Constant Values Research Articles

Probe substrates assay estimates the effect of polyphyllin H on the activity of cytochrome P450 enzymes in human liver microsomes.

Cytochrome P450 enzymes (CYPs) play a crucial role in phase I metabolic reactions. The activity of CYPs would affect therapeutic efficacy and may even induce toxicity. Given the complex components of traditional Chinese medicine, it is important to understand the effect of active ingredients on CYPs activity to guide their prescription. This study aimed to evaluate the effect of polyphyllin H on the activity of CYPs major isoforms providing a reference for the clinical prescription of polyphyllin H and its source herbs. The effects of polyphyllin H were evaluated in pooled human liver microsomes using probe substrates of CYP1A2, 2A6, 2C8, 2C9, 2C19, 2D6, 2E1, and 3A4 to determine their activities. The Lineweaver-Burk was used to model the inhibition, and a time-dependent inhibition experiment was performed to understand the characteristics of the inhibition. Polyphyllin H significantly suppressed the activity of CYP1A2, 2D6, and 3A4 with IC50 values of 6.44, 13.88, and 4.52 μM, respectively. The inhibition of CYP1A2 and 2D6 was best fitted with a competitive model, yielding the inhibition constant (Ki) values of 3.18 and 6.77 μM, respectively. The inhibition of CYP3A4 was fitted with the non-competitive model with the Ki value of 2.38 μM. Moreover, the inhibition of CYP3A4 was revealed to be time-dependent with the inhibition parameters inhibition constant (KI) and inactivation rate constant (Kinact) values of 2.26 μM-1 and 0.045 min-1. Polyphyllin H acted as a competitive inhibitor of CYP1A2 and 2D6 and a non-competitive and time-dependent inhibitor of CYP3A4.

Luminescent Dansyl-Calix[5]arene for the Recognition of Biogenic Amines

: A luminescent calix[5]arene with a covalently linked dansyl chromophore substituent has been successfully used, both in solution and in the gas phase (ESI-MS), for the recognition of biogenic amines that contain linear alkylammonium structural unit. Binding constant values, determined by fluorescence spectroscopy, revealed a greater affinity for cadaverine, spermidine, and L-lysine, in which the terminal ammonium group allows for additional stabilizing interactions with the dansyl moiety.

Azobenzene-Based Main-Chain Liquid Crystalline Polymers Bearing Periodically Installed Alkyl, PEG, or Fluoroalkyl Segments and Photoisomerization Studies

ABSTRACT In the present study, liquid crystalline polymers (LCPs) were prepared by melt-transesterification of azobenzene-bearing diols and diethyl malonate (DEM) derivatized monomers. The effect of the nature and length of the installed pendant segments on the mesomorphic properties of the prepared LCPs was investigated by differential scanning calorimetry (DSC), X-ray diffraction (XRD), and polarized optical microscopy (POM) studies. The formation of layered morphology was inferred from X-ray scattering analysis arising from the colocation of rigid azobenzene moieties in one layer and the flexible pendant segments in alternate layers due to the zigzag folding of the polymer backbone. The linear variation of the interlamellar spacing with the number of carbon atoms in the pendant alkyl segments corroborates the proposed zigzag backbone folding in the polymers. The rate constant values obtained from the photoisomerization studies of the isomeric polymers and model compound, which are in the same ballpark, reveal that the photoisomerization process of such polymers is not affected by the position or size of the azobenzene unit.

Impact of TBAI Doping on the Optical and Dielectric Features of PVC/MoO3/NiMoO4/PANI Polymer Composite for Optoelectronic and Energy Storage Applications

