1,028 research outputs found
Termination of pregnancy using extra-amniotic prostaglandin F2a - experience in a peripheral hospital.
A CAJM clinical report on medically induced pregnancies in a rural hospital in KwaZulu Natal, South Africa.The need for termination of pregnancy, particularly for intra-uterine death, is a common problem facing doctors working in rural hospitals. It is probable that the spread of infection with the Human Immune Deficiency Virus will increase the numbers of pregnancies complicated by intra-uterine death and increase the demand for a safe and effective method of termination of pregnancy which can be used by general practitioners where the services of obstetricians are not available.
The purpose of this study was to evaluate whether extra-amniotic injections of Prostaglandin F2a is such a method
Recommended from our members
Improved chemistry restraints for crystallographic refinement by integrating the Amber force field into Phenix.
The refinement of biomolecular crystallographic models relies on geometric restraints to help to address the paucity of experimental data typical in these experiments. Limitations in these restraints can degrade the quality of the resulting atomic models. Here, an integration of the full all-atom Amber molecular-dynamics force field into Phenix crystallographic refinement is presented, which enables more complete modeling of biomolecular chemistry. The advantages of the force field include a carefully derived set of torsion-angle potentials, an extensive and flexible set of atom types, Lennard-Jones treatment of nonbonded interactions and a full treatment of crystalline electrostatics. The new combined method was tested against conventional geometry restraints for over 22 000 protein structures. Structures refined with the new method show substantially improved model quality. On average, Ramachandran and rotamer scores are somewhat better, clashscores and MolProbity scores are significantly improved, and the modeling of electrostatics leads to structures that exhibit more, and more correct, hydrogen bonds than those refined using traditional geometry restraints. In general it is found that model improvements are greatest at lower resolutions, prompting plans to add the Amber target function to real-space refinement for use in electron cryo-microscopy. This work opens the door to the future development of more advanced applications such as Amber-based ensemble refinement, quantum-mechanical representation of active sites and improved geometric restraints for simulated annealing
Electromagnetic finite-size effects to the hadronic vacuum polarization
In order to reduce the current hadronic uncertainties in the theory
prediction for the anomalous magnetic moment of the muon, lattice calculations
need to reach sub-percent accuracy on the hadronic-vacuum-polarization
contribution. This requires the inclusion of
electromagnetic corrections. The inclusion of electromagnetic interactions in
lattice simulations is known to generate potentially large finite-size effects
suppressed only by powers of the inverse spatial extent. In this paper we
derive an analytic expression for the finite-volume
corrections to the two-pion contribution to the hadronic vacuum polarization at
next-to-leading order in the electromagnetic coupling in scalar QED. The
leading term is found to be of order where is the spatial extent.
A term is absent since the current is neutral and a photon far away
thus sees no charge and we show that this result is universal. Our analytical
results agree with results from the numerical evaluation of loop integrals as
well as simulations of lattice scalar gauge theory with stochastically
generated photon fields. In the latter case the agreement is up to
exponentially suppressed finite-volume effects. For completeness we also
calculate the hadronic vacuum polarization in infinite volume using a basis of
2-loop master integrals.Comment: 42 pages, 11 figure
Human bone marrow mesenchymal stem cell-derived extracellular vesicles attenuate neuroinflammation evoked by focal brain injury in rats
Background Ischemic stroke is the major cause of long-term severe disability and death in aged population. Cell death in the infarcted region of the brain induces immune reaction leading to further progression of tissue damage. Immunomodulatory function of mesenchymal stem cells (MSCs) has been shown in multiple preclinical studies; however, it has not been successfully translated to a routine clinical practice due to logistical, economical, regulatory, and intellectual property obstacles. It has been recently demonstrated that therapeutic effect of intravenously administered MSCs can be recapitulated by extracellular vesicles (EVs) derived from them. However, in contrast to MSCs, EVs were not capable to decrease stroke-induced neuroinflammation. Therefore, the aim of the study was to investigate if intra-arterial delivery of MSC-derived EVs