Luminescence quenching studies of [Ru(dMeObpy)3]2+ complex using the quinone derivative-effect of micelles

Quinones are considered a class of organic compounds having a quinonoid group and are the ultimate electron acceptors. Due to this property, they have favourable redox potential and the ability to form stable hydrogen bonds. Luminescence quenching is one of the most important techniques used to get information regarding the structure and dynamics of a luminophore. A variety of transition metal complexes have been synthesized and studied to comprehend the quinones' electron-accepting characteristics. Among these, Ru(II) polypyridyl complexes have widespread applications in electron transfer reactions due to their well-defined photophysical and photochemical stability. The reaction of excited state Tris(4,4'-dimethoxy-2,2'-bipyridine)ruthenium(II)tetrafluoroborate [Ru(dMeObpy)3](BF4)2 complex with quinones was investigated through photoinduced electron transfer reaction in homogeneous and microheterogenous medium. The luminescence quenching technique has been used to study this reaction. The complex has an absorbance maximum of 448 nm in aqueous medium. The quenching rate constants were deduced using the Stern-Volmer equation. The interaction between the complex and the quinones in a cationic micellar medium, cetyltrimethylammonium bromide (CTAB), was analyzed based on electrostatic interaction and hydrophobicity. The plot between RTlnkq vs. reduction potential of the quinones, as well as the transient absorption spectra, confirmed the oxidative nature of quenching of the ruthenium complex in the presence of quinones. The quenching constant values are influenced by many factors, such as the nature of the ligand, medium, size, and structure of quenchers, and electron transfer distance between the donor and the acceptor. The formation of Ru3+ species is confirmed by its characteristic absorption at 600 nm

Embedding Security into Ferroelectric FET Array via In-Situ Memory Operation

Non-volatile memories (NVMs) have the potential to reshape next-generation memory systems because of their promising properties of near-zero leakage power consumption, high density and non-volatility. However, NVMs also face critical security threats that exploit the non-volatile property. Compared to volatile memory, the capability of retaining data even after power down makes NVM more vulnerable. Existing solutions to address the security issues of NVMs are mainly based on Advanced Encryption Standard (AES), which incurs significant performance and power overhead. In this paper, we propose a lightweight memory encryption/decryption scheme by exploiting in-situ memory operations with negligible overhead. To validate the feasibility of the encryption/decryption scheme, device-level and array-level experiments are performed using ferroelectric field effect transistor (FeFET) as an example NVM without loss of generality. Besides, a comprehensive evaluation is performed on a 128x128 FeFET AND-type memory array in terms of area, latency, power and throughput. Compared with the AES-based scheme, our scheme shows around 22.6x/14.1x increase in encryption/decryption throughput with negligible power penalty. Furthermore, we evaluate the performance of our scheme over the AES-based scheme when deploying different neural network workloads. Our scheme yields significant latency reduction by 90% on average for encryption and decryption processes

FAST: A Fully-Concurrent Access Technique to All SRAM Rows for Enhanced Speed and Energy Efficiency in Data-Intensive Applications

Compute-in-memory (CiM) is a promising approach to improving the computing speed and energy efficiency in dataintensive applications. Beyond existing CiM techniques of bitwise logic-in-memory operations and dot product operations, this paper extends the CiM paradigm with FAST, a new shift-based inmemory computation technique to handle high-concurrency operations on multiple rows in an SRAM. Such high-concurrency operations are widely seen in both conventional applications (e.g. the table update in a database), and emerging applications (e.g. the parallel weight update in neural network accelerators), in which low latency and low energy consumption are critical. The proposed shift-based CiM architecture is enabled by integrating the shifter function into each SRAM cell, and by creating a datapath that exploits the high-parallelism of shifting operations in multiple rows in the array. A 128-row 16-column shiftable SRAM in 65nm CMOS is designed to evaluate the proposed architecture. Postlayout SPICE simulations show average improvements of 4.4x energy efficiency and 96.0x speed over a conventional fully-digital memory-computing-separated scheme, when performing the 8-bit weight update task in a VGG-7 framework.Comment: 5 page

Generation of an induced pluripotent stem cell line that mimics the disease phenotypes from a patient with Fanconi anemia by conditional complementation

Generation of Fanconi anemia (FA) patient-specific induced pluripotent stem cells (iPSCs) has been reported to be technically challenging due to the defects in the FA-pathway in the patients' somatic cells. By inducible complementation of FA-pathway, we successfully reprogrammed the fibroblasts of an FA patient to iPSCs. CSCR19i-indCFANCA, one of the iPSC lines generated by the inducible complementation of FA-pathway, was extensively characterized for its pluripotency and karyotype. In the absence of doxycycline (DOX) and FANCA expression, this line showed the cellular phenotypes of FA, suggesting it is an excellent tool for FA disease modeling and drug screening

Molecular basis of Bernard-Soulier syndrome in 27 patients from India

Background: Bernard–Soulier syndrome (BSS) is an extremely rare (1:1 million) bleeding disorder of platelet adhesion, caused by defects in the glycoprotein (GP)Ib/IX/V complex. Patients and methods:  The diagnosis in 27 patients was based on low platelet count, presence of giant platelets and aggregometry studies. Flow cytometry to assess the surface GPIb/IX/V complex showed reduced (7.7–57%) expression. gDNA was screened for mutations in the GPIBA, GPIBB, GP9 genes using PCR‐conformation sensitive gel electrophoresis (CSGE). Results:  Thirteen different disease‐causing mutations, including missense (54%), frameshifts (38%) and nonsense (8%) mutations, were identified in 27 patients. Eleven of them were novel including five novel frameshifts (GPIbα: p.Gln97_98fsX113, p.Pro402_403fsX52; GPIbβ: p.Arg17fsX14; GPIX: p.Gly24fsX43, p. Pro130fs, a nonsense mutation (GPIX, p.94, Gln>X) and five novel missense mutations (GPIbα: p.492, Tyr>His; GPIbβ: p.65, Pro>Arg, p.129, Gln>His, p.132, Leu>Pro; GPIX: p.55, Phe>Cys). Interestingly, four common mutations, Cys8Arg (n = 6) and Phe55Ser (n = 2), Phe55Cys (n = 2) in GPIX and a novel 22‐bp deletion in the GPIBB gene predicting p.Arg17fsX 14 (n = 10) were seen in 20 patients. Conclusion:  The molecular data presented here is the largest series of BSS patients to be reported so far, adding significantly to the mutation database of this condition and also useful for its genetic diagnosis in India