Admission Blood Glucose Associated with In-Hospital Mortality in Critically III Non-Diabetic Patients with Heart Failure: A Retrospective Study.

Background: Heart failure (HF) is a primary public health issue associated with a high mortality rate. However, effective treatments still need to be developed. The optimal level of glycemic control in non-diabetic critically ill patients suffering from HF is uncertain. Therefore, this study examined the relationship between initial glucose levels and in-hospital mortality in critically ill non-diabetic patients with HF. Methods: A total of 1159 critically ill patients with HF were selected from the Medical Information Mart for Intensive Care-III (MIMIC-III) data resource and included in this study. The association between initial glucose levels and hospital mortality in seriously ill non-diabetic patients with HF was analyzed using smooth curve fittings and multivariable Cox regression. Stratified analyses were performed for age, gender, hypertension, atrial fibrillation, CHD with no MI (coronary heart disease with no myocardial infarction), renal failure, chronic obstructive pulmonary disease (COPD), estimated glomerular filtration rate (eGFR), and blood glucose concentrations. Results: The hospital mortality was identified as 14.9%. A multivariate Cox regression model, along with smooth curve fitting data, showed that the initial blood glucose demonstrated a U-shape relationship with hospitalized deaths in non-diabetic critically ill patients with HF. The turning point on the left side of the inflection point was HR 0.69, 95% CI 0.47-1.02, p = 0.068, and on the right side, HR 1.24, 95% CI 1.07-1.43, p = 0.003. Significant interactions existed for blood glucose concentrations (7-11 mmol/L) (p-value for interaction: 0.009). No other significant interactions were detected. Conclusions: This study demonstrated a U-shape correlation between initial blood glucose and hospital mortality in critically ill non-diabetic patients with HF. The optimal level of initial blood glucose for non-diabetic critically ill patients with HF was around 7 mmol/L.

Effect of heat treatment on microstructure and mechanical properties of selective laser melted Inconel 718 alloy.

In this study, we conducted two heat treatment processes, namely double aging (DA) and solid solution followed by double aging (SA), on the Inconel 718 alloy fabricated by selective laser melting (SLM). The aim was to investigate the microstructure evolution and mechanical properties of Inconel 718 under different heat treatment conditions. To achieve this, we employed advanced techniques such as Scanning Electron Microscope (SEM), electron backscattered diffraction (EBSD), energy dispersive spectroscopy (EDS), x-ray diffraction (XRD), Tofwerk time-of-flight secondary ion mass spectrometer (TOF-SIMS), and transmission electron microscopy (TEM). Our experimental findings reveal the presence of cellular high-density dislocation substructures in the as-received (AR) specimens, with a significant accumulation of Laves phase precipitates at grain boundaries and subgrain boundaries. After the DA treatment, the cellular substructure persists, with higher concentrations of γ" and γ' strengthened phases compared to AR specimen. Conversely, the SA specimen undergoes almost complete recrystallization, resulting in the dissolution of brittle Laves phases and a substantial increase in the content of strengthening phase γ'' and γ'. As a consequence of the precipitation of the γ'' and γ' strengthened phase and the modification of the microstructure, the material exhibits enhanced strength and hardness, albeit at the expense of reduced plasticity. The investigation of the relationship between heat treatment processes and precipitation behavior indicates that the SA heat treatment yields favorable mechanical properties that strike a balance between strength and plasticity.

Crystal structure and function analysis of 6-phosphogluconate dehydrogenase in Mycobacterium tuberculosis.

