1,561 research outputs found
Purification of a factor from human peritoneal fluid that is able to immobilize spermatozoa
Human peritoneal fluid has been claimed to influence sperm motility. This report gives evidence for the presence in mid-cycle peritoneal fluid of a protein-bound, lipidic (hydrophobic) component able to immobilize spermatozoa as a function of time. This component was extracted from molecular weight-sieving and ion-exchange/high pressure liquid chromatography (HPLC)-purified peritoneal fluid fractions by either chloroform/methanol or charcoal treatments; resuspension of the chloroform/methanol extract with BWW-buffer and subsequent testing on spermatozoa resulted in sperm immobilization. Sequential or step-down chromatographic procedures (molecular weight-sievingâcation-exchangeâanion-exchange HPLC separations of native peritoneal fluid) and extensive dialysis against double distilled water allowed the purification of the sperm immobilizing factor, as evidenced by the shorter incubation times necessary for sperm immobilization. Furthermore, the active fraction was found to immobilize spermatozoa without affecting its viability. Separation of the chloroform/methanol extracted immobilizing fraction on thin layer chromatography under conditions for phospholipid detection allowed the identification of a characteristic band which, after re-extraction, was found to be the sperm immobilizing substance. This factor does not contain choline, ethanolamine or serine. These results suggest that some lipidic peritoneal fluid components may influence sperm motilit
Phase diagram and single-particle spectrum of CuO layers within a variational cluster approach to the 3-band Hubbard model
We carry out a detailed numerical study of the three-band Hubbard model in
the underdoped region both in the hole- as well as in the electron-doped case
by means of the variational cluster approach. Both the phase diagram and the
low-energy single-particle spectrum are very similar to recent results for the
single-band Hubbard model with next-nearest-neighbor hoppings. In particular,
we obtain a mixed antiferromagnetic+superconducting phase at low doping with a
first-order transition to a pure superconducting phase accompanied by phase
separation. In the single-particle spectrum a clear Zhang-Rice singlet band
with an incoherent and a coherent part can be seen, in which holes enter upon
doping around . The latter is very similar to the coherent
quasi-particle band crossing the Fermi surface in the single-band model. Doped
electrons go instead into the upper Hubbard band, first filling the regions of
the Brillouin zone around . This fact can be related to the enhanced
robustness of the antiferromagnetic phase as a function of electron doping
compared to hole doping.Comment: 14 pages, 15 eps figure
The effect of vestibular stimulation on motor functions of children with cerebral palsy
Background: Cerebral palsy (CP) has been defined as a nonprogressive disease of movement and posture development. Physical therapy techniques use different forms of sensory stimulation to improve neuromotor development. Aim: The aim of this study was to assess the efficacy of a vestibular stimulation training in improving motor functions in cerebral palsy. Population: Fourteen children with CP were randomly separated into two different groups in a cross-over trial. Methods: Over a period of 10 weeks, each group performed 10 sessions of 50 min of neurodevelopmental treatment (NDT) and 10 sessions of vestibular training (VR). Children were evaluated with the Gross Motor Function Measurement-88 scale, the Goal Attainment Scale and the root mean square of head accelerations. Results: A significant improvement in the GAS-score (p =.003) was noted after NDT+VR. Conclusions: Vestibular stimulation integrated with NDT proved to be an effective complementary strategy for facilitating motor functioning
TIBIO-FIBULAR BONE TRANSPOSITION FOR THE TREATMENT OF ONCOLOGICAL PERIPROSTHETIC INFECTION OF THE KNEE WITH MASSIVE BONE LOSS
Chronic periprosthetic joint infection (PJI) is one of the most relevant complications in orthopaedic
surgery, especially in the case of limb reconstruction with megaprostheses after malignant tumoral
resection. This is the report of a case of a 35-year-old patient, affected by a chronic PJI around a
knee megaprosthesis implanted after the resection of an osteosarcoma of the distal femur. âEn blocâ
resection and limb reconstruction with an expandable megaprothesis of the knee were performed at
the age of 5 years old (1989). PJI occurred after the definitive megaprosthesis implantation (2002),
and became chronic over the years.
In 2019, due to a massive recrudescence of the infection and the severe femoral bone loss, the
patient underwent a wide intercalary resection and a thigh stump reconstruction by transposition of
the fibula and the distal third of the tibia in order to avoid a hip disarticulation.
