193 research outputs found
Electron-nuclei spin relaxation through phonon-assisted hyperfine interaction in a quantum dot
We investigate the inelastic spin-flip rate for electrons in a quantum dot
due to their contact hyperfine interaction with lattice nuclei. In contrast to
other works, we obtain a spin-phonon coupling term from this interaction by
taking directly into account the motion of nuclei in the vibrating lattice. In
the calculation of the transition rate the interference of first and second
orders of perturbation theory turns out to be essential. It leads to a
suppression of relaxation at long phonon wavelengths, when the confining
potential moves together with the nuclei embedded in the lattice. At higher
frequencies (or for a fixed confining potential), the zero-temperature rate is
proportional to the frequency of the emitted phonon. We address both the
transition between Zeeman sublevels of a single electron ground state as well
as the triplet-singlet transition, and we provide numerical estimates for
realistic system parameters. The mechanism turns out to be less efficient than
electron-nuclei spin relaxation involving piezoelectric electron-phonon
coupling in a GaAs quantum dot.Comment: 8 pages, 1 figur
Esophageal Squamous Cell Carcinoma with Marked Eosinophil Infiltration
We report a case of esophageal squamous cell carcinoma (SCC) with marked eosinophil infiltration which was identified postoperatively in the esophageal wall in areas not surrounding the SCC. The eosinophil infiltration was seen in the submucosa, muscle and adventitia, but not in the mucosa. Eosinophilic esophagitis (EoE) is a pathological condition defined as eosinophil infiltration within the esophageal mucosa. Eosinophil infiltration at the invasion front of esophageal SCC is termed tumor-associated tissue eosinophilia (TATE). However, the eosinophil infiltration in this case may be pathologically different from both EoE and TATE. To our knowledge, this is the first report of esophageal SCC with eosinophil infiltration
Angiogenesis inhibitors in the treatment of prostate cancer
Prostate cancer remains a significant public health problem, with limited therapeutic options in the setting of castrate-resistant metastatic disease. Angiogenesis inhibition is a relatively novel antineoplastic approach, which targets the reliance of tumor growth on the formation of new blood vessels. This strategy has been used successfully in other solid tumor types, with the FDA approval of anti-angiogenic agents in breast, lung, colon, brain, and kidney cancer. The application of anti-angiogenic therapy to prostate cancer is reviewed in this article, with attention to efficacy and toxicity results from several classes of anti-angiogenic agents. Ultimately, the fate of anti-angiogenic agents in prostate cancer rests on the eagerly anticipated results of several key phase III studies
Novel therapies in genitourinary cancer: an update
In recent years, new treatment for renal cell carcinoma (RCC) has been a spotlight in the field of cancer therapeutics. With several emerging agents branded as 'targeted therapy' now available, both medical oncologists and urologists are progressively more hopeful for better outcomes. The new remedies may provide patients with improved survival and at the same time less toxicity when compared to traditional cytotoxic agents. This article will center on current and emerging treatment strategies for advanced RCC and other GU malignancies with updates from 2008 annual ASCO meeting
Is there a role for chemotherapy in prostate cancer?
