Subjects -> SCIENCES: COMPREHENSIVE WORKS (Total: 374 journals)
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 Iranian Journal of Science and Technology, Transactions A : ScienceNumber of Followers: 0      Hybrid journal (It can contain Open Access articles) ISSN (Print) 1028-6276 - ISSN (Online) 2364-1819 Published by Springer-Verlag  [2467 journals]
• Evaluation of Proliferative Inhibition Effect of Moringa oleifera Total
Extract on Breast Cancer: An In Vitro and In Vivo Study

Abstract: Abstract The effectiveness of chemical drugs has been reduced by the resistance of cancer cells to chemical drugs, such as breast cancer as one of the most common cancers in women. Hence, it is important to study the development of more effective drugs with fewer side effects, such as herbs. Thus, the present study aimed to assess the effects of Moringa oleifera (MO) grown in Iran with anti-cancer properties in the inhibition of apoptosis and proliferation in breast cancer cells. MO extract was prepared in this study while confirming phenolic compounds, namely quercetin, gallic acid, and folic acid, through HPLC methods. Afterward, the apoptotic and anti-proliferative impacts of phenolic compounds were evaluated on 4T1 breast cancer cells via MTT, BrdU, Annexin V-FITC/PI staining, and caspases-9 and -3 activity assays. Furthermore, ELISA was applied to evaluate BAX/Bcl2 ratio. MO extract (0.02, 0.04, and 0.08 g daily for four weeks) was used to treat the BALB/c mice. The size of tumors was measured. MO reduced the proliferation significantly and induced apoptosis (P < 0.01). Furthermore, tumor volume in MO-treated mice was decreased. The reduction in tumor volume at 0.02 g dose was higher than the other two doses (P < 0.001). According to in vitro results, the apoptotic pathway was possibly induced by activating caspases-9 and -3 and an increase in the Bax/Bcl-2 ratio. Through the in vivo results, and significant reduction in tumor size, new evidence was added to the possible treatment of breast tumor provoking intrinsic apoptotic paths.
PubDate: 2023-03-16

• Wakefield Generation and Enhancement of Electron Energy to the Multi-GeV
in a Magnetized Plasma

Abstract: Abstract The nonlinear interaction of an intense chirped laser pulse with transversely magnetized plasma is studied theoretically. The work described in this investigation is dealing with the characteristics of the wakefield generation by different chirping functions. Numerical results reveal that the amplitude and wavelength of the generated wakefield are highly influenced by the chirping constant and types of chirping function. Moreover, for the linear chirping function the positive chirping constant and for the nonlinear chirping functions the negative chirping constants excite larger wake amplitudes. In addition, it was found that by choosing a proper chirping constant for each chirping functions, one could obtain highly GeV electron energy gain. The maximum energy is obtained for the electron injected in the wakefield induced by the Exp and Linear chirped pulse. The maximum electron energy is about 2.5 GeV for the wake excited by the negative Exp chirp function. Further results revealed that the energy of the electron is significantly enhanced using an external transverse magnetic field.
PubDate: 2023-03-14

• $$^{3}\hbox{He} - \alpha$$ Radiative Capture Reaction by EFT

Abstract: Abstract We have investigated the $$^3\hbox{He} (\alpha ,\gamma ) ^7\hbox{Be}$$ radiative capture reaction using the pionless Effective Field Theory (EFT). The amplitude, cross-section, and S-factor for the $$E_1$$ and $$E_2$$ transitions to the $$^{7}\hbox{Be}$$ ground state have been computed using the Faddeev equation approach up to Next-to Leading Order in the astrophysical energy range. Our aim has been the study of Coulomb interaction effects and the contribution of EFT higher-order calculations in optimizing the results. The computed S-factor for the reaction agrees with experimental data and previous theoretical calculations.
PubDate: 2023-03-14

• The Production of Ultra-low Momentum Neutron on Metallic Hydride Surfaces
by Heavy Electron

