NMR Studies on the Temperature-Dependent Dynamics of Confined Water

We use $^2$H NMR to study the rotational motion of supercooled water in silica pores of various diameters, specifically, in the MCM-41 materials C10, C12, and C14. Combination of spin-lattice relaxation, line-shape, and stimulated-echo analyses allows us to determine correlation times in very broad time and temperature ranges. For the studied pore diameters, 2.1-2.9 nm, we find two crossovers in the temperature-dependent correlation times of liquid water upon cooling. At 220-230 K, a first kink in the temperature dependence is accompanied by a solidification of a fraction of the confined water, implying that the observed crossover is due to a change from bulk-like to interface-dominated water dynamics, rather than to a liquid-liquid phase transition. Moreover, the results provide evidence that $\alpha$ process-like dynamics is probed above the crossover temperature, whereas $\beta$ process-like dynamics is observed below. At 180-190 K, we find a second change of the temperature dependence, which resembles that reported for the $\beta$ process of supercooled liquids during the glass transition, suggesting a value of $T_g\!\approx\!185$ K for interface-affected liquid water. In the high-temperature range, $T\!>\!225$ K, the temperature dependence of water reorientation is weaker in the smaller C10 pores than in the larger C12 and C14 pores, where it is more bulk-like, indicating a significant effect of the silica confinement on the $\alpha$ process of water in the former 2.1 nm confinement. By contrast, the temperature dependence of water reorientation is largely independent of the confinement size and described by an Arrhenius law with an activation energy of $E_a\!\approx\!0.5\$eV in the low-temperature range, $T\!<\!180$K, revealing that the confinement size plays a minor role for the $\beta$ process of water.Comment: 12 pages, 9 figure

NMR studies on the temperature-dependent dynamics of confined water

We use ²H NMR to study the rotational motion of supercooled water in silica pores of various diameters, specifically, in the MCM-41 materials C10, C12, and C14. Combination of spin–lattice relaxation, lineshape, and stimulated-echo analyses allows us to determine correlation times in very broad time and temperature ranges. For the studied pore diameters, 2.1–2.9 nm, we find two crossovers in the temperature-dependent correlation times of liquid water upon cooling. At 220–230 K, a first kink in the temperature dependence is accompanied by a solidification of a fraction of the confined water, implying that the observed crossover is due to a change from bulk-like to interface-dominated water dynamics, rather than to a liquid–liquid phase transition. Moreover, the results provide evidence that α process-like dynamics is probed above the crossover temperature, whereas β process-like dynamics is observed below. At 180–190 K, we find a second change of the temperature dependence, which resembles that reported for the β process of supercooled liquids during the glass transition, suggesting a value of Tg ≈ 185 K for interface-affected liquid water. In the high-temperature range, T > 225 K, the temperature dependence of water reorientation is weaker in the smaller C10 pores than in the larger C12 and C14 pores, where it is more bulk-like, indicating a significant effect of the silica confinement on the α process of water in the former 2.1 nm confinement. By contrast, the temperature dependence of water reorientation is largely independent of the confinement size and described by an Arrhenius law with an activation energy of Ea ≈ 0.5 eV in the low-temperature range, T < 180 K, revealing that the confinement size plays a minor role for the β process of water

Mutations in 12 known dominant disease-causing genes clarify many congenital anomalies of the kidney and urinary tract

Congenital anomalies of the kidney and urinary tract (CAKUT) account for approximately half of children with chronic kidney disease. CAKUT can be caused by monogenic mutations, however, data are lacking on their frequency. Genetic diagnosis has been hampered by genetic heterogeneity and lack of genotype-phenotype correlation. To determine the percentage of cases with CAKUT that can be explained by mutations in known CAKUT genes, we analyzed the coding exons of the 17 known dominant CAKUT-causing genes in a cohort of 749 individuals from 650 families with CAKUT. The most common phenotypes in this CAKUT cohort were 288 with vesicoureteral reflux, 120 with renal hypodysplasia and 90 with unilateral renal agenesis. We identified 37 different heterozygous mutations (33 novel) in 12 of the 17 known genes in 47 patients from 41 of the 650 families (6.3%). These mutations include (number of families): BMP7 (1), CDC5L (1), CHD1L (5), EYA1 (3), GATA3 (2), HNF1B (6), PAX2 (5), RET (3), ROBO2 (4), SALL1 (9), SIX2 (1), and SIX5 (1). Furthermore, several mutations previously reported to be disease-causing are most likely benign variants. Thus, in a large cohort over 6% of families with isolated CAKUT are caused by a mutation in 12 of 17 dominant CAKUT genes. Our report represents one of the most in-depth diagnostic studies of monogenic causes of isolated CAKUT in children

