Effect of volatile versus propofol anaesthesia on major complications and mortality after cardiac surgery: a multicentre randomised trial.

BACKGROUND: The comparative effectiveness of volatile anaesthesia and total intravenous anaesthesia (TIVA) in terms of patient outcomes after cardiac surgery remains a topic of debate. METHODS: Multicentre randomised trial in 16 tertiary hospitals in China. Adult patients undergoing elective cardiac surgery were randomised in a 1:1 ratio to receive volatile anaesthesia (sevoflurane or desflurane) or propofol-based TIVA. The primary outcome was a composite of predefined major complications during hospitalisation and mortality 30 days after surgery. RESULTS: Of the 3123 randomised patients, 3083 (98.7%; mean age 55 yr; 1419 [46.0%] women) were included in the modified intention-to-treat analysis. The composite primary outcome was met by a similar number of patients in both groups (volatile group: 517 of 1531 (33.8%) patients vs TIVA group: 515 of 1552 (33.2%) patients; relative risk 1.02 [0.92-1.12]; P=0.76; adjusted odds ratio 1.05 [0.90-1.22]; P=0.57). Secondary outcomes including 6-month and 1-yr mortality, duration of mechanical ventilation, length of ICU and hospital stay, and healthcare costs, were also similar for the two groups. CONCLUSIONS: Among adults undergoing cardiac surgery, we found no difference in the clinical effectiveness of volatile anaesthesia and propofol-based TIVA. CLINICAL TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR-IOR-17013578).

Phase demodulation method of high line density grating interferometric signal based on wavelet transform.

The increasing line density of the reference grating and the accelerating miniaturization of ultra-precision displacement measurement technology necessitate more stable interferometric signal processing methods for high line density gratings, particularly in low signal-to-noise ratio scenarios. This paper presents a phase demodulation method for dynamic interferometric signals for high line density gratings. The Morlet wavelet transform is utilized to obtain the instantaneous frequency of the interferometric signal, integration of which yields the relative displacement, while adding adjacent relative displacements without gaps provides the absolute displacement during dynamic motion of the grating. In simulations with a signal-to-noise ratio ranging from 40 to 70 dB, the proposed method demonstrates greater robustness compared to the traditional method. By establishing a platform for repeated experiments and comparing it with traditional methods, it was found that the maximum deviation between calculation results obtained using this method and traditional methods is 0.8 nm, further confirming its potential application.

Disease Progression of Data-Driven Subtypes of Parkinson's Disease: 5-Year Longitudinal Study from the Early Parkinson's disease Longitudinal Singapore (PALS) Cohort.

Background: The detailed trajectory of data-driven subtypes in Parkinson's disease (PD) within Asian cohorts remains undisclosed. Objective: To evaluate the motor, non-motor symptom (NMS) progression among the data-driven PD clusters. Methods: In this 5-year longitudinal study, NMS scale (NMSS), Hospital Anxiety Depression Scale (HADS), and Epworth sleepiness scale (ESS) were carried out annually to monitor NMS progression. H& Y staging scale, MDS-UPDRS part III motor score, and postural instability gait difficulty (PIGD) score were assessed annually to evaluate disease severity and motor progression. Five cognitive standardized scores were used to assess detailed cognitive progression. Linear mixed model was performed to assess the annual progression rates of the longitudinal outcomes. Results: Two hundred and six early PD patients, consisting of 43 patients in cluster A, 98 patients in cluster B and 65 subjects in cluster C. Cluster A (severe subtype) had significantly faster progression slope in NMSS Domain 3 (mood/apathy) score (p = 0.01), NMSS Domain 4 (perceptual problems) score (p = 0.02), NMSS Domain 7 (urinary) score (p = 0.03), and ESS Total Score (p = 0.04) than the other two clusters. Cluster A also progressed significantly in PIGD score (p = 0.04). For cognitive outcomes, cluster A deteriorated significantly in visuospatial domain (p = 0.002), while cluster C (mild subtype) deteriorated significantly in executive domain (p = 0.04). Conclusions: The severe cluster had significantly faster progression, particularly in mood and perceptual NMS domains, visuospatial cognitive performances, and postural instability gait scores. Our findings will be helpful for clinicians to stratify and pre-emptively manage PD patients by developing intervention strategies to counter the progression of these domains.

Loss of ADAR1 induces ferroptosis of breast cancer cells.

