No abstract

In this letter, we have studied the optical lateral shifts of transmitted and reflected lights in a defect structure doped by a single layer of graphene nanostructure. For adapting the optical features of the lateral shifts, we have first studied the refractive index properties of the defect layer. We have studied the conditions for achieving the negative and positive refractive index of the graphene monolayer system. After that, we have discussed the optical lateral shifts of the reflected and transmitted light beams when the refractive index of the graphene nanostructure become positive or negative, respectively. We have found that the enhanced lateral shifts for reflected and transmitted lights may be possible for a positive refractive index. For the negative refractive index, we have realized that simultaneous negative or positive lateral shifts are possible for the reflected and transmitted light beams. In our proposed scheme, the lateral shifts at the fixed incident angle are possible only by tuning the optical parameters without needing to change the cavity structure.

Regional anesthesia is an expanding subspecialty and is gaining increasing popularity due to its significant benefits over general anesthesia if appropriately accomplished, which includes superior intraoperative pain control, attenuation of the surgical stress response, minimal systemic impairment, lower incidence of postoperative nausea and vomiting, excellent localized postoperative analgesia, and decreased hospital cost and stay. Needle conduction guide toward the targets always has a great importance. The most commonly used local anesthetics include lidocaine, ropivacaine, bupivacaine, and mepivacaine. The type of local anesthetic, the concentration, the volume administered, and the location of the block will affect the onset, duration and depth /type of block. Due to ineffectivity of neuraxial block in upper limbs, upper extremity blocks may be considered as the sole substitute or supersede method of anesthesia for upper limb surgeries.