Abstract: Abstract The collective motion of protons on the metallic hydride produces strong local electric fields that renormalize electron mass, increasing the mass of the electron known as the heavy electron. The protons can capture heavy electrons to yield extremely low momentum neutrons plus neutrinos. In this study, we present the physics of the heavy electron capture process with the particle-in-box model approach and the production of ultra-low momentum neutrons. The heavy electron is assumed as a classical particle in a 3D box with the L dimension to thoroughly comprehend this emerging phenomenon. The length range of the box was estimated using Campton wavelength and the minimum electron energy to provide the capture settings. According to the calculations, a possibility of electron capture interaction is observed in 400 to 910 femtometers. The energy dependence of the electron, proton, and generated neutron was determined based on the box length to pursue the interactions. Finally, we calculated the ratio of the production power of the interaction of the ultra-low momentum neutron with the surrounding protons $$({{\varvec{P}}}_{n})$$ to the capturing power of the heavy electron and the proton ( $${{\varvec{P}}}_{ep}$$ ) in terms of the box length. We observed that $$\frac{{P}_{n}}{{P}_{ep}}$$ value for $$\mathrm{L}>$$ 400 fm is above 1, which is the desired value.
PubDate: 2023-03-14

• Heterogeneous Degradation Modeling Based on Hierarchical Bayesian Model
and Wiener Process

Abstract: Abstract In this paper, a hierarchical Bayesian model is presented with heterogeneous degradation data populations based on Wiener process and Gaussian mixture model, where the actual degradation path is described by Wiener process, and the Gaussian mixture model is used to capture the heterogeneity between data populations. The Bayesian parameters estimation method is carried out via hierarchical priors and Gibbs sampling algorithm, and DIC and WAIC are the two selection criteria for the optimal model to fit the data. A set of GaAs laser numerical example indicates that the heterogeneous degradation data population with two sub-populations provides a better reliability assessment result than assuming a homogeneous population.
PubDate: 2023-03-13

• Conducting Polymer Modified Glass Fiber Paper Substrate Based Biosensor
for Procalcitonin Detection

Abstract: Abstract An advanced biosensor assembly based on glass fiber paper (GFP) electrodes modified with nanocomposites comprising of poly (3,4-ethylene dioxythiophene) polystyrene sulfonate (PEDOT: PSS) as the main matrix with functionalized gold nanoparticles (GFP/PEDOT: PSS-AuNP) for selective and sensitive detection of procalcitonin (PCT). PCT is a biomarker that is specifically used to detect bacterial infections, and it has received a lot of interest as a potential answer to the challenges with selecting when to use antibiotics. Field emission scanning electron microscopy, ultraviolet–visible spectroscopy and energy dispersive X-ray analysis characterization techniques were used to characterize the prepared PEDOT: PSS-AuNP nanocomposite. For the electrochemical characterization and response study, electrochemical impedance studies study have been presented because it is more sensitive and result accuracy can be obtained through it. This conductive paper-based biosensor exhibits improved detection 0.10 pg mL−1 performance with a linear detection range (1–15 pg mL−1), high sensitivity, and a 24-day life span for PCT antigen detection. In addition, the inclusion of AuNP in PEDOT: PSS resulted in improved electrochemical performance and signal stability. This PEDOT: PSS-AuNP@GFP platform based was used to immobilize anti-PCT antigenic protein for PCT quantification. The results of electrochemical response studies showed that this conductive paper bioelectrode had a good reproducibility sensitivity in physiological ranges (1–15 pg mL−1). Further, the proposed bioelectrode an alternative choice for point-of-care PCT detection has been shown.
PubDate: 2023-03-10

• Stellar Model for Charged and Isotropic Rotating Neutron Stars in
$$f(\mathcal {R},\mathcal {T})$$ Gravity

Abstract: Abstract The modified theories of gravity have received a lot of attention in the last decade. These theories aim to describe the accelerated cosmic expansion by altering the theory of gravity, instead of introducing dark energy. The major goal of this research is to examine the spacetime surrounding charged compact star configurations in the context of $$f(\mathcal {R},\mathcal {T})$$ gravity and develop a workable model employing the Buchdahl metric potential (Phys. Rev. D 116, 1027 (1959)). We consider a simplified separable linear form for arbitrary function $$f(\mathcal {R},\mathcal {T})$$ given by, $$f(\mathcal {R},\mathcal {T})=\mathcal {R}+2\zeta \mathcal {T}$$ with the matter Lagrangian $$\mathcal {L}_\mathcal {M}=\rho$$ to depict the full solution of the modified field equations for the considered matter distribution. We assess various key characteristics, including effective energy density, effective pressure, sound velocities, relativistic adiabatic index, all energy conditions, and surface redshift, to determine the model’s physical viability and stability. For this investigation, we consider a rotating neutron star with isotropic configurations, namely Hercules X-1, as testing candidate. We also examine the effect of coupling constant $$\zeta$$ on the physical attributes of our model. The investigation illustrates that all our derived results lie within the physically accepted regime, demonstrating the model’s feasibility in $$f(\mathcal {R},\mathcal {T})$$ gravity.
PubDate: 2023-03-09