6-phosphogluconate dehydrogenase (6PGDH) is an essential enzyme in energy metabolism and redox reactions, and represents a potential drug target for the development of therapies targeting trypanosomes, plasmodium, or other pathogens. Tuberculosis, caused by Mycobacterium tuberculosis, is a contagious disease that severely affects human health, with approximately one-third of the world's population infected. However, the protein structure, exact oligomeric state, and catalytic mechanism of 6PGDH in Mycobacterium tuberculosis (Mt6PGDH) have remained largely unknown. In this study, we successfully purified and determined the structure of Mt6PGDH, revealing its function as a tetramer in both solution and crystal states. Through structural comparisons, we clarified the tetramer formation mechanism and the oligomeric organization of short-chain 6PGDHs. Additionally, we identified key residues for coenzyme recognition and catalytic activity. This work not only deepens our understanding of the enzymatic function of Mt6PGDH but also lays a foundation for the development of drugs targeting this enzyme.

LDCT image denoising algorithm based on two-dimensional variational mode decomposition and dictionary learning.

Low-dose X-CT scanning method effectively reduces radiation hazards, however, reducing the radiation dose will introduce noise and artifacts during the projection process, resulting in a decrease in the quality of the reconstructed image. To address this problem, we combined 2D variational modal decomposition and dictionary learning. We proposed a low-dose CT (LDCT) image denoising algorithm based on an improved K-SVD algorithm with image decomposition. The dictionary obtained by K-SVD training lacks consideration of image structure information. To address this problem, we employ the two-dimensional variational mode decomposition (2D-VMD) method to decompose the image into distinct modal components. Through the adaptive learning of dictionaries based on the characteristics of each modal component, independent denoising processing is applied to each component, avoiding the loss of structural and detailed information in the image. In addition, we introduce the regularized orthogonal matching pursuit algorithm (ROMP) and dictionary atom optimization method to improve the sparse representation ability of the dictionary and reduce the impact of noise atoms on denoising performance. The experiments show that the proposed method outperforms other denoising methods regarding peak signal-to-noise ratio and structural similarity. The proposed method maintains the denoised image details and structural information while removing LDCT image noise and artifacts. The image quality after denoising is significantly improved and facilitates more accurate detection and analysis of lesion areas.

Fast high quality computational ghost imaging based on saliency variable sampling detection.

Fast computational ghost imaging with high quality and ultra-high-definition resolution reconstructed images has important application potential in target tracking, biological imaging and other fields. However, as far as we know, the resolution (pixels) of the reconstructed image is related to the number of measurements. And the limited resolution of reconstructed images at low measurement times hinders the application of computational ghost imaging. Therefore, in this work, a new computational ghost imaging method based on saliency variable sampling detection is proposed to achieve high-quality imaging at low measurement times. This method physically variable samples the salient features and realizes compressed detection of computational ghost imaging based on the salient periodic features of the bucket detection signal. Numerical simulation and experimental results show that the reconstructed image quality of our method is similar to the compressed sensing method at low measurement times. Even at 500 (sampling rate 0.76 % ) measurement times, the reconstructed image of the method still has the target features. Moreover, the 2160 × 4096 (4K) pixels ultra-high-definition resolution reconstructed images can be obtained at only a sampling rate of 0.11 % . This method has great potential value in real-time detection and tracking, biological imaging and other fields.

Mechanism of assembly of snRNP cores assisted by ICln and the SMN complex in fission yeast.

The spliceosomal snRNP cores, each comprised of a snRNA and a seven-membered Sm ring (D1/D2/F/E/G/D3/B), are assembled by twelve chaperoning proteins in human. However, only six assembly-assisting proteins, ICln and the SMN complex (SMN/Gemin2/Gemin6-8), have been found in Schizosaccharomyces pombe (Sp). Here, we used recombinant proteins to reconstitute the chaperone machinery and investigated the roles of these proteins systematically. We found that, like the human system, the assembly in S. pombe requires ICln and the SMN complex sequentially. However, there are several significant differences. For instance, h_F/E/G forms heterohexamers and heterotrimers, while Sp_F/E/G only forms heterohexamers; h_Gemin2 alone can bind D1/D2/F/E/G, but Sp_Gemin2 cannot. Moreover, we found that Sp_Gemin2 is essential using genetic approaches. These mechanistic studies reveal that these six proteins are necessary and sufficient for Sm core assembly at the molecular level, and enrich our understanding of the chaperone systems in species variation and evolution.

