Real time adaptive probabilistic recurrent Takagi-Sugeno-Kang fuzzy neural network proportional-integral-derivative controller for nonlinear systems.

This paper presents an adaptive probabilistic recurrent Takagi-Sugeno-Kang fuzzy neural PID controller for handling the problems of uncertainties in nonlinear systems. The proposed controller combines probabilistic processing with a Takagi-Sugeno-Kang fuzzy neural system to proficiently address stochastic uncertainties in controlled systems. The stability of the controlled system is ensured through the utilization of Lyapunov function to adjust the controller parameters. By tuning the probability parameters of the controller design, an additional level of control is achieved, leading to enhance the controller performance. Furthermore, it can operate without relying on the system's mathematical model. The proposed control approach is employed in nonlinear dynamical plants and compared to other existing controllers to validate its applicability in engineering domains. Simulation and experimental investigations demonstrate that the proposed controller surpasses alternative controllers in effectively managing external disturbances, random noise, and a broad spectrum of system uncertainties.

Texture analysis using non-contrast MRI to predict estrogen receptor status in breast cancer lesions: Is it feasible?

PURPOSE: We aimed to evaluate the feasibility of non-contrast-enhanced T1 sequence in texture analysis of breast cancer lesions to predict their estrogen receptor status. METHODS: The study included 85 pathologically proven breast cancer lesions in 53 patients. Immunohistochemical studies were performed to determine the estrogen receptor status (ER). Lesions were divided into two groups: ER + ve status and ER-ve status. Texture analysis using the second-order analysis features [The Co-occurrence matrix (11 features)] was applied on both T1 and dynamic contrast-enhanced (DCE) MRI images for each lesion. Texture features gained from both T1 and DCE images were analyzed to obtain cut-off values using ROC curves to sort lesions according to their estrogen receptor status. RESULTS: Angular second momentum and some of the entropy-based features showed statistically significant cut-off values in differentiation between the two groups [P-values for pre- and post-contrast images for AngSecMom (0.001, 0.008), sum entropy (0.003,0.005), and entropy (0.033,0.019), respectively]. On comparing the AUCs between pre- and post-contrast images, we found that differences were statistically insignificant. Sum of squares, sum variance, and sum average showed statistically significant cut-off points only on pre-contrast images [P-values for sum of squares (0.018), sum variance (0.024), and sum average (0.039)]. CONCLUSIONS: Texture analysis features showed promising results in predicting estrogen receptor status of breast cancer lesions on non-contrast T1 images.

Recurrent general type-2 fuzzy neural networks for nonlinear dynamic systems identification.

This paper introduces a recurrent general type-2 Takagi-Sugeno-Kang fuzzy neural network (RGT2-TSKFNN) for the identification of nonlinear systems. In the proposed structure, the general type-2 fuzzy set (GT2FS) and a recurrent fuzzy neural network (RFNN) are combined to obviate the data uncertainties. The fuzzy firing strengths in the developed structure are returned to the network input as internal variables. In the proposed structure, GT2FS is utilized to characterize the antecedent parts while the consequent parts are performed using TSK type. The issues of constructing a RGT2-TSKFNN involve type reduction, structure learning as well as parameter learning. An efficient strategy is developed by utilizing alpha-cuts to decompose a GT2FS into several interval type-2 fuzzy sets (IT2FSs). In order to solve the computation time of the type-reduction issue, a direct defuzzification method is used instead of iterative nature of Karnik-Mendel​ (KM) algorithm. Type-2 fuzzy clustering and Lyapunov criteria are utilized for online structure learning as well as the antecedent and consequent parameters, respectively for reducing the number of rules and guaranteeing the stability of the proposed RGT2-TSKFNN. The reported comparative analysis of the simulation results is utilized to estimate the performance of the proposed RGT2-TSKFNN with respect to other popular type-2 FNNs (T2FNNs) methodologies.

Lyophilized Amorphous Dispersion of Telmisartan in a Combined Carrier-Alkalizer System: Formulation Development and In Vivo Study.

Telmisartan suffers from low oral bioavailability due to its poor water solubility. The research work presents a formulation of solid dispersed (SD) telmisartan formulation as a ternary mixture of a drug, a polymeric carrier (poly(vinylpyrrolidone) (PVP) K30), and an alkalizer (Na2CO3). The preparation method, which was lyophilization of an aqueous solution containing the ingredients, was free from any organic solvent. The developed SD formulations resulted in a significant improvement in in vitro dissolution (>90% drug dissolution in 15 min) compared to pure telmisartan. Solid-state characterization by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and X-ray diffraction (XRD) studies indicated the conversion of crystalline telmisartan into an amorphous form. Fourier transform infrared (FTIR) spectroscopy revealed the drug-polymer interaction that was responsible for reducing the chances of recrystallization. A short-term stability study showed that selected SD formulations were stable in terms of in vitro dissolution and retained their amorphous structure in ambient and accelerated conditions over 2 months. Selected formulations (drug/PVP K30/Na2CO3 as 1:1:2 or 1:2:2 weight ratio) resulted in >2.48 times relative oral bioavailability compared to marketed formulations. It was considered that the incorporation of an alkalizer and a hydrophilic polymer, and amorphization of telmisartan by lyophilization, could enhance in vitro dissolution and improve oral bioavailability.

