Low-grade wind-driven directional flow in anchored droplets.

Low-grade wind with airspeed Vwind < 5 m/s, while distributed far more abundantly, is still challenging to extract because current turbine-based technologies require particular geography (e.g., wide-open land or off-shore regions) with year-round Vwind > 5 m/s to effectively rotate the blades. Here, we report that low-speed airflow can sensitively enable directional flow within nanowire-anchored ionic liquid (IL) drops. Specifically, wind-induced air/liquid friction continuously raises directional leeward fluid transport in the upper portion, whereas three-phase contact line (TCL) pinning blocks further movement of IL. To remove excessive accumulation of IL near TCL, fluid dives, and headwind flow forms in the lower portion, as confirmed by microscope observation. Such stratified circulating flow within single drop can generate voltage output up to ~0.84 V, which we further scale up to ~60 V using drop "wind farms". Our results demonstrate a technology to tap the widespread low-grade wind as a reliable energy resource.

Ionic Liquid Gating Induces Anomalous Permeation through Membrane Channel Proteins.

Membrane channel proteins (MCPs) play key roles in matter transport through cell membranes and act as major targets for vaccines and drugs. For emerging ionic liquid (IL) drugs, a rational understanding of how ILs affect the structure and transport function of MCP is crucial to their design. In this work, GPU-accelerated microsecond-long molecular dynamics simulations were employed to investigate the modulating mechanism of ILs on MCP. Interestingly, ILs prefer to insert into the lipid bilayer and channel of aquaporin-2 (AQP2) but adsorb on the entrance of voltage-gated sodium channels (Nav). Molecular trajectory and free energy analysis reflect that ILs have a minimal impact on the structure of MCPs but significantly influence MCP functions. It demonstrates that ILs can decrease the overall energy barrier for water through AQP2 by 1.88 kcal/mol, whereas that for Na+ through Nav is increased by 1.70 kcal/mol. Consequently, the permeation rates of water and Na+ can be enhanced and reduced by at least 1 order of magnitude, respectively. Furthermore, an abnormal IL gating mechanism was proposed by combining the hydrophobic nature of MCP and confined water/ion coordination effects. More importantly, we performed experiments to confirm the influence of ILs on AQP2 in human cells and found that treatment with ILs significantly accelerated the changes in cell volume in response to altered external osmotic pressure. Overall, these quantitative results will not only deepen the understanding of IL-cell interactions but may also shed light on the rational design of drugs and disease diagnosis.

Effect of Interlayer Spaces and Interfacial Structures on High-Performance MXene/Ionic Liquid Supercapacitors: A Molecular Dynamics Simulation.

The combination of high-capacitance MXenes and wide-electrochemical-window ionic liquids (ILs) has exhibited bright prospects in supercapacitors. Several strategies, such as surficial functionalization and interlayer spacing tuning, have been used to enhance the electrochemical performance of supercapacitors. However, the lack of theoretical guidance on these strategies, including the effects of the microenvironment in the interlayer of confined ILs, hindered the further exploration of such devices. Herein, we performed molecular dynamics simulations to comprehensively investigate the effects of the interlayer space and surface terminations of MXene electrodes on capacity. The results show that the electrical double layer (EDL) structure was found to form on the interface between the MXene electrode and ILs electrolyte by analyzing the ion number density and charge density in the nanometer confined spaces. Under the same potential, the -OH terminations significantly impact the ion orientation in the EDL, particularly near the electrode surface, where cations tend to align vertically, allowing the retention of more cations at the electrode surfaces. Interestingly, such an orientation distribution was decisively from the hydrogen bonds expressed by O-H···O between the -OH termination of MXene and -OH groups of ILs. The differential capacitances of the supercapacitors were calculated by the surficial electron density, and it showed that the capacitance is a nearly one-quarter increase in the 14 Å interlayer spacing compared with that of 10 Å under an applied potential of 2 V. At the same time, the Ti3C2(OH)2 electrode had a higher differential capacitance than the Ti3C2O2 electrode, which possibly originates from the stronger hydrogen bonds to contribute to the vertical aggregation of the cations. Our results highlighted the roles of the interlayer spacing distance and surface terminations of the MXene on the performance of the type of supercapacitor.

