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Zhenhua Qiao

Publications and source records attributed to Zhenhua Qiao.

5 recordsLinked to original sources
PubMed2006

Universal spin-Hall conductance fluctuations in two dimensions.

We report a theoretical investigation on spin-Hall conductance fluctuation of disordered four-terminal devices in the presence of Rashba or/and Dresselhaus spin-orbital interactions in two dimensions. As a function of disorder, the spin-Hall conductance GsH shows ballistic, diffusive, and insulating transport regimes. For given spin-orbit interactions, a universal spin-Hall conductance fluctuation (USCF) is found in the diffusive regime. The value of the USCF depends on the spin-orbit coupling tso but is independent of other system parameters. It is also independent of whether Rashba or Dresselhaus or both spin-orbital interactions are present. When tso is comparable to the hopping energy t, the USCF is a universal number approximately 0.18e/4pi. The distribution of GsH crosses over from a Gaussian distribution in the metallic regime to a non-Gaussian distribution in the insulating regime as the disorder strength is increased.

Journal Article↗
PubMed2004

Th1/Th2 cytokine profiles and their relationship to clinical features in patients following nonmyeloablative allogeneic stem cell transplantation.

An imbalance in helper T-cell type 1 (Th1) and type 2 (Th2) cytokines is suggested to play an important role in the pathogenesis of acute graft-versus-host disease (aGVHD). The aim of this study was to investigate the cytokine bias acquired by T cells after transplantation and its possible influence on relapse of original malignancy. Cytokine levels by peripheral CD4 and CD8 T cells were tested at various pre- and post-transplant time points with fluorescein isothiocyanate-based intracellular cytokine assay after short-term in vitro mitogenic stimulation (phorbol myristate acetate + ionomycin). In both CD4+ and CD8+ cells, interferon (IFN)-gamma-producing cell populations increased, indicating a shift to a Th1 cytokine profile with aGVHD. IFN-gamma-producing T cells was significantly lower in patients who experienced relapse of original disease compared to those who showed no signs of relapse and compared to normal controls. Our studies demonstrate that aGVHD correlates with a Th1 bias and that Th1 response may potentiate an effective immune surveillance.

Adolescent↗
PubMed2003

Flavonoids: promising anticancer agents.

Flavonoids are polyphenolic compounds that are ubiquitously in plants. They have been shown to possess a variety of biological activities at nontoxic concentrations in organisms. The role of dietary flavonoids in cancer prevention is widely discussed. Compelling data from laboratory studies, epidemiological investigations, and human clinical trials indicate that flavonoids have important effects on cancer chemoprevention and chemotherapy. Many mechanisms of action have been identified, including carcinogen inactivation, antiproliferation, cell cycle arrest, induction of apoptosis and differentiation, inhibition of angiogenesis, antioxidation and reversal of multidrug resistance or a combination of these mechanisms. Based on these results, flavonoids may be promising anticancer agents.

Anticarcinogenic Agents↗
PubMed2002

Arsenic trioxide, retinoic acid and Ara-c regulated the expression of annexin II on the surface of APL cells, a novel co-receptor for plasminogen/tissue plasminogen activator.

Annexin II (AnnII), a high-affinity co-receptor for plasminogen/tissue plasiminogen activator, plays a central role in the primary hyperfibrinolysis in acute promyelocytic leukemia (APL). The aberrant expression of annexin II was found on the APL cell surface in the present study. We investigated patients with APL receiving all-trans retinoic acid (ATRA) or arsenic trioxide (As(2)O(3)) treatment, contributing to the downregulation of the expression of annexin II on APL cells, and decreasing the generation of plasmin by tissue plasminogen activator (t-PA). Notably, the clinical improvement of hyperfibrinolysis paralleled the correction of plasma fibrinogen level and amelioration of bleeding. Consistent with in vivo findings, annexin II on NB(4) cell surface and its mRNA content were downregulated with 1 microM As(2)O(3) or 1 microM ATRA, while 2 microg Ara-c enhanced the expression of annexin II and the generation of cell-surface plasmin before its induction of apoptosis. Our data indicate that the inhibition of annexin II expression with ATRA is transcriptionally mediated while As(2)O(3) induces an accelerated degradation of annexin II mRNA. Western blot analysis under treatment conditions showed that both ATRA and As(2)O(3) markedly decreased the production of annexin II, reaching a level near the baseline at 5 and 7 days after treatment, respectively. Annexin II expression of APL cells may be downregulated by ATRA and As(2)O(3.) Therefore, both agents improve hyperfibrinolysis-related hemorrhage of APL, which induced APL cells to difference and apoptosis, respectively.

Adolescent↗