226 research outputs found

    Micro-resonator soliton generated directly with a diode laser

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    An external-cavity diode laser is reported with ultralow noise, high power coupled to a fiber, and fast tunability. These characteristics enable the generation of an optical frequency comb in a silica micro-resonator with a single-soliton state. Neither an optical modulator nor an amplifier was used in the experiment. This demonstration greatly simplifies the soliton generation setup and represents a significant step forward to a fully integrated soliton comb system.Comment: 7 pages, 5 figure

    Tumor-Targeted Synergistic Blockade of MAPK and PI3K from a Layer-by-Layer Nanoparticle

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    Purpose: Cross-talk and feedback between the RAS/RAF/MEK/ERK and PI3K/AKT/mTOR cell signaling pathways is critical for tumor initiation, maintenance, and adaptive resistance to targeted therapy in a variety of solid tumors. Combined blockade of these pathways—horizontal blockade—is a promising therapeutic strategy; however, compounded dose-limiting toxicity of free small molecule inhibitor combinations is a significant barrier to its clinical application. Experimental Design: AZD6244 (selumetinib), an allosteric inhibitor of Mek1/2, and PX-866, a covalent inhibitor of PI3K, were co-encapsulated in a tumor-targeting nanoscale drug formulation—layer-by-layer (LbL) nanoparticles. Structure, size, and surface charge of the nanoscale formulations were characterized, in addition to in vitro cell entry, synergistic cell killing, and combined signal blockade. In vivo tumor targeting and therapy was investigated in breast tumor xenograft-bearing NCR nude mice by live animal fluorescence/bioluminescence imaging, Western blotting, serum cytokine analysis, and immunohistochemistry. Results: Combined MAPK and PI3K axis blockade from the nanoscale formulations (160 ± 20 nm, −40 ± 1 mV) was synergistically toxic toward triple-negative breast (MDA-MB-231) and RAS-mutant lung tumor cells (KP7B) in vitro, effects that were further enhanced upon encapsulation. In vivo, systemically administered LbL nanoparticles preferentially targeted subcutaneous MDA-MB-231 tumor xenografts, simultaneously blocked tumor-specific phosphorylation of the terminal kinases Erk and Akt, and elicited significant disease stabilization in the absence of dose-limiting hepatotoxic effects observed from the free drug combination. Mice receiving untargeted, but dual drug-loaded nanoparticles exhibited progressive disease. Conclusions: Tumor-targeting nanoscale drug formulations could provide a more safe and effective means to synergistically block MAPK and PI3K in the clinic.United States. Department of Defense (OCRP Teal Innovator Award)National Institutes of Health (U.S.) (Grant NIBIB 1F32EB017614-02)Misrock FoundationNational Science Foundation (U.S.)Swiss National Science FoundationDavid H. Koch Institute for Integrative Cancer Research at MIT (Support Grant P30-CA14051)National Cancer Institute (U.S.)National Science Foundation (U.S.) (Massachusetts Institute of Technology. Materials Research Science and Engineering Center. Shared Experimental Facilities Grant DMR-0819762)Breast Cancer Alliance (Exceptional Project Grant

    Genetic Screening of GJB2 and SLC26A4 in Korean Cochlear Implantees: Experience of Soree Ear Clinic

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    ObjectivesGenetic hearing loss is highly heterogeneous and more than 100 genes are predicted to cause this disorder in humans. In spite of this large genetic heterogeneity, mutations in SLC26A4 and GJB2 genes are primarily responsible for the major etiologies of genetic hearing loss among Koreans. The purpose of this study is to investigate the genetic cause of deafness in Korean cochlear implantees by performing a genetic screening of the SLC26A4 and GJB2 genes.MethodsThe study cohort included 421 unrelated Korean patients with sensorineural hearing loss (SNHL) and who had received cochlear implants (CI) at Soree Ear Clinic from July 2002 to December 2010. Among 421 CI patients, we studied 230 cases who had received the genetic screening for SLC26A4 or GJB2 genes. Written informed consent was obtained from all participants. All patients had severe to profound, bilateral hearing loss. For 56 patients who showed enlarged vestibular aqueduct on their computed tomography (CT) scan, we analyzed SLC26A4. For 174 CT negative patients, GJB2 gene was sequenced.ResultsFor the 56 SLC26A4 patients, 32 (57.1%) had two pathogenic recessive mutations in SLC26A4. A single recessive SLC26A4 mutation was identified in 14 patients (25%). H723R and IVS7-2A>G were the most commonly found mutations, accounting for 60.3% (47/78) and 30.8% (24/78) of the mutated alleles, respectively. For the 174 GJB2 patients, 20 patients (11.5%) had two pathogenic recessive mutations in GJB2. 235delC was the most common mutation, accounting for 43.0% (31/72) of mutant alleles.ConclusionThe two major genes, SLC26A4 and GJB2, contribute major causes of deafness in CI patients. Continuous studies are needed to identify new genes that can cause hearing loss to Korean CI patients

