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Cold atmospheric plasma (CAP) has shown its promising application in cancer treatment both in vitro and in vivo. However, the anti-cancer mechanism is still largely unknown. CAP may kill cancer cells via triggering the rise of intracellular ROS, DNA damage, mitochondrial damage, or cellular membrane damage. While, the specific vulnerability of cancer cells to CAP has been observed, the underlying mechanism of such cell-based specific vulnerability to CAP is completely unknown. Here, through the comparison of CAP treatment and H2O2 treatment on 10 different cancer cell lines in vitro, we observed that the H2O2 consumption speed by cancer cells was strongly correlated to the cytotoxicity of CAP treatment on cancer cells. Cancer cells that clear extracellular H2O2 more quickly are more resistant to the cytotoxicity of CAP treatment. This finding strongly indicates that the anti-oxidant system in cancer cells play a key role in the specific vulnerability of cancer cells to CAP treatment in vitro.

An effect of membrane surface charge on mechanical properties of the phospholipid bilayer membrane and pores formation is considered. It is shown that the outer and inner surfaces of the phospholipid membrane is always subject to tension, regardless of magnitude and sign of the charges on its surface. This is due to the fact that the Debye length of the extracellular and intracellular electrolyte is always much smaller than the thickness of the membrane, and accordingly the electric field on the outer surface of the membrane is always much larger than the field inside the membrane. This result contradicts the generally accepted notion that a charged phospholipid membrane is similar to a charged capacitor in a dielectric medium and it is always subject to compression. Phospholipid bilayer membrane will be subject to compression only in a very weak electrolyte (~1mM/L), when Debye length is larger than the membrane thickness. It is also shown that the membrane surface charges lead to pore compression when the pore radius is larger than the Debye radius and to the stretching in the opposite case. Difference in the coefficients of surface and edge tension of phospholipid cell membranes can be explained by taking into account the cell membrane surface charge. Simple experiments are proposed to test the influence of the cell membrane surface charge on its mechanical properties.

Similarity search is the task of retrieving data items that are similar to a given query. In this paper, we introduce the time-sensitive notion of similarity search over endless data-streams (SSDS), which takes into account data quality and temporal characteristics in addition to similarity. SSDS is challenging as it needs to process unbounded data, while computation resources are bounded. We propose Stream-LSH, a randomized SSDS algorithm that bounds the index size by retaining items according to their freshness, quality, and dynamic popularity attributes. We analytically show that Stream-LSH increases the probability to find similar items compared to alternative approaches using the same space capacity. We further conduct an empirical study using real world stream datasets, which confirms our theoretical results.

Today's search engines process billions of online user queries a day over huge collections of data. In order to scale, they distribute query processing among many nodes, where each node holds and searches over a subset of the index called shard. Responses from some nodes occasionally fail to arrive within a reasonable time-interval due to various reasons, such as high server load and network congestion. Search engines typically need to respond in a timely manner, and therefore skip such tail latency responses, which causes degradation in search quality. In this paper, we tackle response misses due to high tail latencies with the goal of maximizing search quality. Search providers today use redundancy in the form of Replication for mitigating response misses, by constructing multiple copies of each shard and searching all replicas. This approach is not ideal, as it wastes resources on searching duplicate data. We propose two strategies to reduce this waste. First, we propose rSmartRed, an optimal shard selection scheme for replicated indexes. Second, when feasible, we propose to replace Replication with Repartition, which constructs independent index instances instead of exact copies. We analytically prove that rSmartRed's selection is optimal for Replication, and that Repartition achieves better search quality compared to Replication. We confirm our results with an empirical study using two real-world datasets, showing that rSmartRed improves recall compared to currently used approaches. We additionally show that Repartition improves over Replication in typical scenarios.

