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Search Results: 1 - 10 of 7474 matches for " Clement KM Ho "
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Activation of the control reporter plasmids pRL-TK and pRL-SV40 by multiple GATA transcription factors can lead to aberrant normalization of transfection efficiency
Clement KM Ho, Jerome F Strauss
BMC Biotechnology , 2004, DOI: 10.1186/1472-6750-4-10
Abstract: We report here that plasmids expressing GATA-4 or GATA-6 transcription factor increased Renilla luciferase gene expression by 2 to 8 fold when co-transfected with pRL-TK or pRL-SV40. This alteration of the control reporter gene activity was shown to cause erroneous normalization of transfection efficiency and thus misinterpretation of results in a transactivation assay. To circumvent the problem, we generated two mutant control plasmids from which putative GATA response elements were deleted. These deletions rendered pRL-SV40 unresponsive to GATA transcription factor stimulation and reduced the response of pRL-TK. A database search also indicates that consensus GATA binding sequences are present in other commercially available Renilla luciferase encoding plasmids; therefore, the latter can potentially be transactivated by GATA transcription factors.Taken together, these findings highlight the importance of the selection of an appropriate control reporter plasmid for the normalization of transfection efficiency.In transient transfection experiments, a promoter sequence of interest coupled to a reporter gene is often co-transfected with a control plasmid whose expression is constitutive in order to normalize for transfection efficiency or cell viability. Reporter plasmids which contain cDNA encoding the Renilla (Renilla reniformis) luciferase enzyme (Rluc) have become increasingly popular as controls for such a purpose. Rluc is not intrinsically expressed in mammalian cells and can function as an enzyme immediately following translation because post-translational modification is not required for its activity. Also, like firefly (Photinus pyralis) luciferase, Renilla luciferase activity can be assayed with high sensitivity and linearity over several orders of magnitude. In the widely used Dual Luciferase Reporter (DLR) assay system (Promega, Madison, WI), activities of firefly and Renilla luciferases are measured sequentially from a single sample based on the different
Venous thromboembolism prophylaxis in hospitalized elderly patients: Time to consider a 'MUST' strategy
Venous thromboembolism prophylaxis in hospitalized elderly patients: Time to consider a ‘MUST’ strategy

Ho Kwok M,Litton Edward,
,Litton E

老年心脏病学杂志(英文版) , 2011,
Abstract: Venous thromboembolism (VTE) is the commonest cause of preventable death in hospitalized patients.Elderly patients have higher risk of VTE because of the high prevalence of predisposing comorbidities and acute illnesses.Clinical diagnosis of VTE in the elderly patient is particularly difficult and,as such,adequate VTE prophylaxis is of pivotal importance in reducing the mortality and morbidities of VTE.Omission of VTE prophylaxis is,however,very common despite continuous education.A simple way to overcome this problem is to implement universal VTE prophylaxis for all hospitalized elderly patients instead of selective prophylaxis for some patients only according to individual's risk of VTE.Although pharmacological VTE prophylaxis is effective for most patients,a high prevalence of renal impairment and drug interactions in the hospitalized elderly patients suggests that a multimodality approach may be more appropriate.Mechanical VTE prophylaxis,including calf and thigh compression devices and/or an inferior vena cava filter,are often underutilized in hospitalized elderly patients who are at high-risk of bleeding and VTE.Because pneumatic compression devices and thigh length stockings are virtually risk free,mechanical VTE prophylaxis may allow early or immediate implementation of VTE prophylaxis for all hospitalized elderly patients,regardless of their bleeding and VTE risk.Although the cost-effectiveness of this Multimodality Universal STat ('MUST') VTE prophylaxis approach for hospitalized elderly patients remains uncertain,this strategy appears to offer some advantages over the traditional `selective and single-modal' VTE prophylaxis approach,which often becomes `hit or miss' or not implemented promptly in many hospitalized elderly patients.A large clustered randomized controlled trial is,however,needed to assess whether early,multimodality,universal VTE prophylaxis can improve important clinical outcomes of hospitalized elderly patients.
A Receiver for Differential Space-Time -Shifted BPSK Modulation Based on Scalar-MSDD and the EM Algorithm
Riediger Michael LB,Ho Paul KM,Kim Jae H
EURASIP Journal on Wireless Communications and Networking , 2005,
Abstract: In this paper, we consider the issue of blind detection of Alamouti-type differential space-time (ST) modulation in static Rayleigh fading channels. We focus our attention on a -shifted BPSK constellation, introducing a novel transformation to the received signal such that this binary ST modulation, which has a second-order transmit diversity, is equivalent to QPSK modulation with second-order receive diversity. This equivalent representation allows us to apply a low-complexity detection technique specifically designed for receive diversity, namely, scalar multiple-symbol differential detection (MSDD). To further increase receiver performance, we apply an iterative expectation-maximization (EM) algorithm which performs joint channel estimation and sequence detection. This algorithm uses minimum mean square estimation to obtain channel estimates and the maximum-likelihood principle to detect the transmitted sequence, followed by differential decoding. With receiver complexity proportional to the observation window length, our receiver can achieve the performance of a coherent maximal ratio combining receiver (with differential decoding) in as few as a single EM receiver iteration, provided that the window size of the initial MSDD is sufficiently long. To further demonstrate that the MSDD is a vital part of this receiver setup, we show that an initial ST conventional differential detector would lead to strange convergence behavior in the EM algorithm.