Physiological and transcriptomic analyses reveal that phytohormone pathways and glutathione metabolism are involved in the arsenite toxicity response in tomatoes.

The main forms of inorganic arsenic (As) in soil are arsenate [As(V)] and arsenite [As(III)]. Both forms inhibit plant growth. Here, we investigate the effects of As(III) toxicity on the growth of tomatoes by integrating physiological and transcriptomic analyses. As(III) toxicity induces oxidative damage, inhibits photosynthetic efficiency, and reduces soluble sugar levels. As(III) toxicity leads to reductions in auxin, cytokinin and jasmonic acid contents by 29 %, 39 % and 55 %, respectively, but leads to increases in the ethylene precursor 1-amino-cyclopropane carboxylic acid, abscisic acid and salicylic acid contents in roots, by 116 %, 79 % and 39 %, respectively, thereby altering phytohormone signalling pathways. The total glutathione, reduced glutathione (GSH) and oxidized glutathione (GSSG) contents are reduced by 59 %, 49 % and 94 % in roots; moreover, a high GSH/GSSG ratio is maintained through increased glutathione reductase activity (increased by 214 %) and decreased glutathione peroxidase activity (decreased by 40 %) in the roots of As(III)-treated tomato seedlings. In addition, As(III) toxicity affects the expression of genes related to the endoplasmic reticulum stress response. The altered expression of aquaporins and ABCC transporters changes the level of As(III) accumulation in plants. A set of hub genes involved in modulating As(III) toxicity responses in tomatoes was identified via a weighted gene coexpression network analysis. Taken together, these results elucidate the physiological and molecular regulatory mechanism underlying As(III) toxicity and provide a theoretical basis for selecting and breeding tomato varieties with low As(III) accumulation. Therefore, these findings are expected to be helpful in improving food safety and to developing sustainable agricultural.

Effects and Mechanisms of Cu Species in Fe-MOFs on Fenton-Like Catalytic Activity and Stability.

Fe-based MOFs (Fe-MOFs) are deemed promising Fenton-like catalysts due to their well-developed pores and accessible active sites. However, their inferior catalytic activity, iron leaching, and low H2O2 utilization always hinder their application as Fe-based MOF catalysts. In this work, we manipulated the structure of Fe-oxo nodes in MIL-88B(Fe) via a CuI species substitution method, affording a mixed-valence (Cu-incorporated Fe-MOFs) with highly improved Fenton-like performance. It is found that the CuI serves as a shuttle to promote transfer between FeII/FeIII, inducing the formation of a larger amount of stable FeII sites, which was proven by experimental and DFT calculation results. A linear relationship was observed for the Fenton-like performance and the amount of CuI species for the catalysts. The corresponding value of the •OH formation is 2.17 eV for Cu-incorporated MIL-88B(Fe), which is significantly lower than that of MIL-88B(Fe) (2.69 eV). Meanwhile, the enriched CuI species suppress Fe species leaching during the catalytic reaction. The Fe-ion leakage of 0.4Cu@MIL-88B is very tiny (0.01-0.03 mg/L), significantly less than that of MIL-88B (2.00-3.02 mg/L). At the same time, H2O2 utilization for 0.4Cu@ MIL-88B(Fe) is 88%, which is almost 4.4 times that of pure MIL-88B(Fe). This work provides insights into the rational design of Fe-MOFs as promising Fenton-like catalysts for wastewater treatment.

The accuracy of simplified calculation of mechanical power: a simulation study.

