Sharif Digital Repository

In budding yeast, the 3′ end processing of mRNA and the coupled termination of transcription by RNAPII requires the CF IA complex. We have earlier demonstrated a role for the Clp1 subunit of this complex in termination and promoter-associated transcription of CHA1. To assess the generality of the observed function of Clp1 in transcription, we tested the effect of Clp1 on transcription on a genomewide scale using the Global Run-On-Seq (GRO-Seq) approach. GRO-Seq analysis showed the polymerase reading through the termination signal in the downstream region of highly transcribed genes in a temperature-sensitive mutant of Clp1 at elevated temperature. No such terminator readthrough was observed... 

In recent years, the need to reduce environmental impacts and increase flexibility in the energy sector has led to increased penetration of renewable energy sources and the shift from concentrated to decentralized generation. A fuel cell is an instrument that produces electricity by chemical reaction. Fuel cells are a promising technology for ultimate energy conversion and energy generation. We see that this system is integrated, where we find that the wind and photovoltaic energy system is complementary between them, because not all days are sunny, windy, or night, so we see that this system has higher reliability to provide continuous generation. At low load hours, PV and electrolysis... 

In recent years, the need to reduce environmental impacts and increase flexibility in the energy sector has led to increased penetration of renewable energy sources and the shift from concentrated to decentralized generation. A fuel cell is an instrument that produces electricity by chemical reaction. Fuel cells are a promising technology for ultimate energy conversion and energy generation. We see that this system is integrated, where we find that the wind and photovoltaic energy system is complementary between them, because not all days are sunny, windy, or night, so we see that this system has higher reliability to provide continuous generation. At low load hours, PV and electrolysis... 

Alkalis, surfactants and/or polymers are usually injected in the injector wells so that the injection fluids can sweep through the reservoir and mobilize/recover more oil. However, the formation of stable emulsion due to the residual chemicals in the recovered crude oil poses problems in the primary separation process. This study focuses on the effect of Alkali-Surfactant-Polymer injection on creaming and coalescence of crude oil and water emulsion produced in the primary gravity separator. In addition, a model is developed in this work to predict the separation effectiveness of oil and water emulsion containing ASP. In this work, the effect of ASP on the stability and the separation of... 

Alkalis, surfactants and/or polymers are usually injected in the injector wells so that the injection fluids can sweep through the reservoir and mobilize/recover more oil. However, the formation of stable emulsion due to the residual chemicals in the recovered crude oil poses problems in the primary separation process. This study focuses on the effect of Alkali-Surfactant-Polymer injection on creaming and coalescence of crude oil and water emulsion produced in the primary gravity separator. In addition, a model is developed in this work to predict the separation effectiveness of oil and water emulsion containing ASP. In this work, the effect of ASP on the stability and the separation of... 

One of the essential requirements of embedded systems is a guaranteed level of reliability. In this regard, fault-tolerance techniques are broadly applied to these systems to enhance reliability. However, fault-tolerance techniques may increase power consumption due to their inherent redundancy. For this purpose, power management techniques are applied, along with fault-tolerance techniques, which generally prolong the system lifespan by decreasing the temperature and leading to an aging rate reduction. Yet, some power management techniques, such as Dynamic voltage and frequency scaling (DVFS), increase the transient fault rate and timing error. For this reason, heterogeneous multicore... 

Purpose: Colon cancer is a leading cause of mortality worldwide. It has a relatively poor prognosis; therefore, new therapies are needed. One of the tumour-related enzymes that has gained considerable interest is CYP4Z1. This enzyme has been expressed in many tumours and has been hypothesized as a potential biomarker or target for novel anticancer therapies. Patients and Methods: CYP4Z1 overexpression was immunohistochemically examined in a large panel of colon tissue types including normal, benign, primary and metastatic ones, and the enzyme’s relation to histopathological features and patient survival was evaluated. Results: A high CYP4Z1 expression was observed in benign, primary and... 

We propose the structured naive Bayes (SNB) classifier, which augments the ubiquitous naive Bayes classifier with structured features. SNB classifiers facilitate the use of complex features, such as combinatorial objects (e.g., graphs, paths and orders) in a general but systematic way. Underlying the SNB classifier is the recently proposed Probabilistic Sentential Decision Diagram (PSDD), which is a tractable representation of probability distributions over structured spaces. We illustrate the utility and generality of the SNB classifier via case studies. First, we show how we can distinguish players of simple games in terms of play style and skill level based purely on observing the games... 

Organoclay modification is receiving attention as a nano-modifier for asphalt binders. Nanoparticles are able to effectively mend the damaged sites of the nanocomposite without external intervention. Particle-polymer interaction results in packing particles into developed cracks, thereby mending the cracks during patch formation. This study investigates the rheological properties of organoclay modified binders with a focus on their fatigue properties. To this end, the dissipated energy concept, the ratio of dissipated energy change and plateau value (PV) energy were examined during fatigue tests using a dynamic shear rheometer. The effects of strain level, frequency and temperature on unaged... 

The dynamics of the nanofluid flow between two plates that are placed parallel to each other is of huge interest due to its numerous applications in different industries. Keeping in view the significance of such flow, investigation of the heat transfer in the Cu-H2O nanofluid is conducted between parallel rotating plates. For more significant results of the study, the squeezing effects are incorporated over the plates that are electrically conducting. The nondimensional flow model is then treated analytically (VPM), and the results are sketched against the preeminent flow parameters. The remarkable heat transfer in the nanofluid is noticed against the Eckert and Prandtl numbers, whereas the... 