will have stronger impact on focal brain injury-induced neuroinflammation, which mimics ischemic stroke, and how it compares to MSCs. Methods The studies were performed in adult male Wistar rats with focal brain injury induced by injection of 1 mu l of 50 nmol ouabain into the right hemisphere. Two days after brain insult, 5 x 10(5) human bone marrow MSCs (hBM-MSCs) labeled with Molday ION or 1.3 x 10(9) EVs stained with PKH26 were intra-arterially injected into the right hemisphere under real-time MRI guidance. At days 1, 3, and 7 post-transplantation, the rats were decapitated, the brains were removed, and the presence of donor cells or EVs was analyzed. The cellular immune response in host brain was evaluated immunohistochemically, and humoral factors were measured by multiplex immunoassay. Results hBM-MSCs and EVs transplanted intra-arterially were observed in the rat ipsilateral hemisphere, near the ischemic region. Immunohistochemical analysis of brain tissue showed that injection of hBM-MSCs or EVs leads to the decrease of cell activation by ischemic injury, i.e., astrocytes, microglia, and infiltrating leucocytes, including T cytotoxic cells. Furthermore, we observed significant decrease of pro-inflammatory cytokines and chemokines after hBM-MSC or EV infusion comparing with non-treated rats with focal brain injury. Conclusions Intra-arterially injected EVs attenuated neuroinflammation evoked by focal brain injury, which mimics ischemic stroke, and this effect was comparable to intra-arterial hBM-MSC transplantation. Thus, intra-arterial injection of EVs might be an attractive therapeutic approach, which obviates MSC-related obstacles
Algebraic Aspects of Abelian Sandpile Models
The abelian sandpile models feature a finite abelian group G generated by the
operators corresponding to particle addition at various sites. We study the
canonical decomposition of G as a product of cyclic groups G = Z_{d_1} X
Z_{d_2} X Z_{d_3}...X Z_{d_g}, where g is the least number of generators of G,
and d_i is a multiple of d_{i+1}. The structure of G is determined in terms of
toppling matrix. We construct scalar functions, linear in height variables of
the pile, that are invariant toppling at any site. These invariants provide
convenient coordinates to label the recurrent configurations of the sandpile.
For an L X L square lattice, we show that g = L. In this case, we observe that
the system has nontrivial symmetries coming from the action of the cyclotomic
Galois group of the (2L+2)th roots of unity which operates on the set of
eigenvalues of the toppling matrix. These eigenvalues are algebraic integers,
whose product is the order |G|. With the help of this Galois group, we obtain
an explicit factorizaration of |G|. We also use it to define other simpler,
though under-complete, sets of toppling invariants.Comment: 39 pages, TIFR/TH/94-3
Spatial and Temporal Changes of Tidal Inlet Using Object-Based Image Analysis of Multibeam Echosounder Measurements: A Case from the Lagoon of Venice, Italy
Scientific exploration of seabed substrata has significantly progressed in the last few years.
Hydroacoustic methods of seafloor investigation, including multibeam echosounder measurements,
allow us to map large areas of the seabed with unprecedented precision. Through time-series of
hydroacoustic measurements, it was possible to determine areas with distinct characteristics in the
inlets of the Lagoon of Venice, Italy. Their temporal variability was investigated. Monitoring the
changes was particularly relevant, considering the presence at the channel inlets of mobile barriers
of the Experimental Electromechanical Module (MoSE) project installed to protect the historical
city of Venice from flooding. The detection of temporal and spatial changes was performed by
comparing seafloor maps created using object-based image analysis and supervised classifiers.
The analysis included extraction of 25 multibeam echosounder bathymetry and backscatter features.
Their importance was estimated using an objective approach with two feature selection methods.
Moreover, the study investigated how the accuracy of classification could be affected by the scale of
object-based segmentation. The application of the classification method at the proper scale allowed
us to observe habitat changes in the tidal inlet of the Venice Lagoon, showing that the sediment
substrates located in the Chioggia inlet were subjected to very dynamic changes. In general, during
the study period, the area was enriched in mixed and muddy sediments and was depleted in sandy
deposits. This study presents a unique methodological approach to predictive seabed sediment
composition mapping and change detection in a very shallow marine environment. A consistent,
repeatable, logical site-specific workflow was designed, whose main assumptions could be applied to
other seabed mapping case studies in both shallow and deep marine environments, all over the world
- …