108 research outputs found
A Statistical Verification Method of Random Permutations for Hiding Countermeasure Against Side-Channel Attacks
As NIST is putting the final touches on the standardization of PQC (Post
Quantum Cryptography) public key algorithms, it is a racing certainty that
peskier cryptographic attacks undeterred by those new PQC algorithms will
surface. Such a trend in turn will prompt more follow-up studies of attacks and
countermeasures. As things stand, from the attackers' perspective, one viable
form of attack that can be implemented thereupon is the so-called "side-channel
attack". Two best-known countermeasures heralded to be durable against
side-channel attacks are: "masking" and "hiding". In that dichotomous picture,
of particular note are successful single-trace attacks on some of the NIST's
PQC then-candidates, which worked to the detriment of the former: "masking". In
this paper, we cast an eye over the latter: "hiding". Hiding proves to be
durable against both side-channel attacks and another equally robust type of
attacks called "fault injection attacks", and hence is deemed an auspicious
countermeasure to be implemented. Mathematically, the hiding method is
fundamentally based on random permutations. There has been a cornucopia of
studies on generating random permutations. However, those are not tied to
implementation of the hiding method. In this paper, we propose a reliable and
efficient verification of permutation implementation, through employing
Fisher-Yates' shuffling method. We introduce the concept of an n-th order
permutation and explain how it can be used to verify that our implementation is
more efficient than its previous-gen counterparts for hiding countermeasures.Comment: 29 pages, 6 figure
Preparation and Characterization of Self-Emulsified Docetaxel
The aim of this paper was to prepare a self-microemulsifying docetaxel (Dtx) using PLGA, Tetraglycol, Labrasol, and Cremophor ELP. The prepared Dtx-loaded self-microemulsifying system (SMES) showed the initial size of the range of 80–100 nm with narrow size distribution and the negative zeta-potential values. Its morphology was a spherical shape by atomic force microscopy. In experiment of stability, Dtx-loaded SMES prepared in DW and BSA condition showed good stability at 37∘C for 7 days. The viability of the B16F10 cells incubated with Dtx-loaded SMES, Dtx-solution, and Taxol were decreased as a function of incubation time. In conclusion, we confirmed that Dtx-loaded SMES showed an inhibitory effect for proliferation of B16F10 melanoma cells
A Statistical Verification Method of Random Permutations for Hiding Countermeasure Against Side-Channel Attacks
As NIST is putting the final touches on the standardization of PQC (Post Quantum Cryptography) public key algorithms, it is a racing certainty that peskier cryptographic attacks undeterred by those new PQC algorithms will surface. Such a trend in turn will prompt more follow-up studies of attacks and countermeasures. As things stand, from the attackers’ perspective, one viable form of attack that can be implemented thereupon is the so-called “side-channel attack”. Two best-known countermeasures heralded to be durable against side-channel attacks are: “masking” and “hiding”. In that dichotomous picture, of particular note are successful single-trace attacks on some of the NIST’s PQC then-candidates, which worked to the detriment of the former: “masking”. In this paper, we cast an eye over the latter: “hiding”. Hiding proves to be durable against both side-channel attacks and another equally robust type of attacks called “fault injection attacks”, and hence is deemed an auspicious countermeasure to be implemented. Mathematically, the hiding method is fundamentally based on random permutations. There has been a cornucopia of studies on generating random permutations. However, those are not tied to implementation of the hiding method. In this paper, we propose a reliable and efficient verification of permutation implementation, through employing Fisher–Yates’ shuffling method. We introduce the concept of an -th order permutation and explain how it can be used to verify that our implementation is more efficient than its previous-gen counterparts for hiding countermeasures
Synthesis and Control of the Shell Thickness of Polyaniline and Polypyrrole Half Hollow Spheres Using the Polystyrene Cores
