5,720 research outputs found
A general weak nonlinearity model for LNAs
This paper presents a general weak nonlinearity model that can be used to model, analyze and describe the distortion behavior of various low noise amplifier topologies in both narrowband and wideband applications. Represented by compact closed-form expressions our model can be easily utilized by both circuit designers and LNA design automation algorithms.\ud
Simulations for three LNA topologies at different operating conditions show that the model describes IM components with an error lower than 0.1% and a one order of magnitude faster response time. The model also indicates that for narrowband IM2@w1-w2 all the nonlinear capacitances can be neglected while for narrowband IM3 the nonlinear capacitances at the drainterminal can be neglected
Effects of anesthesia on conventional and speckle tracking echocardiographic parameters in a mouse model of pressure overload
Genetically‑modified mice are widely applied in cardiovascular studies as model organisms. Echocardiography is a key tool for evaluating cardiac and hemodynamic functions in mice. The present study aimed to examine the effects of isoflurane (ISF) on conventional and speckle tracking echocardiography (STE) parameters under healthy and pathological conditions using a murine model of pressure overload. In addition, the optimal dose of ISF in the process of echocardiographic measurement, with minimum cardiac contraction depression, was investigated. Conventional echocardiographic and STE examinations were performed on 38 adult C57BL/6 male mice. The mice were divided into the following three groups: The sham (n=15); mild thoracic aortic banding (TAB; n=15); and severe TAB (n=8) groups. ISF was administered under deep anesthesia (DA; 1‑2% ISF), light anesthesia (LA; 0.5‑1% ISF) and immediately prior to the mice waking up (awake; 0‑0.5% ISF). Conventional echocardiographic parameters were preserved within the sham and mild TAB groups (P>0.05 for each parameter) under LA and awake conditions. However, under DA conditions, the majority of these parameters were reduced compared with the LA and awake conditions (P<0.05). In the severe TAB group, conventional echocardiographic parameters remained constant under LA, DA and awake conditions. STE parameters in the groups remained similar between the LA and awake conditions, but were significantly reduced under DA conditions. Therefore, conventional echocardiography and STE may be performed using LA induced with low doses of ISF, under various pathological conditions without affecting cardiac function
STRATEGIES FOR BUSINESS IN VIRTUAL WORLDS: CASE STUDIES IN SECOND LIFE
Second Life (SL) is an immersive, virtual 3D social interaction environment developed by Linden Lab where business including monetary transactions can take place. SL is a virtual world that also provides support for virtual organisations; a group of individuals whose members and resources may be dispersed geographically, but who function as a coherent unit through the use of cyber infrastructure. In this paper, we use qualitative and quantitative methodologies to analyse and understand a range of business strategies and activities in SL. We discuss key economic elements in SL and classify firms from the Forbes Global Top 500 companies which have a presence and who operate in B-B, B-C, C-C, and G-C spaces within SL. We develop business cases for three well known firms active in SL, namely IBM, Coca Cola, and Nissan, as a means to explore correlative relationships and potential business strategies future development
Cancer gene therapy : developments and future perspectives
Griffith Health, School of Medical ScienceFull Tex
M^3
M^3 aims to raise students\u27 interest in physics through an interactive and fun video game. Originally planned as a segment in the Cal Poly SLO Seeds in STEM workshop, M^3 is designed with middle and high school students as the intended audience
Clostridial spores for cancer therapy : targeting solid tumour microenvironment
