Publications by authors named "Kexuan Liu"

10 Publications

  • Page 1 of 1

An observation approach in evaluation of ozone production to precursor changes during the COVID-19 lockdown.

Atmos Environ (1994) 2021 Oct 14;262:118618. Epub 2021 Jul 14.

Institute for Environmental and Climate Research, Jinan University, Guangzhou, 511443, China.

The increase of surface ozone during the Corona Virus Disease 2019 (COVID-19) lockdown in China has aroused great concern. In this study, we combine 1.5 years of measurements for ozone, volatile organic compounds (VOCs), and nitrogen oxide (NO) at four sites to investigate the effect of COVID-19 lockdown on surface ozone in Dongguan, an industrial city in southern China. We show that the average concentrations of NO and VOCs decreased by 70%-77% and 54%-68% during the lockdown compared to pre-lockdown, respectively. Based on the source apportionment of VOCs, the contribution of industrial solvent use reduced significantly (86%-94%) during the lockdown, and climbed back slowly along with the re-opening of the industry after lockdown. A slight increase in mean ozone concentration (3%-14%) was observed during the lockdown. The rise of ozone was the combined effect of substantial increase at night (58%-91%) and small reduction in the daytime (1%-17%). These conflicting observations in ozone response between day and night to emission change call for a more detailed approach to diagnostic ozone production response with precursor changes, rather than directly comparing absolute concentrations. We propose that the ratio of daily Ox (i.e. ozone + NO) enhancement to solar radiation can provide a diagnostic parameter for ozone production response during the lockdown period. Smaller ratio of daily O (ozone + NO) enhancement to solar radiation during the lockdown were observed from the long-term measurements in Dongguan, suggesting significantly weakened photochemistry during the lockdown successfully reduces local ozone production. Our proposed approach can provide an evaluation of ozone production response to precursor changes from restrictions of social activities during COVID-19 epidemic and also other regional air quality abatement measures (e.g. public mega-events) around the globe.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.atmosenv.2021.118618DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8277545PMC
October 2021

Screening and Identification of Key Genes, Pathways, and Drugs Associated with Neuropathic Pain in Dorsal Horn: Evidence from Bioinformatic Analysis.

J Pain Res 2021 16;14:1813-1826. Epub 2021 Jun 16.

Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, People's Republic of China.

Purpose: Neuropathic pain is a devastating complex condition occurring post-nervous system damage. Microglia in dorsal horn drives neuropathic pain as a kind of immune cell. We aimed to find potential differentially expressed genes (DEGs) and candidate pathways, which induced neuropathic pain, and to identify some new transcription factors and therapeutic drugs via bioinformatic analysis.

Methods: The microarray profile GSE60670 was downloaded and analyzed. DEGs were screened and analyzed through Gene Ontology (GO), pathway enrichment, and protein-to-protein interaction (PPI) network. Respectively, transcription factors (TFs) and potential therapeutic drugs for DEGs were predicted through NetworkAnalyst and DGIdb databases. At last, we chose top 10 DEGs for external validation.

Results: A total of 100 DEGs were identified. The results of pathway and GO analyses were closely related to malaria inflammatory pathway and inflammatory response. Three necessary PPI modules and 9 hub genes were identified in PPI analysis, and 277 DEG-TF pairs were found among 54 DEGs and 32 TF. Moreover, 22 candidate drugs were found to match 9 hub genes. External validation of 9 of the top 10 DEGs were consistent with bioinformatic analysis.

Conclusion: This study provided comprehensive analyses for the functional gene sets and pathways related to neuropathic pain and promoted our understanding of the mechanism or therapy of neuropathic pain.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2147/JPR.S312117DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8217596PMC
June 2021

High-speed computer-generated holography using an autoencoder-based deep neural network.

Opt Lett 2021 Jun;46(12):2908-2911

Learning-based computer-generated holography (CGH) provides a rapid hologram generation approach for holographic displays. Supervised training requires a large-scale dataset with target images and corresponding holograms. We propose an autoencoder-based neural network (holoencoder) for phase-only hologram generation. Physical diffraction propagation was incorporated into the autoencoder's decoding part. The holoencoder can automatically learn the latent encodings of phase-only holograms in an unsupervised manner. The proposed holoencoder was able to generate high-fidelity 4K resolution holograms in 0.15 s. The reconstruction results validate the good generalizability of the holoencoder, and the experiments show fewer speckles in the reconstructed image compared with the existing CGH algorithms.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/OL.425485DOI Listing
June 2021

Enhanced recovery after surgery for laparoscopic gastrectomy in gastric cancer: A prospective study.

