C-Term Reduction in 3 μm Open-Tubular High-Aspect-Ratio Channels in AC-EOF Vortex Chromatography Operation.

The performance of liquid chromatography operation in open-tubular channels, the ideal chromatographic column format, is limited by slow mass transport between the mobile and stationary phase. We recently introduced a lateral mixing methodology ("vortex chromatography") to reduce Taylor-Aris dispersion by employing (small) AC-EOF (alternating current electroosmotic flow) fields oriented perpendicular to the conventionally applied, axially oriented pressure gradient, resulting in the reduction of the C-term by a factor of 3, studied in 40 × 20 μm (aspect ratio (AR) = 2) channels under unretained conditions. In the present contribution, a further increased performance gain for channel dimensions relevant for chromatographic applications is demonstrated.

Mind the B2: Life-Threatening Neonatal Complications of a Strict Vegan Diet during Pregnancy.

An increasing number of women of reproductive age follow vegan diets. Because vegan diets are deficient in a number of essential nutrients, guidelines address the necessity of supplementations such as iron, zinc, and vitamin B12. However, the risk of riboflavin (vitamin B2) deficiency is not properly addressed.

Application of generalized dispersion theory to vortex chromatography.

Acoustically induced secondary flows are applied to enhance lateral mass transfer beyond the relatively slow diffusion. This has the goal to reduce convective axial dispersion and the resulting band broadening which, in turn, limits the performance of column chromatography. Traditional approaches based on Taylor-Aris model are limited to one-dimensional rectilinear (unidirectional) tube- or channel-flows.

Autonomous capillary microfluidic devices with constant flow rate and temperature-controlled valving.

In this paper, we report on a capillary microfluidic device with constant flow rate and temperature-triggered stop valve function. It contains a PDMS channel that was grafted by a thermo-responsive polymer poly(N-isopropylacrylamide) (PNIPAm). The channel exhibits a constant capillary filling speed.

Inducing AC-electroosmotic flow using electric field manipulation with insulators.

Classically, the configuration of electrodes (conductors) is used as a means to determine AC-electroosmotic flow patterns. In this paper, we use the configuration of insulator materials to achieve AC-electroosmotic flow patterning in a novel approach. We apply AC electric fields between parallel electrodes situated on the top and bottom of a microfluidic channel and separated by an insulating material.

Reduction of Taylor-Aris dispersion by lateral mixing for chromatographic applications.

Chromatographic columns are suffering from Taylor-Aris dispersion, especially for slowly diffusing molecules such as proteins. Since downscaling the channel size to reduce Taylor-Aris dispersion meets fundamental pressure limitations, new strategies are needed to further improve chromatography beyond its current limits. In this work we demonstrate a method to reduce Taylor-Aris dispersion by lateral mixing in a newly designed silicon AC-electroosmotic flow mixer.

Controlled pharmacokinetic anti-cancer drug concentration profiles lead to growth inhibition of colorectal cancer cells in a microfluidic device.

We present a microfluidic device to expose cancer cells to a dynamic, in vivo-like concentration profile of a drug, and quantify efficacy on-chip. About 30% of cancer patients receive drug therapy. In conventional cell culture experiments drug efficacy is tested under static concentrations, e.

Mass Transport Determined Silica Nanowires Growth on Spherical Photonic Crystals with Nanostructure-Enabled Functionalities.

A robust and facile method has been developed to obtain directional growth of silica nanowires (SiO NWs) by regulating mass transport of silicon monoxide (SiO) vapor. SiO NWs are grown by vapor-liquid-solid (VLS) process on a surface of gold-covered spherical photonic crystals (SPCs) annealed at high temperature in an inert gas atmosphere in the vicinity of a SiO source. The SPCs are prepared from droplet confined colloidal self-assembly.

Gradient in the electric field for particle position detection in microfluidic channels.

In this work, a new method to track particles in microfluidic channels is presented. Particle position tracking in microfluidic systems is crucial to characterize sorting systems or to improve the analysis of cells in impedance flow cytometry studies. By developing an electric field gradient in a two parallel electrode array the position of the particles can be tracked in one axis by impedance analysis.

Neurodevelopment of Preterm Infants at 24 Months After Neonatal Supplementation of a Prebiotic Mix: A Randomized Trial.