• Comparison of Nitrogen Gas and Thermal-Insulation Liquid to Control the
Temperature–Pressure Effect in Deep Gas Well

Abstract: Abstract Thermal-insulated liquid and nitrogen gas are two common methods to control the trapped annular pressure caused by the temperature–pressure effect, but few researches analyzed the control performance of these two measures applied in the deep gas well. Therefore, this paper builds a model to compare the control performance and a safety factor is proposed to evaluate the control performance when the tubing is totally blocked. The results indicate that the tubing-casing annulus temperature difference creates the conditions for the trapped annular pressure. Only when the production rate exceeds a certain value, can the thermal-insulated liquid reduce the trapped annular pressure. The nitrogen gas can achieve good control performance after the nitrogen gas volume exceeds 0.03 regardless of the production time and the production rate. To avoid the tubing collapse risk, the annular pressure should be controlled under the critical value. However, the thermal-insulated liquid is not able to reduce the annular pressure to the critical value. The nitrogen gas can prevent tubing collapse under different liquid densities by suitable volume. Therefore, the nitrogen gas is recommend.
PubDate: 2023-03-09

• Optimization of Soil Bacteria for Bioplastic Production Using Organic
Wastes as a Substrate Under Submerged Fermentation

Abstract: Abstract In the perspective of the threats to environment associated with petroium-derived synthetic plastics, there is a critical need to traverse biologically degradable polymeric material. Biologically synthesized polyhydroxyalkanoates are the most promising candidates to be used as bioplastic. Keeping in view the ecofriendly nature of bioplastics, the current study was designed to explore contaminated soil samples for bioplastic producing bacterial strains and use organic wastes as a sole carbon source to reduce cost of bioplastic production. Contaminated soil samples from various areas of Peshawar, Charsada and Dargai were screened for bioplastic producing bacterial strains by using primary stain Sudan black and confirmatory stain Nile blue A. The growth medium and physical parameters were optimized for efficient producers. A variety of organic wastes; fruits and vegetable wastes were used as carbon source in E2 medium under submerged fermentation in 1L flasks for bioplastic production by optimized higher yielding bacterial strain KHA-S-03. E.coli K12 and Ralstonia eutropha MTCC1285 were used as negative and positive control respectively. KHA-S-03 was molecularly identified to be Bacillus megaterium SFK by 16srDNA sequencing and Pha C gene of identified strain was sequenced and phylogenetically analyzed, this strain was able to utilize organic wastes as sole carbon source under optimized condition of incubation time 48 h, pH 7, temperature 37 °C, substrate concentration 5%, C/N ratio 8:1, agitation rate 200 rpm, inoculum size of 5% and nitrogen sources (NH4)2SO4 and NH4Cl. For efficient downstreaming, among various solvents tested, ethylene carbonate (nontoxic solvent) was found to have efficiency near to chloroform (toxic solvent).
PubDate: 2023-03-09

• Geochemical and Tectonic Characterization of Oil–Source Rocks in the
Shadegan Oilfield, Dezful Embayment, SW Iran

