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Wenxiang Zhang,Hucai Zhang,Jie Niu,Guoliang Lei,Fengqin Chang 한국지질과학협의회 2020 Geosciences Journal Vol.24 No.6
Lacustrine deposits can provide insight into chemical weathering and climate change. Based on the analysis of the element concentrations and parameters of the acid-leaching residual fractions (AR) in the lacustrine deposits of the Qaidam Basin (QB), chemical weathering and paleoclimate changes in the northeastern Tibetan Plateau (NETP) have been studied. The results show that the characteristics of trace element concentrations exhibit two kinds of patterns by normalized element arbitrary units (a.u.). The rare earth element (REE) distribution patterns are moderately rich in light rare earth elements (LREEs) with slightly right-tilting and negative Eu anomalies. Triangular plots of the REEs and (La/Yb)n-ΣREE suggest that the sediments have a similar source. The geochemical records of climate proxies indicated warm-wet climate stages during 45.1–31.6 cal. ka BP., further proving that a megalake stage existed in the semi-arid area in marine isotope stage (MIS) 3. Strong evaporation resulted in a high paleolake level history in the northeastern Tibetan Plateau after the late period of MIS 3. Meanwhile, the geochemical records of the Qaidam Basin are synchronous with the global records.
Wei-Yi Lei,Tso-Tsai Liu,Wei-Chuan Chang,Chih-Hsun Yi,Jui-Sheng Hung,Ming-Wun Wong,Shu-Wei Liang,Lin Lin,Chien-Lin Chen 대한소화기 기능성질환∙운동학회 2024 Journal of Neurogastroenterology and Motility (JNM Vol.30 No.1
Background/AimsThis study aims to evaluate the effects of acute codeine administration on primary and secondary esophageal peristalsis in patients with ineffective esophageal motility (IEM). MethodsEighteen IEM patients (8 women; mean age 37.8 years, range 23-64 years) were enrolled in the study. The patients underwent high-resolution manometry exams, consisting of 10 single wet swallows, multiple rapid swallows, and ten 20 mL rapid air injections to trigger secondary peristalsis. All participants completed 2 separate sessions, including acute administration of codeine (60 mg) and placebo, in a randomized order. ResultsCodeine significantly increased the distal contractile integral (566 ± 81 mmHg∙s∙cm vs 247 ± 36 mmHg∙s∙cm, P = 0.001) and shortened distal latency (5.7 ± 0.2 seconds vs 6.5 ± 0.1 seconds, P < 0.001) for primary peristalsis compared with these parameters after placebo treatment. The mean total break length decreased significantly after codeine treatment compared with the length after placebo (P = 0.003). Codeine significantly increased esophagogastric junction-contractile integral (P = 0.028) but did not change the 4-second integrated relaxation pressure (P = 0.794). Codeine significantly decreased the frequency of weak (P = 0.039) and failed contractions (P = 0.009), resulting in increased frequency of normal primary peristalsis (P < 0.136). No significant differences in the ratio of impaired multiple rapid swallows inhibition and parameters of secondary peristalsis were detected. ConclusionsIn IEM patients, acute administration of codeine increases contraction vigor and reduces distal latency of primary esophageal peristalsis, but has no effect on secondary peristalsis. Future studies are required to further elucidate clinical relevance of these findings, especially in the setting of gastroesophageal reflux disease with IEM.
Design of efficient optimized wireless power transfer system
Wu, Qian,Wang, Lei,Ju, Dongqian,Chen, Chang,Chang, Changyuan The Korean Institute of Power Electronics 2020 JOURNAL OF POWER ELECTRONICS Vol.20 No.5
To balance the output stability and maximum efficiency of a system, an efficiency optimization method based on adaptive frequency control is proposed. In this paper, load transmission is carried out using a DC-DC converter at the receiving end. When the load changes, controlling the rectified output voltage is carried out to realize the maximum efficiency point tracking. Meanwhile, the duty cycle of the rear stage DC-DC converter is changed to keep the output voltage constant. The sampled rectified voltage is compared with the estimated value and the resulting error data are sent to the system transmitter through ASK modulation wireless communication. Then the transmitter demodulation communication information through PID algorithm control is used to achieve the frequency of the adaptive adjustment. The feasibility of the proposed method has been verified by the simulation and experimental results. When the output voltage is 5 V, the constant voltage accuracy is within±1%, the maximum efficiency is up to 79.2%, and the dynamic response time is only 160 ms.