Abstract Poly (vinyl chloride, PVC)/MoO3/NiMoO4/polyaniline (PANI)/x wt % tetrabutylammonium iodide (TBAI) polymers were formed using casting and hydrothermal methods. The present study examined the nanocomposites' structural, electrical, and optical features comprising PVC/MoO3/NiMoO4/PANI/x wt %TBAI polymers. X-ray diffraction and scanning electron microscopy were used to investigate the structure and morphology of different samples. The influence of different amounts of TBAI on the linear and nonlinear optical features of PVC/MoO3/NiMoO4/PANI/x wt %TBAI polymers was explored. Adding MoO3/NiMoO4/PANI.TBAI reduced the direct and indirect optical band gaps to their minimum values (3.88, 3.04) eV and (3.58, 2.13) eV, respectively. Doped polymer with MoO3/NiMoO4 has the highest refractive index value. Only PVC filled with MoO3/NiMoO4 exhibits the highest non-linear optical parameters within the visible range. The fluorescence intensity and emitted colors influenced by the kind of dopant. The dielectric constant and ac conductivity values of the host polymer were affected by the amount of TBAI. The maximum energy density value was observed in PVC/MoO3/NiMoO4/PANI/10 wt %TBAI polymer. The Cole-Cole plot demonstrated an irregular shift for doped samples relative to the undoped. The obtained results nominated the nanocomposite films of PVC/MoO3/NiMoO4/PANI/x wt %TBAI to be used in diverse electric and optoelectrical applications.

Microstructural, dielectric, electrical, electromagnetic, and magnetic property enhancements in GdIG /TrIG/ Mn0.2Co0.3Zn0.5Fe2O4 ferrites composites for electronic devices application

Gadolinium garnet ferrite (GdIG) and terbium garnet ferrite (TrIG), known for their favourable magnetic and dielectric characteristics, were combined with doped zinc spinel ferrite (GdIG)x-(TrIG)y/Mn0.2Co0.3Zn0.5Fe2O4(1-x-y) (at x=1 y=0, x=0 y=1, x=y=0.5, x=y=0.25, x=y=0) to achieve improved permittivity, permeability and magnetic properties with reduced magneto-dielectric losses. Our study details the synthesis process and the resulting enhancements in structural, magnetic, and dielectric properties of the prepared samples. Analysis of the X-ray diffraction (XRD) patterns confirmed the presence of a crystalline structure characterized by both cubic spinel and cubic garnet phases in the composites. The microstructures of the composites were analysed with field emission scanning electron microscopy (FESEM), revealing the variation in a grain size from 0.11 μm to 0.96 μm at x =y=0.5. A thorough link between the crystal structure and XRD spectra, transmission electron microscope (TEM), and selected area electron diffraction (SAED) patterns have all been investigated in order to enhance the characterisation of the samples. At 1KHz, the composites exhibit highest electrical resistivity values of 5.9×106 Ωm and 2.6×106 Ωm. With the incorporation of spinel ferrites in garnet ferrite composite (x=y=0.25) the highest value of dielectric constant (885.2) and low value of dielectric loss (0.07) at 100 KHz has been obtained. Permeability values, derived from permittivity data, showed an increase in real permeability values of from 1.4×1012 to 9.2×1017 for x=y=0.5 to x=y=0.25 composite. Vibrating sample magnetometer (VSM) further confirm that the composite x=y=0.25 has highest magnetic saturation (148.8 emu/g), coercivity (502 Oe) and microwave operating frequency (33.6 GHz). The observed high dielectric constant, low loss values, switching field distribution and good magnetic properties suggest the potential suitability of these samples for various electronic devices like: high frequency devices, antennas, switching devices and magnetic recording devices.

Incorporating the cosmological constant in a modified uncertainty principle

This study explores the cosmological constant problem and modified uncertainty principle within a unified framework inspired by a void-dominated scenario for cosmology. In a recent paper [E. Yusofi, M. Khanpour, B. Khanpour, M. A. Ramzanpour and M. Mohsenzadeh, Mon. Not. R. Astron. Soc. 511, L82 (2022)], voids were modeled as spherical bubbles of similar average sizes, and the surface energy on the voids’ borders was calculated across various scales in a heuristic manner. We show that these result in a significant discrepancy of approximately [Formula: see text] between the cosmological constant values from the minimum to the maximum radii of bubbles. Furthermore, when considering the generalized form of the uncertainty principle with both minimum and maximum lengths, i.e. [Formula: see text], a similar order of discrepancy is observed between [Formula: see text] and [Formula: see text], indicating that [Formula: see text]. As a primary outcome of this finding, we offer a novel uncertainty principle that incorporates a nonzero cosmological constant.

