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In the modern era of multi-core systems, the main aim is to utilize the cores properly.This utilization can be done by concurrent programming. But developing a flawless and well-organized concurrent program is difficult. Software Transactional Memory Systems (STMs) are a convenient programming interface which assist the programmer to access the shared memory concurrently without worrying about consistency issues such as priority-inversion, deadlock, livelock, etc. Another important feature that STMs facilitate is compositionality of concurrent programs with great ease. It composes different concurrent operations in a single atomic unit by encapsulating them in a transaction.Many STMs available in the literature execute read/write primitive operations on memory buffers. We represent them as Read-Write STMs or RWSTMs. Whereas, there exist some STMs (transactional boosting and its variants) which work on higher level operations such as insert, delete, lookup, etc. on a hash-table. We refer these STMs as Object Based STMs or OSTMs. The literature of databases and RWSTMs say that maintaining multiple versions 1 A preliminary version of this paper appeared in 20th International Symposium on Stabilization, Safety, and Security of Distributed Systems (SSS 2018) and awarded with the Best Student Paper Award. A poster version of this work received Best Poster Award in NETYS 2018. 2 Author sequence follows the lexical order of last names. All the authors can be contacted at the addresses given above. Archit Somani's phone number: +91 -7095044601. ensures greater concurrency. This motivates us to maintain multiple version at higher level with object semantics and achieves greater concurrency. So, this paper proposes the notion of Optimized Multi-version Object Based STMs or OPT-MVOSTMs which encapsulates the idea of multiple versions in OSTMs to harness the greater concurrency efficiently. For efficient memory utilization, we develop two variations of OPT-MVOSTMs. First, OPT-MVOSTM with garbage collection (or OPT-MVOSTM-GC) which uses unbounded versions but performs garbage collection scheme to delete the unwanted versions. Second, finite version OPT-MVOSTM (or OPT-KOSTM) which maintains at most K versions by replacing the oldest version when (K + 1) th version is created by the current transaction. We propose the OPT-MVOSTMs for hash-table and list objects as OPT-HT-MVOSTM and OPT-list-MVOSTM respectively. For memory utilization, we propose two variants of both the algorithms as OPT-HT-MVOSTM-GC, OPT-HT-KOSTM and OPT-list-MVOSTM-GC, OPT-list-KOSTM respectively. OPT-HT-KOSTM performs best among its variants and outperforms state-of-the-art hash-table based STMs (HT-OSTM, ESTM, RWSTM, HT-MVTO, HT-KSTM) by a factor of 3.62, 3.95, 3.44, 2.75, 1.85 for workload W1 (90% lookup, 8% insert and 2% delete), 1. 44, 2.36, 4.45, 9.84, 7.42 for workload W2 (50% lookup, 25% insert and 25% delete), and 2. 11, 4.05, 7.84, 12.94, 10.70 for workload W3 (10% lookup, 45% insert and 45% delete) respectively. Similarly, OPT-list-KOSTM performs ...

Nitric oxide is a small messenger molecule utilized by nature in cell signalling and the non-specific immune response. At present, nitric oxide releasing prodrugs cannot be efficiently targeted towards a specific body compartment, which restricts their therapeutic applications. To address this limitation, we have designed two photolabile nitric oxide releasing prodrugs, tert-butyl S-nitrosothiol and tert-dodecane S-nitrosothiol, which are based on the S-nitrosothiol functionality. By modulating the prodrugs' hydrophobicity, we postulated that we could increase their stability within the cell by preventing their interaction with hydrophilic thiols and metal ions; processes that are known to inactivate this prodrug class. Our data demonstrate that these prodrugs have improved nitric oxide release kinetics compared to currently available S-nitrosothiols, as they are highly stable in vitro in the absence of irradiation (t 1 ⁄ 2 > 3 h), while their rate of decomposition can be regulated by controlling the intensity or duration of the photostimulus. Nitric oxide release can readily be achieved using non-laser based light sources, which enabled us to characterize photoactivation as a trigger mechanism for nitric oxide release in A549 lung carcinoma cells. Here we confirmed that irradiation induced highly significant increases in cytotoxicity within a therapeutic drug range (1-100 lM), and the utility of this photoactivation switch opens up avenues for exploring the applications of these prodrugs for chemical biology studies and chemotherapy.Key words: chemical biology, drug design, molecular modeling, nitric oxide, S-nitrosothiol Abbreviations: DTPA, diethylenetriaminepentaacetic acid; MbO 2 , oxy-myoglobin; met-Mb, met-myoglobin; MTT, 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide; NO, nitric oxide (nitrogen monoxide); PDT, photodynamic therapy; PI, propidium iodide; SNT, Snitrosothiol; tBuSNO, tert-butyl S-nitrosothiol; tDodSNO, tert-dodecane S-nitrosothiol. Nitric oxide (NO) is a signalling molecule that regulates multiple physiological and pathological processes. NO and downstream nitrogen oxides, collectively termed Reactive Nitrogen Species (RNS), display limited molecular recognition and engage in reactions with many different cellular components (1,2). Due to this lack of specificity, the cellular effects of RNS are determined by the concentration and duration of the NO signal. At low concentrations, NO signals through activation of guanylate cyclase, while at higher levels RNS can act as cellular toxins through nitrosation and nitration reactions, which cause damage to cell membranes and DNA (3). Additionally NO binding can directly alter the function of metalloproteins (4) and sequester iron from iron-sulphur proteins (5).The main drawback to the in vivo use of NO donor drugs is that they do not display organ or tissue specificity. Therefore it is exceedingly challenging to selectively deliver NO to a target compartment, with non-specific NO release causing changes to vascular dynamics that ...

