Grazing represents one of the most common disturbances in drylands worldwide, affecting both ecosystem structure and functioning. Despite the efforts to understand the nature and magnitude of grazing effects on ecosystem components and processes, contrasting results continue to arise. This is particularly remarkable for the biological soil crust (BSC) communities (i.e., cyanobacteria, lichens, ...

We previously demonstrated that N348I in HIV-1 reverse transcriptase confers zidovudine and nevirapine resistance. However, both of these inhibitors are currently infrequently used in developed countries, and the impact of N348I on newer reverse transcriptase inhibitors, such as tenofovir and etravirine, is unknown. In this study, we demonstrate that N348I alone confers no resistance to tenofov...

polymethyl methacrylate (pmma), widely used as a prosthodontic base, has many disadvantages, including a high thermal expansion coefficient and low thermal conductivity, a low elasticity coefficient, low impact strength and low resistance to fatigue. this study aimed to make an in vitro comparison of the thermal conductivity, compressive strength, and tensile strength of the acrylic base of com...

Biological materials immersed in vegetable and mineral oil, such as rattan armor and wooden sleepers, have been extensively used since ancient times because of their excellent mechanical properties. This study quantitatively investigated the viscoelasticity and tribological performance of lignum vitae immersed in poly-alpha-olefin (PAO) and tung oils (Aleuritesfordii Hemsl.) to reveal the mecha...

the effect of impact modifier on creep behavior of wood flour- recycled polypropylene composites has been evaluated in this work. for this purpose, impact modifier (ethylene vinyl acetate) and recycled polypropylene were mixed with wood flour (50/50% w/w) as well as the impact modifier (0, 3%, 6% and 9%) by a counter-rotating twin-screw extruder to manufacture the wood flour- recycled polypropy...

Practically, all chemotherapeutic agents lead to drug resistance. Clinically, it is a challenge to determine whether resistance arises prior to, or as a result of, cancer therapy. Further, a number of different intracellular and microenvironmental factors have been correlated with the emergence of drug resistance. With the goal of better understanding drug resistance and its connection with the...

This paper addresses the static properties and impact resistance of a ‘‘green’’ Ultra-High Performance Hybrid Fibre Reinforced Concrete (UHPHFRC). The design of concrete mixtures aims to achieve a densely compacted cementitious matrix, employing the modified Andreasen & Andersen particle packing model. The flowability, static mechanical properties and impact resistance capacity of UHPHFRC are m...

Abstract: Ball mills are used in the last stage of ore processing for grinding raw materials. Forged 70Cr2 alloy steel and Austempered Ductile Iron (ADI) balls are materials from which grinding balls are made for Sarcheshmeh Copper Plant (SCP) ball mills. In the present study wear and impact properties of these two kinds of balls have been investigated. Some balls randomly were selected as ...

Nylon 6, 6 is regarded as tough and ductile materials since it exhibit high tensile elongation to break and high drop weight impact strengths. However, under conditions of stress concentration such as in the presence of sharp notches or cracks, polyamides exhibit brittle failure. This property, evaluated as notched Izod or Charpy impact tests, indicates that unmodified polyamides exhibit relati...