Asynchronous nanowire crossbar architecture for manufacturability, modularity and robustness

This thesis spotlights the dawn of a promising new nanowire crossbar architecture, the Asynchronous crossbar architecture, in the form of three different articles. It combines the reduced size of the nanowire crossbar architecture with the clock-free nature of Null Conventional Logic, which are the primary advantages. The first paper explains the proposed architecture with illustrations, including the design of an optimized full adder. This architecture has an elementary structure termed as a Programmable Gate Macro Block (PGMB) which is analogous to a threshold gate in NCL. The other two papers concentrate on mapping and placement techniques which are important due to defects involved in crossbars. These defects have to be tolerated and logic has to be routed appropriately for successful functioning of the circuit --Introduction, page 1

Evaluating Performance Tradeoff in Defect-Tolerant Gate Programming Techniques for the Clock-Free Nanowire Crossbar Architecture

A novel asynchronous nanowire crossbar architecture has been recently proposed by authors\u27 research group. The proposed clock-free architecture provides numerous significant benefits over its clocked counterparts which include better manufacturability, scalability, modularity and robustness. We also proposed various gate mapping and reconfiguration algorithms for defect-tolerant programming of PGMB (programmable gate macro blocks) - which is the primary building block of the proposed architecture. These algorithms were tested by simulations and a variety of parameter values were applied to show their performance characteristics. The most important performance metric of the proposed techniques is the programmability (i.e., the ratio of successfully programmed gates to the total number of gates). However, algorithms with higher programmability should come with higher time/space requirements. In this work, we will evaluate the tradeoff between programmability and time/space requirements and suggest a way to find the most suitable algorithm with acceptable combination of programmability and time/space requirements

Redundancy Optimization for Clock-Free Nanowire Crossbar Architecture

In this paper a method is being proposed to find the optimal dimension of Programmable Gate Macro Block (PGMB) in clock-free nanowire crossbar architecture. A PGMB is a nanowire crossbar matrix with discrete number of rows and columns on which the NCL (Null Convention Logic) gates can be programmed. This method uses inherent redundancy to route through defective crosspoints. A 6 X 10 defect-free crossbar can be used to program any of the 27 threshold gates. Due to imperfections and variations in nanoscale manufacturing process, high defect densities are anticipated. Thus, such defects should be located when tested and the logic has to be rerouted around them to maintain proper functionality. This paper discusses this problem and tried to find an optimal solution through simulations. In the final submission, more effective logic mapping techniques will be proposed and validated

Chronological Notes on Byzantine Documents II

Recently, we proposed a new clock-free nanowire crossbar architecture based on a delayinsensitive paradigm called Null Convention Logic (NCL). The proposed architecture has simple periodic structure that is suitable for non-deterministic nanoscale assembly and does not require a clock distribution network - so it is intrinsically free from timing-related failure modes. Even though the proposed architecture offers improved manufacturability, it is still not free from defects. This paper elaborates on the different programming techniques to map a given threshold gate macro on a random PGMB (Programmable Gate Macro Block) with predefined dimension. Defect-Aware and Defect Unaware approaches have been considered to map a given threshold gate onto a PGMB without affecting its functionality. Defect aware approach uses a defect map, gate table which help in efficient programming and also conservative use of resources. Defect unaware approach on the other hand is faster than defect aware approach, does not use defect maps and is not as efficient as defect aware approach. Parametric simulation results using MATLAB are used to show the programmability of these approaches under various circumstances

Implementation of Static and Semi-Static Versions of a Bit-wise Pipelined Dual-rail NCL 2S Complement Multiplier

This paper focuses on implementing a 2s complement 8x8 dual-rail bit-wise pipelined multiplier using the asynchronous NULL Convention Logic (NCL) paradigm. The design utilizes a Wallace tree for partial product summation, and is implemented and simulated in VHDL, the transistor level, and the physical level, using a 1.8V 0.18,um TSMC CMOS process.The multiplier is realized using both static and semi-static Dualversions of the NCL gates; and these two implementations are compared in terms of area, power, and speed