A new class of nonreciprocal spin waves on the edges of 2D antiferromagnetic honeycomb nanoribbons.

Antiferromagnetic two-dimensional (2D) materials are currently under intensive theoretical and experimental investigations in view of their potential applications in antiferromagnet-based magnonic and spintronic devices. Recent experimental studies revealed the importance of magnetic anisotropy and of Dzyaloshinskii-Moriya interactions (DMI) on the ordered ground state and the magnetic excitations in these materials. In this work we present a robust classical field theory approach to study the effects of anisotropy and the DMI on the edge and bulk spin waves in 2D antiferromagnetic nanoribbons. We predict the existence of a new class of nonreciprocal edge spin waves, characterized by opposite polarizations in counter-propagation. These novel edge spin waves are induced by the DMI and are fundamentally different from conventional nonreciprocal spin waves for which the polarization is independent of the propagation direction. We further analyze the effects of the edge structures on the magnetic excitations for these systems. In particular, we show that anisotropic bearded edge nanoribbons act as topologically trivial magnetic insulators with potentially interesting applications in magnonics. Our results constitute an important finding for current efforts seeking to establish unconventional magnonic devices utilizing spin wave polarization.

Discretized dynamics of exchange spin wave bulk and edge modes in honeycomb nanoribbons with armchair edge boundaries.

We develop a field theory to study the dynamics of long wavelength exchange spin wave excitations on honeycomb nanoribbons characterized by armchair edge boundaries and the Néel antiferromagnetic ordering state. Appropriate boundary conditions are established by requiring that the bulk and edge spins precess with the same frequency for any given spin wave eigenmode in these systems. A set of characteristic boundary equations, common for bulk and edge spin wave modes, are hence derived. The equations of motion for the spin dynamics are then solved to determine the propagating and evanescent exchange spin wave modes. We obtain the expected discretized bulk spin waves spectrum due to the finite width of the nanoribbon. For an isotropic magnetic nanoribbon, the Dirac cone is reduced to a single linear dispersion curve due to this discretization. The number and wavelengths of allowed bulk modes for isotropic and anisotropic nanoribbons are determined from the derived characteristic boundary equations. As witnessed by our numerical results for different examples it is shown that the characteristics of these modes depend on the width of the nanoribbon and its antiferromagnetic anisotropy. Further, anisotropic nanoribbons, even those with the slightest anisotropy, present evanescent modes with non-linear dispersion relations. The spatial variation of the amplitudes of the evanescent exchange spin waves across the finite widths of the nanoribbons, is found to be strongly dependent on the system magnetic anisotropy and its width. The developed theoretical approach is general and can be applied for nanoribbons with all types of boundary edges.

Asymmetric dynamics of edge exchange spin waves in honeycomb nanoribbons with zigzag and bearded edge boundaries.

We report on the theoretical prediction of asymmetric edge spin waves, propagating in opposite directions at the boundaries of antiferromagnetic honeycomb nanoribbons with zigzag and bearded edges. The simultaneous propagation of edge spin waves along the same direction on both edges of the nanoribbons is forbidden. These asymmetric exchange spin waves at the edge boundaries are analogous to the nonreciprocal surface spin waves reported in magnetic thin films. Their existence is related to the nontrivial symmetry underlying these nanoribbons types. The discretized bulk and the edge exchange spin waves are calculated for the long wavelength part of the nanoribbon Brillouin zone (BZ), using the classical field spin wave theory and notably appropriate boundary conditions. In the absence of an external magnetic field in our study, the asymmetric edge spin waves propagate with equal frequencies and along opposite directions. The edge spin waves are characterized by linear dispersion relations for magnetically isotropic nanoribbons. For magnetically anisotropic nanoribbons, our calculations show that the energy gap between the edge and bulk spin waves is enhanced for both types of zigzag and bearded nanoribbons. The large energy gap separates the edge modes from overlapping the bulk ones. Also, we explain why our results for anisotropic zigzag nanoribbons go beyond previous studies based on a quantum approach in the linear spin wave approximation.

The evaluation of the 1001.03 keV gamma emission absolute intensity using fundamental parameter method.