Abstract: Abstract Geochemical methods allow us to develop a systematic understanding of petroleum system elements. Geochemical analyses were done out on the shale samples of the Pabdeh and Asmari Formations and on the Asmari reservoir oil samples in the Shadegan oilfield, southwest Iran. Rock–Eval pyrolysis, gas chromatography (GC) and gas chromatography–mass spectrometry (GC–MS) data were utilized. Oil–oil and oil–source correlations using GC and GC–MS analyses indicated that the Pabdeh Formation and the Asmari Formation basal shale layer are two possible sources of Asmari reservoir oil. The results of Rock–Eval pyrolysis revealed the values of the organic matter in the samples of the Asmari Formation basal shale layer are consider poor to fair in total organic carbon content. Therefore, this layer cannot be known as the source rock for the oil in the Asmari reservoir. Based on the thermal maturity parameters including the sterane isomerization ratios and homohopanes isomerization ratio together with Rock–Eval data and 1D burial history model, both Pabdeh and Kazhdumi Formations are in the maturity levels for oil generation. Different biomarker ratios in two oil samples (for well numbers 4 and 17) compared to samples from the Shadegan oilfield, revealed that the oil of these two wells originated from carbonate source rock(s) unlike oils of other wells that originated from a shaly source rock. Oil migration from adjacent oilfields with carbonate source rock (e.g., the Maroon, Ahvaz and Mansouri oilfields) into these wells through natural fractures in paleohighs is considered as one of the controlling factors of observed difference in biomarker ratios.
PubDate: 2023-03-09

• Dependency of Argon Chromium Plasma Coefficients on Power in Magnetron
Sputtering

Abstract: Abstract In this paper, we have studied Cr–Ar plasma in low pressure at 3 mTorr at different powers (40–140) W experimentally and theoretically. We have measured parameters of the plasma (density of plasma, ionic density, electronic temperature, and electron energy density function EEDF) using Langmuir probe. The other parameters which could not measure such as electronic mobility, drift velocity, average electron energy and diffusion coefficients are calculated. The aim of this study is to be determined the Cr–Ar plasma parameters that are necessary for preparing thin films at different powers. We have used SEM and XRD to study the morphology of these films.
PubDate: 2023-03-06

• Sampling Information for Generalized Rayleigh Distribution with
Application to Parameter Estimation

Abstract: Abstract In the current paper, we considered the Fisher information matrix from generalized Rayleigh distribution (GR) distribution in moving extremes ranked set sampling (MERSS). The numerical results show that the ranked set sample carry more information about $$\lambda$$ and $$\alpha$$ than a simple random sample of equivalent size. In order to give more insight into the performance of MERSS with respect to (w.r.t.) simple random sampling (SRS), a modified unbiased estimator and a modified best linear unbiased estimator (BLUE) of scale and shape $$\lambda$$ and $$\alpha$$ from GR distribution in SRS and MERSS are studied. The numerical results show that the modified unbiased estimator and the modified BLUE of $$\lambda$$ and $$\alpha$$ in MERSS are significantly more efficient than the ones in SRS.
PubDate: 2023-03-02

• Solving Three-Dimensional Volterra Integral Equations by Using Operational
Matrix with Block-Pulse Functions

Abstract: Abstract A simple direct method for solving three-dimensional linear Volterra integral equation of the second kind was introduced in this paper. Our method was demonstrated by applying three-dimensional block-pulse functions (3D-BPFs) and their operational matrix of integration. Indeed, we converted an integral equation to a linear system that can be easily solved. The convergence analysis of the method was discussed by convergence of 3D-BPFs and we found a bound for the error. Finally, some numerical examples illustrated that our method is feasible and efficient.
PubDate: 2023-03-01

• Seasonal and Spatial Distribution of Phosphorus Fractions in Surface
Sediments of the Southern Caspian Sea

Abstract: Abstract This study assesses seasonal fluctuations, spatial distribution and fractions of phosphorus (P) in the surface sediment layer of the southern Caspian Sea. Seasonal fluctuations were insignificant (p-value > 0.05) relative to the mean total P (TP) concentrations. Still, the highest levels were in autumn samples (1555 mg kg−1), followed by winter (1405 mg kg−1), spring (1378 mg kg−1), and summer (1130 mg kg−1). These minor temporal fluctuations in P concentrations are explained by seasonal differences in runoff amount and intensity of rivers discharging into the Caspian sea and thereby their sediment loading and physicochemical characteristics. The large riverine influx has led to TP contamination hotspots in the river deltas of Anzali wetland, Babolrood, and Sefidrud, where high loadings of suspended particles are discharged into the sea. The spatial distribution of TP is thus site-specific and uneven. The main P fraction was calcium-bound P (CaP), reflecting the phosphate (PO43−) strong affinity for, and association with, Ca-bearing minerals. Only a minor fraction of P was determined as loosely bound P (LP). The fraction of the mud size particles was the main explanatory factor for the spatial distribution of overall low levels of non-residual (or bioavailable) P forms (i.e., LP and iron- and aluminum- bound P: FeP and AlP, respectively) during spring and summer, while the sand fraction had strongest explanatory value for the distribution of residual (non-bioavailable) P form (CaP) during autumn and winter. This study demonstrates that P bioavailability in sediments is mainly governed by the physicochemical characteristics of the sediment material, which again is steered by seawater chemistry. A low content of bioavailable P fractions could therefore be explained by the relatively low content of fine-grained (< 63 µm, i.e., mud) particles in sediments of the southern Caspian Sea.
PubDate: 2023-02-18