Dynamic combinatorial chemistry at the phospholipid bilayer interface
Friederike M Mansfeld, Ho Au-Yeung, Jeremy KM Sanders, Sijbren Otto
Journal of Systems Chemistry , 2010, DOI: 10.1186/1759-2208-1-12
Abstract: Thioester exchange was found to be a suitable reversible reaction to achieve rapid equilibration of dynamic combinatorial libraries at the egg phosphatidyl choline bilayer interface. Competing thioester hydrolysis can be minimised by judicial choice of the structure of the thioesters and the experimental conditions. Comparison of the library compositions in bulk solution with those in the presence of egg PC revealed that the latter show a bias towards the formation of library members rich in membrane-bound building blocks. This leads to a shift away from macrocyclic towards linear library members.The methodology to perform dynamic combinatorial chemistry at the phospholipid bilayer interface has been developed. The spatial confinement of building blocks to the membrane interface can shift the ring-chain equilibrium in favour of chain-like compounds. These results imply that interfaces may be used as a platform to direct systems to the formation of (informational) polymers under conditions where small macrocycles would dominate in the absence of interfacial confinement.Dynamic combinatorial chemistry [1-3] is a growing field in the general area of systems chemistry [4-11] and revolves around equilibrium mixtures of molecules or supramolecules that can exchange the building blocks from which they are constituted. The resulting dynamic combinatorial libraries (DCLs) are inherently responsive to influences that alter the relative thermodynamic stabilities of the library members. For example, addition of a template (a guest molecule or a biomolecule) to a DCL will result in a stabilization of those library members that bind to the template, inducing a shift in the product distribution, ideally in favour of the best binders and at the expense of the other unwanted library members. This responsiveness makes dynamic combinatorial chemistry an important tool for the discovery of new synthetic receptors [12-21] and ligands for biomolecules [22-25]. Moreover, the technique has
Ito’s Formula for the Discrete-Time Quantum Walk in Two Dimensions  [PDF]
Clement Ampadu
Journal of Quantum Information Science (JQIS) , 2012, DOI: 10.4236/jqis.2012.22008
Abstract: Following Konno [1], it is natural to ask: What is the Ito’s formula for the discrete time quantum walk on a graph different than Z, the set of integers? In this paper we answer the question for the discrete time quantum walk on Z2, the square lattice.
On Some Questions of C. Ampadu Associated with the Quantum Random Walk  [PDF]
Clement Ampadu
Applied Mathematics (AM) , 2014, DOI: 10.4236/am.2014.519291
Abstract: We review (not exhaustively) the quantum random walk on the line in various settings, and propose some questions that we believe have not been tackled in the literature. In a sense, this article invites the readers (beginner, intermediate, or advanced), to explore the beautiful area of quantum random walks.
A profile of the online dissemination of national influenza surveillance data
Calvin KY Cheng, Eric HY Lau, Dennis KM Ip, Alfred SY Yeung, Lai Ho, Benjamin J Cowling
BMC Public Health , 2009, DOI: 10.1186/1471-2458-9-339
Abstract: We searched for national influenza surveillance websites for every country and reviewed the resulting sites where available during the period from November 2008 through February 2009. Literature about influenza surveillance was searched at MEDLINE for relevant hyperlinks to related websites. Non-English websites were translated into English using human translators or Google language tools.A total of 70 national influenza surveillance websites were identified. The percentage of developing countries with surveillance websites was lower than that of developed countries (22% versus 57% respectively). Most of the websites (74%) were in English or provided an English version. The most common surveillance methods included influenza-like illness consultation rates in primary care settings (89%) and laboratory surveillance (44%). Most websites (70%) provided data within a static report format and 66% of the websites provided data with at least weekly resolution.Appropriate dissemination of surveillance data is important to maximize the utility of collected data. There may be room for improvement in the style and content of the dissemination of influenza data to health care professionals and the general public.Upper respiratory viruses cause significant global mortality and morbidity each year [1]. Influenza virus is of particular public health concern due to its association with severe infections and deaths, and its propensity of causing large scale seasonal epidemics and pandemics. Local and national prospective influenza and influenza-like illness surveillance systems provide important and timely information to policy makers and public health practitioners for monitoring trends and disease burden, planning, implementing, and evaluating appropriate prevention and control interventions, and allocating resources [2]. Recent decades have seen dramatic improvements in influenza surveillance systems [3]. Surveillance websites serve as an excellent tool for communicating timely i
The relative length of Pig chromosomes, and a suggestion for a karyotype system
KM Hansen
Genetics Selection Evolution , 1980, DOI: 10.1186/1297-9686-12-4-313
Identification of the X chromosome of the domestic pig (Sus scrofa domestica)
KM Hansen
Genetics Selection Evolution , 1980, DOI: 10.1186/1297-9686-12-3-225
Identification of the chromosomes of the domestic pig (Sus scrofa domestica). An identification key and a landmark system
KM Hansen
Genetics Selection Evolution , 1977, DOI: 10.1186/1297-9686-9-4-517
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