Modified Approach for Extraperitoneal Colostomy Creation in Laparoscopic Abdominoperineal Resection.

BACKGROUND: Parastomal hernia is a major long-term complication after abdominoperineal resection. Extraperitoneal colostomy has been proposed as an effective step for parastomal hernia prevention, but it has not been widely used as it is technically demanding and time-consuming. We proposed a modified approach for extraperitoneal colostomy creation by entering the extraperitoneal space through the arcuate line of the posterior rectus sheath. OBJECTIVE: To evaluate the safety, difficulty, and efficacy of long-term parastomal hernia prevention of the modified approach for extraperitoneal colostomy creation compared with the conventional transperitoneal colostomy approach. DESIGN: This was a retrospective evaluation of a surgical and video database. SETTINGS: This was a single-institution retrospective study. PATIENTS: Clinical data of 74 patients who underwent laparoscopic abdominoperineal resection surgery from January 2019 to January 2020 in the Department of General Surgery, Qilu Hospital of Shandong University, were retrospectively reviewed. MAIN OUTCOME MEASURES: Baseline characteristics, time required for colostomy creation (from skin incision to colostomy maturation), perioperative complications, and long-term colostomy-related complications were compared. RESULTS: Baseline characteristics did not differ between the 2 approaches. The BMI level ranged from 19.5 to 29.4 for patients undergoing extraperitoneal approach. Time required for colostomy creation median [interquartile range], (22 [21-25] minutes for extraperitoneal vs 23 [21-25] minutes for transperitoneal, p = 0.861) were comparable between the 2 approaches. The cumulative incidence of parastomal hernia was significantly greater with transperitoneal colostomy than extraperitoneal colostomy at 2 and 3 years postoperatively (16.2% vs 0%, p = 0.025, and 21.6% vs 0%, p = 0.005). The remaining perioperative complications and long-term colostomy-related complications did not differ between the 2 approaches. LIMITATIONS: This study is limited by its retrospective design and small sample size. CONCLUSIONS: The modified approach for extraperitoneal colostomy creation is safe, technically simple, and effective for long-term parastomal hernia prevention in patients with a BMI of 19.5 to 29.4.

Inhibition of voltage-gated sodium ion channel by corannulene and computational inversion blockage underlying mechanisms.

Corannulene (Cor), a special carbon material, evidenced strong protein binding capacity which regulating lysozyme crystallization and controlling reactive oxygen species (ROS) generation. Ion channel protein play role in regulating ion channel functions to affect physiological functions. However, the interaction between Cor and ion channel protein have not been studied. In this study, PEG/Cor nanoparticles (PEG/Cor Nps) were prepared by mPEG-DSPE. The PEG/Cor Nps localized in cytoplasm and produced cytotoxicity at high concentration. Whole cell patch clamp examined ion channel functions after incubate PEG/Cor Nps with PC-12 cell. we found that PEG/Cor Nps inhibited voltage-gated Na+ ion channels in a dose- and time-dependent manner but not act on voltage-gated K+ ion channels. The potential mechanisms were revealed by all-atom molecular dynamic (MD) simulations. The results showed that PEG/Cor Nps block the pore of sodium ion channel protein due to dose- and time-dependent accumulation. Besides, the orientation angle (θ) configuration of PEG/Cor Nps will be inverted with the accumulation to generate two blocking mechanisms. Different from other carbon nanomaterials, the blockage mechanism of PEG/Cor Nps provides novel insights into the mechanisms of interaction between carbon nanomaterials and protein.

The Effect of Diabetes Management Shared Care Clinic on Glycated Hemoglobin A1c Compliance and Self-Management Abilities in Patients with Type 2 Diabetes Mellitus.

