1.Thalamus segmentation based on resting-state functional magnetic resonance imaging
Jing JIA ; Qiang LI ; Yu BAI ; Liyi ZHANG
International Journal of Biomedical Engineering 2015;38(1):1-4,后插3
Objective To obtain an accurate and effective method for thalamus segmentation based on resting-state functional magnetic resonance imaging (fMRI).Methods Based on the fact that resting-state fMRI technique examined spatial synchronization of spontaneous fluctuations in blood oxygen level-dependent (BOLD) signals indirectly reflect the neuronal and synaptic activity,the in-thalamus BOLD signal correlations were calculated,and then the k-means clustering algorithm was applied to obtain functional connectivity-based thalamus segmentation.Results The thalamus was divided into seven regions.Voxels within the same region were highly correlated with each other.The segmentation result was similar to that divided by functional connectivity between thalamus and the cerebral cortex.Conclusions Resting-state fMRI could provide not only the functional connectivity network between cortical and subcortical brain regions,but also the functional characteristics of thalamus.Segmentation algorithm using only internal information of thalamus shows lower computational complexity and higher processing speed than that based on the functional connectivity between thalamus and the cerebral cortex.
2.VECTORIAL CAPACITY OF ANOPHELES LESTERIANTHROPOPHAGVS IN TRANSMITTING FILARIASIS MALAYIIN LESHAN PREFECTURE, SICHUAN PROVINCE
Xuanming ZHANG ; Liyi BAI ; Funan ZHANG ; Chenglin WEN ; Mingshen WANG ; Suhui LU ; Xiaohong QIAN ; Fang WU ; Wenchao WANG
Chinese Journal of Parasitology and Parasitic Diseases 1987;0(03):-
The mosquito vector of filariasis malayi and its vectorial capacity was investigated In 5 endemic villages in Leshan Prefecture, Sichuan Province. The results showed that the man-biting rate, numan blood index and vectorial capacity of An. lesteri anthropophagus were 0.7, 5.1 and 10.63 times higher than those of An. sinensis. Besides, the natural infection by microfilaria in An, lesteri anthropophagus was also higher than that in An. sinensis by 5 times.From the above result, the authors concluded that An. lesteri anthropophagus was the main vector for transmitting filariasis malayi in the area under study.
3.Does Early Endoscopy Affect the Clinical Outcomes of Patients with Acute Nonvariceal Upper Gastrointestinal Bleeding? A Systematic Review and Meta-Analysis
Liyi BAI ; Wei JIANG ; Rui CHENG ; Yan DANG ; Li MIN ; Shutian ZHANG
Gut and Liver 2023;17(4):566-580
Background/Aims:
In patients with acute nonvariceal upper gastrointestinal bleeding (ANVUGIB), the optimal timing of endoscopy is still a matter of dispute. We conducted a systematic review and meta-analysis to determine the clinical benefit of early endoscopy.
Methods:
A literature search of the MEDLINE, Embase, and Cochrane databases was conducted to identify publications from inception to March 1, 2022. Eligible studies included observational cohort studies and randomized controlled trials that reported clinical outcomes of endoscopy in patients with ANVUGIB. ANVUGIB patients who underwent endoscopy within 24 hours of admission were considered to have had an early endoscopy. The primary outcome was the mortality rate in ANVUGIB patients who had early or nonearly endoscopy.
Results:
The final analysis included five randomized controlled studies (RCTs) and 20 observational studies from the 1,206 identified articles. The mortality rate was not significantly reduced among patients who received endoscopy performed within 24 hours, whether in cohort studies nor in RCTs. For subgroup analysis, a higher mortality rate was found only among patients who received very early endoscopy within 12 hours (odds ratio, 1.66; p<0.001, I 2 =0) in cohort studies. No significant difference in mortality rates was found among patients at high risk of bleeding who received early versus nonearly endoscopy.
Conclusions
Early endoscopy within 24 hours does not appear to significantly reduce the mortality rates of patients with ANVUGIB. Further well-designed studies are warranted to address if very early endoscopy within 12 hours can provide a clinical benefit for patients at high risk of bleeding.