Medicine (Baltimore) 2021 Feb;100(7):e24267

Department of General Surgery.

Background: Laparoscopic distal gastrectomy (LDG) has been highlighted for its safety and better short-term clinical outcomes in treating gastric cancer. However, only a slight reduction of the post-operative hospital stay was observed in gastric cancer patients undergoing LDG with conventional perioperative management, compared to patients undergoing open surgery. Thus, an enhanced recovery after surgery (ERAS) program for LDG is needed to further reduce the post-operative hospital stays. This prospective, open-label, single-arm cohort study aimed to assess the safety and efficacy of the ERAS program for gastric cancer patients undergoing LDG.

Material And Methods: All patients with gastric cancer indicated for LDG were consecutively enrolled from December 2016 to January 2018. The ERAS program included short fasting time, effective perioperative pain management, early, goal-oriented ambulation, and oral feeding. The safety assessment was the incidence of post-operative complications, mortality, and readmission in 30 days. The primary efficacy assessment was recovery time defined by post-operative hospital stays and rehabilitative rate on post-operative day 4.

Results: Ninety-eight of 114 patients were finally enrolled. The incidence of post-operative complication, mortality, and readmission in 30 days was 20. 4%, 0%, 7.1%, respectively. The Clavien-Dindo grade III complication rate was 6.1%, while the pulmonary complication rate was 1% only. The median post-operative stay was 6 days (5.0-7.0 days), and the rehabilitative rate on post-operative day 4 was 78%.

Conclusions: The ERAS program might be optimal perioperative management for gastric cancer patients after LDG without compromising safety.

Trial Number: NCT03016026.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/MD.0000000000024267DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7899858PMC
February 2021

Interleukin-10 expands transit-amplifying cells while depleting Lgr5 stem cells via inhibition of Wnt and notch signaling.

Biochem Biophys Res Commun 2020 12 14;533(4):1330-1337. Epub 2020 Oct 14.

Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China. Electronic address:

Epithelial regeneration is essential for homeostasis and mucosal barrier repair. In this study, we aimed to define the effect of IL-10 on mucosal healing. Intestinal stem cells (ISCs) cultures and mice were treated with recombinant mice IL-10 (rmIL-10). The level of cell proliferation, differentiation, death and related signaling pathways for self-renewal of ISCs were measured in vitro and in vivo. It was uncovered that rmIL-10 increased the size and death, but reduced the total number of organoids. In addition, rmIL-10 depleted Lgr5 ISCs and reduced epithelial proliferation, but enhanced the differentiation of epithelial cells and expanded numbers of transit-amplifying (TA) cells. These changes are related to the decrease of Wnt and Notch signals in vivo and in vitro. Meanwhile, increased expression of Paneth cells and decreased expression of enteroendocrine cells and goblet cells were induced by rmIL-10. Thus, our data indicate that IL-10 reduces the survival of Lgr5 ISCs and proliferation of epithelial cells by inhibiting Notch and Wnt signaling, but promotes enhanced the differentiation of epithelial cells and expanded numbers of TA cells. Therefore, IL-10 acts as an anti-inflammatory factor, but may damage intestinal mucosa repair and maybe a potential target for the treatment of intestinal injury.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bbrc.2020.10.014DOI Listing
December 2020

MicroRNA-378 protects against intestinal ischemia/reperfusion injury via a mechanism involving the inhibition of intestinal mucosal cell apoptosis.

Cell Death Dis 2017 10 12;8(10):e3127. Epub 2017 Oct 12.

Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515 China.