Guo, Yong-Zhong,Pan, Lei,Du, Chang-Jun,Ren, Dun-Qiang,Xie, Xiao-Mei Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.1
Background: Associations between elevated C-reactive protein (CRP) and cancer risk have been reported for many years, but the results from prospective cohort studies remains controversial. A meta-analysis of prospective cohort studies was therefore conducted to address this issue. Methods: Eligible studies were identified by searching the PubMed and EMBASE up to October 2012. Pooled hazard ratios (HR) was calculated by using random effects model. Results: Eleven prospective cohort studies involving a total of 194,796 participants and 11,459 cancer cases were included in this meta-analysis. The pooled HR per natural log unit change in CRP was 1.105 (95% confidence interval (CI): 1.033-1.178) for all-cancer, 1.308 (95% CI: 1.097-1.519) for lung cancer, 1.040 (95% CI: 0.910-1.170) for breast cancer, 1.063 (95% CI: 0.965-1.161) for prostate cancer, and 1.055 (95% CI: 0.925-1.184) for colorectal cancer. Dose-response analysis showed that the exponentiated linear trend for a change of one natural log unit in CRP was 1.012 (95% CI: 1.006-1.018) for all-cancer. No evidence of publication bias was observed. Conclusions: The results of this meta-analysis showed that the elevated levels of CRP are associated with an increased risk of all-cancer, lung cancer, and possibly breast, prostate and colorectal cancer. The result supports a role of chronic inflammation in carcinogenesis. Further research effort should be performed to identify whether CRP, as a marker of inflammation, has a direct role in carcinogenesis.
Analysis of Gene Expression Profiles of Liver Stellate Cells During Liver Regeneration in Rats
Xu Cunshuan,Chen Xiaoguang,Chang Cuifang,Wang Gaiping,Wang Wenbo,Zhang Lianxing,Zhu Qiushi,Wang Lei,Zhang Fuchun 한국분자세포생물학회 2011 Molecules and cells Vol.31 No.1
This study performed a large-scale, high-throughput analy-sis of transcriptional profiling of liver stellate cells (LSCs) at the cellular level to investigate changes in the biological activity of LSCs during rat liver regeneration (LR) and the relation of these changes to LR. First, a rat liver regeneration model was established by partial hepatectomy (PH). Stellate cells were isolated in high purity and yield from the regenerating rat liver by Percoll density gradient centrifugation and immunomagnetic bead sorting. The changes in gene expression of LSCs after PH were examined using a rat genome 230 2.0 array composed of 24622 genes. The results indicated that 10241 of the 24622 genes investigated on the array were differentially expressed in LSCs. Of the 10241 genes, 1563 known genes were related to LR, which were grouped into three major gene expression clusters according to three-fold cut-off threshold: the up-regulated gene cluster, the down-regulated gene cluster, and the cluster composed of genes showing complex changes in expression. Additionally, the genes were grouped into those involved in transcription regulation, signal transduction, transport, cellular metabolism, in-flammation and immunity by functional analysis. When gene expression profiles were combined with the results of gene functional analysis, most of the genes involved in cytokine secretion and retinol metabolism in LSCs were significantly enriched in the cluster characterized by decreased expression, whereas genes involved in lipid metabolism were mostly enriched in the cluster showing increased expression. Based on further analysis of genes expressed in a phase-dependent manner during LR, it was suggested that lipid metabolism in LSCs was enhanced in the whole regeneration process, and that immune response and cytokine secretion were impaired during all three regenerative phases.
Q-Learning based Collision Avoidance for 802.11 Stations with Maximum Requirements
Chang Kyu Lee,Dong-Hyun Lee,Junseok Kim,Xiaoying Lei,이승형 한국인터넷정보학회 2023 KSII Transactions on Internet and Information Syst Vol.17 No.3
The IEEE 802.11 WLAN adopts a random backoff algorithm for its collision avoidance mechanism, and it is well known that the contention-based algorithm may suffer from performance degradation especially in congested networks. In this paper, we design an efficient backoff algorithm that utilizes a reinforcement learning method to determine optimal values of backoffs. The mobile nodes share a common contention window (CW) in our scheme, and using a Q-learning algorithm, they can avoid collisions by finding and implicitly reserving their optimal time slot(s). In addition, we introduce Frame Size Control (FSC) algorithm to minimize the possible degradation of aggregate throughput when the number of nodes exceeds the CW size. Our simulation shows that the proposed backoff algorithm with FSC method outperforms the 802.11 protocol regardless of the traffic conditions, and an analytical modeling proves that our mechanism has a unique operating point that is fair and stable.