Polyaniline (Pani) and polypyrrole (Ppy) half hollow spheres with different shell thicknesses were successfully synthesized by three steps process using polystyrene (PS) as the core. The PS core was synthesized by emulsion polymerization. Aniline and pyrrole monomers were polymerized on the surface of the PS core. The shells of Pani and Ppy were fabricated by adding different amounts of aniline and pyrrole monomers. PS cores were dissolved and removed from the core shell structure by solvent extraction. The thicknesses of the Pani and Ppy half hollow spheres were observed by FE-SEM and FE-TEM. The chemical structures of the Pani and Ppy half hollow spheres were characterized by FT-IR spectroscopy and UV-Vis spectroscopy. The shell thicknesses of the Pani half hollow spheres were 30.2, 38.0, 42.2, 48.2, and 52.4 nm, while the shell thicknesses of the Ppy half hollow spheres were 16.0, 22.0, 27.0, and 34.0 nm. The shell thicknesses of Pani and Ppy half hollow spheres linearly increased as the amount of the monomer increased. Therefore, the shell thickness of the Pani and Ppy half hollow spheres can be controlled in these ranges
Ambient Oxygen Promotes Tumorigenesis
Oxygen serves as an essential factor for oxidative stress, and it has been shown to be a mutagen in bacteria. While it is well established that ambient oxygen can also cause genomic instability in cultured mammalian cells, its effect on de novo tumorigenesis at the organismal level is unclear. Herein, by decreasing ambient oxygen exposure, we report a ∼50% increase in the median tumor-free survival time of p53−/− mice. In the thymus, reducing oxygen exposure decreased the levels of oxidative DNA damage and RAG recombinase, both of which are known to promote lymphomagenesis in p53−/− mice. Oxygen is further shown to be associated with genomic instability in two additional cancer models involving the APC tumor suppressor gene and chemical carcinogenesis. Together, these observations represent the first report directly testing the effect of ambient oxygen on de novo tumorigenesis and provide important physiologic evidence demonstrating its critical role in increasing genomic instability in vivo
Homeobox gene Dlx-2 is implicated in metabolic stress-induced necrosis
<p>Abstract</p> <p>Background</p> <p>In contrast to tumor-suppressive apoptosis and autophagic cell death, necrosis promotes tumor progression by releasing the pro-inflammatory and tumor-promoting cytokine high mobility group box 1 (HMGB1), and its presence in tumor patients is associated with poor prognosis. Thus, necrosis has important clinical implications in tumor development; however, its molecular mechanism remains poorly understood.</p> <p>Results</p> <p>In the present study, we show that Distal-less 2 (Dlx-2), a homeobox gene of the Dlx family that is involved in embryonic development, is induced in cancer cell lines dependently of reactive oxygen species (ROS) in response to glucose deprivation (GD), one of the metabolic stresses occurring in solid tumors. Increased Dlx-2 expression was also detected in the inner regions, which experience metabolic stress, of human tumors and of a multicellular tumor spheroid, an <it>in vitro </it>model of solid tumors. Dlx-2 short hairpin RNA (shRNA) inhibited metabolic stress-induced increase in propidium iodide-positive cell population and HMGB1 and lactate dehydrogenase (LDH) release, indicating the important role(s) of Dlx-2 in metabolic stress-induced necrosis. Dlx-2 shRNA appeared to exert its anti-necrotic effects by preventing metabolic stress-induced increases in mitochondrial ROS, which are responsible for triggering necrosis.</p> <p>Conclusions</p> <p>These results suggest that Dlx-2 may be involved in tumor progression via the regulation of metabolic stress-induced necrosis.</p
Successful Treatment of Syncope with Chemotherapy Irresponsive to Cardiac Pacemaker in Head and Neck Cancer
Recurrent syncope as a complication of recurrent neck malignancy is an uncommon but well documented association. The syncope is presumed to occur when a tumor mass invades the baroreceptor within the carotid sinus or when it disrupts the afferent nerve fibers of the glossopharyngeal nerve. A 59-year-old man presented with recurrent syncope and headache. He had a wide local excision including tonsillectomy and modified left radical neck dissection for tonsilar cancer 4 years ago. A computed tomography scan revealed ill-defined lesions in left parapharyngeal, carotid space and right upper jugular region. After clinical evaluation, cardiac pacemaker was placed, but he still suffered from the syncope. Then, he received the chemotherapy with docetaxel and cisplatin. The last hypotension event occurred on day 10 of the chemotherapy. Six months after 3 cycles of chemotherapy, he remained in complete remission and resolution of syncope. We report a case in which syncope was associated with a recurrence of tonsilar cancer and successfully treated with chemotherapy
Regulation of Tumor Progression by Programmed Necrosis