Adenosine deaminases acting on RNA 1(ADAR1), an RNA editing enzyme that converts adenosine to inosine by deamination in double-stranded RNAs, plays an important role in occurrence and progression of various types of cancer. Ferroptosis has emerged as a hot topic of cancer research in recent years. We have previously reported that ADAR1 promotes breast cancer progression by regulating miR-335-5p and METTL3. However, whether ADAR1 has effects on ferroptosis in breast cancer cells is largely unknown. In this study, we knocked down ADAR1 using CRISPR-Cas9 technology or over-expressed ADAR1 protein using plasmid expressing ADAR1 in MCF-7 and MDA-MB-231 breast cancer cell lines, then detected cell viability, and levels of ROS, MDA, GSH, Fe2+, GPX4 protein and miR-335-5p. We showed that the cell proliferation was inhibited, levels of ROS, MDA, Fe2+, and miR-335-5p were increased, while GSH and GPX4 levels were decreased after loss of ADAR1, compared to the control group. The opposite effects were observed after ADAR1 overexpression in the cells. Further, we demonstrated that ADAR1-controlled miR-335-5p targeted Sp1 transcription factor of GPX4, a known ferroptosis molecular marker, leading to inhibition of ferroptosis by ADAR1 in breast cancer cells. Moreover, RNA editing activity of ADAR1 is not essential for inducing ferroptosis. Collectively, loss of ADAR1 induces ferroptosis in breast cancer cells by regulating miR-335-5p/Sp1/GPX4 pathway. The findings may provide insights into the mechanism by which ADAR1 promotes breast cancer progression via inhibiting ferroptosis.

Network pharmacology to explore the mechanism of traditional Chinese medicine in the treatment of ground glass nodules.

Background: Ground glass nodules (GGNs) in the lung are considered to be a high-risk factor of lung adenocarcinoma. Immediate surgery is not recommended for GGNs patients, and low-dose computed tomography (CT) is often used for observation and follow-up, which brings high psychological and economic burden to the patient. Methods: Three traditional Chinese medicine (TCM) prescriptions for the treatment of GGNs were found through database including PubMed, Google Scholar, and China National Knowledge Infrastructure (CNKI), Scopus and so on. The possible targets of the active ingredients of the TCM preparations and the gene targets of GGNs were screened out from Traditional Chinese Medicine Systems Pharmacology (TCMSP), UniProt and GeneCards. Network visualization was realized via STRING, Cytoscape 3.7.2, Evenn, DAVID and Hiplot. Finally, molecular docking Vina and PyMOL software were performed to further explore the possibility of drug-target interactions using PubChem compounds, protein data bank (PDB) database, Autodocktools and Autodock. Results: Three TCM preparations could target the same 13 potential therapeutic targets in GGNs. From network pharmacology, 14 signaling pathways, the functions of the significant targets, an effective ingredient in TCM prescriptions and its functions were obtained. Conclusions: Chinese herbal formulas containing quercetin could be a potential treatment for GGNs, targeting C-reactive protein (CRP), tumor necrosis factor (TNF), interferon gamma (IFN-γ), intercellular adhesion molecule 1 (ICAM-1), and vascular endothelial growth factor A (VEGFA) through the hypoxia-inducible factor 1 (HIF-1) pathway, mitogen-activated protein kinase (MAPK) signaling pathway, and leukocyte transendothelial migration.

Droplet-based mechanical transducers modulated by the symmetry of wettability patterns.

Asymmetric mechanical transducers have important applications in energy harvesting, signal transmission, and micro-mechanics. To achieve asymmetric transformation of mechanical motion or energy, active robotic metamaterials, as well as materials with asymmetric microstructures or internal orientation, are usually employed. However, these strategies usually require continuous energy supplement and laborious fabrication, and limited transformation modes are achieved. Herein, utilizing wettability patterned surfaces for precise control of the droplet contact line and inner flow, we demonstrate a droplet-based mechanical transducer system, and achieve multimodal responses to specific vibrations. By virtue of the synergistic effect of surface tension and solid-liquid adhesion on the liquid dynamics, the droplet on the patterned substrate can exhibit symmetric/asymmetric vibration transformation when the substrate vibrates horizontally. Based on this, we construct arrayed patterns with distinct arrangements on the substrate, and employ the swarm effect of the arrayed droplets to achieve three-dimensional and multimodal actuation of the target plate under a fixed input vibration. Further, we demonstrate the utilization of the mechanical transducers for vibration management, object transport, and laser modulation. These findings provide a simple yet efficient strategy to realize a multimodal mechanical transducer, which shows significant potential for aseismic design, optical molding, as well as micro-electromechanical systems (MEMS).

