1,173 research outputs found
The crystal structure of sacrofanite, the 74 Å phase of the cancrinite–sodalite supergroup
Sacrofanite, a = 12.903(2) Å, c = 74.284(8) Å, space group View the MathML source, belongs to the cancrinite–sodalite supergroup of minerals, and displays a 28-layer stacking sequence along the c axis. Its stacking sequence is ABCABACACABACBACBACABABACABC…, where A, B and C stand for the positions of six-member rings of tetrahedra in each layer. It corresponds to the Zhdanov symbol |12(8)21|12(8)21|, and gives rise to a framework with topological symmetry P63/mmc. The ordering of Si and Al in the tetrahedral sites reduces the symmetry to View the MathML source. The members of this supergroup of minerals belong to the wider ABC-6 family, where also double rings of tetrahedra may occur. They share many structural features with zeolites, showing structural cages hosting extra-framework ions as well as H2O molecules. The crystal structure of sacrofanite has been modelled on the basis of High Resolution Transmission Electron Microscopy (HRTEM) images. The resulting model has been successfully refined by using both single-crystal synchrotron radiation and laboratory data. The refinements converged to R = 0.083 for 4228 unique reflections, and to R = 0.096 for 15,795 unique reflections, respectively. The resulting framework is formed by eight cancrinite and four sodalite cages superimposed along [0, 0, z], whereas one cancrinite, four sodalite, two losod, and one liottite cages occur along [1/3, 2/3, z] and [2/3, 1/3, z]. The structural formula of sacrofanite, as obtained from the refinement and by crystal chemical considerations, is (Na61K19Ca32)∑=112(Si84Al84O336)(SO4)26Cl2F6·2H2O
Dye diffusion during laparoscopic tubal patency tests may suggest a lymphatic contribution to dissemination in endometriosis: A prospective, observational study
Aim Women with adenomyosis are at higher risk of endometriosis recurrence after surgery. This study was to assess if the lymphatic vessel network drained from the uterus to near organs where endometriosis foci lied. Methods A prospective, observational study, Canadian Task Force Classification II-2, was conducted at Sacro Cuore Don Calabria Hospital, Negrar, Italy. 104 white women aged 18–43 years were enrolled consecutively for this study. All patients underwent laparoscopy for endometriosis and a tubal dye test was carried out. Results Evidence of dye dissemination through the uterine wall and outside the uterus was noted in 27 patients (26%) with adenomyosis as it permeated the uterine wall and a clear passage of the dye was shown in the pelvic lymphatic vessels regardless whether the tubes were unobstructed. Histological assessment of the uterine biopsies confirmed adenomyosis. Conclusion Adenomyosis is characterized by ectatic lymphatics that allow the drainage of intrauterine fluids (the dye and, perhaps, menstrual blood) at minimal intrauterine pressure from the uterine cavity though the lymphatic network to extrauterine organs. Certainly, this may not be the only explanation for endometriosis dissemination but the correlation between the routes of the dye drainage and location of endometriosis foci is highly suggestive
Lactoferrin's anti-cancer properties. Safety, selectivity, and wide range of action
Despite recent advances in cancer therapy, current treatments, including radiotherapy, chemotherapy, and immunotherapy, although beneficial, present attendant side effects and long-term sequelae, usually more or less affecting quality of life of the patients. Indeed, except for most of the immunotherapeutic agents, the complete lack of selectivity between normal and cancer cells for radio- and chemotherapy can make them potential antagonists of the host anti-cancer self-defense over time. Recently, the use of nutraceuticals as natural compounds corroborating anti-cancer standard therapy is emerging as a promising tool for their relative abundance, bioavailability, safety, low-cost effectiveness, and immuno-compatibility with the host. In this review, we outlined the anti-cancer properties of Lactoferrin (Lf), an iron-binding glycoprotein of the innate immune defense. Lf shows high bioavailability after oral administration, high selectivity toward cancer cells, and a wide range of molecular targets controlling tumor proliferation, survival, migration, invasion, and metastasization. Of note, Lf is able to promote or inhibit cell proliferation and migration depending on whether it acts upon normal or cancerous cells, respectively. Importantly, Lf administration is highly tolerated and does not present significant adverse effects. Moreover, Lf can prevent development or inhibit cancer growth by boosting adaptive immune response. Finally, Lf was recently found to be an ideal carrier for chemotherapeutics, even for the treatment of brain tumors due to its ability to cross the blood-brain barrier, thus globally appearing as a promising tool for cancer prevention and treatment, especially in combination therapies
