As(V) removal from aqueous media using α-MnO2 nanorods-impregnated laterite composite adsorbents

We present a novel way of enhancing the utility of low cost readily available laterite by impregnating it with the α-MnO₂ nanorods, thus making a composite material suitable for the removal of As(V) from aqueous media. The composites were synthesized by two methods: (i) ball-milling of a physical blend of laterite with pre-synthesized MnO₂; and (ii) in situ formation of MnO₂ in the presence of laterite. The BET surface area of composites prepared by both methods was markedly higher compared to un-modified laterite, and the presence of MnO₂ in the composite was also confirmed by XRD analysis and TEM microscopy. The adsorption capacity for As(V) was found to be highly pH dependent and the adsorption kinetics followed a pseudo second-order kinetic model. The Langmuir adsorption isotherm was found to be the best model to describe the adsorption equilibrium of As(V) onto un-modified laterite as well both ball-milled and in situ formed composite. The adsorption capacities at room temperature and pH 7.0 were found to be 1.50 mg g^?1, 8.93 mg g^?1 and 9.70 mg g^?1, for un-modified laterite, ball-milled and in situ formed composite, respectively.     

Osteoporosis Prediction for Trabecular Bone using Machine Learning: A Review

Trabecular bone holds the utmost importance due to its significance regarding early bone loss. Diseases like osteoporosis greatly affect the structure of the Trabecular bone which results in different outcomes like high risk of fracture. The objective of this paper is to inspect the characteristics of the Trabecular Bone by using the Magnetic Resonance Imaging (MRI) technique. These characteristics prove to be quite helpful in studying different studies related to Trabecular bone such as osteoporosis. The things that were considered before the selection of the articles for the systematic review were language, research field, and electronic sources. Only those articles written in the English language were selected as it is the most prominent language used in scientific, engineering, computer science, and biomedical researches. This literature review was conducted on the articles published between 2006 and 2020. A total of 62 research papers out of 1050 papers were extracted which were according to our topic of review after screening abstract and article content for the title and abstract screening. The findings from those researches were compiled at the end of the result section. This systematic literature review presents a comprehensive report on scientific researches and studies that have been done in the medical area concerning trabecular bone.     

Symmetrical craniofacial hypertrophy in patients with tertiary hyperparathyroidism and high‐dose cinacalcet exposure

We are reporting on a series of two patients with end‐stage renal disease on hemodialysis, presented for surgical parathyroidectomy secondary refractory hyperparathyroidism. Both patients had failed maximized medical managements, including higher‐than‐usual doses of the calcimimetic cinacalcet (270 and 180 mg/day, respectively). On physical exam, both patients had marked symmetrical craniofacial hypertrophy with coarse distortion of facial features, similar in appearance to past reports of Sagliker syndrome. On X‐ray and computed tomographic exam, they had peculiar areas of bone absorption on the skull, imitating the radiologic appearance of multiple myeloma. Bone biopsy of the maxilla, however, did not show the expected brown tumor, but rather described only fibrosis and reactive bone formations. This phenotype developed while being on cinacalcet, progressed despite escalation of therapy, and improved only after parathyroidectomy. Both patients developed massive “hungry bone syndrome” after parathyroidectomy necessitating prolonged IV calcium infusion. This pattern of severe facial distortion likely represented an adverse consequence of severe tertiary hyperparathyroidism, along with supraphysiologic dose of cinacalcet administration and 25‐hydroxy vitamin D deficiency in sensitive individuals. The genetic base of this observation remained unexplained.     

Which fluid space is affected by ultrafiltration during hemodiafiltration?