In this study, 490 nm thin tin selenide thin films were deposited by facile co-evaporation techniques using Sn and Se sources on a clean glass substrate. The thin films were annealed at moderate annealing temperature followed by characterization and analysis. The thin annealed films possess polycrystalline nature and orthorhombic structure with an average grain size of 130 nm. The band gap assessed from absorption spectra for the highly annealed sample was 1.52 eV. The resistivity and sheet resistance were measured with four-probe techniques and the sheet resistance was =1.362 × 104 ohm for the highly annealed film. © 2021 John Wiley & Sons Ltd  

The dynamics of the nanofluid flow between two plates that are placed parallel to each other is of huge interest due to its numerous applications in different industries. Keeping in view the significance of such flow, investigation of the heat transfer in the Cu-H2O nanofluid is conducted between parallel rotating plates. For more significant results of the study, the squeezing effects are incorporated over the plates that are electrically conducting. The nondimensional flow model is then treated analytically (VPM), and the results are sketched against the preeminent flow parameters. The remarkable heat transfer in the nanofluid is noticed against the Eckert and Prandtl numbers, whereas the... 

In this study, 490 nm thin tin selenide thin films were deposited by facile co-evaporation techniques using Sn and Se sources on a clean glass substrate. The thin films were annealed at moderate annealing temperature followed by characterization and analysis. The thin annealed films possess polycrystalline nature and orthorhombic structure with an average grain size of 130 nm. The band gap assessed from absorption spectra for the highly annealed sample was 1.52 eV. The resistivity and sheet resistance were measured with four-probe techniques and the sheet resistance was =1.362 × 104 ohm for the highly annealed film. © 2021 John Wiley & Sons Ltd  

For the 4th IUPAP International Conference of Women in Physics, we report on activities in science and engineering in Iran, and conditions for women in physics, in the three years since the 3rd IUPAP International Conference of Women in Physics was held in 2008. Iran has made prominent advancements and astonishing progress in laser technology, biotechnology, nanotechnology, genetics, computer software and hardware, and robotics. Iranian scientists have been very productive in several experimental fields, such as pharmaceutical, organic, and polymer chemistry. Conditions for women in physics have improved greatly in recent years. A project to improve the environment for learning physics, and... 

Background: cervical cancer is one of the most common malignancies in women worldwide and its management remains challenging and complex. As Cytochrome4Z1 (CYP4Z1) is overex-pressed in many tumours, its expression in cervical cancer is unknown. Therefore, the present study aimed to evaluate CYP4Z1 expression in cervical cancers. Methods: CYP4Z1 expression was immunohistochemically assessed in 100 cases of cervical cancers along with ten normal cervix tissues, and the enzyme’s relationship to several clinicopathological features and survival was explored. Results: CYP4Z1 was strongly expressed in 55% of cervical cancer patients. Normal cervix samples were negative for CYP4Z1 expression.... 

The lead is a heavy metal with hazardous impacts on environment and human life. Lead-free perovskite solar cells have attracted much attention in recent years, due to eco-friendly characteristics. Meanwhile, Pb-containing cells showed the highest efficiencies among the various types of cells. Hence, designing novel Pb-free solar cells with comparable or better performance than the Pb-containing ones is highly required. In this work, a lead-free methyl-ammonium-germanium-iodide (MAGeI3)-based perovskite solar cell with ITO/TiO2/MAGeI3/Spiro-OMeTAD/Ag multilayer nanostructure has been proposed and its main characteristics including open-circuit voltage (VOC) and power conversion efficiency (η)... 

Characterizing the electrical resistance of the formation rock is of great importance in, for example, interpreting the well log data, calculating the porosity, and water saturation for the formation rocks. The relation between the resistivity factor and porosity and also between the resistivity index and water saturation (Archie equation) in the formation rock uses the parameters, such as the cementation factor and saturation exponent. However, the direct application of Archie equation to carbonate rocks that are very heterogeneous and mostly oil-wet needs further investigation. In this experimental work, the effects of overburden pressure, temperature, and interfacial tension on the... 

Core/shell structure of ZnO nanowires coated with a monolayer of TiO 2 is investigated using Density Functional Theory (DFT). The electronic states of the semiconductor is calculated and compared before and after coating of the TiO2 monolayer on a ZnO [101 0] surface. The effect of TiO2 coating induce surface states changes and shifts the conduction and valence band edges to higher energies. Our results, in qualitative agreement with the experimental work of Matt Law et al. (J. Phys. Chem. B, 110, 22652), show an increase in open circuit voltage and a decrease in short circuit current in ZnO/TiO2 core shell dye sensitized solar cells. Regarding the semiconductor density of states (DOS), TiO2... 

Due to the important role of commitment and trust in the relationship marketing, the factors which can directly result in a committed relationship along with the factors which can influence the commitment through influencing trust, according to the model of commitment and trust by (Morgan & Hunt, 1994) have been introduced and their level of importance has been investigated here. The article uses fuzzy cognitive maps (FCMs) in the proposed model to find the most important paths leading to relationship commitment. The FCM analyzes the responses of a group of 30 people including general practitioners in dentistry, managers of dental departments in some of the public clinics and hospitals who... 

Conventionally, a film of TiO2 particles of 300 nm size is employed in Dye-sensitized solar cells (DSCs) as the back reflector film to enhance the light harvesting. Perfect reflectance of silver in visible and near infrared motivates to investigate its potential as the material for the light back reflector film in DSCs. In this study, light back reflector films consisting of 300 nm-sized silver particles, as well as vacuum evaporated silver flat film, were fabricated and compared to 300 nm-sized rutile-type TiO2 particulate reflector film to study their optical aspects. Conventional TiO2 rutile-type particulate film demonstrates slightly lower performance...