Enhanced bifunctional catalytic activities are shown by monobasic tridentate Cu(ii) Schiff-base complexes.

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Software Transactional Memory systems (STMs) have garnered significant interest as an elegant alternative for addressing synchronization and concurrency issues with multi-threaded programming in multi-core systems. For STMs to be efficient, they must guarantee some progress properties. This work explores the notion of one of the progress property, i.e., starvation-freedom, in STMs. An STM system is said to be starvation-free if every thread invoking a transaction gets the opportunity to take a step (due to the presence of a fair scheduler) such that the transaction eventually commits.A few starvation-free algorithms have been proposed in the literature in context of single-version STMs. These algorithms are priority based i.e. if two transactions are in conflict, then the transaction with lower priority will abort. A transaction running for a long time will eventually have the highest priority and hence commit. But the drawback with this approach is that if a set of high-priority transactions become slow, then they can cause several other transactions to abort. So, we propose multi-version starvation-free STM system which addresses this issue.Multi-version STMs maintain multiple-versions for each transactional object. By storing multiple versions, these systems can achieve greater concurrency. In this paper, we propose multi-version starvation-free STM, KSFTM, which as the name suggests achieves starvation-freedom while storing K-versions of each t-object. Here K is an input parameter fixed by the application programmer depending on the requirement. Our algorithm is dynamic which can support different values of K ranging from one to infinity. If K is infinite, then there is no limit on the number of versions. But a separate garbage-collection mechanism is required to collect unwanted versions. On the other hand, when K is one, it becomes the same as a single-version starvation-free STM system. We prove the correctness and starvation-freedom property of the KSFTM algorithm.To the best of our knowledge, this is the first multi-version STM system that satisfies starvation-freedom. We implement KSFTM and compare its performance with single-version starvation-free STM system (SV-SFTM) which works on the priority principle. Our experiments show that KSFTM gives an average speedup on the worst-case time to commit of a transaction by a factor of 1.22, 1.89, 23.26 and 13.12 times over PKTO, SV-SFTM, NOrec STM and ESTM respectively for counter application. KSFTM performs 1.5 and 1.44 times better than PKTO and SV-SFTM but 1.09 times worse than NOrec for low contention KMEANS application of STAMP benchmark whereas KSFTM performs 1.14, 1.4 and 2.63 times better than PKTO, SV-SFTM and NOrec for LABYRINTH application of STAMP benchmark which has high contention with long-running transactions. * A preliminary version of this work was accepted in AADDA 2017 as work in progress. † A part of this work was submitted towards the fulfillment of M.Tech thesis requirement by the author. ‡ Author sequence follows a lexical order of last...

Green synthesis has made us an exciting approach in the field of nanotechnology. Biogenic zinc oxide nanoparticles (ZnONPs) were synthesized using leaf extracts of Calotropis gigantea (L.) Dryand. in the presence of zinc nitrate hexahydrate as a precursor molecule. ZnONPs were characterized using scanning electron microscope (SEM), X-ray diffraction (XRD) patterns, and Fourier transform infrared spectroscopy (FT-IR) analysis and further in understanding the biomedical applications of antimicrobial (minimum inhibitory concentration method) and anticancer (apoptosis assay) activities, cytology (flow cytometry) and cytotoxicity (% cell viability), deoxyribonucleic acid (DNA) fragmentation (reverse transcriptase polymerase chain reaction (RT-PCR)), and caspase assay (polymerase chain reactions (PCR)) studies. The morphology of nanoparticles was determined by SEM analysis. XRD pattern showed the value of highest peak of 36.15°with 101 plane region among the ten recorded peaks. FTIR spectrum indicated stretching vibration of O-H at 3441.77 cm −1 . The antibacterial activity of biogenic ZnO nanoparticles was studied against human pathogenic bacteria-Campylobacter jejuni ATCC 29428 and Neisseria gonorrhoeae ATCC 49226-and showed 50% zone of inhibition. A cytotoxic study against the breast cancer cell lines of MDAMB-231 revealed that the ZnONPs as a good anticancer agent could be sliced by all existing and metabolically active cells. Biosynthesized ZnONPs potentially alter the apoptotic protein expression and trigger apoptosis in the MDAMB-231 cells. Therefore, the biogenic ZnO nanoparticles would be useful and have the great potential in the field of biomedical applications.

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