Background: Mechanical ventilation (MV) is an important life-saving method in the intensive care unit (ICU). A lower mechanical power (MP) is associated with a better MV strategy. However, traditional MP calculating methods are complicated, and algebraic formulas seem to be rather practical. The aim of the present study was to compare the accuracy and application of different algebraic formulas calculating MP. Methods: A lung simulator, TestChest, was used to simulate pulmonary compliance variations. Using the TestChest system software, the parameters, including compliance and airway resistance, were set to simulate various acute respiratory distress syndrome (ARDS) lungs. Ventilator was also set to volume- and pressure-controlled modes with various parameter values (respiratory rate, RR, time of inspiration, Tinsp, positive end-expiratory pressure, PEEP) to ventilate the simulated lung of ARDS (with various respiratory system compliance, Crs). For the lung simulator, resistance of airway (Raw) was fixed to 5 cmH2O/L/s. Crs below lower inflation point (LIP) or above upper inflation point (UIP) was set to 10 mL/cmH2O. The reference standard geometric method was calculated offline with a customized software. Three algebraic formulas for volume-controlled and three for pressure-controlled were used to calculate MP. Results: The performances of the formulas were different, although the derived MP were significantly correlated with that derived from the reference method (R2>0.80, P<0.001). Under volume-controlled ventilation, medians of MP calculated with one equation was significantly lower than that with the reference method (P<0.001). Under pressure-controlled ventilation, median of MP calculated with two equations were significantly higher (P<0.001). The maximum difference was over 70% of the MP value calculated with the reference method. Conclusions: The algebraic formulas may introduce considerably large bias under the presented lung conditions, especially in moderate to severe ARDS. Cautious is required when selecting adequate algebraic formulas to calculate MP based on the formula's premises, ventilation mode, and patients' status. In clinical practice, the trend rather than the value of MP calculated by formulas should require more attention.

An investigation on the respiratory mechanics of mechanically ventilated patients during spontaneous breathing trials with enhanced low-level pressure support ventilation.

INTRODUCTION: Low-level pressure support ventilation (PSV) is most commonly adopted in spontaneous breathing trials (SBTs), and some have proposed setting the positive end-expiratory pressure (PEEP) to 0 cmH2 O in order to shorten the observation time of SBTs. This study aims to investigate the effects of two PSV protocols on the patients' respiratory mechanics. MATERIAL AND METHOD: A prospective randomized self-controlled crossover design was adopted in this study, which involved enrolling 30 difficult-to-wean patients who were admitted to the intensive care unit of the First Affiliated Hospital of Guangzhou Medical University between July 2019 and September 2021. Patients were subjected to the S group (pressure support: 8 cmH2 O, PEEP: 5 cmH2 O) and S1 group (PS: 8 cmH2 O, PEEP: 0 cmH2 O) for 30 min in a random order, and respiratory mechanics indices were dynamically monitored via a four-lumen multi-functional catheter with an integrated gastric tube. Among the 30 enrolled patients, 27 were successfully weaned. RESULT: The S group showed higher airway pressure (Paw), intragastric pressure (Pga) and airway pressure-time product (PTP) than the S1 group. The S group also showed a shorter inspiratory trigger delay, (93.80 ± 47.85) versus (137.33 ± 85.66) ms (P = 0.004); and fewer abnormal triggers, (0.97 ± 2.65) versus (2.67 ± 4.48) (P = 0.042) compared with the S1 group. Stratification based on the causes of mechanical ventilation revealed that under the S1 protocol, patients with chronic obstructive pulmonary disease (COPD) had a longer inspiratory trigger delay compared to both post-thoracic surgery (PTS) patients and patients with acute respiratory distress syndrome. Despite providing greater respiratory support, S group led to significant reductions in inspiratory trigger delay and less abnormal triggers compared to S1 group, especially among patients with chronic obstructive pulmonary disease. CONCLUSION: These findings suggest that the zero PEEP group was more likely to induce a higher number of patient-ventilator asynchronies in difficult-to-wean patients.

PRMT6 promotes tumorigenicity and cisplatin response of lung cancer through triggering 6PGD/ENO1 mediated cell metabolism.

