Graphene based quantum dots

Laterally localized electronic states are identified on a single layer of graphene on ruthenium by low temperature scanning tunneling spectroscopy (STS). The individual states are separated by 3 nm and comprise regions of about 90 carbon atoms. This constitutes a highly regular quantum dot-array with molecular precision. It is evidenced by quantum well resonances (QWRs) with energies that relate to the corrugation of the graphene layer. The dI/dV conductance spectra are modeled by a layer height dependent potential-well with a delta-function potential that describes the barrier for electron penetration into graphene. The resulting QWRs are strongest and lowest in energy on the isolated 'hill' regions with a diameter of 2 nm, where the graphene is decoupled from the surface.

Photonic chip based transmitter optimization and receiver demultiplexing of a 1.28 Tbit/s OTDM signal

We demonstrate chip-based Tbaud optical signal processing for all-optical performance monitoring, switching and demultiplexing based on the instantaneous Kerr nonlinearity in a dispersion-engineered As(2)S(3) planar waveguide. At the Tbaud transmitter, we use a THz bandwidth radio-frequency spectrum analyzer to perform all-optical performance monitoring and to optimize the optical time division multiplexing stages as well as mitigate impairments, for example, dispersion. At the Tbaud receiver, we demonstrate error-free demultiplexing of a 1.28 Tbit/s single wavelength, return-to-zero signal to 10 Gbit/s via four-wave mixing with negligible system penalty (< 0.5 dB). Excellent performance, including high four-wave mixing conversion efficiency and no indication of an error-floor, was achieved. Our results establish the feasibility of Tbaud signal processing using compact nonlinear planar waveguides for Tbit/s Ethernet applications.

Apoptosis induced by emodin is associated with alterations of intracellular acidification and reactive oxygen species in EC-109 cells

Emodin (1,3,8-trihydroxy-6-methylanthraquinone), a natural anthraquinone derivative found in several herbal medicines, is highly active in suppressing the proliferation of various tumor cells such as breast, hepatocellular, and lung cancer cells under in vitro conditions. The mechanism of emodin-induced apoptosis in esophagus carcinoma cells, EC-109, is not completely understood. In this study, EC-109 cells treated with emodin underwent rapid apoptosis as judged by morphological changes and flow cytometry analysis. The addition of emodin to EC-109 cells led to the inhibition of growth in a time- and dose-dependent manner. Fluorescence measurements of cells indicated that the intracellular pH (pHi) decreased significantly by 0.47-0.78 units. The results obtained from flow cytometry suggested that bursts of reactive oxygen species took place after the application of emodin. The present study indicates that emodin may be a strong anticancer drug against esophagus cancer cells by causing various early events leading to growth inhibition, including the production of reactive oxygen species and decrease of pHi, which may result in cellular apoptosis.

Establishment and evaluation of a model of a community health service in an underdeveloped area of China

OBJECTIVES

To develop and evaluate an applicable model for a community health service (CHS) in an underdeveloped area of China that ensures efficient, convenient and affordable primary healthcare access for all residents.

STUDY DESIGN

The current study was carried out in Puyang, a typical medium-sized city in central-eastern China. Based on the healthcare requirements of the residents in Puyang, a CHS network was set up and its operation was evaluated from 1999 to 2006. The system is characterized by its focus on community health education (CHE).

METHODS

Firstly, 8231 residents, selected at random, were surveyed to investigate the healthcare requirements of the local residents. Meanwhile, the operation of the pre-existing healthcare resources was investigated in Puyang. Based on the information gained, a network-based CHS system was proposed and established, with CHE as the major focus. This study compared CHS operation prior to and after establishment of the network. Finally, an analytic hierarchy process based evaluation model was applied to evaluate the operation of the CHS network.

RESULTS

There was a high prevalence (86.98 per thousand) of chronic diseases among the residents who participated in this investigation. The majority (84.39%) of the residents who had healthcare requirements resorted to professional health care; the other residents did not have access to health services. Among those residents who sought professional treatment, 71.3% visited primary healthcare institutions. This information reflects the enormous requirement for a CHS in primary health care but the lack of accessibility among the residents; this motivated the authors to establish a system to solve the problem. The improvement in CHS operation after the network was established suggests the importance of a network for optimizing the primary healthcare system. The improvement was indicated by better understanding of the residents regarding the CHS, and enhanced capability of self-monitoring for chronic diseases such as hypertension after the network was established. Moreover, the residents' knowledge of health care was significantly increased and, accordingly, the incidence of health risk behaviour was reduced after the network was established. Furthermore, the CHE index between 1999 and 2006 showed good correlation (r=0.988, p<0.005) with the CHS index, suggesting the important role of CHE in CHS development.