The impact on Cd bioavailability and accumulation in rice (Oryza sativa L.) induced by dry direct-seeding cultivation method in field-scale experiments.

Dry direct-seeded rice cultivation has gained popularity and expanded its cultivated area due to reduced labor requirements and water consumption. However, the impact of this cultivation method on cadmium (Cd) bioavailability in soil and the accumulation levels in grains remains uncertain. Field experiments were conducted in acidic soils at two locations in southern China to compare rice varieties and evaluate the dry direct-seeding method alongside the wet direct-seeding and traditional transplanting methods. Dry direct-seeded rice reached significantly higher Cd concentrations in its tissues starting from the heading stage than transplanted rice. Cd accumulation levels by the maturation stage in the brown rice of dry direct-seeded rice were 18.33 %-150.69 % higher than those of wet direct-seeded and transplanted rice, with a considerable ability to translocate Cd into brown rice. Furthermore, dry direct seeding decreased iron plaque formation, particularly in the amorphous Fe form; it resulted in high soil temperature and low moisture content during tillering, elevating Cd availability in the soil. Additionally, the proportion of ions and more labile forms of Cd in the soil solution was high. Moreover, the soil under dry direct seeding had high urease and acid phosphatase enzyme activities. However, low richness and diversity in the bacterial community were characterized by a significant increase in the relative abundance of Actinobacteria and Gammaproteobacteria at the class level, while exhibiting decreased relative abundances of Alphaproteobacteria, Bacilli, and KD4-96, along with fewer biomarkers. Nonetheless, these differences are gradually reduced during the maturation stage. Overall, although dry direct seeding offers several advantages, it is crucial to implement additional measures to mitigate the increased health risks linked to rice cultivation through this approach in Cd-contaminated areas.

Catalytic Hairpin Assembly-Based Self-Ratiometric Gel Electrophoresis Detection Platform for Reliable Nucleic Acid Analysis.

The development of gel electrophoresis-based biodetection assays for point-of-care analysis are highly demanding. In this work, we proposed a ratiometric gel electrophoresis-based biosensing platform by employing catalytic hairpin assembly (CHA) process functions as both the signal output and the signal amplification module. Two types of nucleic acids, DNA and miRNA, are chosen for demonstration. The proposed strategy indeed provides a new paradigm for the design of a portable detection platform and may hold great potential for sensitive diagnoses.

Heatwaves increase road traffic injury morbidity risk and burden in China and its provinces.

Previous studies have demonstrated health impacts of climate change, but evidence on heatwaves' associations with road traffic injury (RTI) is limited. In this study, individual information of RTI cases in May-September during 2006-2021 in China were obtained from the National Injury Surveillance System. Daily maximum temperatures (TMmax) during 2006-2021 were collected from the ERA-5 reanalysis, and the projected daily TMmax during 2020-2099 were obtained from the latest Coupled Model Intercomparison Project Phase 6 Shared Socioeconomic Pathways scenarios (SSPs). We used a time-stratified case-crossover analysis to investigate the association between short-term exposure (lag01 days) to heatwaves (exceeding the 92.5th percentile of daily TMmax for ≥ three consecutive days) and RTI, and to project heatwave-related RTI until 2099 across China. Finally, a total of 1 031 082 RTI cases were included in the analyses. Compared with non-heatwaves, the risks of RTI increased by 3.61 % during heatwaves. Greater associations were found in people aged 15-64 years, in people with transportation occupation, for non-motor traffic vehicle injuries, for severe RTI cases, and in Western China particularly in Qinghai province. We projected substantial increases in attributable fraction (AF) of heatwave-related RTI in the future, particularly in Western and Southwest China. The national average increase in AF (per decade) during 2020s-2090s was 0.036 % for SSP1-2.6 scenario, and 0.267 % for SSP5-8.5 scenario. This study provided evidence on the associations of heatwaves with RTI, and the heatwave-related RTI will substantially increase in the future.

Associations of ambient temperature with the CO poisoning risk in China.

