170 research outputs found
Anti-cancer efficiency of natural killer cells differentiated from human adipose tissue-derived mesenchymal stem cells and transfected with miRNA150
Aim: The aim of this study is to investigate the effects of miR150 transfection on NK-like cells differentiated from adipose tissue derived mesenchymal stem cells (AD-MSCs). Methods: NK-like cells were differentiated from AD-MSCs and activated by miR150 transfection. Transfected/non-transfected NK-like cells were characterized by immunohistochemical and RTPCR analyzes. Apoptotic efficiency of the transfected/non-transfected NK-like cells on pancreatic cancer cells PANC1 were determined by TUNEL and RT-PCR. Results: In miR150-transfected cells, the increased expression of NK cell-specific genes such as GZMB, KIR2DL2, CD16, CD56, NKG2D, NKp46 and increased immunoreactivity of NK cell-specific surface marker CD314 (NKG2D) were evident. TUNEL assays showed that NK-like cells with/without transfection induced apoptosis in PANC1 cells in the same manner. The decrease in oncogene expression and the increase in the tumor suppressor gene expression in PANC1 cells upon co-culture with NK-like cells differentiated from AD-MSCs were more prominent following miRNA150 transfection. Conclusion: It was shown in vitro that NK-like cells could be obtained by differentiation from AD-MSCs and their efficiency could be increased via miR150 transfection. The results are encouraging for further clinical studies in improvement of immunotherapeutic approaches for cancer therapy
Lifetime determination of excited states in Cd-106
Two separate experiments using the Differential Decay Curve Method have been performed to extract mean lifetimes of excited states in 106 Cd. The inedium-spin states of interest were populated by the Mo-98(C-12, 4n) Cd-106 reaction performed at the Wright Nuclear Structure Lab., Yale University. From this experiment, two isomeric state mean lifetimes have been deduced. The low-lying states were populated by the Mo-96(C-13, 3n)Cd-106 reaction performed at the Institut fur Kernphysik, Universitat zu Koln. The mean lifetime of the I-pi = 2(1)(+) state was deduced, tentatively, as 16.4(9) ps. This value differs from the previously accepted literature value from Coulomb excitation of 10.43(9) ps
Revisiting anomalous \u3cem\u3eB\u3c/em\u3e(\u3cem\u3eE\u3c/em\u3e2;4\u3csup\u3e+\u3c/sup\u3e\u3csub\u3e1\u3c/sub\u3e→2\u3csup\u3e+\u3c/sup\u3e\u3csub\u3e1\u3c/sub\u3e)/\u3cem\u3eB\u3c/em\u3e(\u3cem\u3eE\u3c/em\u3e2;2\u3csup\u3e+\u3c/sup\u3e\u3csub\u3e1\u3c/sub\u3e→0\u3csup\u3e+\u3c/sup\u3e\u3csub\u3e1\u3c/sub\u3e) values in \u3csup\u3e98\u3c/sup\u3eRu and \u3csup\u3e180\u3c/sup\u3ePt
Recently, a set of nine nonmagic nuclei with anomalous values of the B(E2) ratio B4/2 ≡ B(E2; 4+1 → 2+1)/B(E2; 2+1 → 0+1) were identified. Such values are outside the range allowed by current collective models. In the present work, the B(E2; 4+1 → 2+1) values for two of these nuclei, 98Ru and 180Pt, were re-measured to determine if the current literature values for these nuclei are correct. 98Ru was studied in a 27Al(98Ru,98Ru∗) Coulomb excitation experiment in inverse kinematics, while the lifetime of the 4+1 state in 180Pt was measured in a 122Sn(62Ni, 4n)180Pt recoil distance method (RDM) experiment. For both nuclei, the remeasured B4/2 values are well above 1, removing the deviations from collective models
Measurement of Conversion Coefficients in Normal and Triaxial Strongly Deformed Bands in \u3csup\u3e167\u3c/sup\u3eLu
Internal conversion coefficients have been measured for transitions in both normal deformed and triaxial strongly deformed bands in 167Lu using the Gammasphere and ICE Ball spectrometers. The results for all in-band transitions are consistent with E2 multipolarity. Upper limits are determined for the internal conversion coefficients for linking transitions between TSD Band 2 and TSD Band 1, the nw = 1 and nw = 0 wobbling bands, respectively
Isomeric Decay of \u3csup\u3e208\u3c/sup\u3eRa
Low-energy excited states of 208Ra were investigated using the 182W(30Si, 4n) reaction at the Wright Nuclear Structure Laboratory of Yale University. Fusion evaporation recoils were selected using the gas-filled spectrometer SASSYER. Delayed γ rays, following isomeric decays, were detected at the focal plane of SASSYER with a small array of three clover Ge detectors. Transitions following a proposed J π = 8+ isomer were observed, and the half-life was measured