Solid tumour accounts for 90% of all cancers. The current treatment approach for most solid tumours is surgery, however it is limited to early stage tumours. Other treatment options such as chemotherapy and radiotherapy are non-selective, thus causing damage to both healthy and cancerous tissue. Past research has focused on understanding tumour cells themselves, and conventional wisdom has aimed at targeting these cells directly. Recent research has shifted towards understanding the tumour microenvironment and it’s differences from that of healthy cells/tissues in the body and then to exploit these differences for treatmeat of the tumour. One such approach is utilizing anaerobic bacteria. Several strains of bacteria have been shown to selectively colonize in solid tumours, making them valuable tools for selective tumour targeting and destruction. Amongst them, the anaerobic Clostridium has shown great potential in penetration and colonization of the hypoxic and necrotic areas of the tumour microenvironment, causing significant oncolysis as well as enabling the delivery of therapeutics directly to the tumour in situ. Various strategies utilizing Clostridium are currently being investigated, and represent a novel area of emerging cancer therapy. This review provides an update review of tumour microenvironment as well as summary of the progresses and current status of Clostridial spore-based cancer therapies
The Natural History and Outcomes of the Patients with Carcinosarcoma Involving Kidney and Renal Pelvis
Background. The objective of this paper was to examine the epidemiology, natural history, and prognostic factors of carcinosarcoma of the kidney and renal pelvis (CSKP) using population-based registry. Patients and Methods. Forty-three patients with CSKP, diagnosed between January 1973 and December 2007, were identified from the national Surveillance, Epidemiology, and End Results (SEER) database and reviewed. Results. 79% of all patients with known SEER stage were classified as having regional or distant stage; almost all the patients with known histology grade had poorly or undifferentiated histology. The median cancer specific survival was 6 months (95% CI 4–9). The 1-year cancer-specific survival rate for entire cohort was 30.2%. There were no differences in terms of age at diagnosis, histological grade, tumor stage on presentation, and frequency of nephrectomy between carcinosarcoma of kidney (CSK) or renal pelvis (CSP). In multivariate analysis, age at diagnosis, tumor stage, and year of diagnosis were found to be significant predictors for cancer-specific survival. Conclusion. CSKP commonly presented as high-grade, advanced stage disease, and was associated with a poor prognosis regardless of location
Mid-IR frequency measurement using an optical frequency comb and a long-distance remote frequency reference
We have built a frequency chain which enables to measure the absolute
frequency of a laser emitting in the 28-31 THz frequency range and stabilized
onto a molecular absorption line. The set-up uses an optical frequency comb and
an ultrastable 1.55 m frequency reference signal, transferred from
LNE-SYRTE to LPL through an optical link. We are now progressing towards the
stabilization of the mid-IR laser via the frequency comb and the extension of
this technique to quantum cascade lasers. Such a development is very
challenging for ultrahigh resolution molecular spectroscopy and fundamental
tests of physics with molecules
Dipeptidyl Peptidase 10 (DPP10789): A Voltage Gated Potassium Channel Associated Protein Is Abnormally Expressed in Alzheimer’s and Other Neurodegenerative Diseases
Copyright © 2014 Tong Chen et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.The neuropathological features associated with Alzheimer’s disease (AD) include the presence of extracellular amyloid- peptidecontaining
plaques and intracellular tau positive neurofibrillary tangles and the loss of synapses and neurons in defined regions of
the brain. Dipeptidyl peptidase 10 (DPP10) is a protein that facilitates Kv4 channel surface expression and neuronal excitability. This
study aims to explore DPP10789 protein distribution in human brains and its contribution to the neurofibrillary pathology of AD
and other tauopathies. Immunohistochemical analysis revealed predominant neuronal staining of DPP10789 in control brains, and
the CA1 region of the hippocampus contained strong reactivity in the distal dendrites of the pyramidal cells. In AD brains, robust
DPP10789 reactivity was detected in neurofibrillary tangles and plaque-associated dystrophic neurites, most of which colocalized
with the doubly phosphorylated Ser-202/Thr-205 tau epitope. DPP10789 positive neurofibrillary tangles and plaque-associated
dystrophic neurites also appeared in other neurodegenerative diseases such as frontotemporal lobar degeneration, diffuse Lewy
body disease, and progressive supranuclear palsy. Occasional DPP10789 positive neurofibrillary tangles and neurites were seen in
some aged control brains.Western blot analysis showed both full length and truncatedDPP10789 fragments with the later increasing
significantly in AD brains compared to control brains. Our results suggest that DPP10789 is involved in the pathology of AD and
other neurodegenerative diseases
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