• NMDA Receptors Contribute to Postnatal Developmental Downregulation of
Connexin Expressions in the Rat Locus Coeruleus

Abstract: Abstract It has been shown that during postnatal development, gap junctions decrease. This phenomenon overlaps with the major period of chemical synapse formation and increased synaptic activity during postnatal weeks 1–3. In current study, the expression of connexin 36 (Cx36), Cx32, and Cx43 proteins in locus coeruleus (LC) was examined using Western blot analysis in (postnatal day) PND14 and PND28 following blockade of NMDA receptors in rats to evaluate the role of these receptors in the expression of Cxs. MK801, as an NMDA receptor antagonist, was injected subcutaneously from the first day of birth until 14 or 28 days depending on the experimental groups. The control group received a saline injection in the same volume. Expression of Cxs declined in PND28 compared to PND14 in LC neurons. Also, we found that the expression of Cx36, Cx32, and Cx43 augmented in the rats’ LC in PND14 and PND28 following the blockade of NMDA receptors. The present results suggest that the activity of NMDA receptors may contribute to the downregulation of Cx36, Cx32, and Cx43 in LC during postnatal development.
PubDate: 2023-02-17

• Emission Pattern of NORMs and 137Cs in the Sediments of the Gaz River and
the Gorgan Bay, North Iran

Abstract: Abstract Information on the distribution and emission patterns of natural and artificial radionuclides and their radiation level in the environment is very important for assessing the health effects of people living in a given region. In this study, the specific activity of radionuclides was measured using high purity germanium detector and a map of their distribution was drawn. The samples were collected from the Gaz River sediment in northern Iran, in the mountains of Golestan Province, and sediments on the middle and southern side of Gorgan Bay. The average of specific activities of 226Ra, 232Th, 40K, and 137Cs was 17.61, 35.91, 398.65, and 4.01 Bq/kg, respectively, which for natural radioactive nuclei are lower than the global average. The highest concentration of 40K was obtained in the sediments of the Gaz River estuary due to the use of potassium fertilizers for agriculture in this region. The highest concentration of 137Cs was obtained in the sediments of Gorgan Bay because 137Cs is injected both directly through the atmosphere and transfer by river water from upstream points to the Gorgan Bay. The diffusion pattern of 137Cs in the Gorgan Bay was exactly the opposite of 232Th and showed the tendency of 137Cs to precipitate in calm areas in the middle of the Bay.
PubDate: 2023-02-17

