1,687 research outputs found
Congenital stenosis of the posterior urethra with resultant congenital bilateral hydronephrosis with dilation of the ureters and dilation and hypertrophy of the urinary bladde abdnd posterior urethra
1. The point at which the obstruction occurs is at the
junction of the Pars prostatica and the Pars
membranacea.2. No folds have been demonstrated at this point.3. A thickening of the muscular wall of the urethra
exists from this point backwards towards the
bladder.4. The folds or what may be taken as valve -like
structures when present, have developed from the
normally existing folds in the prostatic urethra and
in the drawing of the cases in literature can be
traced to their origin in the verumontanum. They
arise from the verumontanum either from its
anterior or posterior edge or from its middle.5. In some cases no folds exist and where they do, they
occur in those cases that have survived for some
time after birth. Only in one case have valves
been reported in a full time foetus.6. The folds are the result of mechanical pressure
exerted by the urine on the normal structures. In
this respect it is noted that mucous folds are
produced in the pylorus even where no folds
originally exist.7. The muscle hypertrophy is due to the over -action
caused by a want of harmony between the
parasympathetic and sympathetic systems of the
autonomic fibres either by direct action on the
muscle itself or on the vessels.8. In some cases other deformities are present as in
this case a deficiency and scarring of the anterior
abdominal wall above the pubis, probably due to
some action on the bloodvessels.9. Cure of the retention may be effected in early
cases by the passage of instruments causing
dilatation of the narrowed urethra similar to
Lorenze's operations for Congenital stricture of
the pylorus. But in later cases in which the
verumontanum flaps have developed, cutting of the
folds may be necessary.10. Analogous sites for a similar condition are found
in the
(1) Lower end of oesophagus.
(2) Pylorus.
(3) Lower end of Ileum.
(4) Rectum
Evidence of Deep Water Penetration in Silica during Stress Corrosion Fracture
We measure the thickness of the heavy water layer trapped under the stress corrosion fracture surface of silica using neutron reflectivity experiments. We show that the penetration depth is 65–85 Å, suggesting the presence of a damaged zone of ~100 Å extending ahead of the crack tip during its propagation. This estimate of the size of the damaged zone is compatible with other recent results
Transcriptional interference by RNA polymerase III affects expression of the Polr3e gene.
Overlapping gene arrangements can potentially contribute to gene expression regulation. A mammalian interspersed repeat (MIR) nested in antisense orientation within the first intron of the Polr3e gene, encoding an RNA polymerase III (Pol III) subunit, is conserved in mammals and highly occupied by Pol III. Using a fluorescence assay, CRISPR/Cas9-mediated deletion of the MIR in mouse embryonic stem cells, and chromatin immunoprecipitation assays, we show that the MIR affects Polr3e expression through transcriptional interference. Our study reveals a mechanism by which a Pol II gene can be regulated at the transcription elongation level by transcription of an embedded antisense Pol III gene
Retrospective study of anaesthetic management of pregnancy patients with mechanical heart valve prosthesis and anticoagulants
Pregnancies among patients with a mechanical prosthetic valve and receiving anticoagulant medication are rare. Informations about their anesthetic management is poor. The objective of this study was to investigate the anaesthetic management of these patients in a reference medical centre as well as to identify possible ways for improvement. To this aim, the medical records of patients with a mechanical heart valve prosthesis having given birth at our center were analysed. In particular, the characteristics of patients and deliveries, the management of anticoagulation, as well as the type of anaesthesia performed, were collected and analysed. Eighteen cases were studied and compared to 36 controls. All studied cases were being administered anticoagulants. Five of these 8 patients delivered vaginally, one with epidural analgesia. Three of them have had a caesarean during labor, all under general anaesthesia. During the anticoagulation window, the teams had to perform an epidural in 3 (37%) of these 8 patients. Ten cases (55%) had a planned caesarean delivery, all performed under general anaesthesia. The anticoagulation interruption allowed spinal anaesthesia for 4 out of 10 caesarean delivery. The reoperation rate for secondary haemorrhage was significantly higher (P=0.0032) and the duration of the hospitalisation was extended (P<0.001). A context of anticoagulant overdose was identified in 60% of the bleeding cases. Progress can be made in the anaesthetic management of those patients by optimising the use of neuraxial anaesthesia and by improving the management of bleeding risk after delivery
Oxytocin is an age-specific circulating hormone that is necessary for muscle maintenance and regeneration.