Implementation of Static and Semi-Static Versions of a 24+8x8 Quad-rail NULL Convention Multiply and Accumulate Unit

This paper focuses on implementing a 2s complement 8x8 dual-rail bit-wise pipelined multiplier using the asynchronous null convention logic (NCL) paradigm. The design utilizes a Wallace tree for partial product summation, and is implemented and simulated in VHDL, the transistor level, and the physical level, using a 1.8V 0.18mum TSMC CMOS process. The multiplier is realized using both static and semi-static versions of the NCL gates; and these two implementations are compared in terms of area, power, and speed

Clock-Free Nanowire Crossbar Architecture Based on Null Convention Logic (NCL)

There have been numerous nanowire crossbar architectures proposed till date, although all of them are envisioned to be synchronous (i.e., clocked). The clock is an important part in a circuit and it needs to be connected to all the components to synchronize their operation. Considering non-deterministic nature of nanoscale integration, realizing them on a nano wire crossbar system would be quite cumbersome. Unlike the conventional clocked counterparts, a new clock-free crossbar architecture is proposed to resolve the issues with clocked counterparts in this paper, where the use of clock is eliminated from the architecture. This has been done by implementing delay-insensitive logic encoding technique called Null Convention Logic (NCL). A delay-insensitive full adder has been implemented on the proposed architecture to demonstrate the feasibility in this paper

Chemistry, Pharmacology and Therapeutic Potential of Swertiamarin – A Promising Natural Lead for New Drug Discovery and Development

Nur Sakinah Muhamad Fadzil,1 Mahendran Sekar,1 Siew Hua Gan,2 Srinivasa Reddy Bonam,3 Yuan Seng Wu,4 Jaishree Vaijanathappa,5 Subban Ravi,6 Pei Teng Lum,1 Shivsharan B Dhadde7 1Department of Pharmaceutical Chemistry, Faculty of Pharmacy and Health Sciences, Universiti Kuala Lumpur Royal College of Medicine Perak, Ipoh, Perak, Malaysia; 2School of Pharmacy, Monash University Malaysia, Bandar Sunway, Selangor, Malaysia; 3Institut National de la Santé et de la Recherche Médicale, Centre de Recherche des Cordeliers, Equipe-Immunopathologie et Immunointervention Thérapeutique, Sorbonne Université, Université de Paris, Paris, France; 4Department of Biochemistry, School of Medicine, Faculty of Medicine, Bioscience and Nursing, MAHSA University, Bandar Saujana Putra, Selangor, Malaysia; 5Department of Pharmaceutical Chemistry, JSS College of Pharmacy, Mysuru, Karnataka, India; 6Department of Chemistry, Karpagam Academy of Higher Education, Coimbatore, Tamil Nadu, India; 7D.S.T.S. Mandal’s College of Pharmacy, Solapur, Maharashtra, IndiaCorrespondence: Mahendran SekarDepartment of Pharmaceutical Chemistry, Faculty of Pharmacy and Health Sciences, Universiti Kuala Lumpur Royal College of Medicine Perak, No. 3 Jalan Greentown, Ipoh, 30450, Perak, MalaysiaTel +6016 – 3346653Fax +605 – 2536634Email [email protected]: Swertiamarin, a seco-iridoid glycoside, is mainly found in Enicostemma littorale Blume (E. littorale) and exhibits therapeutic activities for various diseases. The present study aimed to provide a review of swertiamarin in terms of its phytochemistry, physicochemical properties, biosynthesis, pharmacology and therapeutic potential. Relevant literature was collected from several scientific databases, including PubMed, ScienceDirect, Scopus and Google Scholar, between 1990 and the present. This review included the distribution of swertiamarin in medicinal plants and its isolation, characterization, physicochemical properties and possible biosynthetic pathways. A comprehensive summary of the pharmacological activities, therapeutic potential and metabolic pathways of swertiamarin was also included after careful screening and tabulation. Based on the reported evidence, swertiamarin meets all five of Lipinski’s rules for drug-like properties. Thereafter, the physicochemical properties of swertiamarin were detailed and analyzed. A simple and rapid method for isolating swertiamarin from E. littorale has been described. The present review proposed that swertiamarin may be biosynthesized by the mevalonate or nonmevalonate pathways, followed by the seco-iridoid pathway. It has also been found that swertiamarin is a potent compound with diverse pharmacological activities, including hepatoprotective, analgesic, anti-inflammatory, antiarthritis, antidiabetic, antioxidant, neuroprotective and gastroprotective activities. The anticancer activity of swertiamarin against different cancer cell lines has been recently reported. The underlying mechanisms of all these pharmacological effects are diverse and seem to involve the regulation of different molecular targets, including growth factors, inflammatory cytokines, protein kinases, apoptosis-related proteins, receptors and enzymes. Swertiamarin also modulates the activity of several transcription factors, and their signaling pathways in various pathological conditions are also discussed. Moreover, we have highlighted the toxicity profile, pharmacokinetics and possible structural modifications of swertiamarin. The pharmacological activities and therapeutic potential of swertiamarin have been extensively investigated. However, more advanced studies are required including clinical trials and studies on the bioavailability, permeability and administration of safe doses to offer swertiamarin as a novel candidate for future drug development.Keywords: swertiamarin, Enicostemma littorale, biosynthesis, metabolic pathway, molecular targets, inflammatory cytokine