Crystal structure of afghanite, the eight-layer member of the cancrinite-group: Evidence for long-range Si,Al ordering
Afghanite, ideally [(Na,K)(22)Ca-10][Si24Al24O96](SO4)(6)Cl-6, is the eight-layer member of the cancrinite-group (ABABACAC stacking sequence). Its structure was refined in the P31c space group to R = 4.5% by means of single-crystal X-ray diffraction data. The cell parameters are a = 12.8013(7) Angstrom, c = 21.4119(18) Angstrom. The P6(3)mc space group proposed in a previous structure refinement is not consistent with the ordered Si,AI pattern suggested by an Si/Al ratio equal to 1 shown by afghanite and other members of the cancrinite-group. The Si-O and Al-O bond distances, 1.61(2) Angstrom and 1.72(2) Angstrom respectively, found in the structure refinement, are in accordance with an ordered Si,AI distribution which is allowed by the P31c space group, a maximal non isomorphic subgroup of P6(3)mc. Afghanite contains six 11-hedra (cancrinite) cages and two 23-hedra (liottite) cages. Four cancrinite cages are stacked along [0 0 z]. They contain a regular....Ca-Cl-Ca-Cl.... chain similar to that observed in davyne and related phases: in particular Ca is located near the center of the bases whereas Cl is near the center of the cage. A liottite cage with a base-sharing cancrinite cage is stacked along [2/3 1/3 z] and [1/3 2/3 z]. The liottite cage hosts a maximum of three sulphate groups which alternate regularly with cation-containing planes. The cancrinite cage, that shares the bases with the liottite cages, presents a disordered distribution of Cl and F reading to two possible configurations similar to those observed in liottite
Design of Cloud Robotic Services for Senior Citizens to Improve Independent Living and Personal Health Management
A cloud robotics solution was designed and initially tested with a mobile robotic platform and a smart environment, in order to provide health-care management services to senior citizens and improve their independent living. The solution was evaluated in terms of Quality of Service (QoS) and tested in the realistic scenario of the DomoCasa Living Lab, Peccioli, Italy. In particular, a medication reminding service, a remote home monitoring and a user indoor localization algorithm were outsourced in the cloud and provided to the robots, users and carers. The system acquired data from a smart environment and addressed the robot to the user for service delivery. Experiments showed a service's Reliability of Response at least of the 0.04 % and a Time of Response of the same order of magnitude of the processing time required by the user localization algorithm
Experimental Analysis of RSSI-based Indoor Location Systems with WL Circularly Polarized Antennas
Circularly polarized antennas are used in 2.4 GHz ZigBee radio modules to evaluate performance improvement of RSSI (Received Signal Strength Indicator) based location techniques, with respect to conventional linearly polarized antennas. Experimental RSSI measurements in an indoor environment clearly show that multipath fading is significantly reduced when CP antennas are used; this determines a more reliable estimation of the field amplitude decay law as a function of the distance of the mobile node from the fixed access point, and then a higher location accuracy. At the best of authors' knowledge, it is the first time that the circular polarization features are applied to RSSI-based radio location techniques
Adsorption performance and thermodynamic analysis of SAPO-34 silicone composite foams for adsorption heat pump applications
Abstract In the present work, adsorption performances of an innovative composite adsorber, based on SAPO-34-silicone composite macro-cellular foams, are reported. The choice of a foamed structure was assessed to improve the water vapor access towards the embedded zeolite keeping good adsorption heat pump dynamic performance. Depending on zeolite amount used as filler, zeolite/silicone foams evidenced a soft and open cell configuration (low zeolite content) or rigid and closed one (high zeolite content). Morphological analysis evidenced that the cellular structure of the foam is homogeneous and well distributed along the foam cross section. Adsorption tests showed that the adsorbent foamed samples have very effective adsorption capabilities indicating that the porous structure of the filled pure zeolite was not obstructed. SAPO-34 filler contributed actively, with an efficiency above 90%, to the adsorption performances of the composite foam. Starting from experimental equilibrium data, a simple thermodynamic analysis based on energy balances was carried out for air conditioning application. Results of the analysis demonstrated that foam technology can guarantee cooling COP up to 7% higher than that estimated for the typical adsorber solution based on loose adsorbent grains inside an aluminum finned-flat tube heat exchanger, which is very promising for practical application in adsorption heat pumps
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