Holographic description of an anisotropic Dirac semimetal

Holographic quantum matter exploits the AdS/CFT correspondence to study systems in condensed matter physics. An example of these systems are strongly correlated semimetals, which feature a rich phase diagram structure. In this work, we present a holographic model for a Dirac semimetal in 2 + 1 dimensions that features a topological phase transition. Our construction relies on deforming a relativistic UV fixed point with some relevant operators that explicitly break rotations and some internal symmetries. The phase diagram for different values of the relevant coupling constants is obtained. The different phases are characterized by distinct dispersion relations for probe fermionic modes in the AdS geometry. We find semi-metallic phases characterized by the presence of Dirac cones and an insulating phase featuring a mass gap with a mild anisotropy. Remarkably, we find as well an anisotropic semi-Dirac phase characterized by a massless a fermionic excitation dispersing linearly in one direction while quadratically in the other.

Upheaval of Negative Dielectric Permittivity and Semiconductor to Metallic Transition in a Thermally Induced Sn-Doped β-Ga2O3 (-201) Single Crystal.

Thermally induced dielectric and conductivity properties of an Sn-doped β-Ga2O3 (-201) single crystal were investigated by frequency-domain impedance spectroscopy in the frequency window from 100 Hz to 1 MHz with temperatures between 293 and 873 K. The (-201) plane-orientated single crystalline nature and the presence of an Sn dopant in β-Ga2O3 were confirmed by X-ray diffraction (XRD) and X-ray photoelectron (XPS) spectroscopy. Two different trends of impedance spectra have been discussed by the modulation of relaxation times and semiconductor to metallic transition after ∼723 K due to activation of a significant number of Sn dopants and their movements with temperature. The negative impedance values were encountered in the Nyquist plots (Z' vs Z″) after 573 K and constitute a reverse movement after 723 K with temperature. The average normalized change (ΔZ'/Δf)/Z0 of impedance exhibits a broad downward relaxation plateau near 723 K, indicating a weak electrical transition. The increases in the positive value of the dielectric constant (εr') below a percolating threshold temperature 573 K is attributed to the interfacial and dipolar polarizations, and the plasma oscillation of delocalized electrons governed by the Drude theory is responsible for the negative dielectric constant above 573 K. The 3D projections of the real dielectric constant create a sharp downward sinkhole near 723 K, indicating the existence of negative dielectric permittivity. The electrical conductivity dramatically changes its trends after 523 K and confirms a transition from hopping conduction (dielectric or semiconductor) following Jonscher's power law to metallic conduction by Drude theory. Below the percolating threshold temperature, a nonoverlapping small polaron tunneling conduction mechanism was unveiled with defect-induced activation energy of 0.21 eV. The Sn-doped β-Ga2O3 exhibits unique and tailored electromagnetic responses with temperatures that can be associated with a variety of applications in electromagnetic wave manipulations, cloaking devices, antennas, sensors, medical imaging, seismic wave propagation, etc.

Exploring the impact of CuCl2 modification on structural variations and dielectric constant in bismuth borate tellurite glasses