Ultrafiltration (UF) is a common procedure performed during almost all dialysis sessions. During UF, several liters of fluid are removed; however, what proportion of this fluid is removed from which fluid space could not be clinically measured easily until now; we designed this study to evaluate the fluid spaces most affected by UF. This is a prospective cohort study of 40 prevalent chronic hemodialysis patients receiving thrice weekly hemodiafiltration (HDF). We measured the patients' fluid spaces using a whole‐body bioimpedance apparatus to evaluate the changes of fluid spaces before and immediately after the HDF sessions. We recorded the data on fluid spaces, UF volume, and blood pressures. The cohort consisted of 40 prevalent HDF patients, aged 60.0 ± 5.2 years (37.5% men; 27.5% people with diabetes), and body weight 71.03 ± 15.48 kg. Achieved UF was 2.38 ± 0.98 L on HDF (measured fluid overload: 2.35 ± 1.44 L). The extracellular fluid (EC) volume decreased from 16.84 ± 3.52 to 14.89 ± 3.06 L (P < 0.0001) and intracellular fluid (IC) volume from 16.88 ± 4.40 to 16.55 ± 4.48 L (P = 0.45). Although urea volume of distribution remained effectively unchanged (31.38 ± 7.28 vs. 30.70 ± 7.32 L; P = 0.45), the degree of EC volume overload decreased from 13.60% ± 7.30% to 3.83% ± 8.32% (P < 0.0001). The mean arterial pressure also decreased from 122.95 ± 19.02 to 108.50 ± 13.91 mmHg (P < 0.0001). We conclude that source of net fluid loss by ultrafiltration is almost exclusively the EC fluid space. The intracellular fluid space is not significantly affected immediately after HDF.     

Kinetics of phase transitions and dielectric relaxations in poly-bis(trifluorethoxy- phosphazene) (PBFP)

The kinetics of the high temperature (isotropic mesophase) and low temperature (mesophase crystalline) transition of PBFP at T_m and T(1), respectively, and its local dynamics were studied by differential scanning calorimetry (DSC) at variable heating and cooling rate and by dielectric relaxation spectroscopy (DRS). While on heating no substantial effect of the rate on both transition temperatures was found, T(1) and T_m showed a strong dependence on the cooling rate. The high temperature transition revealed thermally activated behaviour with an activation energy of E_a = 400 kJ/mol, whereas the transition at T(1) showed the typical signature of supercooling. This finding is consistent with the picture that the isotropic/mesophase transition at T_m is controlled by long-range, strongly hindered, chain diffusion that leads to the long-range orientational mesomorphic order. In contrast, the low temperature transition, the enthalpy of which is far larger and the temperature of which depending linearly on the cooling rate, indicates a kinetical control by nucleation as characteristic for a (2D 3D) crystallization process.Complementary information about the molecular dynamics in the various phases was obtained by DRS that revealed three relaxation processes, which were assigned to the dynamic glass transition (), local motions of CF₃—groups in the glassy state ( -process) and cooperative fluctuations of side-groups both in the mesophase and crystalline state ( -process). Interestingly, both the Arrhenius-type - and -relaxation are characterised by a non-zero activation entropy, which indicates the cooperative nature of the underlying molecular dynamics.     

Inverse magnetocaloric effect in ferromagnetic Ni-Mn-Sn alloys

The magnetocaloric effect (MCE) in paramagnetic materials has been widely used for attaining very low temperatures by applying a magnetic field isothermally and removing it adiabatically. The effect can also be exploited for room-temperature refrigeration by using giant MCE materials. Here we report on an inverse situation in Ni-Mn-Sn alloys, whereby applying a magnetic field adiabatically, rather than removing it, causes the sample to cool. This has been known to occur in some intermetallic compounds, for which a moderate entropy increase can be induced when a field is applied, thus giving rise to an inverse magnetocaloric effect. However, the entropy change found for some ferromagnetic Ni-Mn-Sn alloys is just as large as that reported for giant MCE materials, but with opposite sign. The giant inverse MCE has its origin in a martensitic phase transformation that modifies the magnetic exchange interactions through the change in the lattice parameters.     

Analysis of an automobile assembly line as a network of closed loops working in both,stationary and transitory regimes

In this work a real automobile assembly line and the correspondent preassembly lines have been analyzed as a network of closed loops of machines decoupled by intermediate buffers. This work deals with some important aspects, which have still not been investigated in earlier literature, such as: machines processing pallets, which are not related to each other and depend on an external variable in a network with closed loops of machines and intermediate buffers, machines working at different cycle times in a network of closed loops of machines and intermediate buffers, machines working in both, stationary and transitory regime and the relationships between the cycle times of the machines in the stationary working regime in order to guarantee the production rate of the system. Finally how the transient results can be used to improve the performance of the system under certain working conditions is discussed.     