The accurate evaluation of the absolute intensity of the gamma-ray transition 1001.03 keV of 234mPa is crucial for accurate determination of 238U in nuclear material and environmental samples. Over the last decades, a wide range of 1001.03 keV absolute intensity values were published by different researchers and ranged from 0.59 to 1.12%. Nowadays, one of the most commonly used values is 0.847 ± 0.008% that seems not accurate and would eventually lead to an overestimation of 238U activity concentration. The absolute intensity of 1001.03 keV gamma transition was re-evaluated using different fundamental parameter method (FPM) modes, uranium ore and granite samples, samples' geometries, sample-to-detectors' geometries and gamma ray spectrometers. The mean ± standard deviation of newly optimized absolute intensity value is 1.067 ± 0.084% with an average relative bias of - 20% from the commonly used value.

The re-evaluation of the 234mPa's 1001.03 keV gamma emission absolute intensity for the precise assessment of 238U.

In this study the commonly used f-value for the 1001.03 keV (0.835 ± 0.004%) energy transition of the 234mPa was re-evaluated due to an obvious consistent overestimation of the 238U activity concentration. Different calibration protocols, samples' matrices and geometries, and gamma-ray spectrometers were exploited in order to assure the accuracy of the derived data. An average positive relative bias of about 24% from the currently used f-value was estimating leading to newly adopted f-value of 1.037 ± 0.052%. This newly suggested f-value will lead to an improvement in the accurate assessment process of the 238U using gamma-ray spectrometry in both environmental and nuclear safeguard fields.

Analysis of genomic mutation and immunohistochemistry of platelet-derived growth factor receptors in canine vascular tumours.

We examined whether mutation of the platelet-derived growth factor receptor protein tyrosine kinase (PDGFR)-α and PDGFR-ß genes contributes to their overexpression in canine vascular tumours. Genomic sequences of trans- or juxtamembrane regions of PDGFR-α and PDGFR-ß were analysed with immunohistochemical staining and polymerase chain reaction-direct sequencing using DNA from paraffin-embedded neoplastic tissues of 27 hemangiosarcomas (HSAs) and 20 hemangiomas (HAs). Immunohistochemically, 75% of the HA cases were positive for PDGFR-α and almost most of the HA cases were negative for PDGFR-ß. Of the HSA cases, 55.6% were negative for PDGFR-α and 63% were strongly positive for PDGFR-ß. Among the HA cases, 1 missense mutation was detected in PDGFR-α exon 18 and 1 in PDGFR-ß exon 17. Two HSA cases had missense mutations in exon 14 and 1 in exon 17 of PDGFR-ß. Thus, genomic mutation of trans- or juxtamembrane regions of PDGFRs was not the main mechanism driving the activation of receptors in HSA and HA.

Expression of platelet-derived growth factor and its receptors in spontaneous canine hemangiosarcoma and cutaneous hemangioma.

Hemangiosarcoma (HSA) is a malignant neoplasia of vascular endothelial cells (ECs). Our previous report on the expression of vascular endothelial growth factor, basic fibroblast growth factor, and their receptors in canine HSA suggested an autocrine/ paracrine mechanism of tumor growth. However, the influence of other angiogenic growth factors in canine HSA was not elucidated; therefore, the expression of platelet-derived growth factor (PDGF) and its receptors was investigated by immunohistochemical analysis. Forty-six canine HSAs and 21 canine cutaneous hemangiomas (HAs) were analyzed. For immunohistochemistry, anti-PDGF-BB, anti-PDGFR-α, and anti-PDGFR-ß antibodies were utilized as primary antibodies. Immunoreactivities were scored as strongly positive (>25% positive neoplastic cells), weakly positive (1-25% positive neoplastic cells), and negative if not staining at all. In cutaneous HA, 33.3% and 57.1% of cases were strongly and weakly positive, respectively, and 43.5% and 13.0% of HSAs were strongly and weakly positive for PDGF-BB, respectively. Moreover, 38.1% and 28.6% of cutaneous HAs cases were strongly and weakly positive, respectively, and 23.9% and 4.3% of HSAs cases were strongly and weakly positive, respectively, for PDGFR-α. Thirty-five HSAs cases (76.1%) were strongly positive, and the remaining 11 (23.9%) were weakly positive for PDGFR-ß. In contrast, 18 (72.0%) cutaneous HAs were negative, and only 3 cases (12.0%) were weakly positive, for PDGFR-ß. The proportion of strongly positive cases of HSAs was significantly higher than that of cutaneous HA for PDGFR-ß (P<0.01), while PDGFR-α was highly expressed in cutaneous HA and may be related to pathogenesis of cutaneous HA. Therefore, PDGFR-ß may be associated with the malignant nature of canine HSA.

A simplified gamma-ray self-attenuation correction in bulk samples.