Hydrogen peroxide (H2O2) is an important signaling molecule in cancer cells. However, the significant secretion of H2O2 by cancer cells have been rarely observed. Cold atmospheric plasma (CAP) is a near room temperature ionized gas composed of neutral particles, charged particles, reactive species, and electrons. Here, we first demonstrated that breast cancer cells and pancreatic adenocarcinoma cells generated micromolar level H2O2 during just 1 min of direct CAP treatment on these cells. The cell-based H2O2 generation is affected by the medium volume, the cell confluence, as well as the discharge voltage. The application of cold atmospheric plasma (CAP) in the cancer treatment has been intensively investigated over the past decade. Several cellular responses to the CAP treatment have been observed including the consumption of the CAP-originated reactive species, the rise of intracellular reactive oxygen species, the damage on DNA and mitochondria, as well as the activation of apoptotic events. This is a new previously unknown cellular response to CAP, which provides a new prospective to understand the interaction between CAP and cells.

Contrary to common belief, a recent work by Ellen, Gelashvili, Shavit, and Zhu has shown that computability does not require multicore architectures to support "strong" synchronization instructions like compare-and-swap, as opposed to combinations of "weaker" instructions like decrement and multiply. However, this is the status quo, and in turn, most efficient concurrent data-structures heavily rely on compare-and-swap (e.g. for swinging pointers and in general, conflict resolution). We show that this need not be the case, by designing and implementing a concurrent linearizable Log data-structure (also known as a History object), supporting two operations: append(item), which appends the item to the log, and get-log(), which returns the appended items so far, in order. Readers are wait-free and writers are lock-free, and this data-structure can be used in a lock-free universal construction to implement any concurrent object with a given sequential specification. Our implementation uses atomic read, xor, decrement, and fetch-and-increment instructions supported on X86 architectures, and provides similar performance to a compare-and-swap-based solution on today's hardware. This raises a fundamental question about minimal set of synchronization instructions that the architectures have to support.

Experiments have revealed a nontrivial cancer-inhibiting capability of liquid media treated by the plasma jet capable of forming thinly stratified self-organized patterns at a plasma-liquid interface. A pronounced cancer depressing activity towards at least two kinds of human cancer cells, namely breast cancer MDA-MB-231 and human glioblastoma U87 cancer lines, was demonstrated. After a short treatment at the thinly stratified self-organized plasma-liquid interface pattern, the cancer inhibiting media demonstrate well pronounced depression and apoptosis activities towards tumor cells, not achievable without interfacial stratification of plasma jet to thin (of several um) current filaments, which therefore play a pivotal (yet still not completely clear) role in building up the cancer inhibition properties. Moreover, thinly stratified, self-organized interfacial discharge is capable to efficiently control the ROS and RNS concentrations in the cancer-inhibiting media, and in particular, abnormal ROS/RNS ratios not achievable in discharges which do not form stratified thin-filament patterns could be obtained. These results were explained in terms of interaction of thin plasma filaments of the self-organized pattern with gas and liquid, where the unusual interaction conditions (i.e., high surface-to-volume ratios etc.) cause accumulation of ROS, RNS and other species in unusual ratios and concentrations, thus forming potentially efficient anti-cancer cocktail. Our funding could be extremely important for handling the cancer proliferation problem, and hence, it should be brought to light to attract due attention of the researchers and explore the possible potential of this approach in tackling the challenging problem of high cancer-induced mortality and rising morbidity trends.