CONCLUSIONS

A network-characterized CHS system was established in Puyang, and improved the primary healthcare situation. This study provides a feasible model for the development of a CHS in medium and small cities in underdeveloped parts of China.

Salvianolic acid A inhibits platelet activation and arterial thrombosis via inhibition of phosphoinositide 3-kinase

BACKGROUND AND OBJECTIVE

Salvianolic acid A (SAA) is a water-soluble component from the root of Salvia miltiorrhiza Bunge, a herb that is widely used for atherothrombotic disease treatment in Asian medicine. As platelets play pivotal roles in atherothrombogenesis, we studied the effect of SAA on platelet activation and its underlying mechanisms.

METHODS AND RESULTS

SAA dose-dependently inhibited platelet aggregation induced by ADP, thrombin, collagen and U46619. It reduced ADP-enhanced platelet P-selectin expression and fibrinogen binding, which consequently hampered ADP-induced platelet-leukocyte aggregation. SAA also inhibited platelet spreading on fibrinogen, a process mediated by outside-in signaling. Under an arterial shear rate of 1000 s(-1), SAA decreased platelet adhesion on collagen surfaces by approximately 40%. Western blot analysis showed that SAA, like the phosphoinositide 3-kinase (PI3K) inhibitors LY294002 and TGX-221, potently inhibited PI3K, as shown by reduced Akt phosphorylation. The in vitro findings were further evaluated in the mouse model of arterial thrombosis, in which SAA prolonged the mesenteric arterial occlusion time in wild-type mice (35 + or - 2 min without SAA and 56 + or - 4 min with SAA; P < 0.01). Interestingly, SAA could even counteract the shortened arterial occlusion time in Ldlr(tm1Her) mutant mice (21 + or - 2 min without SAA and 45 + or - 4 min with SAA; P < 0.01).

CONCLUSIONS

SAA inhibits platelet activation via the inhibition of PI3K, and attenuates arterial thrombus formation in vivo. Our data suggest that SAA may be developed as a novel therapeutic agent for the prevention of thrombotic disorders.

Lithium niobate photonic wires

LN photonic wires of cross-section dimensions down to 1 x 0.73 microm2 were fabricated by Ar milling of a single-crystalline LiNbO3 (LN) film bonded to a SiO2/LiNbO3 substrate. Mode intensity distributions, propagation losses, and group indices of refraction were measured at 1.55 microm wavelength and compared with simulation results. Moreover, effective mode indices and end face reflectivities were numerically evaluated. The waveguide of 1 microm top width is the smallest LN photonic wire reported to date; it has a mode size of approximately 0.4 microm2 (0.5 microm2) only and propagation losses of 9.9 dB/cm (12.9 dB/cm) for qTM (qTE) polarization.

An Approach To Correlate the Temporal Information To Facilitate Specimen Selection in the Breast Cancer Research Project

Background: Temporal information management is very important in translational research. In the Clinical Breast Care Project (CBCP), the information on subjects and their specimens may be collected at multiple time points using multiple instruments.All such information is stored in an in-house data warehouse. Currently, 4000+ subjects have been enrolled in the study following HIPAA-compliant IRB-approved protocols with 35,000+ specimens collected. Some of the patient's information is static but other data are time dependent. As a result, selecting samples for experiments is a challenge due to complicated temporal relationships between samples and information collected through various instruments.Methods and Results: In the CBCP, the clinical information, blood, and solid tissues of a subject may be collected at multiple time points, associated with the completion of a Core Questionnaire (CQ) for clinical information, and/or a Pathology Checklist (PC) for pathology and sample information. We have designed and implemented an algorithm to use a set of pre-defined flags to precisely describe each sample related to patient's clinical and pathology information in the temporal domain. Five categories (flags) were created to describe the relationship between the sample date (SD) and the CQ date based on whether SD is within 60 days of the CQ date or there is missing data or not. The relationship between blood samples and pathology information is more complicated. Within 90 days, any of the 15 surgical procedures might be performed on a patient and blood samples might be collected before, at the time of, or between any procedures. For some experiments, it is crucial to select blood samples taken before tumor is impacted or severely impacted. Thus, we defined a dozen categories to describe the relationship between the SD and the procedure date (PD), including when the SD is earlier than any PD, equals to the first PD, or between certain procedures. Using these flags we have characterized the relationships between SDs and CQ dates, and between SDs and PDs for all the samples and all the subjects, and stored all the information into two relational tables. The temporal criteria for sample selection are now represented by the relationships between these flags, and can be implemented through several filtering processes. The described algorithm drastically reduces the time needed for precise sample selection from several days for manual efforts to several hours.Discussion: We are in the process of developing a general data model for temporal information management. The method described here is a transitional solution that fulfills our current needs. As an initial effort some of the thresholds for categorizing different temporal conditions are arbitrary, and we are validating them with experimental results for future improvement. Nonetheless, this algorithm has greatly enhanced the efficiency of our subject and specimen selection for wet bench experiments. The same principle can be applied to the future temporal data model solution, for CBCP and other human disease studies.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4173.

