1,721,079 research outputs found
A unified description of cryptosystems: From classical to quantum protocols
No full textThe launch of quantum computing has created new challenges in the field of cryptography. Nowadays this field of research is extremely active in physics, mathematics and computer science. In this paper we present an overview of the most common classical and quantum protocols. The former are usually defined through a 5-uple given by a plaintext space, a ciphertext space, an encryption and decryption space, an encryption function and a decryption function. Here, we show how to unify quantum and classical protocols by using the same formalism of the 5-uple mentioned above
A left 3-Engel element whose normal closure is not nilpotent
No full textWe give an example of a locally nilpotent group G containing a left 3-Engel element x where 〈x〉G is not nilpotent
Upper bounds for the product of element orders of finite groups
Full text linkLet G be a finite group of order n, and denote by ρ(G) the product of element orders of G. The aim of this work is to provide some upper bounds for ρ(G) depending only on n and on its least prime divisor, when G belongs to some classes of non-cyclic groups
On the structure of finite groups determined by the arithmetic and geometric means of element orders
Full text linkIn this paper we consider two functions related to the arithmetic and geometric means of element orders of a finite group, showing that certain lower bounds on such functions strongly affect the group structure. In particular, for every prime p, we prove a sufficient condition for a finite group to be p-nilpotent, that is, a group whose elements of (Formula presented.) -order form a normal subgroup. Moreover, we characterize finite cyclic groups with prescribed number of prime divisors
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Cancer stem cells in solid tumors: an overview and new approaches for their isolation and characterization.
No full textPrimary tumors are responsible for 10%
of cancer deaths. In most cases, the main cause of
mortality is the formation of metastases. Accumulating
evidence suggests that a subpopulation of tumor cells with
distinct stem-like properties is responsible for tumor
initiation, invasive growth, and metastasis formation. This
population is defined as cancer stem cells (CSCs). Existing
therapies have enhanced the length of survival after
diagnosis of cancer but have completely failed in terms of
recovery. CSCs appear to be resistant to chemotherapy,
may remain quiescent for extended periods, and have
affinity for hypoxic environments. The CSCs can be
identified and isolated by different methodologies, including
isolation by CSC-specific cell surface marker
expression, detection of side population phenotype by
Hoechst 33342 exclusion, assessment of their ability to
grow as floating spheres, and aldehyde dehydrogenase
(ALDH) activity assay. None of the methods mentioned
are exclusively used to isolate the solid tumor CSCs,
highlighting the imperative to delineate more specific
markers or to use combinatorial markers and methodologies.
This review provides an overview of the main
characteristics and approaches used to identify, isolate,
and characterize CSCs from solid tumors.—Tirino, V.,
Desiderio, V., Paino, F., De Rosa, A., Papaccio, F., La
Noce, M., Laino, L., De Francesco, F., Papaccio, G.
Cancer stem cells in solid tumors: an overview and new
approaches for their isolation and characterization.
FASEB J. 27, 000–000 (2013). www.fasebj.or
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