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711.
Juanli Mao Mingjun Gao Bin Cui Yingying Zhang Xiaojiao Wang Siyu Liang Changjing Zuo Peng Chen Aisheng Dong 《Molecules (Basel, Switzerland)》2022,27(14)
68Ga-prostate specific membrane antigen (PSMA)-11 PET/CT has been widely used in the diagnosis of prostate cancer (PCa); however, the urine lead shielding resulting from the urinary metabolism of tracers may obstruct the detection of surrounding metastasis. In this research, the additive value of super early scanning in diagnosing primary lesions and metastasis in the pelvic cavity was evaluated. Firstly, the differentiation efficiency of 68Ga-PSMA-11 PET scanned at 3 min post-injection (min P.I.) was measured in PSMA-positive (22rv1 cells) and PSMA-negative (PC3 cells) model mice. Secondly, 106 patients were scanned at 3 min P.I. for the pelvic cavity and then scanned as a standard protocol at 45 min P.I. In the results, the differential diagnosis of PSMA expression was completely reflected as early as 3 min P.I. for mice models. For patients, when correlated with the Gleason score, the quantitative results of the super early scan displayed a comparable correlation coefficient with the routine scan. The target to bladder ratios increased from 1.44 ± 2.40 at 45 min to 10.10 ± 19.10 at 3 min (p < 0.001) for the primary lesions, and it increased from 0.99 ± 1.88 to 9.27 ± 23.03 for metastasis. Meanwhile, the target to background ratios increased from 2.21 ± 2.44 at 3 min to 19.13 ± 23.93 at 45 min (p < 0.001) for the primary lesions, and it increased from 1.68 ± 2.71 to 12.04 ± 18.73 (p < 0.001) for metastasis. In conclusion, super early scanning of 68Ga-PSMA-11 PET/CT added referable information for metastasis detection in order to avoid disturbing tracer activity in the urinary system. 相似文献
712.
713.
为探讨超声心动图诊断胎儿卵圆孔血流受限或提前闭合(FO-R/C)的价值,本文分析了 31例FO-R/C胎儿(观察组)和30例正常胎儿(对照组)超声心动图资料,以病理或出生后超声心动图诊断结果为准,分析超声心动图诊断FO-R/C的效能.结果显示,观察组胎儿卵圆孔最大流度、右室与左室内径比值(RV/LV)、右房与左房内径比... 相似文献
714.
人血清血卟啉荧光光谱的双正交样条小波识别 总被引:2,自引:0,他引:2
人血清中血卟啉含量很低,其荧光光谱强度很弱,往往呈肩峰形态,难以识别其位置和荧光强度。双正交样条小波可实现对其弱信号的分辨。在血清背景荧光光谱上叠加血卟啉荧光信号,并改变其荧光强度,得到一系列强度改变的 血清血卟啉荧光光谱。用双正交样条小波bior5.5对获取的荧光光谱通过7次小波分解,将背景与卟啉荧光信号分离,得到了离散逼近信号(a1~a7)和离散细节信号(d1~d7)。结果 表明,信号频率随着分解次数的增加逐步降低。当分解到第7次时,出现了血卟啉荧光特征峰。信号峰的位置随着信号强度的下降蓝移约2.5 nm,而通过小波滤波器提取的信号峰的位置不变。随着信号的强度降低,信号峰的位置逐渐消失 ,因而其荧光强度与荧光峰的位置无法确定,而通过小波滤波器提取的信号则不受影响,且灵敏度高,从而实现了用双正交样条小波对人血清血卟啉荧光光谱的识别。由于小波变换是线性变换,离散细节信号保持信号原有的线性关系,可 以用来对血清中所含血卟啉的准确成份和定量信息,从而进行定性和定量分析,为血清荧光光谱用于肿瘤的早期诊断提供了一种方法。 相似文献
715.
Mahmoud Parvazinia 《国际化学动力学杂志》2023,55(1):49-60
The gas-phase ethylene polymerizations with SiO2-supported Ziegler–Natta (ZN) catalyst at early moments of reaction is modeled. The experimental data used in this work show that at initial stages of the polymerization there is a sharp reduction in the reaction rate and a sharp rise in molecular weight. In the modeling, multi-active sites assumption and diffusion limitations inside the particle are studied. Energy balance to calculate the temperature at early moment is applied. Kinetic model including initiation, propagation, chain transfers and active site deactivation steps are used to predict the reaction rate and molecular weights. Polymeric flow model (PFM) is applied for single particle model (SPM). The results show two distinct regions. First region with sharp gradient for reaction rate and molecular weights and then, shortly there is a smooth region in which the changes in rate and molecular weights are slow. To fit this sharp gradient followed by a nearly steady state behavior two types of active sites are necessary. A group of highly active sites which deactivated soon and the active sites with lower activity and relatively long-lasting. 相似文献
716.
Fulvio Melia 《Annalen der Physik》2023,535(9):2300157
The energy conditions in general relativity are introduced to establish powerful theorems without having to restrict their applicability to specific choices of the stress-energy tensor. They are famously invoked, e.g., to prove the singularity theorems of Penrose and Hawking, but have also been applied elsewhere, including various tests of certain cosmological theories. These conditions have become somewhat controversial, however, because they appear to be violated by commonly accepted scenarios, such as inflation shortly after the Big Bang and late-time acceleration of the cosmic expansion. But accommodating these processes by abandoning all of the energy conditions will promote other disquieting possibilities, including the breakdown of causality with traversable wormholes and closed timeloops. This paper advocates for the opposite viewpoint, demonstrating that the ‘numen’ scalar field, derived from the zero active mass condition in general relativity, satisfies all of the energy conditions in the early Universe. This unique feature among scalar fields adds to its success in accounting for the observed properties of the cosmic microwave background better than its inflationary counterpart. Specifically, numen's complete consistency with all of the energy conditions, and inflation's violation of at least one of them, provides additional justification for theoretically favoring the former over the latter. 相似文献