Objective: We aim to evaluate the impact of diabetes management shared care clinic (DMSCC) on glycated hemoglobin A1c (HbA1c) compliance and self-management abilities in patients with type 2 diabetes mellitus (T2DM). Methods: This study was a prospective cohort study of patients with T2DM participating in the DMSCC. At baseline and after management, the HbA1c levels were measured, the HbA1c compliance rate were calculated, and the Summary of Diabetes Self-Care Activities-6 (SDSCA-6), Diabetes Empowerment Scale-DAWN Short Form (DES-DSF), and Problem Areas in Diabetes Scale-Five-item Short Form (PAID-5) were completed. These pre- and post-management data were compared. Results: A total of 124 eligible patients were enrolled. After the diabetes management of DMSCC, the average HbA1c decreased and the HbA1c compliance rate increased significantly (P < 0.01). SDSCA-6 showed significant improvement in physical activity, glycemic monitoring, smoking (P < 0.01), and taking medication (P < 0.05). DES-DSF suggested a greater willingness to try to effectively treat diabetes (P < 0.05). PAID-5 indicated significant improvement in diabetes-related emotional distress. Conclusion: DMSCC can help patients with T2DM reduce HbA1c, increase HbA1c compliance, improve diabetes self-management behaviors, empowerment, and diabetes-related emotional distress and serve as an effective exploration and practice of diabetes self-management education and support.

Strong sequentially bridged MXene sheets.

Titanium carbide (Ti3C2Tx) MXene has great potential for use in aerospace and flexible electronics due to its excellent electrical conductivity and mechanical properties. However, the assembly of MXene nanosheets into macroscopic high-performance nanocomposites is challenging, limiting MXene's practical applications. Here we describe our work fabricating strong and highly conductive MXene sheets through sequential bridging of hydrogen and ionic bonding. The ionic bonding agent decreases interplanar spacing and increases MXene nanosheet alignment, while the hydrogen bonding agent increases interplanar spacing and decreases MXene nanosheet alignment. Successive application of hydrogen and ionic bonding agents optimizes toughness, tensile strength, oxidation resistance in a humid environment, and resistance to sonication disintegration and mechanical abuse. The tensile strength of these MXene sheets reaches up to 436 MPa. The electrical conductivity and weight-normalized shielding efficiency are also as high as 2,988 S/cm and 58,929 dB∙cm2/g, respectively. The toughening and strengthening mechanisms are revealed by molecular-dynamics simulations. Our sequential bridging strategy opens an avenue for the assembly of other high-performance MXene nanocomposites.

Ultratough graphene-black phosphorus films.

Graphene-based films with high toughness have many promising applications, especially for flexible energy storage and portable electrical devices. Achieving such high-toughness films, however, remains a challenge. The conventional mechanisms for improving toughness are crack arrest or plastic deformation. Herein we demonstrate black phosphorus (BP) functionalized graphene films with record toughness by combining crack arrest and plastic deformation. The formation of covalent bonding P-O-C between BP and graphene oxide (GO) nanosheets not only reduces the voids of GO film but also improves the alignment degree of GO nanosheets, resulting in high compactness of the GO film. After further chemical reduction and π-π stacking interactions by conjugated molecules, the alignment degree of rGO nanosheets was further improved, and the voids in lamellar graphene film were also further reduced. Then, the compactness of the resultant graphene films and the alignment degree of reduced graphene oxide nanosheets are further improved. The toughness of the graphene film reaches as high as ∼51.8 MJ m-3, the highest recorded to date. In situ Raman spectra and molecular dynamics simulations reveal that the record toughness is due to synergistic interactions of lubrication of BP nanosheets, P-O-C covalent bonding, and π-π stacking interactions in the resultant graphene films. Our tough black phosphorus functionalized graphene films with high tensile strength and excellent conductivity also exhibit high ambient stability and electromagnetic shielding performance. Furthermore, a supercapacitor based on the tough films demonstrated high performance and remarkable flexibility.