Polyhydroxy-<i>N</i>-alkyl-2-pyrrolidinones as a new class of glycolipid analogues with immune modulation potential

<p></p> <p>A focused library of novel <i>N</i>-alkyl-2-pyrrolidinone derivatives <b>3a–e</b> was synthesized from d-galactose employing a multistep chiron approach. These novel glycolipid analogues exhibited lipopolysaccharide-mediated splenocyte proliferation with no apparent toxicity against murine splenocytes. Various immunological assays on dendritic cells, macrophages, and human peripheral blood mononuclear cells have ascertained the immunostimulatory activity of these new glycolipid analogues.</p

Chemistry, pharmacology and therapeutic potential of swertiamarin – a promising natural lead for new drug discovery and development

Swertiamarin, a seco-iridoid glycoside, is mainly found in Enicostemma littorale Blume (E. littorale) and exhibits therapeutic activities for various diseases. The present study aimed to provide a review of swertiamarin in terms of its phytochemistry, physicochemical properties, biosynthesis, pharmacology and therapeutic potential. Relevant literature was collected from several scientific databases, including PubMed, ScienceDirect, Scopus and Google Scholar, between 1990 and the present. This review included the distribution of swertiamarin in medicinal plants and its isolation, characterization, physicochemical properties and possible biosynthetic pathways. A comprehensive summary of the pharmacological activities, therapeutic potential and metabolic pathways of swertiamarin was also included after careful screening and tabulation. Based on the reported evidence, swertiamarin meets all five of Lipinski’s rules for drug-like properties. Thereafter, the physicochemical properties of swertiamarin were detailed and analyzed. A simple and rapid method for isolating swertiamarin from E. littorale has been described. The present review proposed that swertiamarin may be biosynthesized by the mevalonate or nonmevalonate pathways, followed by the seco-iridoid pathway. It has also been found that swertiamarin is a potent compound with diverse pharmacological activities, including hepatoprotective, analgesic, anti-inflammatory, antiarthritis, antidiabetic, antioxidant, neuroprotective and gastroprotective activities. The anticancer activity of swertiamarin against different cancer cell lines has been recently reported. The underlying mechanisms of all these pharmacological effects are diverse and seem to involve the regulation of different molecular targets, including growth factors, inflammatory cytokines, protein kinases, apoptosis-related proteins, receptors and enzymes. Swertiamarin also modulates the activity of several transcription factors, and their signaling pathways in various pathological conditions are also discussed. Moreover, we have highlighted the toxicity profile, pharmacokinetics and possible structural modifications of swertiamarin. The pharmacological activities and therapeutic potential of swertiamarin have been extensively investigated. However, more advanced studies are required including clinical trials and studies on the bioavailability, permeability and administration of safe doses to offer swertiamarin as a novel candidate for future drug development