26,619 research outputs found
Production of heavy isotopes in transfer reactions by collisions of U+U
The dynamics of transfer reactions in collisions of two very heavy nuclei
U+U is studied within the dinuclear system (DNS) model.
Collisions of two actinide nuclei form a super heavy composite system during a
very short time, in which a large number of charge and mass transfers may take
place. Such reactions have been investigated experimentally as an alternative
way for the production of heavy and superheavy nuclei. The role of collision
orientation in the production cross sections of heavy nuclides is analyzed
systematically. Calculations show that the cross sections decrease drastically
with increasing the charged numbers of heavy fragments. The transfer mechanism
is favorable to synthesize heavy neutron-rich isotopes, such as nuclei around
the subclosure at N=162 from No (Z=102) to Db (Z=105).Comment: 4 pages, 4 figure
Formation of superheavy nuclei in cold fusion reactions
Within the concept of the dinuclear system (DNS), a dynamical model is
proposed for describing the formation of superheavy nuclei in complete fusion
reactions by incorporating the coupling of the relative motion to the nucleon
transfer process. The capture of two heavy colliding nuclei, the formation of
the compound nucleus and the de-excitation process are calculated by using an
empirical coupled channel model, solving a master equation numerically and
applying statistical theory, respectively. Evaporation residue excitation
functions in cold fusion reactions are investigated systematically and compared
with available experimental data. Maximal production cross sections of
superheavy nuclei in cold fusion reactions with stable neutron-rich projectiles
are obtained. Isotopic trends in the production of the superheavy elements
Z=110, 112, 114, 116, 118 and 120 are analyzed systematically. Optimal
combinations and the corresponding excitation energies are proposed.Comment: 18 pages, 8 figure
Relationship between integrin ανβ3 and α6β1 expression levels and clinicopathological characteristics of cervical cancer
Purpose: The study was aimed at investigating the relationship between integrin ανβ3 and α6β1 expression levels and clinicopathological characteristics of cervical cancer. Methods: A total of 78 cases of pathologically confirmed cervical cancer patients admitted to our hospital from April 2012 to September 2013 were selected. The expression levels of integrin ανβ3 and α6β1 in the cervical cancer tissue (study group, n=78) and adjacent normal tissue (control group, n=49) were detected by immunohistochemistry. Then, the relationship between the expression of two indicators in cervical cancer tissues and the clinicopathological features of patients were analyzed. Results: Positive expression rate of integrin ανβ3 in cervical cancer tissues was significantly higher than that in adjacent normal tissues (73.08% vs 2.04%, P<0.05). For integrin α6β1, the positive expression rate in cervical cancer tissues was significantly higher than that in adjacent normal tissues (67.95% vs 8.16%, P<0.05). The expression level of integrin ανβ3 in cervical cancer tissues with different degree of differentiation, tumor diameter, depth of invasion, and lymph node metastasis was significantly different (P<0.05). Integrin α6β1, the expressed in cervical cancer tissues with significantly different degrees of differentiation, infiltration depth and lymph node metastasis (P<0.05). Conclusion: The integrin ανβ3 and α6β1 are highly expressed in cervical cancer tissue. The expression level of integrin ανβ3 was related to the differentiation degree, diameter of tumor, infiltration depth and lymph node metastasis, while the expression of integrin α6β1 was related to the clinicopathological features, such as the differentiation degree of cancer tissues, depth of invasion, and lymph node metastasis
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