New Dipyrroloquinones from a Plant-Derived Endophytic Fungus Talaromyces sp.

Two new dipyrroloquinones, namely talaroterreusinones A (1) and B (2), together with four known secondary metabolites, terreusinone A (3), penicillixanthone A (4), isorhodoptilometrin (5), and chrysomutanin (6), were isolated from the solid culture of the endophytic fungus Talaromyces sp. by integrating mass spectrometry-based metabolic profiling and a bioassay-guided method. Their planar structures and stereochemistry were elucidated by comprehensive spectroscopic analysis including NMR and MS. The absolute configuration at C-1″ of terreusinone A (1) was established by applying the modified Mosher's method. Compounds 1-6 were evaluated for anti-inflammatory activity and cytotoxicity. As a result, 1-3 inhibited the LPS-stimulated NO production in macrophage RAW264.7 cells, with IC50 values of 20.3, 30.7, and 20.6 µM, respectively. Penicillixanthone A (4) exhibited potent cytotoxic activity against Hep G2 and A549 cell lines, with IC50 values of 117 nM and 212 nM, respectively, and displayed significant antitumour effects in A549 cells by inhibiting the PI3K-Akt-mTOR signalling pathway.

Structure Regulation of MOF Nanosheet Membrane for Accurate H2 /CO2 Separation.

High-purity H2 production accompanied with a precise decarbonization opens an avenue to approach a carbon-neutral society. Metal-organic framework nanosheet membranes provide great opportunities for an accurate and fast H2 /CO2 separation, CO2 leakage through the membrane interlayer galleries decided the ultimate separation accuracy. Here we introduce low dose amino side groups into the Zn2 (benzimidazolate)4 conformation. Physisorbed CO2 served as interlayer linkers, gently regulated and stabilized the interlayer spacing. These evoked a synergistic effect of CO2 adsorption-assisted molecular sieving and steric hinderance, whilst exquisitely preserving apertures for high-speed H2 transport. The optimized amino membranes set a new record for ultrathin nanosheet membranes in H2 /CO2 separation (mixture separation factor: 1158, H2 permeance: 1417 gas permeation unit). This strategy provides an effective way to customize ultrathin nanosheet membranes with desirable molecular sieving ability.

Three-Electron Transfer-Based High-Capacity Organic Lithium-Iodine (Chlorine) Batteries.

Conversion-type batteries apply the principle that more charge transfer is preferable. The underutilized electron transfer mode within two undermines the electrochemical performance of halogen batteries. Here, we realised a three-electron transfer lithium-halogen battery based on I- /I+ and Cl- /Cl0 couples by using a common commercial electrolyte saturated with Cl- anions. The resulting Li||tetrabutylammonium triiodide (TBAI3 ) cell exhibits three distinct discharging plateaus at 2.97, 3.40, and 3.85 V. Moreover, it has a high capacity of 631 mAh g-1 I (265 mAh g-1 electrode , based on entire mass loading) and record-high energy density of up to 2013 Wh kg-1 I (845 Wh kg-1 electrode ). To support these findings, experimental characterisations and density functional theory calculations were conducted to elucidate the redox chemistry involved in this novel interhalogen strategy. We believe our paradigm presented here has a foreseeable inspiring effect on other halogen batteries for high-energy-density pursuit.

Ionic Liquid-Based Extraction System for In-Depth Analysis of Membrane Protein Complexes.