    Expression of HSP70 and Its Relation with Other Cytokines in Human Middle Ear Effusion

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    ObjectivesWhile other cytokines are known to be associated with otitis media with effusion (OME), the involvement of heat shock protein 70 (HSP70) in middle ear effusion (MEE) is unknown. This study was undertaken to investigate the possibility of there being a HSP70 expression in human MEE and to determine its potential role as a cytokine in OME.MethodsThe levels of HSP70, tumor necrosis factor-alpha and interleukin-1beta were measured by enzyme-linked immunosorbent assay in the effusion of different groups of OME patient following collection of the MEE using our new collection system. The clinical characteristics of the OME patients and the MEE status were analyzed.ResultsHSP70 was expressed in all the types of MEE. The mucous and seromucous effusions showed higher HSP70 levels than that of the serous effusion. The HSP70 level was correlated with the levels of tumor necrosis factor (TNF)-α and interleukin (IL)-1β in the effusions. The positive correlations between HSP70, TNF-α and IL-1β were statistically significant (P<0.05).ConclusionThe highly elevated level of HSP70 in the seromucous and mucous effusions implicates this protein in the chronicity of OME

    Sentinel Lymph Node Radiolocalization with 99mTc Filtered Tin Colloid in Clinically Node-Negative Squamous Cell Carcinomas of the Oral Cavity

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    The objective of this study was to evaluate the feasibility of sentinel lymph node biopsy by using a radiotracer lymphatic mapping technique in patients with squamous cell carcinoma of the oral cavity, and the diagnostic value of this technique. We studied twenty patients with previously untreated squamous cell carcinomas of the oral cavity and N0 necks. After the peritumoral injection of 99mTc filtered tin colloid preop-eratively, lymphoscintigraphy and intraoperative mapping using a gamma detector were performed to localize sentinel nodes. An open biopsy of the sentinel node was followed by complete neck dissection. We identified the sentinel nodes in 19 of 20 patients (95.0%) by lymphoscintigraphy and in all (100%) by intraoperative gamma detector. In all cases, the status of the sentinel node accurately predicted the pathologic status of the neck with the false negative rate being 0%. The negative predictive value for the absence of cervical metastases was 100%. In conclusion, our radio-localization technique of sentinel nodes using 99mTc filtered tin colloid in N0 squamous cell carcinomas of the oral cavity is technically feasible and appears to accurately predict the presence of the occult metastatic disease

    Desenvolvimento e modelagem de quadrirrotor: um estudo de caso

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    TCC (graduação) - Universidade Federal de Santa Catarina. Centro Tecnológico. Engenharia Elétrica.Este trabalho apresenta um estudo sobre o desenvolvimento e modelagem de um veículo quadrirrotor. Este documento acompanha o processo de desenvolvimento de uma dessas aeronaves, partindo de um estudo sobre as principais dinâmicas de voo e características desse tipo de sistema. No estudo é apresentado um processo de caracterização usando as diferentes componentes do aparelho, o que permitiu a modelagem e simulação do sistema. É proposto também uma solução para implementação e controle a partir desse modelo simulado

    Detection of Sentinel Lymph Nodes in patients with Early Stage Cervical Cancer

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    The purpose of this study was to determine the feasibility of identifying the sentinel lymph nodes (SNs) as well as to evaluate factors that might influence the SN detection rate in patients with cervical cancer of the uterus. Eighty nine patients underwent intracervical injection of 1% isosulfan blue dye at the time of planned radical hysterectomy and lymphadenectomy between January 2003 and December 2003. With the visual detection of lymph nodes that stained blue, SNs were identified and removed separately. Then all patients underwent complete pelvic lymph node dissection and/or para-aortic lymph node dissection. SNs were identified in 51 of 89 (57.3%) patients. The most common site for SN detection was the external iliac area. Metastatic nodes were detected in 21 of 89 (23.5%) patients. One false negative SN was obtained. Successful SN detection was more likely in patients younger than 50 yr (p=0.02) and with a history of preoperative conization (p=0.05). However, stage, histological type, surgical procedure and neoadjuvant chemotherapy showed no significant difference for SN detection rate. Therefore, the identification of SNs with isosulfan blue dye is feasible and safe. The SN detection rate was high in patients younger than 50 yr or with a history of preoperative conization
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