Although complex, the proposed treatment allowed improved outcomes in a young patient with
high function requests, justifying the global surgical invasiveness
Octocrylene: From Sunscreens to the Degradation Pathway during Chlorination Processes: Formation of Byproducts and Their Ecotoxicity Assessment
Octocrylene is an organic sunscreen whose main action is to absorb UVB radiation and short UVA wavelengths; it is used in various cosmetic products in order to provide an adequate sun-protection factor or to protect the cosmetic formulations themselves from UV radiation. This filter is believed to be a possible endocrine disruptor and is also questioned due to its allergic and/or photoallergic potential. However, it continues to be widely used, and it has been found in various environments, not least those of swimming pools, where it is evidently released by consumers, to the point that it is now considered an emerging micropollutant. The present investigation presents the possible chemical fate of octocrylene in the typical chlorination conditions of wastewater or swimming pools. A total of 11 disinfection byproducts were identified, and 6 were identified for the first time, and separated by HPLC. These products were identified through careful mass spectrometry studies and 1D and 2D NMR experiments. A formation mechanism has been proposed that justifies the chemical structures of all of the compounds identified. The ecotoxicological assessment of octocrylene and their products was carried out by employing Phaeodactylum tricornutum, Brachionus plicatilis and Aliivibrio fischeri as bioindicators. The ecotoxicity results reveal that toxic byproducts might be generated during the oxidation process, increasing the potential risk to the marine environment
A family of kojic acid derivatives aimed to remediation of Pb2+ and Cd2+
The present work analyzes the complex formation ability towards Pb2+ and Cd2+ of a series of kojic acid derivatives that join the chelating properties of the pyrone molecules and those of polyamines, with the aim of evaluating how the different effects of oxygen and nitrogen coordinating groups act on the stability of metal complexes. Experimental research is carried out using potentiometric and spectrophotometric techniques supported by 1H and 13C NMR spectroscopy and DFT calculations. Actually, a different coordination mechanism toward Pb2+ and Cd2+ was proved: in the case of Pb2+, coordination takes place exclusively via the oxygen atoms, while the contribute of the nitrogen atoms appears relevant in the case of Cd2+. Lead complexes of all the studied ligands are characterized by significantly stronger stability than those of cadmium. Finally, on the basis of the measured complex formation stabilities, some of the proposed molecules seems promising effective ligands for lead and cadmium ion decorporation from polluted soils or waste waters
EDIpack: A parallel exact diagonalization package for quantum impurity problems
We present EDIpack, an exact diagonalization package to solve generic quantum
impurity problems. The algorithm, based on a generalization of the look-up
method introduced by Lin and Gubernatis, enables a massively parallel execution
of the matrix-vector linear operations required by Lanczos and Arnoldi
algorithms. We show that a suitable Fock basis organization is crucial to
optimize the inter-processors communication in distributed memory setup and,
thus, to reach sub-linear scaling in sufficiently large systems. We discuss the
algorithm in details, indicating how to deal with multiple-orbitals and
electron-phonon coupling. Finally, we detail the download, installation and
functioning of this package.Comment: 33 pages, 6 figure
DNA structure directs positioning of the mitochondrial genome packaging protein Abf2p
The mitochondrial genome (mtDNA) is assembled into nucleo-protein structures termed nucleoids and maintained differently compared to nuclear DNA, the involved molecular basis remaining poorly understood. In yeast (Saccharomyces cerevisiae), mtDNA is a similar to 80 kbp linear molecule and Abf2p, a double HMG-box protein, packages and maintains it. The protein binds DNA in a non-sequence-specific manner, but displays a distinct 'phased-binding' at specific DNA sequences containing poly-adenine tracts (A-tracts). We present here two crystal structures of Abf2p in complex with mtDNA-derived fragments bearing A-tracts. Each HMG-box of Abf2p induces a 90. bend in the contacted DNA, causing an overall U-turn. Together with previous data, this suggests that U-turn formation is the universal mechanism underlying mtDNA compaction induced by HMG-box proteins. Combining this structural information with mutational, biophysical and computational analyses, we reveal a unique DNA binding mechanism for Abf2p where a characteristic N-terminal flag and helix are crucial for mtDNA maintenance. Additionally, we provide the molecular basis for A-tract mediated exclusion of Abf2p binding. Due to high prevalence of Atracts in yeast mtDNA, this has critical relevance for nucleoid architecture. Therefore, an unprecedented A-tract mediated protein positioning mechanism regulates DNA packaging proteins in the mitochondria, and in combination with DNA-bending and U-turn formation, governs mtDNA compaction
Methods, data and tools for facilitating a 3D cultural heritage space
In recent years, the cultural heritage (CH) sector has experienced a rapid evolution due to the introduction of increasingly powerful digital technologies and ICT (Information and Communication Technologies) solutions. As for many other domains, digital data, Artificial Intelligence (AI), and Extended Reality (XR) are opening up extraordinary opportunities for expanding heritage knowledge capabilities while boosting the research on innovative solutions for its valorisation and preservation. Being aware of the fundamental and strategic role of CH in the history and identity of the European countries, the European Commission has assumed a central role in fuelling the policy debate and putting together stakeholders to take a step forward in CH digitization and use, primarily through initiatives, programs, and recommendations. Within this framework, the ongoing European 5DCulture project (https://www.5dculture.eu/) has been funded to enrich the offer of 3D CH digital assets in the common European Data Space for Cultural Heritage by creating high-quality 3D contents and to foster their re-use in several sectors, from tourism to education. Through 8 re-use scenarios around historic buildings and cityscapes, archaeology, and fashion, the project aims to deliver a set of digital tools and increase the capacity of CH institutions to more effectively re-use their 3D digital assets
Thermodynamic Stability at the Two-Particle Level
We show how the stability conditions for a system of interacting fermions
that conventionally involve variations of thermodynamic potentials can be
rewritten in terms of local one- and two-particle correlators. We illustrate
the applicability of this alternative formulation in a multi-orbital model of
strongly correlated electrons at finite temperatures, inspecting the lowest
eigenvalues of the generalized local charge susceptibility in proximity of the
phase-separation region. Additionally to the conventional unstable branches, we
address unstable solutions possessing a positive, rather than negative
compressibility. Our stability conditions require no derivative of free energy
functions with conceptual and practical advantages for actual calculations and
offer a clear-cut criterion for analyzing the thermodynamics of correlated
complex systems.Comment: 7 (+6) pages, 4 figure
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