Limited by the rare efficient extraction system in extracting hydrophobic membrane protein complexes (MPCs) without compromising the stability of protein-protein interactions (PPIs), the in-depth functional study of MPCs has lagged far behind. In this study, the first systematic screening of ionic liquids (ILs) was performed and showed that triethylammonium acetate (TEAA) IL exhibited excellent performance in stabilizing PPIs, which was further confirmed by molecular docking simulations. By combining TEAA with the conventional detergent Nonidet P-40 (NP-40), a novel IL-based extraction system, i-TAN (TEAA IL with 1% NP-40), was proposed, which demonstrated superior performance in extracting and stabilizing MPCs, attributed to its larger size, more uniform distribution, and closer-to-neutral microenvironment of micelles. Extraction of MPCs with i-TAN allowed the confident identification of more hydrophobic EGFR-interacting proteins that are easily dissociated during the extraction process. Quantitative analysis of the difference in EGFR complexes between trastuzumab-sensitive and trastuzumab-resistant breast cancer cells provided comprehensive insights to understand the drug resistance mechanism, suggesting that i-TAN has great potential in interactomics and functional analysis of MPCs. This study provides a novel strategy for MPC extraction and downstream processing.

Cytotoxic Cyclodepsipeptides and Cyclopentane Derivatives from a Plant-Associated Fungus Fusarium sp.

In this work, four new cyclodepsipeptides, fusarihexins C-E (1-3) and enniatin Q (4), four new cyclopentane derivatives, fusarilins A-D (5-8), together with eight known compounds (9-16), were isolated from cultures of the endophytic fungus Fusarium sp. The structures of the isolated compounds were elucidated by analysis of HRMS and NMR spectroscopic data. The absolute configurations were determined using Marfey's method, a modified Mosher's method, single-crystal X-ray diffraction analysis, and ECD analysis. The antitumor activities of the isolated compounds in vitro were evaluated. Cyclodepsipeptides displayed cytotoxicities against the Huh-7, MRMT-1, and HepG-2 cell lines. Compounds 4, 9, 10, and 12 with IC50 values of 1.0-9.1 µM exhibited the most potent cytotoxicities against the three cell lines as compared to the positive control-5-fluorouracil. Compounds 1-3 and 11 exhibited moderate cytotoxic activities (IC50 values of 10.7-20.1 µM).

The retropharyngeal steroid use during operation on the fusion rate and dysphagia after ACDF? A systematic review and meta-analysis.

PURPOSE: The aim of this meta-analysis was to investigate the effects of retropharyngeal steroid use during operation on bony fusion and dysphagia rate after ACDF. METHODS: We searched the electronic literature database of PubMed, Embase and the Cochrane Library published from January 1990 to February 2020. The size of each group, mean age, proportion of female patients, dysphagia events and fusion rate at one-year follow-up were extracted. RevMan 5.3 was used for the meta-analysis. RESULTS: A total of eight studies including six RCTs and two case-control studies met the inclusion criteria. This meta-analysis showed that retropharyngeal steroids could achieve significantly lower dysphagia rates (p < 0.001), higher fusion rates (p = 0.01), less moderate and severe events rates according to the Bazaz stratification (p < 0.001). However, there was no significant difference between two groups regarding operation time (p = 0.67), blood loss (p = 0.33), VAS scores at one day (p = 0.90) and VAS scores at two weeks (p = 0.80). CONCLUSIONS: Retropharyngeal steroid use is an effective method in reducing dysphagia rate, severe dysphagia rate and increasing fusion rate during ACDF surgery, without increasing operating time, blood loss or VAS scores at one day and two weeks. LEVEL OF EVIDENCE I: Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding.

Short-term posterior C1-C2 pedicle screw fixation without fusion to treat type II odontoid fracture among people under 60 years.

