118,159 research outputs found
CHO microRNA engineering is growing up : recent successes and future challenges
microRNAs with their ability to regulate complex pathways that control cellular behavior and phenotype have been proposed as potential targets for cell engineering in the context of optimization of biopharmaceutical production cell lines, specifically of Chinese Hamster Ovary cells. However, until recently, research was limited by a lack of genomic sequence information on this industrially important cell line. With the publication of the genomic sequence and other relevant data sets for CHO cells since 2011, the doors have been opened for an improved understanding of CHO cell physiology and for the development of the necessary tools for novel engineering strategies. In the present review we discuss both knowledge on the regulatory mechanisms of microRNAs obtained from other biological models and proof of concepts already performed on CHO cells, thus providing an outlook of potential applications of microRNA engineering in production cell lines
Intensity-dependent resonant transmission of x-rays in solid-density aluminum plasma
X-ray free-electron lasers (XFELs) provide unique opportunities to generate and investigate dense plasmas. The absorption and transmission properties of x-ray photons in dense plasmas are important in characterizing the state of the plasmas. Experimental evidence shows that the transmission of x-ray photons through dense plasmas depends greatly on the incident XFEL intensity. Here, we present a detailed analysis of intensity-dependent x-ray transmission in solid-density aluminum using collisional-radiative population kinetics calculations. Reverse saturable absorption (RSA), i.e., an increase in x-ray absorption with intensity has been observed for photon energies below the K-absorption edge and in the intensity range of 1016-1017 W/cm2 for XFEL photons with 1487 eV. At higher intensities, a transition from RSA to saturable absorption (SA) is predicted; thus, the x-ray absorption decreases with intensity above a threshold value. For XFEL photon energies of 1501 eV and 1515 eV, the transition from RSA to SA occurs at XFEL intensities between 1017-1018 W/cm2. Electron temperatures are predicted to be in the range of 30-50 eV for the given experimental conditions. Detailed population kinetics of the charge states explains the intensity-dependent absorption of x-ray photons and the fast modulation of XFEL pulses for both RSA and SA. © 2018 Author(s
Cho, M., Song, M., Yeom, S., Wang, Il., Choi, Byung.
In a healthcare environment, it is essential to manage the emergency room process since its connectivity to the quality of care. In managing clinical operations, quantitative process performance analysis is typically performed with process mining, and there have been several approaches to utilize process mining in emergency room process analysis. These research provide a comprehensive methodology to analyze the emergency room processes using process mining; however, performance indicators for directly assessing the emergency room processes are lacking. To overcome the limitation, this paper proposes a framework of process performance indicators utilized in emergency rooms. The proposed framework starts with the devil’s quadrangle, i.e., time, cost, quality, and flexibility. Based on four perspectives, we suggest specific process performance indicators with a formal explanation. To validate the applicability of this research, we present a case study result with the real-life clinical data collected from a tertiary hospital in Korea.1
The antihypertensive effects of the Jamaican Cho-Cho (Sechium edule)
The experiments reported in this study constitute a preliminary investigation into the possible hypotensive effect of the Jamaican Cho-Cho (Sechium edule). Experiments were conducted in a random and blind fashion on two sub species of Sechium edule. Both the pulp and the peel were examined for hypotensive activity. Water-soluble extracts were prepared from these components of the fruit and injected into anaesthetised rats. Various cardiovascular parameters were measured including heart rate, mean arterial pressure (MAP) and several ECG intervals. We report that all extracts tested produced a fall in blood pressure with little change in ECG intervals. Extract B produced the least change in heart rate with a fall in MAP of approximately 23 mmHg. Changes in heart rate with all extracts appeared to be minimal as an ED25 value could only be determined for extract A, and ED10 values could not be evaluated for extracts C and D. The mechanism(s) by which these extracts produce their hypotensive effects could not be determined in these preliminary experiments. However, it appears not to involve direct effects on cardiac tissue. This conclusion is based on the finding that it took a minimum of 10 to 15 seconds for the hypotensive action to manifest post bolus. Future experiments will be aimed at delineating the mechanism(s) involved in decreasing MAP.Peer reviewedfinal article publishe
1H NMR Spectroscopy Profiling of Metabolic Reprogramming of Chinese Hamster Ovary Cells upon a Temperature Shift during Culture
We report an NMR based approach to determine the metabolic reprogramming of Chinese hamster ovary cells upon
a temperature shift during culture by investigating the extracellular cell culture media and intracellular metabolome of
CHOK1 and CHO-S cells during culture and in response to cold-shock and subsequent recovery from hypothermic
culturing. A total of 24 components were identified for CHOK1 and 29 components identified for CHO-S cell systems
including the observation that CHO-S media contains 5.6 times the level of glucose of CHOK1 media at time zero.