There is evidence from randomised-controlled trials that patients with symptomatic hormone-refractory prostate cancer may experience palliative benefit from chemotherapy with mitoxantrone and prednisone. This treatment is well tolerated, even by elderly patients, although the cumulative dose of mitoxantrone is limited by cardiotoxicity. Treatment with docetaxel or paclitaxel, with or without estramustine, appears to convey higher rates of prostate-specific antigen response in phase II trials, but is more toxic. Large phase III trials comparing docetaxel with mitoxantrone have completed accrual. There is no role for chemotherapy in earlier stages of disease except in the context of a well-designed clinical trial
Phase I study of pegylated liposomal doxorubicin and the multidrug-resistance modulator, valspodar
Valspodar, a P-glycoprotein modulator, affects pharmacokinetics of doxorubicin when administered in combination, resulting in doxorubicin dose reduction. In animal models, valspodar has minimal interaction with pegylated liposomal doxorubicin (PEG-LD). To determine any pharmacokinetic interaction in humans, we designed a study to determine maximum tolerated dose, dose-limiting toxicity (DLT), and pharmacokinetics of total doxorubicin, in PEG-LD and valspodar combination therapy in patients with advanced malignancies. Patients received PEG-LD 20–25 mg m−2 intravenously over 1 h for cycle one. In subsequent 2-week cycles, valspodar was administered as 72 h continuous intravenous infusion with PEG-LD beginning at 8 mg m−2 and escalated in an accelerated titration design to 25 mg m−2. Pharmacokinetic data were collected with and without valspodar. A total of 14 patients completed at least two cycles of therapy. No DLTs were observed in six patients treated at the highest level of PEG-LD 25 mg m−2. The most common toxicities were fatigue, nausea, vomiting, mucositis, palmar plantar erythrodysesthesia, diarrhoea, and ataxia. Partial responses were observed in patients with breast and ovarian carcinoma. The mean (range) total doxorubicin clearance decreased from 27 (10–73) ml h−1 m−2 in cycle 1 to 18 (3–37) ml h−1 m−2 with the addition of valspodar in cycle 2 (P=0.009). Treatment with PEG-LD 25 mg m−2 in combination with valspodar results in a moderate prolongation of total doxorubicin clearance and half-life but did not increase the toxicity of this agent
The 100 most cited articles investigating the radiological staging of oesophageal and junctional cancer: a bibliometric analysis
Objectives
Accurate staging of oesophageal cancer (OC) is vital. Bibliometric analysis highlights key topics and publications that have shaped understanding of a subject. The 100 most cited articles investigating radiological staging of OC are identified.
Methods
The Thomas Reuters Web of Science database with search terms including “CT, PET, EUS, oesophageal and gastro-oesophageal junction cancer” was used to identify all English language, full-script articles. The 100 most cited articles were further analysed by topic, journal, author, year and institution.
Results
A total of 5,500 eligible papers were returned. The most cited paper was Flamen et al. (n = 306), investigating the utility of positron emission tomography (PET) for the staging of patients with potentially operable OC. The most common research topic was accuracy of staging investigations (n = 63). The article with the highest citation rate (38.00), defined as the number of citations divided by the number of complete years published, was Tixier et al. investigating PET texture analysis to predict treatment response to neo-adjuvant chemo-radiotherapy, cited 114 times since publication in 2011.
Conclusion
This bibliometric analysis has identified key publications regarded as important in radiological OC staging. Articles with the highest citation rates all investigated PET imaging, suggesting this modality could be the focus of future research
Education Impact Study: The Global Recession and the Capacity of Colleges and Universities to Serve Vulnerable Populations in Asia
This paper reviews the capacity of colleges and universities to serve poor and vulnerable populations during past and present economic shocks. The main argument is that the environment of the global recession - an Asia far more economically integrated than during past economic shocks, with more unified aspirations to be globally competitive and socially responsible - need not delay reforms in higher education. In fact, the global recession is an opportune time for higher education in the Asia and Pacific region to continue reforming governance and administration, access and equity, internal and external efficiency, and regional collaboration. This paper proposes a series of measures to increase the resilience of higher education systems in serving poor and vulnerable populations during the economic recession. These measures include: (i) tuition assistance, subsidies, and loans; (ii) information and guidance for first-generation college students on choosing appropriate programs of study; (iii) community-based vocational and technical higher education that provides jobs in a rapidly changing labor market; (iv) innovative forms of cost sharing between public and private institutions of higher education; (v) resource decisions made on the basis of performance-based objectives; (vi) intensification of philanthropic culture that provides scholarships for poor students; (vii) upgrading of research about problems confronting poor communities; and (viii) regional strategies across the Asia and Pacific region for closer instructional program collaboration among colleges and universitie
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