Copper chloride doped boro-tellurite-based glass series with compositions 60TeO2-(25-x) Bi2O3–15B2O3-xCuCl2 (x = 0, 5, 10, 15, and 20) were synthesized using the traditional melt-quench procedure. The X-ray diffraction patterns of the examined glasses reveal their amorphous nature. The effect of CuCl2 addition on the glass network/structural units was studied using vibrational (FTIR/Raman) spectroscopy, and CuCl2 inclusion in the glass matrix resulted in a transformation from compact TeO4 to TeO3 structural units This shows that copper chloride acts as a modifier in the examined glass series, resulting in the creation of non-bridging oxygen (NBOs), meaning that the loosening of the glass network is further supported by a decrease in the glass transition temperature as CuCl2 content increases. UV–Vis DRS spectra of examined glasses reveal an absorption band corresponding to the typical transition of Cu2+ ions from 2B1g → 2B2g, situated in deformed octahedral sites in absorption spectra. As Cu+ concentration rises, the indirect optical band gap values drop from 2.94 eV to 1.75 eV. The metallization criterion values lie between 0.383 and 0.300 suggesting that these glasses are potential candidates for nonlinear optical applications. With an increase in Cu+ concentration, the values of molar refractive index (Rm) and molar electronic polarizability αm increases from 22.412 to 26.205 and 8.894 to 10.398 respectively, which correlate with increasing dielectric constant (ε′) values as the Cu+ amount increases. Further dielectric studies reveal non-Debye-type relaxation behaviour.

Constructing ESIPT-Capable α-Cyanostilbene Luminogens: Influence of Different Aromatic Substitutions Tethered to H-Acceptor (CH = N) on Photophysical Properties, Cu2+ and Fe3+ Detection.

Herein, two excited-state intramolecular proton transfer (ESIPT)-capable α-cyanostilbene luminogens were synthesized by Schiff base reaction of salicylaldehyde-like α-cyanostilbene candidate with 1-naphthylamine and 3-biphenylamine, respectively. We systematically analyzed their photophysical properties compared with their analogue, and demonstrated that their fluorescence behaviors could be elaborately modulated by different aromatic substitutions tethered to H-acceptor (CH = N). In virtue of the outstanding solid fluorescence, the 3-biphenylamine-decorated fluorophore was applied for monitoring Cu2+/Fe3+ qualitatively on the TLC-based test strip in real time and sensing Cu2+/Fe3+ quantitatively in the THF/H2O medium (fw = 90%, pH = 7.4). When the probe chelated with Cu2+/Fe3+, similar "turn-off" fluorescence signal outputs were triggered. From the fluorescence titration experiments, the detection limits were evaluated as 7.97 × 10- 8 M for Cu2+ and 8.24 × 10- 8 M for Fe3+, and the binding constant (Kα) values of the complexes were found to be 7.80 × 104 M-1 for Cu2+ and 9.06 × 104 M-1 for Fe3+. Job's plots indicated that probe complexed with Cu2+/Fe3+ in a 2:1 binding stoichiometry ratio. Furthermore, the probe was used to accurately quantify the Fe3+ spiked in real water specimens. This study offered a new perspective to construct ESIPT-capable α-cyanostilbene luminogen as the potential luminescent probe.

Physical and mechanical characterization of solid waste collected from rural areas of China: Experimental study

To support the landfill design and waste management in rural areas of China, solid waste covering eight provisional regions was collected and tested in the laboratory to characterize its physical properties (composition, moisture content, specific gravity, dry unit weight) and mechanical properties (compressibility and shear strength). The results show that, compared with solid wastes from urban areas (MSW), solid waste from rural areas (RSW) comprised a much lower content of soil-like, gravel, and inert waste and a significantly higher content of combustible waste, thereby yielding a much lower specific gravity and dry unit weight. Similar to MSW, the compression index of RSW correlated well with its physical properties. However, its strength properties displayed divergence. Notably, the friction angle φ' of RSW remained relatively consistent, ranging from 28.4° to 30.9°. This narrow range is attributed to RSW's higher combustible-to-inert (CI) ratio compared to MSW. The cohesion intercept c' of RSW ranged from 13.5 to 24.9 kPa, showing a positive correlation with the fiber content without considering contribution from paper waste. This finding combined with data from the literature further revealed that the trend of increasing cohesion intercept with increasing fiber content became weakened over time. Relationships between φ' and c' versus C/I for RSW observed in this study will serve as an extension to the existing finding reported for MSW in the literature, i.e., for predominately combustible waste with C/I exceeding 10, constant values of strength parameters (i.e., moderate values φ' = 30°, c' = 20 kPa) are recommended. The results of this study are useful for the capacity design and slope stability analysis of landfills as well as waste recycle and reuse, ensuring a sustainable development of environment in China.

