for establishing objective and reliable screening procedures in addition to teacher referral in identifying children in need of special services. Possible factors mediating previous estimates of incidence and the implications of these findings are discussed.

Consistency of hand preference: predictions to intelligence and school achievement.

Gottfried and Bathurst (1983) reported that hand preference consistency measured over time during infancy and early childhood predicts intellectual precocity for females, but not for males. In the present study longitudinal assessments of children previously classified by Gottfried and Bathurst as consistent or nonconsistent in cross-time hand preference were conducted during middle childhood (ages 5 to 9). Findings show that (a) early measurement of hand preference consistency for females predicts school-age intellectual precocity, (b) the locus of the difference between consistent vs. nonconsistent females is in verbal intelligence, and (c) the precocity of the consistent females was also revealed on tests of school achievement, particularly tests of reading and mathematics.

Development of stereopsis in infants and young children.

A limited number of studies have been done on stereopsis performance and clinical testing of infants and young children. As optometrists increasingly begin to examine young children there arises a need to know if stereopsis is a developmentally derived skill and if so, what are the normal skill levels for each age. This study shows that stereoacuity response follows a developmental trend and provides preliminary data on levels of performance for infants (18-24 months) and young children (30-60 months).

Visual skills and intellectual development: a relationship in young children.

The development of convergence, ocular motilities; stereopsis and form perception for infants and young children was evaluated in a previous paper. This study examines the relationship between these visual skills and intellectual development. Young children (n = 130) were assessed longitudinally every six months from the ages of 12- to 42-months. The results showed positive and significant correlations between visual skills and intellectual development during infancy and the preschool years. Stereopsis and form perception correlated most highly and consistently with intellectual development.

Hand preference across time is related to intelligence in young girls, not boys.

Consistency of hand preference was examined in a longitudinal study of children between 18 and 42 months of age. Results showed a sex-specific relationship between hand consistency and intellectual development. Across a variety of intellectual abilities at all ages, females with consistency of handedness were precocious compared to females without such consistency. This relationship did not hold for males.

Development of visual skills in infants and young children.

The development of ocular motilities, convergence, form perception and depth perception were studied for 128 infants at the ages of 18, 24 and 30 months of age. Developmental trends were evident in ocular motilities and form perception. Convergence ability was relatively good at 18 months and remained constant. Depth perception did not show a specific trend over the period studied.

Infants' cross-modal transfer from solid objects to their graphic representations.

12-month-old infants were familiarized either tactually or visually with objects and then tested for visual recognition memory using either (1) the familiar and a novel object, (2) colored pictures of the objects, or (3) outline drawings of them. In Study 1, infants showed recognition memory on all 3 visual intramodal problems but showed cross-modal transfer only when objects were used as test stimuli. With increased familiarization times in Study 2, transfer from tactually presented samples to both pictorial displays was achieved, indicating that after feeling an object the infants were able to recognize it visually solely on the basis of its contour. With reduced familiarization times in Study 3, there was no evidence for transfer from visually presented samples to the 2 pictorial displays, replicating the pattern of results observed cross-modally in Study 1 and suggesting that, at least in certain respects, cross-modal and intramodal perception follow similar principles.

Physical and social environment of newborn infants in special care units.

Infants in newborn intensive and convalescent care units are exposed to large amounts of sensory stimulation of various sorts. Although infants in these units do not lack visual, auditory, and tactile stimulation, they receive relatively infrequent coordinated sensory experiences. Furthermore, there is no diurnal rhythmicity in physical and social stimulation across days.