Gamma-ray spectrometry is a very powerful tool for radioactivity measurements. For accurate gamma-ray spectrometry, certain correction measures should be considered, for instance, systematic uncertainty in the photo-peak efficiency due to the differences between the matrix (density and chemical composition) of the reference and the other bulk samples. Therefore, gamma-ray attenuation correction factors are of major concern for precise gamma-ray spectrometry. Simple practical correction for the photo-peak efficiency, due to discrepancies in both the samples' matrices and densities (self-attenuation), is performed in this study. This study suggests a brief measurement of relative photons transmission through both reference and unknown bulk samples where the variations of photon transmissions are assumed to be linearly correlated to the samples' densities. Specific correction factors would be produced for each analyzed sample to be considered when their activities are calculated. Practically, the suggested method was verified and succeeded in improving the obtained results.

Magnon coherent conductance via atomic nanocontacts.

A calculation for the coherent scattering and conductance of magnons via atomic nanocontacts is presented. The model system is composed of two groups of semi-infinite magnetically ordered Heisenberg monatomic chains, joined together by the magnetic nanocontact, and the system is supported on a non-magnetic substrate and considered otherwise free from magnetic interactions. The coherent transmission and reflection coefficients are derived as elements of a Landauer-type scattering matrix. Transmission and reflection scattering cross sections are calculated specifically for three distinct symmetric and asymmetric geometric configurations of the nanocontact. Three cases of local magnetic exchange on the nanocontact domain are analysed for each configuration to investigate the influence of softening and hardening of the magnetic boundary conditions. In analogy with coherent electronic transport, we calculate the magnon coherent transport. The numerical results show the interference effects between the incident scattered magnons and the localized spin states on the nanocontact, with characteristic Fano resonances. The numerical results yield an understanding of the relationship between the coherent magnon conductance and the architecture of the embedded magnetic nanocontact.

Evaluation of aural manifestations in temporo-mandibular joint dysfunction.

Thirty patients with temporo-mandibular joint dysfunction were selected to investigate the changes in otoacoustic emissions before and after conservative treatment of their temporo-mandibular joints. Pure tone audiometry, transient-evoked otoacoustic emissions (TEOAE), distortion-product otoacoustic emissions (DPOAE) as well as a tinnitus questionnaire were administered to all patients before and after therapy. Therapy was conservative in the form of counselling, physiotherapy, anti-inflammatory agents, muscle relaxants, and occlusal splints. Results indicated insignificant changes in the TEOAEs, whereas there were significant increases in distortion product levels at most of the frequency bands. These results were paralleled to subjective improvement of tinnitus.

Radiological impacts of natural radioactivity in Abu-Tartor phosphate deposits, Egypt.

Phosphate and environmental samples were collected from Abu Tartor phosphate mine and the surrounding region. The activity concentration of 226Ra (238U) series, 232Th series and 40K were measured using a gamma-ray spectrometer. The activities of uranium isotopes (238U, 235U and 234U) and 210Pb were measured using an alpha spectrometer and a low-background proportional gas counting system, respectively, after radiochemical separation. The results are discussed and compared with the levels in phosphate rocks from different countries. It seems that the Abu Tartor phosphate deposit has the lowest radioactivity level of exploited phosphate of sedimentary origin. 226Ra/238U, 210Pb/226Ra, 234U/238U and 226Ra/228Ra activity ratios were calculated and are discussed. The radioactivity levels in the surrounding region and the calculated exposure dose (nGy/h) will be considered as a pre-operational baseline to estimate the possible radiological impacts due to mining, processing and future phosphate industrial activities. To minimize these impacts, the processing wastes should be recycled to the greatest possible extent.

Effect of iloprost on serum creatine kinase and lactate dehydrogenase isoenzymes after isoprenaline-induced cardiac damage in rats.

The effect of iloprost was investigated in an experimental model of cardiac damage in rats after isoprenaline (isoproterenol) treatment. Iloprost was administered by continuous subcutaneous infusion at a dose of 0.44 micrograms/kg body weight (b.w.)/min over a total period of 9 days. On day 8, 5 mg isoprenaline/kg b.w. was applied subcutaneously to induce the cardiac damage. The determinations of creatine kinase (CK, EC 2.7.3.2) and CK isoenzymes, lactate dehydrogenase (LDH, EC 1.1.1.27) and LDH isoenzymes as well as a-hydroxybutyrate dehydrogenase (a-HBDH, no EC) were performed 2, 6 and 24 h after isoprenaline application. Immediately after the last blood sampling, the animals were sacrificed and the hearts were examined histologically. Iloprost-pretreated animals showed a reduction in the rise in heart-specific isoenzymes CK-MB and LDH1-3 in the serum after isoprenaline application. A decrease in isoenzymes CK-BB and LDH4-5 in the serum was also observed in iloprost-pretreated rats. However, no difference could be detected histologically in the extent of myocardial necrosis between animals treated with isoprenaline alone or in combination with iloprost. These results suggest a biochemical cardioprotective effect of iloprost in this rat model after isoprenaline application and the lack of correlation with histological findings is discussed.