Effects of interfacial oxygen diffusion on the magnetic properties and thermal stability of Pd/CoFeB/Pd/Ta heterostructure

We investigated the effects of annealing temperatures (TA) on a Pd (5 nm)/CoFeB (10 nm)/Pd (3 nm)/Ta (10 nm) multilayer structure. The as-deposited sample showed an amorphous state with in-plane uniaxial magnetic anisotropy (UMA), resulting in low coercivity and moderate Gilbert damping constant (α) values. Increasing TA led to crystallization, forming bcc-CoFe (110) crystals, which increased in-plane coercivity and introduced isotropic magnetic anisotropy, slightly reducing the α. The two-fold UMA persists up to 600 °C, and the thermal stability of the in-plane magnetic anisotropy remains intact even TA = 700 °C. The TA significantly influenced the magnetic properties such as in-plane saturation magnetization (Ms//), in-plane and out-of-plane coercivities (Hc// and Hc⊥), and in-plane effective magnetic anisotropy energy density (Keff). Above 600 °C, Keff decreased, indicating a transition towards uniaxial perpendicular magnetic anisotropy. Interfacial oxidation and diffusion from the Ta capping layer to the Pd/CoFeB/Pd interfaces were observed, influencing chemical bonding states. Annealing at 700 °C, reduced oxygen within TaOx through a redox reaction involving Ta crystallization, forming TaB, PdO, and BOx states. Ferromagnetic resonance spectra analysis indicated variations in resonance field (Hr) due to local chemical environments. The α reduction, reaching a minimum at 300 °C annealing, was attributed to reduced structural disorder from inhomogeneities. Tailoring magnetic anisotropy and spin dynamic properties in Pd/CoFeB/Pd/Ta structures through TA-controlled oxygen diffusion/oxidation highlights their potential for SOT, DMI, and magnetic skyrmion-based spintronic devices.

Exotic phases induced by RKKY interaction in the square lattice

We study a model of Ising spins in which direct exchange interactions compete with the Ruderman-Kittel-Kasuya-Yosida (RKKY) coupling, which may arise effectively from itinerant electrons. We consider the model in the two-dimensional square lattice and focus on values of the RKKY coupling constant (JRKKY) and the Fermi momentum (kF) that induce strong frustration. We study the low-temperature magnetic field phase diagram using Monte Carlo simulations, considering several nearest neighbors in the RKKY interaction. Magnetic frustration yields a rich phase diagram with a variety of exotic phases. We compute the structure factors and define appropriate order parameters to describe the transitions. We also discuss the validity of the approximation made for long-range couplings and analytically demonstrate the change in the coexistence lines in the phase diagram by including up to the tenth nearest neighbors.

The formation and stability of single-peak and multi-peak gap nematicons in a periodic potential

ABSTRACT The formation and stability of single-peak and multi-peak gap nematicons in a periodic potential are investigated using numerical methods. Both the stationary solutions and the dynamic solutions have been studied in the first band gap. Single-peak and multi-peak gap nematicons can be found in the first band gap. The single-peak gap nematicons are obtained for a wide range of propagation constants. Multi-peak gap nematicons can exist only above a certain minimum value of propagation constant. The intensity distribution among various peaks in a multi-peak gap nematicon highly depends on input beam intensity. The stability of the stationary solution against small perturbations has been studied using Bogoliubov-de Gennes equations. Single-peak gap nematicons are stable. The multi-peak gap nematicons having the same amplitudes for various peaks are stable, whereas those with unequal amplitudes among peaks are unstable.