Quadrupole Moment Measurements of TSD1 and TSD2 Bands in \u3csup\u3e167\u3c/sup\u3eLu
The triaxial strongly deformed (TSD) bands in 167Lu were populated by the 123Sb(48Ca, 4n) reaction with a beam energy of 203 MeV. Gamma rays, requiring fivefold or more in prompt coincidence, were detected with the Gammasphere spectrometer. Of particular interests are TSD bands 1 and 2 which have previously been interpreted as zero phonon and one phonon wobbling bands, respectively. Using the Doppler shift attenuation method (DSAM), a preliminary transition quadrupole moment of 6.9+0.3−0.3 eb was extracted for the TSD1 band. Data analysis continues for TSD2 which is considerably more weakly populated
\u3cem\u3eg\u3c/em\u3e Factor of the 2\u3csup\u3e+\u3c/sup\u3e\u3csub\u3e1\u3c/sub\u3e State of \u3csup\u3e170\u3c/sup\u3eHf
The g factor of the 2+1 state of 170Hf was measured by perturbed γ-γ angular correlation in a static external magnetic field. The result, g(2+1) = 0.28(5), extends the systematics of g factors of even-even Hf isotopes to N = 98 and enables a better test of theoretical models. The g(2+1) experimental values of these isotopes exhibit a remarkable constancy as a function of neutron number. This phenomenon, which was also observed for other isotopic chains in the Gd–W range, is explained in terms of a recently proposed empirical model
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Estimation of (\u3cem\u3en, f\u3c/em\u3e) Cross Sections by Measuring Reaction Probability Ratios
Neutron-induced reaction cross sections on unstable nuclei are inherently difficult to measure due to target activity and the low intensity of neutron beams. In an alternative approach, named the “surrogate” technique, one measures the decay probability of the same compound nucleus produced using a stable beam on a stable target to estimate the neutron-induced reaction cross section. As an extension of the surrogate method, in this paper we introduce a new technique of measuring the fission probabilities of two different compound nuclei as a ratio, which has the advantage of removing most of the systematic uncertainties. This method was benchmarked in this report by measuring the probability of deuteron-induced fission events in coincidence with protons, and forming the ratio P[236U(d,pf)]/P [238U(d,pf)], which serves as a surrogate for the known cross section ratio of 236U(n, f)/238U(n, f). In addition, the P[238U(d, d f)]/P [236U(d, df)] ratio as a surrogate for the 237U(n, f)/235U(n, f) cross section ratio was measured for the first time in an unprecedented range of excitation energies
Isomers and Seniority in the Trans-Pb Nuclei
Low-energy excited states of 210Ra and 208Ra were investigated at the Wright Nuclear Structure Laboratory of Yale University. Fusion evaporation recoils were selected using the gas-filled spectrometer, SASSYER. Delayed γ -rays, following isomeric decays, were detected at the focal plane of SASSYER with a small array of HPGe detectors. Transitions following the proposed J π = 8+ isomers were observed, and the half-lives measured. The experiments are discussed and results compared to expectations from the seniority scheme
Measuring Reaction Probability Ratios to Simulate Neutron-Induced Cross-sections of Short-Lived Nuclei
Measuring the neutron-induced fission cross-sections of short-lived nuclei represents an experimental challenge due to target activity and the low intensity of neutron beams. One way to alleviate the problems inherent in the direct measurement is to use the surrogate method, where one measures the decay probability of the same compound nucleus formed using a charged beam and a stable target. The decay probability of the compound nucleus is then used to estimate the neutron-induced cross-section. As an extension to the surrogate method, we introduce a new method of reporting the fission probabilities of two compound nuclei as a ratio, which has the advantage of removing most of the systematic uncertainties. The ratio method was checked in a known case, the 236U (n, f) /238U (n, f) cross-section ratio, which turned out to be the same as the probability ratio of P (236U (d, pf))/P (238U (d, pf)). As an application, the 237U(n, f )/235U(n, f ) cross-section ratio was inferred, on the basis of the measured P(238U(d, d f ))/P (236U(d, d f )) probability ratio
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