Objectives: Fetal brain maturation is disrupted by preterm birth. Inflammation during the neonatal period may further harm neurodevelopmental outcomes. The present study aimed to determine the effect of short-chain galacto-oligosaccharides/long-chain fructo-oligosaccharides/pectin-derived acidic oligosaccharides (scGOS/lcFOS/pAOS) on neurodevelopmental outcomes measured by Bayley Scales of Infant and Toddler Development in preterm infants at 24 months.

Response on Pneumococcal Vaccine in Preterm Infants After Neutral and Acidic Oligosaccharides Supplementation.

Background: Supplementation of oligosaccharides in premature infants was shown to influence the immune system. We determined the effect of combined short-chain galacto-oligosaccharides (scGOS), long-chain fructo-oligosaccharides (lcFOS) and pectin-derived acidic oligosaccharides (pAOS) on antibody concentrations after pneumococcal conjugate vaccination in very preterm infants.

Methods: Very preterm infants with gestational age <32 weeks and/or birth weight <1500 g were randomized to receive enteral supplementation with scGOS/lcFOS/pAOS or placebo between days 3 and 30 of life.

Lower transplacental antibody transport for measles, mumps, rubella and varicella zoster in very preterm infants.

Background: Maternal antibodies, transported over the placenta during pregnancy, contribute to the protection of infants from infectious diseases during the first months of life. In term infants, this protection does not last until the first recommended measles-mumps-rubella vaccination at 14 months in the Netherlands, while these viruses still circulate. The aim of the study was to investigate the antibody concentration against measles, mumps, rubella and varicella (MMRV) in mothers and preterm infants or healthy term infants at birth.

Neutral and acidic oligosaccharides supplementation does not increase the vaccine antibody response in preterm infants in a randomized clinical trial.

Background: In preterm infants, a decreased immunological response and lower serological effectiveness are observed after immunizations due to ineffectiveness of both humoral and cellular immune mechanisms.

Objective: To determine the effect of 80% neutral oligosaccharides [small-chain galacto-oligosaccharides/long-chain fructo-oligosaccharides (scGOS/lcFOS)] in combination with 20% pectin-derived acidic oligosaccharides (pAOS) on antibody concentrations after DTaP-IPV-Hib immunization in preterm infants.

Design: In this randomized clinical trial, preterm infants with gestational age <32 weeks and/or birth weight <1500 g received enteral supplementation with scGOS/lcFOS/pAOS or placebo (maltodextrin) between days 3 and 30 of life.

Neonatal modulation of serum cytokine profiles by a specific mixture of anti-inflammatory neutral and acidic oligosaccharides in preterm infants.

Infections are common in preterm infants and cause differences in cytokine levels. Aim of this study was to measure cytokine levels in preterm infants during the first year of life and to determine the effect of feeding a specific non-digestible carbohydrate mixture (scGOS/lcFOS/pAOS). Furthermore, other perinatal factors in relation to these cytokine levels were analysed.

Neurodevelopmental outcome during the first year of life in preterm infants after supplementation of a prebiotic mixture in the neonatal period: a follow-up study.

Aim: The study aimed to determine the effect of enteral supplementation of a prebiotic mixture (neutral and acidic oligosaccharides) in the neonatal period on neurodevelopmental outcome in preterm infants with a gestational age of less than 32 weeks and/or birth weight of less than 1,500 g in the first year of life.

Methods: Neurodevelopmental outcome consisted of tone and motility according to Touwen, motor ability according to the Alberta Infant Motor Scale, as well as vision and hearing were evaluated at 0, 3, 6, and 12 months corrected age (CA). To adjust for potential confounders, data were analyzed by multinomial or logistic regression.

Effect of non-human neutral and acidic oligosaccharides on allergic and infectious diseases in preterm infants.

Unlabelled: Short-term supplementation of non-human neutral and acidic oligosaccharides during the first postnatal weeks may enhance the maturation of the immune response in preterm infants and may lead to less allergic and infectious diseases during the first year of life. In a randomized controlled trial, 113 preterm infants (gestational age <32 weeks and/or birth weight <1500 g) were allocated to receive enteral neutral and acidic oligosaccharide supplementation or placebo between days 3 and 30 of life. The median age at follow-up was not different in both groups: 12 months corrected age (interquartile range [IQR], 11-15) in the prebiotic mixture group and 12 months corrected age in the placebo group (IQR, 10-19), respectively.