Although studies have explored the relationship between temperature and CO poisoning, the results are not consistent, and there is still a lack of early warning criteria of temperature related to CO poisoning. In order to comprehensively study the exposure-response relationship between daily average temperature and CO poisoning, and to further explore the early warning criteria of temperature related to CO poisoning, we used daily cases of CO poisoning in 31 National Injury Surveillance System (NISS) surveillance sites in seven administrative geographical regions of China and daily meteorological data obtained from the China Meteorological Science Data Sharing Service Platform from 2009 to 2019 to do the analysis. Daily meteorological data of 698 weather stations across China were interpolated at a 0.01° × 0.01°spatial resolution, which were then applied to extract the daily meteorological data of all included NISS sites. The Distributed Lag Non-linear Model (DLNM) model was applied to estimate the exposure-response associations (relative risk, RR) of daily mean temperature with CO poisoning, which was then further used to identify early warning criteria of temperature related to CO poisoning. A total of 10,618 CO poisoning cases were included in this study, with an average of 0.4 cases per day. There was generally a reverse J-shaped association between temperature and CO poisoning risk, indicating that both low and high temperature may increase the risk of CO poisoning, but low temperature usually has a longer lagged effects than high temperature. Spatialy, the exposure-response associations between temperatue and CO poisoning largely varied among regions, with greater effects of low temperatures in Southern China than in Northern China. The cumulative effects (RR, lag0-6 days) of 10 % percentile temperature ranged from 1.13 (95%CI: 1.01,1.26) in East China to 1.73 (95%CI:1.63,1.83) in South China. We also observed significant spatial variations in the early warning criteria of temperature related to CO poisoning across China. However, the patterns of high temperature effects on CO poisoning and the warning criteria of high temperature were mixed across China. In conclusions, both low temperature and high temperature may increase the risk of CO poisoning in China, and the effect of low temperature is more obvious, especially in South China, Northeast China, and North China. In addition, there is an urgent need to establish air temperature early warning and grading criteria for CO poisoning in different areas of China.

Improving grating duty cycle uniformity: amplitude-splitting flat-top beam laser interference lithography.

Laser interference lithography is an effective approach for grating fabrication. As a key parameter of the grating profile, the duty cycle determines the diffraction characteristics and is associated with the irradiance of the exposure beam. In this study, we developed a fabrication technique amplitude-splitting flat-top beam interference lithography to improve duty cycle uniformity. The relationship between the duty cycle uniformity and irradiance of the exposure beam is analyzed, and the results indicate that when the beam irradiance nonuniformity is less than 20%, the grating duty cycle nonuniformity is maintained below ±2%. Moreover, an experimental amplitude-splitting flat-top beam interference lithography system is developed to realize an incident beam irradiance nonuniformity of 21%. The full-aperture duty cycle nonuniformity of the fabricated grating is less than ±3%. Amplitude-splitting flat-top beam interference lithography improves duty cycle uniformity, greatly reduces energy loss compared to conventional apodization, and is more suitable for manufacturing highly uniform gratings over large areas.

Impact of meteorological factors on Cd availability and average concentration prediction in rice growth cycle.

During the rice growth cycle, the average available cadmium concentration (CA-Cd) in the soil determines the Cd content in rice plant. Given defined soil properties and rice varieties, the meteorological factors play a crucial role in soil's available cadmium concentration (CCd) during the rice growth cycle. Thus, it is significant to investigate the influence of meteorological factors in CCd during the rice growth cycle and develop a predictive model for CA-Cd. The rice was cultivated under seven different sowing dates in Cd and As-contaminated soil in Hunan Province. Studied the impact of meteorological factors on paddy soil. The results showed that accumulated temperature (AT) and total precipitation (TP) were key factors affecting the soil CCd. The correlation coefficients between AT and TP with soil CA-Cd were 0.98 and -0.94 (p < 0.01), respectively. However, there was no significant correlation with CAs. AT mainly influenced the CCd during the grouting and maturity stages. A straightforward empirical prediction model was developed, capable of accurately forecasting CA-Cd during the rice growth cycle by considering meteorological factors and the initial soil CCd. This study supported a novel foundation for the precise prediction of Cd content in rice.

Modular intercalary prosthetic reconstruction for malignant and metastatic tumours of the proximal femur.