Gravity-wave-induced cross-isentropic mixing: a DEEPWAVE case study

Orographic gravity waves (i.e., mountain waves) can potentially lead to cross-isentropic fluxes of trace gases via the generation of turbulence. During the DEEPWAVE (Deep Propagating Gravity Wave Experiment) campaign in July 2014, we performed tracer measurements of carbon monoxide (CO) and nitrous oxide (N2O) above the Southern Alps during periods of gravity wave activity. The measurements were taken along two stacked levels at 7.9 km in the troposphere and 10.9 km in the stratosphere. A detailed analysis of the observed wind components shows that both flight legs were affected by vertically propagating gravity waves with momentum deposition and energy dissipation between the two legs. Corresponding tracer measurements indicate turbulent mixing in the region of gravity wave occurrence. For the stratospheric data, we identified mixing leading to a change of the cross-isentropic tracer gradient of N2O from the upstream to the downstream region of the Southern Alps. Based on the quasi-inert tracer N2O, we identified two distinct layers in the stratosphere with different chemical composition on different isentropes as given by constant potential temperature 2. The CO–N2O relationship clearly indicates that irreversible mixing between these two layers occurred. Further, we found a significant change of the vertical profiles of N2O with respect to 2 from the upstream to the downstream side above the Southern Alps just above the tropopause. A scale-dependent gradient analysis reveals that this cross-isentropic gradient change of N2O is triggered in the region of gravity wave occurrence

Nabelvenenkatheter- und periphere zentrale katheterassoziierte Komplikationen bei Frühgeborenen mit einem Geburtsgewicht < 1250 g : Ergebnisse einer Umfrage in Österreich und Deutschland

Background and objective Umbilical venous catheters (UVC) and peripherally inserted central catheters (PICC) are commonly used in preterm infants but have been associated with a number of serious complications. We performed a survey in Austria and Germany to assess the use of UVCs and PICCs in preterm infants with a birth weight < 1250 g and associated rates of catheter-related adverse events. Methods Electronic survey of participating centers of the NeoVitaA trial. Main outcome parameter was the reported rates of UVC- and PICC-associated complications (infection, thrombosis, emboli, organ injury, arrhythmia, dislocation, miscellaneous). Results In total, 20 neonatal intensive care units (NICU) providing maximal intensive care in Austria and Germany (level I) were contacted, with a senior neonatologist response rate of 12/20 (60%). The reported rates for UVC with a dwell time of 1–10 days were bacterial infection: 4.2 ± 3.4% (range 0–10%); thrombosis: 7.3 ± 7.1% (0–20%); emboli: 0.9 ± 2.0% (0–5%); organ injury: 1.1 ± 1.9% (0–5%); cardiac arrhythmia: 2.2 ± 2.5% (0–5%); and dislocation: 5.4 ± 8.7% (0–30%); and for PICCs with a dwell time of 1–14 days bacterial infection: 15.0 ± 3.4% (range 2.5–30%); thrombosis; 4.3 ± 3.5% (0–10%); emboli: 0.8 ± 1.6% (0–5%); organ injury: 1.5 ± 2.3% (0–5%); cardiac arrhythmia: 1.5 ± 2.3% (0–5%), and dislocation: 8.5 ± 4.6% (0–30%). Conclusion The catheter-related complication rates reported in this survey differed between UVCs and PICCs and were higher than those reported in the literature. To generate more reliable data on this clinically important issue, we plan to perform a large prospective multicenter randomized controlled trial investigating the non-inferiority of a prolonged UVC dwell time (up to 10 days) against the early change (up to 5 days) to a PICC.Hintergrund und Ziel Nabelvenenkatheter („umbilical venous catheters“ [UVC]) und periphere zentrale Venenkatheter (PICC) werden häufig bei Frühgeborenen eingesetzt, sind jedoch mit einer Reihe von schwerwiegenden Komplikationen verbunden. In Österreich und Deutschland wurde eine Umfrage durchgeführt, um die Verwendung von UVC und PICC bei Frühgeborenen mit einem Geburtsgewicht < 1250 g und die damit verbundenen Raten von katheterbedingten unerwünschten Ereignissen zu bewerten. Methoden Elektronische Befragung der teilnehmenden Zentren der NeoVitaA-Studie. Hauptergebnisparameter waren die gemeldeten Raten von UVC- und PICC-assoziierten Komplikationen (Infektion, Thrombose, Embolie, Organverletzung, Arrhythmie, Dislokation, Sonstiges). Ergebnisse Insgesamt wurden 20 neonatale Intensivstationen (NICU) mit maximaler Intensivpflege in Österreich und Deutschland (Level I) kontaktiert, wobei 12/20 (60 %) von leitenden Neonatologen beantwortet wurden. Die gemeldeten Raten für UVC mit einer Verweildauer von 1 bis 10 Tagen waren bakterielle Infektionen: 4,2 ± 3,4 % (Bereich: 0–10 %); Thrombose: 7,3 ± 7,1 % (0–20 %); Embolie: 0,9 ± 2,0 % (0–5 %); Organverletzung: 1,1 ± 1,9 % (0–5 %); Herzrhythmusstörungen: 2,2 ± 2,5 % (0–5 %); und Dislokation: 5,4 ± 8,7% (0–30 %); und bei PICC mit einer Verweildauer von 1 bis 14 Tagen bakterielle Infektionen: 15,0 ± 3,4 % (Bereich: 2,5–30 %); Thrombose: 4,3 ± 3,5 % (0–10 %); Embolie: 0,8 ± 1,6 % (0–5 %); Organverletzung: 1,5 ± 2,3 % (0–5 %); Herzrhythmusstörungen: 1,5 ± 2,3 % (0–5 %) und Verrenkungen: 8,5 ± 4,6 % (0–30 %). Schlussfolgerung Die in dieser Umfrage berichteten katheterbedingten Komplikationsraten unterschieden sich zwischen UVC und PICC und waren höher als die in der Literatur berichteten. Um zuverlässigere Daten zu diesem klinisch wichtigen Thema zu erhalten, ist eine große prospektive, multizentrische, randomisierte, kontrollierte Studie geplant, in der die Nichtunterlegenheit einer verlängerten UVC-Verweildauer (bis zu 10 Tage) gegenüber dem frühen Wechsel (bis zu 5 Tage) zu einem PICC untersucht werden soll