Metabolic reprogramming is a hallmark of cancer, including lung cancer. However, the exact underlying mechanism and therapeutic potential are largely unknown. Here we report that protein arginine methyltransferase 6 (PRMT6) is highly expressed in lung cancer and is required for cell metabolism, tumorigenicity, and cisplatin response of lung cancer. PRMT6 regulated the oxidative pentose phosphate pathway (PPP) flux and glycolysis pathway in human lung cancer by increasing the activity of 6-phospho-gluconate dehydrogenase (6PGD) and α-enolase (ENO1). Furthermore, PRMT6 methylated R324 of 6PGD to enhancing its activity; while methylation at R9 and R372 of ENO1 promotes formation of active ENO1 dimers and 2-phosphoglycerate (2-PG) binding to ENO1, respectively. Lastly, targeting PRMT6 blocked the oxidative PPP flux, glycolysis pathway, and tumor growth, as well as enhanced the anti-tumor effects of cisplatin in lung cancer. Together, this study demonstrates that PRMT6 acts as a post-translational modification (PTM) regulator of glucose metabolism, which leads to the pathogenesis of lung cancer. It was proven that the PRMT6-6PGD/ENO1 regulatory axis is an important determinant of carcinogenesis and may become a promising cancer therapeutic strategy.

GATR: A Road Network Traffic Violation Prediction Method Based on Graph Attention Network.

Prediction of traffic violations plays a key role in transportation safety. Combining with deep learning to predict traffic violations has become a new development trend. However, existing methods are based on regular spatial grids which leads to a fuzzy spatial expression and ignores the strong correlation between traffic violations and road network. A spatial topological graph can express the spatiotemporal correlation more accurately and then improve the accuracy of traffic violation prediction. Therefore, we propose a GATR (graph attention network based on road network) model to predict the spatiotemporal distribution of traffic violations, which adopts a graph attention network model combined with historical traffic violation features, external environmental features, and urban functional features. Experiments show that the GATR model can express the spatiotemporal distribution pattern of traffic violations more clearly and has higher prediction accuracy (RMSE = 1.7078) than Conv-LSTM (RMSE = 1.9180). The verification of the GATR model based on GNN Explainer shows the subgraph of the road network and the influence degree of features, which proves GATR is reasonable. GATR can provide an important reference for prevention and control of traffic violations and improve traffic safety.

Increasing the Light Extraction Efficiency of Organic Light-Emitting Devices by Electrochemically Corroded Patterned Substrates.

A substrate with microstructure can increase the light extraction efficiency of OLEDs. However, the present preparation methods for micro- and nanostructures are not suited for broad-area manufacturing. In this research, we suggested an electrochemical etching approach to patterning Si substrates and effectively generated a vast area of micro-/nanostructures on the surface of Si. We created OLEDs using this patterned substrate. It was discovered through this study that when the current density is 100 mA/cm2, the brightness increases by 1.67 times and the efficiency increases by 1.43 times, over a planar equivalent. In the future, this electrochemical etching process for patterned silicon substrates might give rise to a new approach to the large-scale manufacture of microstructured silicon substrates.

PIKE-A Modulates Mitochondrial Metabolism through Increasing SDHA Expression Mediated by STAT3/FTO Axis.

Previous studies have shown that phosphoinositide 3-kinase enhancer-activating Akt (PIKE-A) is involved in the regulation of several biological processes in cancer. In our previous study, we demonstrated a crucial function of PIKE-A in cancer energy metabolism by regulating pentose phosphate pathway (PPP) flux. However, whether PIKE-A regulates energy metabolism through affecting mitochondrial changes are poorly understood. In the present study, we show that PIKE-A promotes mitochondrial membrane potential, leading to increasing proliferation of glioblastoma cell. Mechanistically, PIKE-A affects the expression of respiratory chain complex Ⅱ succinate dehydrogenase A (SDHA), mediated by regulating the axis of STAT3/FTO. Taken together, these results revealed that inhibition of PIKE-A reduced STAT3/FTO/SDHA expression, leading to the suppression of mitochondrial function. Thus, our findings suggest the PIKE-A/STAT3/FTO/SDHA axis as promising anti-cancer treatment targets.