To illustrate the surgical technique and explore clinical outcomes of the reconstruction for the malignant and metastatic bone tumour of proximal femur with metallic modular intercalary prosthesis. Sixteen patients who underwent modular intercalary prosthetic reconstruction after tumour resection were included from April 2012 and October 2020. Prosthesis and screws parameters, resected bone length and residual bone length, clinical outcomes and survivorship were analyzed. All patients were followed up for an average of 19 months (range 1-74). In our series, 12 patients died of the progression of the primary disease at the final follow-up. The cumulative survivorship since the treatment of proximal femoral metastasis was 78.6% (11 patients) at 6 months and 38.5% (5 patients) at 1 year. The mean MSTS score was 22.25 ± 4.55 among all patients. There were no cases of loosening or breakage of the prostheses, plates or screws, despite the various measurements of prostheses and residual bones. Modular intercalary prosthetic reconstruction was an effective method for malignant tumour of the proximal femur, including the advantages of providing early pain relief, quickly restoring postoperative function, required a short operation time, and preserving the adjacent joints.

Variability of BMP-2 content in DBM products derived from different long bone.

Demineralized bone matrix (DBM) has been regarded as an ideal bone substitute as a native carrier of bone morphogenetic proteins (BMPs) and other growth factors. However, the osteoinductive properties diverse in different DBM products. We speculate that the harvest origin further contributing to variability of BMPs contents in DBM products besides the process technology. In the study, the cortical bone of femur, tibia, humerus, and ulna from a signal donor were prepared and followed demineralizd into DBM products. Proteins in bone martix were extracted using guanidine-HCl and collagenase, respectively, and BMP-2 content was detected by sandwich enzyme-linked immunosorbent assay (ELISA). Variability of BMP-2 content was found in 4 different DBM products. By guanidine-HCl extraction, the average concentration in DBMs harvested from ulna, humerus, tibia, and femur were 0.613 ± 0.053, 0.848 ± 0.051, 3.293 ± 0.268, and 21.763 ± 0.344, respectively (p < 0.05), while using collagenase, the levels were 0.089 ± 0.004, 0.097 ± 0.004, 0.330 ± 0.012, and 1.562 ± 0.008, respectively (p < 0.05). In general, the content of BMP-2 in long bones of Lower limb was higher than that in long bones of upper limb, and GuHCl had remarkably superior extracted efficiency for BMP-2 compared to collagenase. The results suggest that the origin of cortical bones harvested to fabricate DBM products contribute to the variability of native BMP-2 content, while the protein extracted method only changes the measured values of BMP-2.

Effects of the Host Plants of the Maize-Based Intercropping Systems on the Growth, Development and Preference of Fall Armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae).

In this paper, the effects of maize and its three intercropping plants, sweet potato, soybean and peanut, on the growth and development of FAW, feeding preference of larvae, olfactory response and oviposition preference of adults were studied in the laboratory. The results showed that maize and peanut were suitable for the survival and development of FAW, while sweet potato and soybean were not suitable for multigenerational reproduction. The larvae significantly preferred to feed on maize compared to the other three plants. The olfactory response test indicated that soybean showed a strong deterrent effect against FAW adults. Furthermore, the intercropping plants reduced the host selection rate of adults compared to maize alone. In two-choice tests of the maize vs. the intercropping plants, the female adult preferred to oviposit and lay more eggs on maize rather than on the intercropping plants. The intercropping plants significantly reduced the oviposition selection of FAW adults when the combination (maize + intercropping plant), especially soybean and sweet potato, was compared to maize alone. These may be the reasons for why the maize-soybean intercropping system reduced FAW damage in the field. We also speculated that the maize-sweet potato system may also reduce the FAW damage. This study provided a theoretical basis for the comprehensive management of FAW by utilizing an intercropping system.

Factors Associated with Respiratory Insufficiency in Children with Guillain-Barré Syndrome.