Intestinal ischemia/reperfusion (I/R) injury remains a major clinical event and contributes to high morbidity and mortality rates, but the underlying mechanisms remain elusive. Recent studies have demonstrated that microRNAs (miRNAs) have important roles in organ I/R injury, but the changes and potential roles of miRNAs in intestinal I/R-induced intestinal injury are unclear. This study was designed to analyze the miRNA expression profiles in intestinal mucosa after I/R injury and to explore the role of target miRNA during this process. Using miRNA microarray analysis, we found changes of 19 miRNAs from the expression profile of miRNAs in a mouse model of intestinal I/R and further verified them by RT-qPCR. Here, we report that miR-378 is one of the markedly decreased miRNAs and found the putative target mRNA that is linked to cell death after applying the TargetScan, miRanda, CLIP-Seq and miRDB prediction algorithms. Our results show that the overexpression of miR-378 significantly ameliorated intestinal tissue damage in wild-type and transgenic mice and oxygen glucose deprivation/reperfusion-challenged IEC-6 cell injury. Moreover, miR-378 overexpression reduced intestinal epithelial cell apoptosis in both in vivo and in vitro ischemic models and attenuated cleaved caspase-3 expression. Collectively, our results revealed that the suppression of caspase-3 activation by miRNA-378 overexpression may be involved in the protective effects of intestinal ischemic damage. MiRNA-378 may serve as a key regulator and therapeutic target in intestinal I/R injury.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/cddis.2017.508DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5682673PMC
October 2017

Necroptosis is a key mediator of enterocytes loss in intestinal ischaemia/reperfusion injury.

J Cell Mol Med 2017 03 28;21(3):432-443. Epub 2016 Sep 28.

Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou, China.

Cell death is an important biological process that is believed to have a central role in intestinal ischaemia/reperfusion (I/R) injury. While the apoptosis inhibition is pivotal in preventing intestinal I/R, how necrotic cell death is regulated remains unknown. Necroptosis represents a newly discovered form of programmed cell death that combines the features of both apoptosis and necrosis, and it has been implicated in the development of a range of inflammatory diseases. Here, we show that receptor-interacting protein 1/3 (RIP1/3) kinase and mixed lineage kinase domain-like protein recruitment mediates necroptosis in a rat model of ischaemic intestinal injury in vivo. Furthermore, necroptosis was specifically blocked by the RIP1 kinase inhibitor necrostatin-1. In addition, the combined treatment of necrostatin-1 and the pan-caspase inhibitor Z-VAD acted synergistically to protect against intestinal I/R injury, and these two pathways can be converted to one another when one is inhibited. In vitro, necrostatin-1 pre-treatment reduced the necroptotic death of oxygen-glucose deprivation challenged intestinal epithelial cell-6 cells, which in turn dampened the production of pro-inflammatory cytokines (tumour necrosis factor-α and interleukin-1β), and suppressed high-mobility group box-1 (HMGB1) translocation from the nucleus to the cytoplasm and the subsequent release of HMGB1 into the supernatant, thus decreasing the activation of Toll-like receptor 4 and the receptor for advanced glycation end products. Collectively, our study reveals a robust RIP1/RIP3-dependent necroptosis pathway in intestinal I/R-induced intestinal injury in vivo and in vitro and suggests that the HMGB1 signalling is highly involved in this process, making it a novel therapeutic target for acute ischaemic intestinal injury.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/jcmm.12987DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5323854PMC
March 2017

Multiple-, but not single-, dose of parecoxib reduces shoulder pain after gynecologic laparoscopy.

Int J Med Sci 2012 23;9(9):757-65. Epub 2012 Oct 23.

Department of Anesthesiology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.

Background: The aim of this study was to investigate effect of single- and multiple-dose of parecoxib on shoulder pain after gynecologic laparoscopy.

Methods: 126 patients requiring elective gynecologic laparoscopy were randomly allocated to three groups. Group M (multiple-dose): receiving parecoxib 40mg at 30min before the end of surgery, at 8 and 20hr after surgery, respectively; Group S (single-dose): receiving parecoxib 40mg at 30min before the end of surgery and normal saline at the corresponding time points; Group C (control): receiving normal saline at the same three time points. The shoulder pain was evaluated, both at rest and with motion, at postoperative 6, 24 and 48hr. The impact of shoulder pain on patients' recovery (activity, mood, walking and sleep) was also evaluated. Meanwhile, rescue analgesics and complications were recorded.