• Dose-dependent Effects of Bio-AgNPs on Rubia tinctorum Callus and Root
Biomass

Abstract: Abstract Silver nanoparticles have frequently been used in many areas of biotechnology. These nanomaterials, especially biologically synthetized silver nanoparticles (bio-AgNPs), have some beneficial effects on plant biosystems because of their ethylene-inhibiting and auxin-stimulating effects which make them practical and cost-effective alternatives for synthetic plant growth regulators. The variety of the plants’ responses to bio-AgNPs is dose-dependent, and the effects show a wide variety for every plant, explant and culture types. In our study, bio-AgNPs derived from Syzygium aromaticum flowers were used in stem cultures of Rubia tinctorum. At 0–30 mg/L concentrations, their efficacies were evaluated on the basis of biomass and chemical accumulations. Bio-AgNPs affected the growth parameters and content of biomass depending on their concentrations. The highest biomass accumulations were detected at 10 mg/L concentration (up to 3.4 times higher compared to control). Callus and root regenerations were triggered at 5 and 10 mg/L concentrations. Total phenolic concentrations were detected at the highest level (16.54 and 18.86 mg GAE/g, respectively) at 15 mg/l concentration, whereas total flavonoid concentrations were the highest at 15 and 20 mg/L concentrations (5.63 and 5.42 mg QE/g, respectively). Total antioxidant capacity and radical scavenging activity enhanced in response to bio-AgNPs. The highest total antioxidant capacity was detected at 107.53 mg AAE/g at 1 mg/L concentration in root biomass (1.6 times higher than the control). Total anthraquinone concentrations reached their highest values at 30 mg/L bio-AgNP concentration in both callus and root tissues. The results revealed that bio-AgNPs acted as elicitors or/and biomass enhancers in response to their concentrations.
PubDate: 2023-02-14

• Selection of Optimal Regression-like Equations for Circular Regression
Model via Mallows’ $$C_p$$ and AIC Criteria

Abstract: Abstract The problem of choosing the best regressors to fit the circular regression data has not been addressed. We focus on the problem of finding the optimal regression-like equations (ORLE) in the Sarma and Jammalamadaka (SJ) circular regression model (Sarma and Jammalamadaka 1993). First, the issues of under-fitting and over-fitting of regression equations in the SJ model are addressed. Then, we extend Mallows’ $$C_p$$ and AIC and their robust versions to the SJ circular regression model. A simulation study is used to investigate the performance of the proposed criteria. Results showed that robust circular Mallows’ $$C_p$$ and AIC are effective in selecting an accurate ORLE for circular regression models in both the clean and contaminated data sets. An application of the proposed procedures is discussed using a real medical data set.
PubDate: 2023-02-11

• Solving Fractional Optimal Control Problems Involving Caputo–Fabrizio
Derivative Using Hermite Spline Functions

Abstract: Abstract In the current research, we develop a collocation method based on the biorthogonal Hermite cubic spline functions to solve a class of fractional optimal control problems using Caputo–Fabrizio derivative operator. We design dual bases for Hermite cubic spline functions for the first time in this work. So, we present two direct and efficient algorithms to solve a class of fractional optimal control problems. Two new operational matrices of Caputo–Fabrizio fractional derivative are derived using Hermite cubic spline functions. By employing these matrices, we reduce these problems to systems of algebraic equations. Illustrative examples are examined to demonstrate the important features of the new algorithm.
PubDate: 2023-02-08

• Classes of Operators Related to Polynomially Normal Operators

Abstract: Abstract In this paper, we introduce new classes of operators related to the class of polynomially normal operators which are described as follows: (i) $$m$$ -quasi polynomially normal operators includes polynomially normal operators recently studied in [7, 6]. A bounded linear operator $$S$$ on a complex Hilbert space $$\mathcal{H}$$ is said to be $$m$$ -quasi polynomially normal operator if there exists a nontrivial polynomial $$P={\sum }_{0\le k\le n}{b}_{k}{z}^{k}\in {\mathbb{C}}[z]$$ for which $${S}^{*m}(P(S){S}^{*}-{S}^{*}P(S)){S}^{m}=\,0$$ $$(\Leftrightarrow \sum_{0\le k\le n}{b}_{k}{S}^{*m}({S}^{k}{S}^{*}-{S}^{*}{S}^{k}){S}^{m}=\,0),$$ where $$m$$ is a natural number. (ii) Polynomially $$C$$ -normal operators includes $$C$$ -normal operators studied in [13, 23, 25]. An operator $$S$$ is called polynomially $$C$$ -normal operator if there exists a nontrivial polynomial $$P\in {\mathbb{C}}[z]$$ and a conjugation operator $$C$$ on $$\mathcal{H}$$ for which $$CP(S){S}^{*}-{S}^{*}P(S)C=\,0(\Leftrightarrow \sum_{0\le k\le n}{b}_{k}(C{S}^{k}{S}^{*}-{S}^{*}{S}^{k}C)=\,0).$$ A detailed study of certain properties of some members of the first class has been presented. However, an initiation to the study of the second class has been given.
PubDate: 2023-02-07

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