OBJECTIVE: The risk factors for respiratory insufficiency in children with Guillain-Barré syndrome (GBS) are poorly known. This study aimed to investigate the factors associated with respiratory insufficiency in children with GBS. METHODS: This retrospective study included children diagnosed with GBS by pediatric neurologists and admitted at the Wuhan Children's Hospital and other hospitals from January 2013 to October 2022. The patients were divided into the respiratory insufficiency and nonrespiratory insufficiency groups according to whether they received assist breathing during treatment. RESULTS: The median (interquartile range) age of onset of 103 patients were 5 (3.1-8.5) years, 69 (67%) were male, and 64 (62.1%) had a history of precursor infection. Compared with the nonrespiratory insufficiency group, the respiratory insufficiency group showed more facial and/or bulbar weakness (p = 0.002), a higher Hughes Functional Grading Scale (HFGS) at admission (p < 0.001), and a shorter onset-to-admission interval (p = 0.017). Compared with the acute motor axonal neuropathy (AMAN) subtype, the acute inflammatory demyelinating polyneuropathy (AIDP) subtype showed longer days from onset to lumbar (p = 0.000), lower HFGS at admission (p = 0.04), longer onset-to-admission interval (p = 0.001), and more cranial nerve involvement (p = 0.04). The incidence of respiratory insufficiency between AIDP and AMAN showed no statistical difference (p > 0.05). CONCLUSION: In conclusion, facial and/or bulbar weakness, HFGS at admission, and onset-to-admission interval were associated with respiratory insufficiency and might be useful prognostic markers in children with GBS.

SHMT2 Mediates Small-Molecule-Induced Alleviation of Alzheimer Pathology Via the 5'UTR-dependent ADAM10 Translation Initiation.

It is long been suggested that one-carbon metabolism (OCM) is associated with Alzheimer's disease (AD), whereas the potential mechanisms remain poorly understood. Taking advantage of chemical biology, that mitochondrial serine hydroxymethyltransferase (SHMT2) directly regulated the translation of ADAM metallopeptidase domain 10 (ADAM10), a therapeutic target for AD is reported. That the small-molecule kenpaullone (KEN) promoted ADAM10 translation via the 5' untranslated region (5'UTR) and improved cognitive functions in APP/PS1 mice is found. SHMT2, which is identified as a target gene of KEN and the 5'UTR-interacting RNA binding protein (RBP), mediated KEN-induced ADAM10 translation in vitro and in vivo. SHMT2 controls AD signaling pathways through binding to a large number of RNAs and enhances the 5'UTR activity of ADAM10 by direct interaction with GAGGG motif, whereas this motif affected ribosomal scanning of eukaryotic initiation factor 2 (eIF2) in the 5'UTR. Together, KEN exhibits therapeutic potential for AD by linking OCM with RNA processing, in which the metabolic enzyme SHMT2 "moonlighted" as RBP by binding to GAGGG motif and promoting the 5'UTR-dependent ADAM10 translation initiation.

The effect and safety assessment of monitoring ethanol concentration in exhaled breath combined with intelligent control of renal pelvic pressure on the absorption of perfusion fluid during flexible ureteroscopic lithotripsy.

PURPOSE: Previously, we designed a ureteral access sheath with the capability of renal pelvic pressure (RPP) measurement and a medical perfusion and aspiration platform, allowing for the intelligent control of RPP. However, the effect of different RPP levels on perfusion fluid absorption remains unclear. This randomized controlled trial aimed to investigate the effects of exhaled ethanol concentration monitoring and intelligent pressure control on perfusion fluid absorption during flexible ureteroscopic lithotripsy. METHODS: Eighty patients scheduled for flexible ureteroscopic lithotripsy were randomly divided into four groups. In groups A, B, and C, the RPPs were set at 0, - 5, and - 10 mmHg, respectively. Group D was regarded as the controls with unfixed RPP. Isotonic saline containing 1% ethanol was used as the irrigation fluid, with an average irrigation flow rate of 100 mL/min. The primary outcome of this study was the absorption of perfusion fluid that was calculated based on the exhaled ethanol concentration. The secondary outcomes included duration of operation and amounts of perfusion fluid used. Postoperative complications, pre- and postoperative renal function, infection markers, and blood gas analysis were also recorded for safety assessment. RESULTS: In all, 76 patients were involved in this study, whose demographic characteristics and preoperative conditions were comparable among groups. Under the same perfusion flow rate, the groups with fixed RPP exhibited reduced absorption of perfusion fluid, duration of operation, and perfusion volume. In particular, the lowest values were observed in group C (RPP = - 10 mmHg). In contrast to the unfixed RPP group, no considerable difference were observed in levels of BUN, Scr, WBC, CRP, and blood gas values among the fixed RPP groups. Moreover, postoperative complications showed no significant difference among groups. CONCLUSION: In flexible ureteroscopic lithotripsy, the groups with fixed RPP had less absorption of perfusion fluid and perfusion volume, shorter duration of surgery, and higher safety than the unfixed group.