Converting Paper Medical Records to Electronic Version To Support Breast Cancer Translational Research and Clinical Practice

Background: The healthcare system has extremely large volumes of patients' paper medical records (PMRs) scattered throughout various medical facilities. Currently the industry is transitioning to Electronic Medical Records (EMR). Although each source of information is equally important, a complete longitudinal health record is rarely available or currently attainable. The goal of this effort is to convert the existing PMRs into searchable electronic equivalents and merge them with existing EMRs to create a more complete longitudinal health record to support clinical care and biomedical research.Method: Using a subset of PMRs for subjects enrolled in the Clinical Breast Care Project at Walter Reed Army Medical Center, (WRAMC), we are developing an automated method to digitize and index the records, extract the biomedical information and prepare the data for delivery to clinicians and researchers. The electronic records were loaded into a database for immediate access by clinicians. To support translational research, MRs need to be de-identified, and information extracted and loaded into a research database; we used ten MRs to develop the operational method. Several methods were tested in the de-identification process: 1) manually, by striking out the protected health information (PHI) on paper before it was digitized and 2) “electronically”, by redacting the record electronically on the computer after it was digitized. We are in the process of testing automated data extraction tools and natural language processors to automatically de-identify and extract data from the EMR.Result: We quickly realized that only 10% of PMRs existed onsite at WRAMC; remaining MRs were held by the patients or other medical facilities. Approximately 300 PMRs, containing 66,600 pages, were scanned and digitized for this project. We have created a successful digitization process, which includes creating PDFs with hidden and searchable information. We have compared the effort and accuracy of various redaction methods. To de-identify 10 records, it took ∼10 hours manually and ∼20 hours electronically. It took longer electronically because of the preparations to ensure the removed information could not be retrieved. We expect that automated redaction tools will greatly reduce that effort. We also found that the electronic method had a 99% accuracy compared to 96% for the paper method. A portal prototype to allow access to medical records by clinicians and researchers is currently being tested and evaluated.Discussion: Conversion of non-searchable data into an explorable and computable format will enable clinicians to acquire needed information more conveniently in their clinical care including treatment plan development. Similarly, properly de-identified, complete MRs will serve as a rich source of clinical information to support translational research. Although the method we are developing will initially satisfy the CBCP need for clinical service and research, it will be further developed into a full solution to expand into other disease condition fields.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5123.

Microarray Data Analysis Using Peripheral Blood Samples Suggests Differential Enrichment of Signaling Pathways between Breast Cancer Patients and Normal Subjects