The propulsion type plasma in oblique external magnetic field is studied in 2D3V PIC MCC simulations. A periodical structure with maxima of electron and ion densities appears with an increase of an obliqueness of magnetic field. These ridges of electron and ion densities are aligned with the magnetic field vector and shifted relative each other. As a result the two-dimensional double-layers structure forms in cylindrical plasma chamber. The ion and electron currents on the side wall are essential modulated by the oblique magnetic field., Comment: 6 pages, 8 figures

Cold atmospheric plasma (CAP) was shown to affect cells not only directly, but also indirectly by means of plasma pre-treated solution. This study investigated a new application of CAP generated in deionized (DI) water for the cancer therapy. In our experiments, the CAP solution was generated in DI water using helium as carrier gas. We report on the effects of this plasma solution in breast (MDA-MD-231) and gastric (NCI-N87) cancer cells. The results revealed that apoptosis efficiency was dependent on the plasma exposure time and on the levels of reactive oxygen and nitrogen species (ROS and RNS). The plasma solution that resulted from 30-minute treatment of DI water had the most significant effect in the rate of apoptosis., Comment: arXiv admin note: text overlap with arXiv:1605.05345

Non-thermal atmospheric plasma (NTAP) can be applied to living tissues and cells as a novel technology for cancer therapy. Even though studies report on the successful use of NTAP to directly irradiate cancer cells, this technology can cause cell death only in the upper 3-5 cell layers. We report on a NTAP argon solution generated in DI water for treating human gastric cancer cells (NCl-N87). Our findings showed that the plasma generated in DI water during a 30-minute treatment had the strongest affect in inducing apoptosis in cultured human gastric cancer cells. This result can be attributed to presence of reactive oxygen species (ROS) and reactive nitrogen species (RNS) produced in water during treatment. Furthermore, the data showed that elevated levels of RNS may play an even more significant role than ROS in the rate of apoptosis in gastric cancer cells., Comment: arXiv admin note: text overlap with arXiv:1607.06775

Cold atmospheric plasma (CAP) has been emerged as a novel technology for cancer treatment. CAP can directly treat cells and tissue but such direct application is limited to skin or can be invoked as a supplement during open surgery. In this study we report indirect plasma treatment using CAP discharged in DI water using three gases as carriers (argon, helium and nitrogen). Plasma stimulated water was applied to human breast cancer cell line (MDA-MB-231). MTT assay tests showed that using argon plasma had the strongest effect on inducing apoptosis in cultured human breast cancer cells. This result is attributed to the elevated production of the reactive oxygen species and reactive nitrogen species in water in the case of argon plasma., Comment: arXiv admin note: text overlap with arXiv:1607.06775

We present NearBucket-LSH, an effective algorithm for similarity search in large-scale distributed online social networks organized as peer-to-peer overlays. As communication is a dominant consideration in distributed systems, we focus on minimizing the network cost while guaranteeing good search quality. Our algorithm is based on Locality Sensitive Hashing (LSH), which limits the search to collections of objects, called buckets, that have a high probability to be similar to the query. More specifically, NearBucket-LSH employs an LSH extension that searches in near buckets, and improves search quality but also significantly increases the network cost. We decrease the network cost by considering the internals of both LSH and the P2P overlay, and harnessing their properties to our needs. We show that our NearBucket-LSH increases search quality for a given network cost compared to previous art. In many cases, the search quality increases by more than 50%.

Dynamic distributed storage algorithms such as DynaStore, Reconfigurable Paxos, RAMBO, and RDS, do not ensure liveness (wait-freedom) in asynchronous runs with infinitely many reconfigurations. We prove that this is inherent for asynchronous dynamic storage algorithms, including ones that use $\Omega$ or $\diamond S$ oracles. Our result holds even if only one process may fail, provided that machines that were successfully removed from the system's configuration may be switched off by an administrator. Intuitively, the impossibility relies on the fact that a correct process can be suspected to have failed at any time, i.e., its failure is indistinguishable to other processes from slow delivery of its messages, and so the system should be able to reconfigure without waiting for this process to complete its pending operations. To circumvent this result, we define a dynamic eventually perfect failure detector, and present an algorithm that uses it to emulate wait-free dynamic atomic storage (with no restrictions on reconfiguration rate). Together, our results thus draw a sharp line between oracles like $\Omega$ and $\diamond S$, which allow some correct process to continue to be suspected forever, and a dynamic eventually perfect one, which does not.