A multiverse outside of the swampland

A multiverse can arise from landscapes without de Sitter minima. It can be populated during a period of eternal inflation without trans-Planckian field excursions and without flat potentials. This multiverse can explain the values of the cosmological constant and of the weak scale. In the process of proving these statements, we derive a few simple, but counterintuitive results. We show that it is easy to write models of eternal inflation compatible with the distance and refined de Sitter conjectures. Secondly, tunneling transitions that move fields from a lower-energy vacuum to a higher-energy vacuum and generate baby universes are possible, and occur during eternal inflation. Finally, we relax the assumption of no de Sitter minima and show that this more standard multiverse can be populated by Coleman-de Luccia transitions in about 100 e-folds of inflation. Published by the American Physical Society 2024

Classical Dynamical r-matrices for the Chern–Simons Formulation of Generalized 3d Gravity

AbstractClassical dynamical r-matrices arise naturally in the combinatorial description of the phase space of Chern–Simons theories, either through the inclusion of dynamical sources or through a gauge fixing procedure involving two punctures. Here we consider classical dynamical r-matrices for the family of Lie algebras which arise in the Chern–Simons formulation of 3d gravity, for any value of the cosmological constant. We derive differential equations for classical dynamical r-matrices in this case and show that they can be viewed as generalized complexifications, in a sense which we define, of the equations governing dynamical r-matrices for $$\mathfrak {su}(2)$$ su ( 2 ) and $$\mathfrak {sl}(2,{\mathbb {R}})$$ sl ( 2 , R ) . We obtain explicit families of solutions and relate them, via Weierstrass factorization, to solutions found by Feher, Gabor, Marshall, Palla and Pusztai in the context of chiral WZWN models.

Applicability of modified Gauss–Bonnet gravity models on the existence of stellar structures

In this paper, we explore the existence of spherically symmetric strange quark configurations coupled with anisotropic fluid setup in the framework of modified Gauss–Bonnet theory. In this regard, we adopt two models such as (i)f(G)=βG2, and (ii)f(G)=δ1Gx(δ2Gy+1), and derive the field equations representing a static sphere. We then introduce bag constant in the gravitational equations through the use of MIT bag model, so that the quarks’ interior can be discussed. Further, we work out the modified equations under the use of Tolman IV ansatz to make their solution possible. Junction conditions are also employed to find the constants involved in the considered metric potentials. Afterwards, different values of model parameters and bag constant are taken into account to graphically exploring the resulting solutions. This analysis is done by considering five strange quark objects like Her X-I, LMC X-4, 4U 1820-30, PSR J 1614-2230, and Vela X-I. Certain tests are also applied on the developed models to check their physical feasibility. It is much interesting that this modified gravity under its both considered functional forms yield physically viable and stable results for certain parametric values.

Optical, AC conductivity and antibacterial activity enhancement of chitosan-silver nanocomposites for optoelectronic and biomedical applications

This study is aimed to prepare and investigate the optical, electrical and antibacterial activity of the environmentally friendly (green) chitosan (Cs)/silver nanocomposites. TEM demonstrated that AgNPs have a spherical shape with particle size ranged from 3 nm to 25 nm. UV analysis spectra of Cs and Cs/Ag nanocomposites showed that, increasing the content of AgNPs led to a noticeable increase in the values of Urbach energy (E U ) and a dramatic decrease in both the indirect (E ig ) and direct (E dg ) optical bandgap energies. It is found that (E ig ) and (E dg ) are decreased from (4.72/5.31 eV) to (2.47/4.19 eV). The formation of the AgNPs is verified by the existence of surface plasmon resonance (SPR) peak at ∼ (421–450) nm. Wemple-DiDomenico and Sellmeier oscillator models are employed and displayed a clear enrichment in the dispersion energy (E d ) and oscillator energy (E 0) as well as the linear and nonlinear optical parameters of Cs. It is observed that the linear (χ(1)) and nonlinear (χ(3) and n2) parameters are enhanced from 0.083, 0.868 × 10−14 and 1.584 × 10−12 to 0.153, 9.762 × 10−14 and 4.088 × 10−12. The novel results in our study nominate Cs/Ag nanocomposites for applications in linear/nonlinear optical devices. AC conductivity behavior of Cs and Cs/Ag nanocomposites is analyzed based on Jonscher’s law and the analysis showed that the overlapping large polaron tunneling (OLPT) is the dominant conduction mechanism for our samples. It is clear that the values of dielectric constant (ε′) of Cs and Cs/Ag nanocomposites are higher confirming the presence of interface polarization (IP) relaxation. Moreover, it is found that the antibacterial activity of Cs against Gram-negative (P. aeruginosa) and Gram-positive (B. thuringiensis) bacteria is found to be enhanced with increasing the content of Ag NPs. These results suggested that Cs/Ag nanocomposites will be good source for preparing bio-nanocomposites for use in many biomedical and industrial applications.