We confirm that an NMR metabolic approach provides quantitative analysis of components such as glucose and
alanine with both cell lines responding in a similar manner and comparable to previously reported data. However,
analysis of lactate confirms a differentiation between CHOK1 and CHO-S and that reprogramming of metabolism in
response to temperature was cell line specific. The significance of our results is presented using principal component
analysis (PCA) that confirms changes in metabolite profile in response to temperature and recovery. Ultimately, our
approach demonstrates the capability of NMR providing real-time analysis to detect reprogramming of metabolism
upon cellular perception of cold-shock/sub-physiological temperatures. This has the potential to allow manipulation of
metabolites in culture supernatant to improve growth or productivity
All-optical wavelength conversion with multicasting at 4 x 10 Gbits/s up and down using a Fabry-Perot laser diode
We demonstrate an all-optical wavelength converter with multicasting at 4 x 10 Gbits/s up and down conversion using gain modulation in an FP-LD. We also explain the gain modulation technique using the bistability behavior of the injection locked FP-LD. The wavelength converter shows the average power penalty of 1.5 dB at a bit error rate of 10(-9) and the extinction ratio of outputs over 12 dB, both for up and down conversions
Dr. Glendon Swarthout
Hosted by Roger M. Busfield, MSU Assistant Professor of Speech and Theater, Meet the Author is designed to introduce a general audience to a contemporary author and their work through in-depth interviews. This episode features a conversation between Dr. Glendon Swarthout, prolific author and English professor at MSU, and assistant professors Sam S. Baskett and Theodore B. Strandness
Differential effects of protein kinase A sub-units on Chinese-hamster-ovary cell cycle and proliferation
It has been shown that a marked increase in the levels of RI alpha sub-units and a decrease in RII beta sub-unit levels correlate with neoplastic transformation or with the mitogenic response of normal cells to hormones and growth factors. The selective down-regulation of RI alpha and the following induction of RII beta determine cell-growth arrest and differentiation of several cancer cells. To directly address the question whether the 2 protein-kinase-A(PKA) isoforms play different roles in the control of proliferation and cell-cycle distribution, we introduced and over-expressed the different PKA sub-units in Chinese-hamster-ovary (CHO) cells via retroviral-vector-mediated gene transfer. Whereas CHO cells treated with RI alpha anti-sense oligodeoxynucleotides were growth arrested and accumulated in the G0/G1 phases of the cell cycle, infection of CHO cells with a retroviral vector in order to over-express RI alpha determined growth advantages in monolayer conditions and substantially increased their cloning efficiency in soft agar. These events correlated with a sustained percentage of cells in S phase induced by RI alpha over-expression in the infected cells. In contrast, CHO cells infected with retroviral vectors over-expressing either a RII beta sub-unit or a C alpha catalytic sub-unit of PKA exhibited growth arrest within a few days of culture and accumulated in the G2-M phase of the cell cycle. The results of our study demonstrate that the different PKA sub-units play different and specific roles in the control of cell growth and cell-cycle distribution
Measurement of the mass difference m(D-s(+))-m(D+) at CDF II
We present a measurement of the mass difference m(D-s(+))-m(D+), where both the D-s(+) and D+ are reconstructed in the phipi(+) decay channel. This measurement uses 11.6 pb(-1) of data collected by CDF II using the new displaced-track trigger. The mass difference is found to be m(D-s(+))-m(D+)=99.41+/-0.38(stat)+/-0.21(syst) MeV/c(2)
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