Rapidly growing malignant tumors frequently encounter hypoxia and nutrient (e.g., glucose) deprivation, which occurs because of insufficient blood supply. This results in necrotic cell death in the core region of solid tumors. Necrotic cells release their cellular cytoplasmic contents into the extracellular space, such as high mobility group box 1 (HMGB1), which is a nonhistone nuclear protein, but acts as a proinflammatory and tumor-promoting cytokine when released by necrotic cells. These released molecules recruit immune and inflammatory cells, which exert tumor-promoting activity by inducing angiogenesis, proliferation, and invasion. Development of a necrotic core in cancer patients is also associated with poor prognosis. Conventionally, necrosis has been thought of as an unregulated process, unlike programmed cell death processes like apoptosis and autophagy. Recently, necrosis has been recognized as a programmed cell death, encompassing processes such as oncosis, necroptosis, and others. Metabolic stress-induced necrosis and its regulatory mechanisms have been poorly investigated until recently. Snail and Dlx-2, EMT-inducing transcription factors, are responsible for metabolic stress-induced necrosis in tumors. Snail and Dlx-2 contribute to tumor progression by promoting necrosis and inducing EMT and oncogenic metabolism. Oncogenic metabolism has been shown to play a role(s) in initiating necrosis. Here, we discuss the molecular mechanisms underlying metabolic stress-induced programmed necrosis that promote tumor progression and aggressiveness
Biodegradable Metallic Glass for Stretchable Transient Electronics
Biodegradable electronics are disposable green devices whose constituents decompose into harmless byproducts, leaving no residual waste and minimally invasive medical implants requiring no removal surgery. Stretchable and flexible form factors are essential in biointegrated electronic applications for conformal integration with soft and expandable skins, tissues, and organs. Here a fully biodegradable MgZnCa metallic glass (MG) film is proposed for intrinsically stretchable electrodes with a high yield limit exploiting the advantages of amorphous phases with no crystalline defects. The irregular dissolution behavior of this amorphous alloy regarding electrical conductivity and morphology is investigated in aqueous solutions with different ion species. The MgZnCa MG nanofilm shows high elastic strain (approximate to 2.6% in the nano-tensile test) and offers enhanced stretchability (approximate to 115% when combined with serpentine geometry). The fatigue resistance in repeatable stretching also improves owing to the wide range of the elastic strain limit. Electronic components including the capacitor, inductor, diode, and transistor using the MgZnCa MG electrode support its integrability to transient electronic devices. The biodegradable triboelectric nanogenerator of MgZnCa MG operates stably over 50 000 cycles and its fatigue resistant applications in mechanical energy harvesting are verified. In vitro cell toxicity and in vivo inflammation tests demonstrate the biocompatibility in biointegrated use
Occurrence and characterization of oseltamivir-resistant influenza virus in children between 2007-2008 and 2008-2009 seasons
PurposeThere was a global increase in the prevalence of oseltamivir-resistant influenza viruses during the 2007-2008 influenza season. This study was conducted to investigate the occurrence and characteristics of oseltamivir-resistant influenza viruses during the 2007-2008 and 2008-2009 influenza seasons among patients who were treated with oseltamivir (group A) and those that did not receive oseltamivir (group B).MethodsA prospective study was conducted on 321 pediatric patients who were hospitalized because of influenza during the 2007-2008 and 2008-2009 influenza seasons. Drug resistance tests were conducted on influenza viruses isolated from 91 patients.ResultsThere was no significant difference between the clinical characteristics of groups A and B during both seasons. Influenza A/H1N1, isolated from both groups A and B during the 2007-2008 and 2008-2009 periods, was not resistant to zanamivir. However, phenotypic analysis of the virus revealed a high oseltamivir IC50 range and that H275Y substitution of the neuraminidase (NA) gene and partial variation of the hemagglutinin (HA) gene did not affect its antigenicity to the HA vaccine even though group A had a shorter hospitalization duration and fewer lower respiratory tract complications than group B. In addition, there was no significant difference in the clinical manifestations between oseltamivir-susceptible and oseltamivir-resistant strains of influenza A/H1N1.ConclusionEstablishment of guidelines to efficiently treat influenza with oseltamivir, a commonly used drug for treating influenza in Korean pediatric patients, and a treatment strategy with a new therapeutic agent is required
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