APPROACH TO A PATIENT WITH CLINICALLY AND BIOCHEMICALLY ACTIVE PRIMARY HYPERPARATHYROIDISM DESPITE NEGATIVE SESTAMIBI 99MTC

Introduction: Primary hyperparathyroidism (PHPT) resulting from increased parathyroid hormone (PTH) secretion. In 80% of cases the cause is a solitary adenoma. It occurs more often in women. The gold standard in the diagnosis of PHPT is MIBI 99m Tc scintigraphy. Patient presentation. A 35-year-old women is referred to outpatient clinic due to high values of PTH, calcium and frequent recurring nephrolithiasis. From the laboratory analysis we show: PTH 317 pg/ml, Ionized calcium 1.71 (1.16 to 1.31 mmol/L); phosphates 0.73mmol/L; Vitamine D3 18.68 ng/ml. The patient is referred for neck ultrasound and bone densitometry (DEXA). A hypoechoic nodule with dimensions of 0.69x0.63x0.67 cm is visualized on ultrasound under the right lobe of the thyroid gland. In the DEXA scan, osteopenia is detected (T-score -2.2). Sestamibi scintigraphy was performed in two repetitions where no adenoma of the parathyroid gland was detected. The patient is referred for neck computed tomography (CT); a small nodule suspicious for parathyroid adenoma is visualized. Due to the clinical manifestation and the constant high values of hypercalcemia, the patient is referred for parathyroidectomy. After the operation, a few days later, the values of PTH (63.5 pg/ml) and ionized calcium (1.18 mmol/L) were normal. Conclusion. Sestamibi scintigraphy is rarely negative during clear clinical and biochemical signs. The sensitivity of Sestamibi is 80-100%, and in cases where it is negative, especially when the volume of the nodule in PHPT is small, additional analyzes such as neck CT, 18FCholine PET/CT enable the decision-making of the definitive treatment – parathyroidectomy in PHPT.

Treatment and nutrient recovery from landfill leachate by sequential persulfate oxidation and struvite precipitation: An evaluation of technical feasibility.

The technical feasibility of advanced oxidation process, in particular persulfate (PS) oxidation followed by struvite precipitation for landfill leachate treatment and nutrient recovery has been depicted in the current study. Furthermore, the impact of activation of PS with thermal and ultraviolet (UV) irradiation techniques on COD removal efficiency is also investigated. A maximum COD removal efficiency of 96% is accomplished at 65°C together with supply of UV irradiation. The impact of persulfate dose, pH, and PS/65°C/UV system on COD and biodegradability is also illustrated in the current study. Additionally, decomposition rate constant values are also ascertained in the present study. Afterwards, nutrient recovery using struvite precipitation is carried out for sustainable utilization of resources. Preliminary treatment of leachate with PS/65°C/UV system is greatly conducive to recovering high quality struvite crystals. Besides, 94.9%, 83.5%, and 91.3% of PO43- -P, NH4+ -N, and Mg2+ recovery efficiency attained respectively at pH 9.5 and 1.2:1:1 molar ratio of Mg2+: NH4+-N: PO43--P. Additionally, all the nutrient recovery studies are validated using chemical equilibrium model Visual MINTEQ. Later, bioavailable fraction of PO43--P in the recovered struvite is also investigated for utilization as fertilizer. The presence of Cu and Zn in the recovered struvite precipitate enhanced its economic value as a fertilizer. Since Cu and Zn are vital micronutrients for growth of plants. The low soluble values of recovered struvite precipitate confirmed its utilization as slow releasing fertilizer.