The regenerative capacity of skeletal muscle declines with age. Previous studies suggest that this process can be reversed by exposure to young circulation; however, systemic age-specific factors responsible for this phenomenon are largely unknown. Here we report that oxytocin--a hormone best known for its role in lactation, parturition and social behaviours--is required for proper muscle tissue regeneration and homeostasis, and that plasma levels of oxytocin decline with age. Inhibition of oxytocin signalling in young animals reduces muscle regeneration, whereas systemic administration of oxytocin rapidly improves muscle regeneration by enhancing aged muscle stem cell activation/proliferation through activation of the MAPK/ERK signalling pathway. We further show that the genetic lack of oxytocin does not cause a developmental defect in muscle but instead leads to premature sarcopenia. Considering that oxytocin is an FDA-approved drug, this work reveals a potential novel and safe way to combat or prevent skeletal muscle ageing
Universal scattering behavior of co-assembled nanoparticle-polymer clusters
Water-soluble clusters made from 7 nm inorganic nanoparticles have been
investigated by small-angle neutron scattering. The internal structure factor
of the clusters was derived and exhibited a universal behavior as evidenced by
a correlation hole at intermediate wave-vectors. Reverse Monte-Carlo
calculations were performed to adjust the data and provided an accurate
description of the clusters in terms of interparticle distance and volume
fraction. Additional parameters influencing the microstructure were also
investigated, including the nature and thickness of the nanoparticle adlayer.Comment: 5 pages, 4 figures, paper published in Physical Review
Attosecond dispersive soft X-ray absorption fine structure spectroscopy in graphite
Phase transitions of solids and structural transformations of molecules are
canonical examples of important photo-induced processes, whose underlying
mechanisms largely elude our comprehension due to our inability to correlate
electronic excitation with atomic position in real time. Here, we present a
decisive step towards such new methodology based on water-window-covering (284
eV to 543 eV) attosecond soft X-ray pulses that can simultaneously access
electronic and lattice parameters via dispersive X-ray absorption
fine-structure (XAFS) spectroscopy. We validate attoXAFS with an identification
of the {\sigma}* and {\pi}* orbital contributions to the density of states in
graphite simultaneously with its lattice's four characteristic bonding
distances. This work demonstrates the concept of attoXAFS as a powerful
real-time investigative tool which is equally applicable to gas-, liquid- and
condensed phase
The dominant role of structure for solute transport in soil: experimental evidence and modelling of structure and transport in a field experiment
International audienceA classical transport experiment was performed in a field plot of 2.5 m2 using the dye tracer brilliant blue. The measured tracer distribution demonstrates the dominant role of the heterogeneous soil structure for solute transport. As with many other published experiments, this evidences the need of considering the macroscopic structure of soil to predict flow and transport. We combine three different approaches to represent the relevant structure of the specific situation of our experiment: i) direct measurement, ii) statistical description of heterogeneities and iii) a conceptual model of structure formation. The structure of soil layers was directly obtained from serial sections in the field. The sub-scale heterogeneity within the soil horizons was modelled through correlated random fields with estimated correlation lengths and anisotropy. Earthworm burrows played a dominant role at the transition between the upper soil horizon and the subsoil. A model based on percolation theory is introduced that mimics the geometry of earthworm burrow systems. The hydraulic material properties of the different structural units were obtained by direct measurements where available and by a best estimate otherwise. From the hydraulic structure, the 3-dimensional velocity field of water was calculated by solving Richards' Equation and solute transport was simulated. The simulated tracer distribution compares reasonably well with the experimental data. We conclude that a rough representation of the structure and a rough representation of the hydraulic properties might be sufficient to predict flow and transport, but both elements are definitely required
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