Background: Breast cancer is the second most common cancer among women in the United States and the second leading cause of cancer death in women. Early and accurate diagnosis is crucial for better treatment and reduction of mortality. Diagnostics based on blood samples are being developed for many diseases including a variety of cancers.Gene expression profiling has been widely used to investigate the mechanisms of tumorigenesis with the goal of developing novel treatment strategies. We have applied microarray technology to study the gene expression signatures in blood samples from patients with invasive breast cancer, with benign breast disease and from disease free (normal) control groups to find potential diagnostic patterns. We have identified differentially expressed genes in each group and investigated the pathways these genes are involved in and how these are regulated.Material and Methods: Human blood samples from 102 invasive breast cancer patients, 57 patients with benign breast disease and 102 normal controls were collected for this study. Patients are enrolled in the Clinical Breast Care Project (CBCP) following HIPAA-compliant IRB approved protocols, with proven breast pathology diagnosis categories. Affymetrix HG-U133 Plus 2 GeneChips were used to investigate the gene expression profile. Microarray experiments were performed following Affymetrix protocols. CEL files were then analyzed with RMA algorithm for the calculation of gene expression matrix. Differentially expressed genes were identified between different groups using Wilcoxon rank sum test. We also applied Gene Set Enrichment Analysis (GSEA) to the entire gene expression profiles to investigate the gene sets or pathways enriched in different groups.Results: We identified about 2,051 differentially expressed genes between normal and invasive groups (p &lt; 0.001 and Fold Change &gt; 1.2). Furthermore, about 445 and 51 genes were identified in normal vs. benign and benign vs. invasive groups respectively. We performed GSEA using 395 gene sets from pathway databases, initially focusing on normal vs. invasive groups. 123 gene sets are highly expressed in the normal group and 272 gene sets are highly expressed in the invasive group. For the normal group, 10 gene sets are significantly enriched and 22 gene sets are significantly enriched in the invasive group (p &lt; 0.05). These results show that some important pathways are down regulated in the invasive group, such as, the B-cell antigen receptor pathway, the BCR signaling pathway, the T-cell signal transduction pathway, the IL4 receptor pathway, the PIP3 pathway, the ERK pathway, etc. The pathways up regulated in the invasive group are oxidative phosphorylation pathway, ATP synthesis, etc.Discussion: Our results suggest that a list of genes differentially expressed in different groups and they may be used to compose cancer marker panels which can be integrated with currently clinical procedures for cancer diagnosis. We also find some crucial pathways enriched in each group. Most of the pathways downregulated in the blood of patients in the invasive group are related to the immune response. In contrast, most of pathways upregulated in the blood of patients in the invasive group are associated with metabolism.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3024.

Differential Benign Breast Disease Co-Occurrence with Cancer in Caucasian and African American Women

Background: Breast Cancers (BCs) in Caucasian (CA) and African American (AA) women have different characteristics. Recently, there have been reports, mostly focusing on Caucasians that Benign Breast Diseases (BBDs) may be risk factors for BCs. There are also a few reports of different co-occurring patterns of BBDs with BCs between the two populations. In the Clinical Breast Care Project (CBCP) more than 4,000 subjects have been enrolled following HIPAA-compliant, IRB-approved protocols, with more than 35,000 biospecimens collected. For patients requiring biopsies, an expanded pathology report for research is completed. The occurrences of any of the 131 pathologic conditions, including 66 BBDs, are recorded. All the results are reviewed by the same pathologist. The CBCP provides a uniformed pathology dataset for a comprehensive characterization of the association of BBDs with BCs.Method: The diagnoses were made from potentially multiple biopsies obtained over a short period of time, mostly within 60 days. CBCP subjects with BBD diagnosis and ethnicity information from their most recent visit were selected, giving a dataset totaling 1479 CA and 484 AA women. We studied the association between BBDs and BCs (including in situ, invasive, and malignant NOS) in these two groups using the chi-square test.Results: In both populations 6 BBDs are positively associated with BCs, including atypical ductal hyperplasia (ADH) (4% vs 15% for AA p&lt;3.8E-05, meaning 4% cancer-free cases with ADH compared to 15% cancer cases co-occurring with it; 7% vs 16% for CA p&lt;1.9E-08), microcalcifications (27% vs 56% for AA p&lt;1.2E-09, 35% vs 53% for CA p&lt;8.0E-12), multiple (peripheral) papillomas (6% vs 16% for AA p&lt;0.0005, 4% vs 8% for CA p&lt;0.0002), columnar cell hyperplasia (9% vs 21% for AA p&lt;0.0003, 6% vs 18% for CA p&lt;3.5E-12), and moderate intraductal hyperplasia (IDH) (14% vs 28% for AA p&lt;0.0002, 14% vs 18% for CA p&lt;0.03). On the contrary, 3 BBDs are negatively associated with BCs including fibroadenoma (30% vs 10% for AA p&lt;4.9E-07; 21% vs 7% for CA p&lt;1.0E-13), and mild IDH (10% vs 2% for AA p&lt;0.003; 13% vs 7% for CA p&lt;0.0002). Eight BBDs differentially co-occur with BCs between AA and CA. BCs in AA are associated with sclerosing adenosis (13% vs 31%, p&lt;4.5E-06), fibrocystic changes (45% vs 61%, p&lt;0.001), fibroadenomatoid nodule (6% vs 12%, p&lt;0.042), and cysts (42% vs 57%, p&lt;0.004). BCs in CA are positively associated with columnar cell hyperplasia with atypia (3% vs 8% p&lt;3.6E-05), atypical lobular hyperplasia (1% vs 5%, p&lt;6.0E-05), and radiation changes (0% vs 1.4% p&lt;0.004), but negatively associated with duct ectasia (10% vs 2%, p&lt;7.9E-10).Discussion Our findings are in accordance with established BC risk factors such as ADH and moderate IDH for both ethnic groups. We further found that 8 BBDs differentially co-occur with BCs between AA and CA groups, and interestingly the 4 significant BBDs detected in the AA group typically show &gt;10% increased co-occurrence rate in cancer cases compared to cancer-free cases, whereas the 4 BBDs detected in the CA group almost always show a &lt;10% co-occurrence rate overall. More research is undergoing to understand the implications of this distinct co-occurrence pattern.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3066.