Results: The overall incidence of shoulder pain in group M (37.5%) was lower than that in group C (61.9%) (difference=-24.4%; 95% CI: 3.4~45.4%; P=0.023). Whereas, single-dose regimen (61.0%) showed no significant reduction (difference with control=-0.9%; 95% CI: -21.9~20.0%; P=0.931). Moreover, multiple-dose regimen reduced the maximal intensity of shoulder pain and the impact for activity and mood in comparison to the control. Multiple-dose of parecoxib decreased the consumption of rescue analgesics. The complications were similar among all groups and no severe complications were observed.

Conclusions: Multiple-, but not single-, dose of parecoxib may attenuate the incidence and intensity of shoulder pain and thereby improve patients' quality of recovery following gynecologic laparoscopy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.7150/ijms.4916DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3491434PMC
April 2013

Comparison of intravenous general anaesthesia vs endotracheal intubation in the surgical management of juvenile onset recurrent respiratory papillomatosis.

Acta Otolaryngol 2010 Feb;130(2):281-5

National Key Disciplines of Otorhinolaryngology, Otorhinolaryngology Hospital, Otorhinolaryngology Institute, First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, PR China.

Conclusions: Both intravenous general anaesthesia (IVGA) and general anaesthesia with endotracheal intubation (GA with ET) are applicable for the procedure of juvenile onset recurrent respiratory papillomatosis (JO-RRP). GA with ET was found to be better for JO-RRP patients with dyspnoea, as it provided better stabilization of the vital signs with fewer postoperative complications.

Objectives: To evaluate the safety and efficacy of two different anaesthetic techniques in the removal of JO-RRP.

Methods: A total of 52 JO-RRP patients with mild dyspnoea were included in the study. Each case underwent two procedures, one by IVGA and the other by GA with ET. A total of 104 procedures were performed. The effectiveness and safety of the two anaesthetic techniques were pairwise compared.

Results: There were no significant differences in anaesthetic recovery time, operative time or postoperative voice quality between the two anaesthetic groups. However, significant differences in heart rate, oxygen saturation and carbon dioxide saturation were observed. Some patients who underwent IVGA developed apnoea (28.8%) and laryngeal spasm (19.2%). These complications were not observed in the GA with ET group.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3109/00016480903051643DOI Listing
February 2010

Study on pretreatment of FPS-1 in rats with hepatic ischemia-reperfusion injury.

Am J Chin Med 2009 ;37(2):323-37

Department of Anesthesiology, The First Affiliated Hospital of Zhongshan University, Guangzhou 510800, China.

This study was designed to determine whether FPS-1, the water-soluble polysaccharide isolated from fuzi, protected against hepatic damage in hepatic ischemia-reperfusion injury in rats, and its mechanism. SD rats were subjected to 60 min of hepatic ischemia, followed by 120 min reperfusion. FPS-1 (160 mg/kg/day) was administered orally for 5 days before ischemia-reperfusion injury in treatment group. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and albumin (ALB) were assayed to evaluate liver functions. Liver samples were taken for histological examination and determination of malondialdehyde (MDA), superoxide dismutase (SOD), that catalase (CAT) in liver. Na(+)-K(+)-ATPase and Ca(2+)-ATPase in mitochondria were measured with colorimetry method. Morphological changes were also investigated by using both light microscopy and electron microscopy (EM). In addition, apoptosis and oncosis were detected by Annexin V-FITC/PI immunofluorescent flow cytometry analysis. Serum AST and ALT levels were elevated in groups exposed to ischemia-reperfusion (p < 0.05). Ischemia-reperfusion caused a marked increase in MDA level, and significant decreases in hepatic SOD and CAT (p < 0.05). Na(+)-K(+)-ATPase and Ca(2+)-ATPase were reduced in ischemia-reperfusion groups compared to the sham group (p < 0.05). Oncosis and apoptosis were also observed in ischemia-reperfusion groups. Pretreatment with FPS-1 reversed all these biochemical parameters as well as histological alterations, evidently by increased SOD, CAT, reduced MDA and histological scores compared to the model group (p < 0.05). FPS-1 could attenuate the necrotic states by the detection of immunofluorescent flow cytometry analysis. Pretreatment with FPS-1 reduced hepatic ischemia-reperfusion injury through its potent antioxidative effects and attenuation of necrotic states.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1142/S0192415X09006874DOI Listing
March 2010