Autoimmunity, immunodeficiency and mucosal infections: chronic intestinal inflammation as a sensitive indicator of immunoregulatory defects in response to normal luminal microflora

Despite the fact that target antigens and the genetic basis of several autoimmune diseases are now better understood, the initial events leading to a loss of tolerance towards self-components remain unknown. One of the most attractive explanations for autoimmune phenomena involves various infections as possible natural events capable of initiating the process in genetically predisposed individuals. The most accepted explanation of how infection causes autoimmunity is based on the concept of "molecular mimicry" (similarity between the epitopes of an autoantigen and the epitopes in the environmental antigen). Infectious stimuli may also participate in the development of autoimmunity by inducing an increased expression of stress proteins (hsp), chaperones and transplantation antigens, which leads to abnormal processing and presentation of self antigens. Superantigens are considered to be one of the most effective bacterial components to induce inflammatory reactions and to take part in the development and course of autoimmune mechanisms. It has long been known that defects in the host defense mechanism render the individual susceptible to infections caused by certain microorganisms. Impaired exclusion of microbial antigens can lead to chronic immunological activation which can affect the tolerance to self components. Defects in certain components of the immune system are associated with a higher risk of a development of autoimmune disease. The use of animal models for the studies of human diseases with immunological pathogenesis has provided new insights into the influence of immunoregulatory factors and the lymphocyte subsets involved in the development of disease. One of the most striking conclusion arising from work with genetically engineered immunodeficient mouse models is the existence of a high level of redundancy of the components of the immune system. However, when genes encoding molecules involved in T cell immunoregulatory functions are deleted, spontaneous chronic inflammation of the gut mucosa (similar to human inflammatory bowel disease) develops. Surprisingly, when such immunocompromised animals were placed into germfree environment, intestinal inflammation did not develop. Impairment of the mucosal immune response to the normal bacterial flora has been proposed to play a crucial role in the pathogenesis of chronic intestinal inflammation. The use of immunodeficient models colonized with defined microflora for the analysis of immune reactivity will shed light on the mode of action of different immunologically important molecules responsible for the delicate balance between luminal commensals, nonspecific and specific components of the mucosal immune system.     

Evaluation of Structural and Optical Properties of Mn-Doped ZnO Thin Films Synthesized by Sol-Gel Technique

Undoped ZnO and Mn-doped ZnO (MZO) films with 0.25, 0.50, and 0.75?mol pct were synthesized onto glass substrates by sol-gel spin-coating technique, and the effects of Mn on structural, morphologic, and optical properties were investigated. The XRD results indicate that the films have wurtzite structure with polycrystalline nature. However, the dominant peak was (002) diffraction peak for all samples; other diffraction peaks with less intensity such as (100), (101), (102), (110), (103), (112), and (004) were observed for the undoped ZnO. The lattice parameter values of MZO thin films were lower than that of the undoped ZnO. Plane stress values indicated that the films had the tensile stress. A decrease in the grain sizes was observed with the increasing Mn mole?percent. The optical transmission values were found to be 82?pct for the undoped ZnO and 80, 78, and 75?pct for the MZO with 0.25, 0.50, and 0.75?mol?pct, respectively, at the wavelength of 405?nm. The optical band gap values decreased from 3.287 to 3.270?eV, the surface roughness values increased from 58.13 to 60.67?nm, Urbach energy values increased??a 18.3-meV difference in Urbach energy was observed??and in addition, the steepness parameters decreased with increasing Mn content from 0 to 0.75?mol?pct.     

Prevalence of osteoporosis in the Czech Republic

BACKGROUND: The objective of this study was to evaluate the prevalence of osteoporosis and osteopenia in Czech women and men aged 50 to 75 years. METHODS AND RESULTS: Bone mineral density was assessed in an age-stratified random sample of 713 women and 429 men from two cities (Prague and Litom?rice) in the lumbar spine, proximal femur and total body by dual X-ray absorptiometry and in the distal forearm by single X-ray absorptiometry. The proportion of women and men in each age group with bone density below specified levels at any of these skeletal sites was projected to the population structure of the Czech Republic. With advancing age, in women at 55 years and in men at 65 years of age the population with normal bone mineral density becomes smaller, and a greater proportion has osteopenia or osteoporosis. Overall, an estimated 428,000 women and 195,000 men over age 50 have osteoporosis and another 680,000 women and 435,000 men have osteopenia. CONCLUSIONS: The results of this first population-based cross sectional study in the Czech Republic document a high prevalence of osteoporosis and osteopenia which is comparable with that published for the Netherlands and the United States. The results offer a basis for economical considerations in diagnosis, treatment and consequences of osteoporosis.