The effect of enteral supplementation of specific neutral and acidic oligosaccharides on the faecal microbiota and intestinal microenvironment in preterm infants.

We aimed to determine the effects of enteral supplementation of a prebiotic mixture of neutral and acidic oligosaccharides (scGOS/lcFOS/pAOS) on the faecal microbiota and microenvironment in preterm infants. Furthermore, we determined the influence of perinatal factors on the development of the faecal microbiota. In a randomised controlled trial, preterm infants with gestational age <32 weeks and/or birth weight <1,500 g received enteral supplementation of scGOS/lcFOS/pAOS or placebo (maltodextrin) between days 3 and 30 of life.

The effect of neutral and acidic oligosaccharides on stool viscosity, stool frequency and stool pH in preterm infants.

Aim: To determine the effect of neutral oligosaccharides [small-chain galacto-oligosaccharides/long-chain fructo-oligosaccharides (scGOS/lcFOS)] in combination with acidic oligosaccharides (pAOS) on stool viscosity, stool frequency and stool pH in preterm infants.

Methods: In this explorative RCT, preterm infants with gestational age <32 weeks and/or birth weight <1500 g received enteral supplementation with scGOS/lcFOS/pAOS or placebo (maltodextrin) between days 3 and 30 of life. Stool samples were collected at day 30 after birth.

Effect of neutral and acidic oligosaccharides on fecal IL-8 and fecal calprotectin in preterm infants.

The gastrointestinal inflammatory response may play a role in the susceptibility of preterm infants for infections. We previously reported a trend toward lower endogenous infection morbidity after enteral supplementation of neutral and acidic oligosaccharides (SC GOS/LC FOS/AOS). We hypothesize that enteral supplementation of prebiotics may decrease infectious morbidity by reducing intestinal inflammation.

Transplacental transport of IgG antibodies to preterm infants: a review of the literature.

Newborn infants, especially preterm infants, have an immature immune system, which is not capable to actively protect against vaccine-preventable infections. Therefore, the newborn is dependent on transplacental transport of Immunoglobulin G (IgG), an active, FcRn receptor mediated process. Fetal IgG rises from approximately 10% of the maternal concentration at 17-22weeks of gestation to 50% at 28-32weeks of gestation.

The effect of enteral supplementation of a prebiotic mixture of non-human milk galacto-, fructo- and acidic oligosaccharides on intestinal permeability in preterm infants.

Preterm infants have an impaired gut barrier function. We aimed to determine the effects of enteral supplementation of a prebiotic mixture consisting of neutral oligosaccharides (short-chain galacto-oligosaccharides (SCGOS)/long-chain fructo-oligosaccharides (LCFOS)) and acidic oligosaccharides (AOS) on intestinal permeability of preterm infants as measured by the sugar absorption test in the first week of life. Furthermore, we determined host- and treatment-related factors associated with intestinal permeability.

Transplacental transport of IgG antibodies specific for pertussis, diphtheria, tetanus, haemophilus influenzae type b, and Neisseria meningitidis serogroup C is lower in preterm compared with term infants.

Background: Maternal antibodies, transported through the placenta during pregnancy, contribute to the protection of infants from infectious diseases during the first months of life. The aim of this study was to measure the concentration of antibodies against several vaccine-preventable diseases in paired maternal and cord blood serum samples in preterm and term infants and to assess placental transfer ratios and infant antibody concentrations against vaccine-preventable diseases.

Methods: Antibody concentrations specific against pertussis proteins (pertussis toxin, filamentous hemagglutinin, pertactin, and fimbriae), diphtheria and tetanus toxins, and antibody concentrations specific against polysaccharides from Haemophilus influenzae type b and Neisseria meningitidis serogroup C were measured in cord blood samples from preterm (<32 weeks and 1500 g) and term infants and maternal serum samples, using a fluorescent bead-based multiplex immunoassay.

Neutral and acidic oligosaccharides in preterm infants: a randomized, double-blind, placebo-controlled trial.

Background: Serious infectious morbidity is high in preterm infants. Enteral supplementation of prebiotics may reduce the incidence of serious infections, especially infections related to the gastrointestinal tract.

Objective: The objective was to determine the effect of enteral supplementation of a prebiotic mixture consisting of neutral oligosaccharides ((SC)GOS/(LC)FOS) and acidic oligosaccharides (AOS) on serious infectious morbidity in preterm infants.