INTRODUCTION: Posterior C1-C2 pedicle screw fixation is a reliable technique used in treatment of type II odontoid fracture. However, the loss of cervical range of rotation motion (RORM) was inevitable. There were few studies focusing on the influence of short-term C1-C2 fixation with nonfusion technique to preserve cervical function in patients younger than 60 years. The purpose of this study was to compare cervical RORM which was measured by an improved goniometer, and the clinical outcomes between short-term and long-term C1-C2 fixation techniques in the treatment of Grauer type 2B and 2C odontoid fracture. MATERIALS AND METHODS: This study represents a retrospective analysis, including patients who underwent primary C1-C2 fixation surgery. These patients were divided into short-term and long-term groups based on whether underwent a fixation removal operation. The clinical results were collected and compared between the two groups. Independent T test and Chi-square analyses were used to identify significant differences between the two groups and dependent T test was used within each group. Statistical significance was set at p < .05. RESULTS: There were no severe postoperative complications, and all 60 patients achieved spinal stabilization after primary surgery. The mean rotation angle in the short-term group at last follow-up time was 138.39 ± 21.06°, which was better than 83.59 ± 13.06° in the long-term group (p < .05). The same statistical difference was observed in flexion-extension angle, which was 71.11 ± 18.73° in short-term group and 53.34 ± 18.23° in long-term group. The mean NDI score in short-term group at last follow-up time was 1.23 ± 0.86 and better than 8.24 ± 3.17 in long-term group. However, the VAS score in short-term group was 1.82 ± 0.54 which was worse compared to 0.64 ± 0.29 in long-term group. CONCLUSIONS: The results demonstrated that primary C1-C2 fixation with nonfusion technique could support satisfactory clinical effects. In addition, the removal of instruments after bony fusion could improve the function of cervical movement significantly in patients under 60 years.

Poly(ionic liquid)-Armored MXene Membrane: Interlayer Engineering for Facilitated Water Transport.

Two-dimensional (2D) MXene-based lamellar membranes bearing interlayers of tunable hydrophilicity are promising for high-performance water purification. The current challenge lies in how to engineer the pore wall's surface properties in the subnano-confinement environment while ensuring its high selectivity. Herein, poly(ionic liquid)s, equipped with readily exchangeable counter anions, succeeded as a hydrophilicity modifier in addressing this issue. Lamellar membranes bearing nanochannels of tailorable hydrophilicity are constructed via assembly of poly(ionic liquid)-armored MXene nanosheets. By shifting the interlayer galleries from being hydrophilic to more hydrophobic via simple anion exchange, the MXene membrane performs drastically better for both the permeance (by two-fold improvement) and rejection (≈99 %). This facile method opens up a new avenue for building 2D material-based membranes of enhancing molecular transport and sieving effect.

Two-Electron Redox Chemistry Enabled High-Performance Iodide-Ion Conversion Battery.

A single-electron transfer mode coupled with the shuttle behavior of organic iodine batteries results in insufficient capacity, a low redox potential, and poor cycle durability. Sluggish kinetics are well known in conventional lithium-iodine (Li-I) batteries, inferior to other conversion congeners. Herein, we demonstrate new two-electron redox chemistry of I- /I+ with inter-halogen cooperation based on a developed haloid cathode. The new iodide-ion conversion battery exhibits a state-of-art capacity of 408 mAh gI-1 with fast redox kinetics and superior cycle stability. Equipped with a newly emerged 3.42 V discharge voltage plateau, a recorded high energy density of 1324 Wh kgI-1 is achieved. Such robust redox chemistry is temperature-insensitive and operates efficiently at -30 °C. With systematic theoretical calculations and experimental characterizations, the formation of Cl-I+ species and their functions are clarified.

Understanding Structural and Transport Properties of Dissolved Li2 S8 in Ionic Liquid Electrolytes through Molecular Dynamics Simulations.

Lithium-sulfur batteries with high energy density are considered as one of the most promising future energy storage devices. However, the parasitic lithium polysulfides shuttle phenomenon severely hinders the commercialization of such batteries. Ionic liquids have been found to suppress the lithium polysulfides solubility, diminishing the shuttle effect effectively. Herein, we performed classical molecular dynamics simulations to explore the microscopic mechanism and transport behaviors of typical Li2 S8 species in ionic liquids and ionic liquid-based electrolyte systems. We found that the trifluoromethanesulfonate anions ([OTf]- ) exhibit higher coordination strength with lithium ions compared with bis(trifluoromethanesulfonyl)imide anions ([TFSI]- ) in static microstructures. However, the dynamical characteristics indicate that the presence of the [OTf]- anions in ionic liquid electrolytes bring faster Li+ exchange rate and easier dissociation of Li+ solvation structures. Our simulation models offer a significant guidance to future studies on designing ionic liquid electrolytes for lithium-sulfur batteries.