Modeling vaccination campaigns and the Fall/Winter 2009 activity of the new A(H1N1) influenza in the Northern Hemisphere

The unfolding of pandemic influenza A(H1N1) for Fall 2009 in the Northern Hemisphere is still uncertain. Plans for vaccination campaigns and vaccine trials are underway, with the first batches expected to be available early October. Several studies point to the possibility of an anticipated pandemic peak that could undermine the effectiveness of vaccination strategies. Here, we use a structured global epidemic and mobility metapopulation model to assess the effectiveness of massive vaccination campaigns for the Fall/Winter 2009. Mitigation effects are explored depending on the interplay between the predicted pandemic evolution and the expected delivery of vaccines. The model is calibrated using recent estimates on the transmissibility of the new A(H1N1) influenza. Results show that if additional intervention strategies were not used to delay the time of pandemic peak, vaccination may not be able to considerably reduce the cumulative number of cases, even when the mass vaccination campaign is started as early as mid-October. Prioritized vaccination would be crucial in slowing down the pandemic evolution and reducing its burden.

Migraine and cardiovascular disease: possible mechanisms of interaction

Migraine, especially migraine with aura (MA), is an established risk factor for ischemic lesions of the brain. Recent evidence has also linked migraine to a broader range of ischemic vascular disorders including angina, myocardial infarction, coronary revascularization, claudication, and cardiovascular mortality. The mechanisms which link migraine to ischemic vascular disease remain uncertain and are likely to be complex. Cortical spreading depression, the presumed substrate of aura, may directly predispose to brain lesions and that would explain why MA is consistently demonstrated as a risk factor for cerebral ischemia, while for migraine without aura (MO), the evidence is less consistent. Additionally, individuals with migraine have a higher prevalence of risk factors known to be associated with cardiovascular disease (CVD), including hypertension, diabetes, and hyperlipidemia. The increased prevalence of CVD risk factors is also higher for MA than for MO. Since the evidence linking migraine and CVD is getting robust, neurologists should be aware of this association. Individuals with MO seem to be at little increased risk of CVD. MA is associated with an increased risk of ischemic stroke and likely also for other ischemic CVD events. Accordingly, heightened vigilance is recommended for modifiable cardiovascular risk factors in migraineurs, especially with MA. Ultimately, it will be important to determine whether MA is a modifiable risk factor for CVD and if preventive medications for migraine or antiplatelet therapy might reduce the risk of CVD in patients with MA.

Local periodic poling of ridges and ridge waveguides on X- and Y-Cut LiNbO3 and its application for second harmonic generation

Fabrication, characterization and application of periodical ferroelectric domains in ridges and Ti in-diffused ridge waveguides on X- and Y-cut Lithium Niobate (LN) are reported. The ridge waveguides of 3.5 microm height and 9 microm width were fabricated by inductively coupled plasma (ICP) etching followed by Ti in-diffusion into the ridges only. Appropriate electrodes on their side walls enabled domain inversion restricted to the ridge. The domain structure was investigated by selective chemical etching. Second harmonic generation in a 1.4 cm long ridge waveguide on an X-cut substrate was demonstrated at 1548 nm fundamental wavelength with an efficiency of 17% W(-1).