Ultra-Smooth and Efficient NiO/Ag/NiO Transparent Electrodes for Flexible Organic Light-Emitting Devices.

We demonstrate highly flexible and efficient organic light-emitting devices (OLEDs) using an ultra-smooth NAN anode. A template-stripping process was employed to create an ultra-smooth NAN anode on a photopolymer substrate. The flexible OLEDs obtained by this method maintained good electroluminescent properties and mechanical stability after bending. The efficiency of the flexible OLEDs was improved by 30.6% compared with conventional OLEDs deposited on PET/ITO substrate due to the enhanced hole injection from the ultra-smooth anode.

Functional metabolome profiling may improve individual outcomes in colorectal cancer management implementing concepts of predictive, preventive, and personalized medical approach.

Objectives: Colorectal cancer (CRC) is one of the most common solid tumors worldwide, but its diagnosis and treatment are limited. The objectives of our study were to compare the metabolic differences between CRC patients and healthy controls (HC), and to identify potential biomarkers in the serum that can be used for early diagnosis and as effective therapeutic targets. The aim was to provide a new direction for CRC predictive, preventive, and personalized medicine (PPPM). Methods: In this study, CRC patients (n = 30) and HC (n = 30) were recruited. Serum metabolites were assayed using an ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) technology. Subsequently, CRC cell lines (HCT116 and HCT8) were treated with metabolites to verify their function. Key targets were identified by molecular docking, thermal shift assay, and protein overexpression/inhibition experiments. The inhibitory effect of celastrol on tumor growth was also assessed, which included IC50 analysis, nude mice xenografting, molecular docking, protein overexpression/inhibition experiments, and network pharmacology technology. Results: In the CRC group, 15 serum metabolites were significantly different in comparison with the HC group. The level of glycodeoxycholic acid (GDCA) was positively correlated with CRC and showed high sensitivity and specificity for the clinical diagnostic reference (AUC = 0.825). In vitro findings showed that GDCA promoted the proliferation and migration of CRC cell lines (HCT116 and HCT8), and Poly(ADP-ribose) polymerase-1 (PARP-1) was identified as one of the key targets of GDCA. The IC50 of celastrol in HCT116 cells was 121.1 nM, and the anticancer effect of celastrol was supported by in vivo experiments. Based on the potential of GDCA in PPPM, PARP-1 was found to be significantly correlated with the anticancer functions of celastrol. Conclusion: These findings suggest that GDCA is an abnormally produced metabolite of CRC, which may provide an innovative molecular biomarker for the predictive identification and targeted prevention of CRC. In addition, PARP-1 was found to be an important target of GDCA that promotes CRC; therefore, celastrol may be a potential targeted therapy for CRC via its effects on PARP-1. Taken together, the pathophysiology and progress of tumor molecules mediated by changes in metabolite content provide a new perspective for predictive, preventive, and personalized medical of clinical cancer patients based on the target of metabolites in vivo.Clinical trials registration number: ChiCTR2000039410. Supplementary Information: The online version contains supplementary material available at 10.1007/s13167-021-00269-8.

Weaning critically ill patients from mechanical ventilation: a protocol from a multicenter retrospective cohort study.

BACKGROUND: Mechanical ventilation (MV) is an important lifesaving method in intensive care unit (ICU). Prolonged MV is associated with ventilator associated pneumonia (VAP) and other complications. However, premature weaning from MV may lead to higher risk of reintubation or mortality. Therefore, timely and safe weaning from MV is important. In addition, identification of the right patient and performing a suitable weaning process is necessary. Although several guidelines about weaning have been reported, compliance with these guidelines is unknown. Therefore, the aim of this study is to explore the variation of weaning in China, associations between initial MV reason and clinical outcomes, and factors associated with weaning strategies using a multicenter cohort. METHODS: This multicenter retrospective cohort study will be conducted at 17 adult ICUs in China, that included patients who were admitted in this 17 ICUs between October 2020 and February 2021. Patients under 18 years of age and patients without the possibility for weaning will be excluded. The questionnaire information will be registered by a specific clinician in each center who has been evaluated and qualified to carry out the study. DISCUSSION: In a previous observational study of weaning in 17 ICUs in China, weaning practices varies nationally. Therefore, a multicenter retrospective cohort study is necessary to be conducted to explore the present weaning methods used in China. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR) (No. ChiCTR2100044634).