Tracking the Micro-Heterogeneity and Hydrogen-Bonding Interactions in Hydroxyl-Functionalized Ionic Liquid Solutions: A Combined Experimental and Computational Study.

Ionic liquids (ILs) are an important class of media that are usually used in combination with polar solvents to reduce costs and tune their physicochemical properties. In this regard, it is essential to understand the influence of adding solvents on the properties of ILs. In this work, the micro-heterogeneity and H-bonding interactions between a hydroxyl-functionalized IL, [HOEmim][TFSI], and acetonitrile (ACN) were investigated by attenuated total reflection Fourier transform infrared spectroscopy and molecular simulations. All studied IL-ACN mixtures were found to deviate from the ideal mixtures. The degree of deviations reaches the maximum at about x(ACN)=0.7 with the presence of both homogeneous clusters of pure IL/ACN and heterogeneous clusters of IL-ACN. With the addition of ACN to IL, the mixtures undergo the transformation from "ACN solvated in [HOEmim][TFSI]" to "[HOEmim][TFSI] solvated in ACN". It is found that the newly formed H-bonding interactions between the IL and ACN is the main factor that contributes to the red shifts of O-H, C2 -H, C4,5 -H, and Calkyl -H of [HOEmim]+ cation, and the blue shifts of C-D, C≡N of ACN, and C-F, S=O of [TFSI]- anion. These in-depth studies on the mixtures of hydroxyl-functionalized IL and acetonitrile would help to understand the micro-heterogeneity and H-bonding interactions of miscible solutions and shed light on exploring their applications.

Early Versus Late Preventive Ileostomy Closure Following Colorectal Surgery: Systematic Review and Meta-analysis With Trial Sequential Analysis of Randomized Controlled Trials.

BACKGROUND: Most preventive ileostomy following colorectal surgery requires a closure procedure. The intervals between primary surgery and ileostomy closure remain controversial. OBJECTIVE: This study aimed to compare early versus late closure of preventive ileostomy following colorectal surgery. DATA SOURCE: A systematic literature search was performed in conference papers, MEDLINE, EMBASE, the Cochrane Library, and the Clinicaltrials.gov database. STUDY SELECTION: Randomized clinical trials published through October 2019 comparing early versus late closure of ileostomy following colorectal surgery were selected. MAIN OUTCOME MEASURES: Morbidity, leak of the primary anastomosis, reoperation, surgical site infection, small-bowel obstruction/postoperative ileus, total operative time, and postoperative length of hospital stay were measured. Results were synthesized using meta-analysis and were rated as firm or weak evidence by trial sequential analysis. RESULTS: A total of 6 randomized controlled trials were included. Firm evidence from trial sequential analysis demonstrated that the early closure of ileostomy after colorectal surgery reduced the incidence of small-bowel obstruction/postoperative ileus and required less total operative time, but increased the incidence of surgical site infection, compared with late closure of ileostomy; postoperative length of hospital stay tended to be longer with early versus late closure of ileostomy. Weak evidence showed that there was no difference between early and late closure in morbidity, reoperation, or leak of the primary anastomosis. LIMITATIONS: The study was limited by some evidence rated as weak from trial sequential analysis, combined analysis of small-bowel obstruction and postoperative ileus, and exclusion of the influence of chemo- or radiotherapy. CONCLUSIONS: In selected patients, early closure of ileostomy after colorectal surgery can be considered, with a lower incidence of postoperative small-bowel obstruction/postoperative ileus and less total operative time, but a relatively high surgical site infection rate. PROSPERO registration number: CRD42020160989.