Reverse end-diastolic flow in a fetus with a rare liver malformation: a case report

<p>Abstract</p> <p>Introduction</p> <p>We describe a case of early and persistent reverse end-diastolic flow in the middle cerebral artery in a fetus with severe ascites. These features are associated with a rare liver malformation known as ductal plate malformation.</p> <p>Case presentation</p> <p>A 28-year-old Caucasian woman was referred to our high-risk obstetric unit at 24 weeks' gestation for fetal ascites detected during a routine ultrasound examination. During her hospitalization we performed medical investigations, including a fetal paracentesis, to detect the etiology of fetal ascites. The cause of fetal ascites (then considered non-immune or idiopathic) was not evident, but a subsequent ultrasound examination at 27 weeks' gestation showed a reverse end-diastolic flow in the middle cerebral artery without any other Doppler abnormalities. A cesarean section was performed at 28 weeks' gestation because of the compromised fetal condition. An autopsy revealed a rare malformation of intrahepatic bile ducts known as ductal plate malformation.</p> <p>Conclusion</p> <p>Persistent reverse flow in the middle cerebral artery should be considered a marker of adverse pregnancy outcome. We recommend careful ultrasound monitoring in the presence of this ultrasonographic sign to exclude any other cause of increased intracranial pressure. To better understand the nature of these ultrasonographic signs, additional reports are deemed necessary. In fact in our case, as confirmed by histopathological examination, the fetal condition was extremely compromised due to failure of the fetal liver. Ductal plate malformation altered the liver structures causing hypoproteinemia and probably portal hypertension. These two conditions therefore explain the severe hydrops that compromised the fetal situation.</p

Purification of single-walled carbon nanotubes

We present a study of purification of single-walled carbon nanotubes (SWCNTs) using different oxidation temperatures and chemical treatments. We have developed a simple two annealing-steps procedure resulting in high nanotube purity with minimal sample loss. The process involves annealing the SWCNTs at 300˚C for 2 h with subsequent reflux in 6 M HCl at 130˚C, followed by further annealing at 350˚C for 1 h with reflux in 6 M HCl at 130˚C. The process results in effective removal of carbon impurities and metal particles which are associated with SWCNTs production. The process is less time-consuming (complete in 4.5 h) than conventional acid purification methods which require over 5 h, and less destructive than conventional methods with a yield of 26%. SWCNT purity was assessed using Raman spectroscopy, thermogravimetry and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy

Solid-state fermentation of oil palm frond petiole for lignin peroxidase and xylanase-rich cocktail production

In current practice, oil palm frond leaflets and stems are re-used for soil nutrient recycling, while the petioles are typically burned. Frond petioles have high commercialization value, attributed to high lignocellulose fiber content and abundant of juice containing free reducing sugars. Pressed petiole fiber is the subject of interest in this study for the production of lignocellulolytic enzyme. The initial characterization showed the combination of 0.125 mm frond particle size and 60% moisture content provided a surface area of 42.3 m2/g, porosity of 12.8%, and density of 1.2 g/cm3, which facilitated fungal solid-state fermentation. Among the several species of Aspergillus and Trichoderma tested, Aspergillus awamori MMS4 yielded the highest xylanase (109 IU/g) and cellulase (12 IU/g), while Trichoderma virens UKM1 yielded the highest lignin peroxidase (222 IU/g). Crude enzyme cocktail also contained various sugar residues, mainly glucose and xylose (0.1–0.4 g/L), from the hydrolysis of cellulose and hemicellulose. FT-IR analysis of the fermented petioles observed reduction in cellulose crystallinity (I900/1098), cellulose–lignin (I900/1511), and lignin–hemicellulose (I1511/1738) linkages. The study demonstrated successful bioconversion of chemically untreated frond petioles into lignin peroxidase and xylanase-rich enzyme cocktail under SSF condition

Fungal enzyme sets for plant polysaccharide degradation

Enzymatic degradation of plant polysaccharides has many industrial applications, such as within the paper, food, and feed industry and for sustainable production of fuels and chemicals. Cellulose, hemicelluloses, and pectins are the main components of plant cell wall polysaccharides. These polysaccharides are often tightly packed, contain many different sugar residues, and are branched with a diversity of structures. To enable efficient degradation of these polysaccharides, fungi produce an extensive set of carbohydrate-active enzymes. The variety of the enzyme set differs between fungi and often corresponds to the requirements of its habitat. Carbohydrate-active enzymes can be organized in different families based on the amino acid sequence of the structurally related catalytic modules. Fungal enzymes involved in plant polysaccharide degradation are assigned to at least 35 glycoside hydrolase families, three carbohydrate esterase families and six polysaccharide lyase families. This mini-review will discuss the enzymes needed for complete degradation of plant polysaccharides and will give an overview of the latest developments concerning fungal carbohydrate-active enzymes and their corresponding families