Optimal Positive End Expiratory Pressure Levels in Ventilated Patients Without Acute Respiratory Distress Syndrome: A Bayesian Network Meta-Analysis and Systematic Review of Randomized Controlled Trials.

Background: To find the optimal positive end expiratory pressure (PEEP) in mechanical ventilated patients without Acute Respiratory Distress Syndrome (ARDS), we conducted a Bayesian network meta-analysis and systematic review of randomized controlled trials (RCTs) comparing different level of PEEP based on a novel classification of PEEP level: ZEEP group (PEEP = 0 cm H2O); lower PEEP group (PEEP = 1-6 cm H2O); intermediate PEEP group (PEEP = 7-10 cm H2O); higher PEEP group (PEEP > 10 cm H2O). Result: Twenty eight eligible studies with 2,712 patients were included. There were no significant differences in the duration of mechanical ventilation between higher and intermediate PEEP (MD: 0.020, 95% CI: -0.14, 0.28), higher and lower PEEP (MD: -0.010, 95% CI: -0.23, 0.22), higher PEEP and ZEEP (MD: 0.010, 95% CI: -0.40, 0.22), intermediate and lower PEEP (MD: -0.040, 95% CI: -0.18, 0.040), intermediate PEEP and ZEEP (MD: -0.010, 95% CI: -0.42, 0.10), lower PEEP and ZEEP (MD: 0.020, 95% CI: -0.32, 0.13), respectively. Higher PEEP was associated with significantly higher PaO2/FiO2 ratio(PFR) when compared to ZEEP (MD: 73.24, 95% CI: 11.03, 130.7), and higher incidence of pneumothorax when compared to intermediate PEEP, lower PEEP and ZEEP (OR: 2.91e + 12, 95% CI: 40.3, 1.76e + 39; OR: 1.85e + 12, 95% CI: 29.2, 1.18e + 39; and OR: 1.44e + 12, 95% CI: 16.9, 8.70e + 38, respectively). There was no association between PEEP levels and other secondary outcomes. Conclusion: We identified higher PEEP was associated with significantly higher PFR and higher incidence of pneumothorax. Nonetheless, in terms of other outcomes, no significant differences were detected among four levels of PEEP. Systematic Review Registration: The study had registered on an international prospective register of systematic reviews, PROSPERO, on 09 April 2021, identifier: [CRD42021241745].

Critical Review of the Scientific Evidence and Recommendations in COVID-19 Management Guidelines.

BACKGROUND: Little is known about the quality and potential impacts of the guidelines for coronavirus disease 2019 (COVID-19) management. METHODS: We systematically searched PubMed, Web of Science, Cochrane Library, guideline databases, and specialty society websites to evaluate the quality of the retrieved guidelines using the Appraisal of Guidelines for Research and Evaluation II. RESULTS: A total of 66 guidelines were identified. Only 24% were categorized as "recommended" for clinical practice. The 211 identified recommendations for COVID-19 management were classified into 4 topics: respiratory support (27), acute respiratory distress syndrome management (31), antiviral or immunomodulatory therapy (95), or other medicines (58). Only 63% and 56% of recommendations were supported by, respectively, assessment of the strength of the recommendations or level of evidence. There were notable discrepancies between the different guidelines regarding the recommendations on COVID-19 management. CONCLUSIONS: The quality of the guidelines for COVID-19 management is heterogeneous, and the recommendations are rarely supported by evidence.