Whole exome resequencing reveals recessive mutations in TRAP1 in individuals with CAKUT and VACTERL association

Congenital abnormalities of the kidney and urinary tract (CAKUT) account for approximately half of children with chronic kidney disease and they are the most frequent cause of end-stage renal disease in children in the US. However, its genetic etiology remains mostly elusive. VACTERL association is a rare disorder that involves congenital abnormalities in multiple organs including the kidney and urinary tract in up to 60% of the cases. By homozygosity mapping and whole exome resequencing combined with high-throughput mutation analysis by array-based multiplex PCR and next-generation sequencing, we identified recessive mutations in the gene TNF receptor-associated protein 1 (TRAP1) in two families with isolated CAKUT and three families with VACTERL association. TRAP1 is a heat shock protein 90-related mitochondrial chaperone possibly involved in antiapoptotic and endoplasmic reticulum-stress signaling. Trap1 is expressed in renal epithelia of developing mouse kidney E13.5 and in the kidney of adult rats, most prominently in proximal tubules and in thick medullary ascending limbs of Henle’s loop. Thus, we identified mutations in TRAP1 as highly likely causing CAKUT or CAKUT in VACTERL association

Research perspectives in the etiology of congenital anorectal malformations using data of the International Consortium on Anorectal Malformations: evidence for risk factors across different populations

Contains fulltext : 89406.pdf (publisher's version ) (Closed access)PURPOSE: The recently established International Consortium on Anorectal Malformations aims to identify genetic and environmental risk factors in the etiology of syndromic and nonsyndromic anorectal malformations (ARM) by promoting collaboration through data sharing and combined research activities. METHODS: The consortium attempts to recruit at least 1,000 ARM cases. DNA samples are collected from case-parent triads to identify genetic factors involved in ARM. Several genetic techniques will be applied, including SNP arrays, gene and whole exome sequencing, and a genome-wide association study. Questionnaires inquiring about circumstances before and during pregnancy will be used to obtain environmental risk factor data. RESULTS: Currently, 701 ARM cases have been recruited throughout Europe. Clinical data are available from all cases, and DNA samples and questionnaire data mainly from the Dutch and German cases. Preliminary analyses on environmental risk factors in the Dutch and German cohort found associations between ARM and family history of ARM, fever during first trimester of pregnancy and maternal job exposure to cleaning agents and solvents. CONCLUSION: First results show that both genetic and environmental factors may contribute to the multifactorial etiology of ARM. The International Consortium on Anorectal Malformations will provide possibilities to study and detect important genes and environmental risk factors for ARM, ultimately resulting in better genetic counseling, improved therapies, and primary prevention.1 november 201

Copy number variations in 375 patients with oesophageal atresia and/or tracheoesophageal fistula

Oesophageal atresia (OA) with or without tracheoesophageal fistula (TOF) are rare anatomical congenital malformations whose cause is unknown in over 90% of patients. A genetic background is suggested, and among the reported genetic defects are copy number variations (CNVs). We hypothesized that CNVs contribute to OA/TOF development. Quantifying their prevalence could aid in genetic diagnosis and clinical care strategies. Therefore, we profiled 375 patients in a combined Dutch, American and German cohort via genomic microarray and compared the CNV profiles with their unaffected parents and published control cohorts. We identified 167 rare CNVs containing genes (frequency<0.0005 in our in-house cohort). Eight rare CNVs - in six patients - were de novo, including one CNV previously associated with oesophageal disease. (hg19 chr7:g.(143820444-143839360)-(159119486-159138663)del) 1.55% of isolated OA/TOF patients and 1.62% of patients with additional congenital anomalies had de novo CNVs. Furthermore, three (15q13.3, 16p13.3 and 22q11.2) susceptibility loci were identified based on their overlap with known OA/TOF-associated CNV syndromes and overlap with loci in published CNV association case-control studies in developmental delay. Our study suggests that CNVs contribute to OA/TOF development. In addition to the identified likely deleterious de novo CNVs, we detected 167 rare CNVs. Although not directly disease-causing, these CNVs might be of interest, as they can act as a modifier in a multiple hit model, or as the second hit in a recessive condition