[Effects of postoperative urine protein levels on predicting acute kidney injury in critically ill patients undergoing non-cardiac surgery]

Objective: To investigate the predictive value of postoperative urine protein level in critically ill patients undergoing non-cardiac surgery with acute kidney injury (AKI). Methods: A total of 661 critically ill patients undergoing non-cardiac surgery, who visited the Department of Critical Care Medicine of Peking University First Hospital from May 20, 2019 to November 24, 2020, were enrolled in this prospective study. The clinical data of the patient's age, gender, body mass index, laboratory examination, surgical status, etc. were collected. AKI diagnostic criteria of the 2012 KDIGO guidelines were used to diagnose the occurrence of AKI after surgery. The independent predictors of AKI were determined by multivariate logistic regression. Results: The age of this patient cohort was (69±15) years. The prevalence of AKI was 45.4% (300/661). Multivariate logistic regression showed that urine protein semi-quantitative ≥2+(OR=2.62, 95%CI: 1.05-6.56, P=0.039) was independent factor for postoperative AKI in critically ill patients undergoing non-cardiac surgery, other independent factors include higher age (OR=1.04, 95%CI: 1.02-1.06, P=0.001), higher body mass index (BMI) (OR=1.12, 95%CI: 1.04-1.21, P=0.004), lower plasma hemoglobin level (OR=0.98, 95%CI: 0.97-1.00, P=0.019), lower central venous pressure (OR=0.89, 95%CI: 0.83-0.97, P=0.005) and lower total hypotension time (OR=1.01, 95%CI: 1.00-1.01, P=0.041). Conclusions: Urine protein semi-quantitative ≥2+after surgery is an independent predictive factor for the occurrence of postoperative AKI in critically ill patients undergoing non-cardiac surgery. It is important to check urine routine immediately after surgery to detect and deal with high-risk patients.

Giant Biquadratic Exchange in 2D Magnets and Its Role in Stabilizing Ferromagnetism of NiCl_{2} Monolayers

Two-dimensional (2D) van der Waals (vdW) magnets provide an ideal platform for exploring, on the fundamental side, new microscopic mechanisms and for developing, on the technological side, ultracompact spintronic applications. So far, bilinear spin Hamiltonians have been commonly adopted to investigate the magnetic properties of 2D magnets, neglecting higher order magnetic interactions. However, we here provide quantitative evidence of giant biquadratic exchange interactions in monolayer NiX_{2} (X=Cl, Br and I), by combining first-principles calculations and the newly developed machine learning method for constructing Hamiltonian. Interestingly, we show that the ferromagnetic ground state within NiCl_{2} single layers cannot be explained by means of the bilinear Heisenberg Hamiltonian; rather, the nearest-neighbor biquadratic interaction is found to be crucial. Furthermore, using a three-orbitals Hubbard model, we propose that the giant biquadratic exchange interaction originates from large hopping between unoccupied and occupied orbitals on neighboring magnetic ions. On a general framework, our work suggests biquadratic exchange interactions to be important in 2D magnets with edge-shared octahedra.

Four Inorganic-Organic Hybrid Borates: From 2D Layers to 3D Oxoboron Cluster Organic Frameworks

Four inorganic-organic hybrid borates, K[B₆O₉(OH)(en)]·H₂O (1, en = ethylenediamine), K[B₆O₉(OH)(1,3-dap)]·H₂O (2, 1,3-dap = 1,3-diaminopropane), K[B₆O₉(OH)(1,6-dah)_0.5]·H₂O (3, 1,6-dah = 1,6-diaminlhexane) and [(1,3-dap)Cd@B₅O₈(OH)]·0.5H₂O (4), were made under solvothermal conditions. 1 and 2 are isostructural and feature a 2D layer built by B₆O₉(OH) clusters and modified by en and 1,3-dap via B-N-C linkages. By replacing en and 1,3-dap with longer and more flexible 1,6-dah, a new type of oxoboron cluster organic framework 3 was obtained, which was composed of the same B₆O₉(OH) cluster layers as in 1 and 2 and 1,6-dah linkers. By replacing alkali metal K with transition metal Cd under similar synthetic conditions, another type of oxoboron cluster organic framework 4 was made in which the Cd-centered wheel cluster layers and 1,3-dap linkers were connected via Cd-N-C linkages.

LiB9O15·H2dap·H2O: A Cotemplated Acentric Layer-Pillared Borate Built by Mixed Oxoboron Clusters

An acentric layer-pillared borate, LiB₉O₁₅·H₂dap·H₂O (1, dap = 1,3-diaminopropane), cotemplated by organic and inorganic cations and build by mixed oxoboron cluster units of B₆O₁₃^8- and B₃O₇^5-, has first been made under solvothermal conditions, in which the B₆O₁₃^8- clusters link each other to form 2D layers containing 9-membered ring (MR) windows, while the B₃O₇^5- clusters join together to produce 1D chains that further perform as the pillars to connect neighboring layers, resulting in a 3D layer-pillared framework with 13- and 7-MR channels located by H₂dap²⁺ and Li⁺ cations, respectively. Its second harmonic generation shows a response of ∼2.1 times that of KDP (KH₂PO₄).

Retrospective Study of Critically Ill COVID-19 Patients With and Without Extracorporeal Membrane Oxygenation Support in Wuhan, China

Background: Extracorporeal membrane oxygenation (ECMO) might benefit critically ill COVID-19 patients. But the considerations besides indications guiding ECMO initiation under extreme pressure during the COVID-19 epidemic was not clear. We aimed to analyze the clinical characteristics and in-hospital mortality of severe critically ill COVID-19 patients supported with ECMO and without ECMO, exploring potential parameters for guiding the initiation during the COVID-19 epidemic.

Methods: Observational cohort study of all the critically ill patients indicated for ECMO support from January 1 to May 1, 2020, in all 62 authorized hospitals in Wuhan, China.

Results: Among the 168 patients enrolled, 74 patients actually received ECMO support and 94 not were analyzed. The in-hospital mortality of the ECMO supported patients was significantly lower than non-ECMO ones (71.6 vs. 85.1%, P = 0.033), but the role of ECMO was affected by patients' age (Logistic regression OR 0.62, P = 0.24). As for the ECMO patients, the median age was 58 (47–66) years old and 62.2% (46/74) were male. The 28-day, 60-day, and 90-day mortality of these ECMO supported patients were 32.4, 68.9, and 74.3% respectively. Patients survived to discharge were younger (49 vs. 62 years, P = 0.042), demonstrated higher lymphocyte count (886 vs. 638 cells/uL, P = 0.022), and better CO₂ removal (PaCO2 immediately after ECMO initiation 39.7 vs. 46.9 mmHg, P = 0.041). Age was an independent risk factor for in-hospital mortality of the ECMO supported patients, and a cutoff age of 51 years enabled prediction of in-hospital mortality with a sensitivity of 84.3% and specificity of 55%. The surviving ECMO supported patients had longer ICU and hospital stays (26 vs. 18 days, P = 0.018; 49 vs. 29 days, P = 0.001 respectively), and ECMO procedure was widely carried out after the supplement of medical resources after February 15 (67.6%, 50/74).

Conclusions: ECMO might be a benefit for severe critically ill COVID-19 patients at the early stage of epidemic, although the in-hospital mortality was still high. To initiate ECMO therapy under tremendous pressure, patients' age, lymphocyte count, and adequacy of medical resources should be fully considered.

Direct Measurement of the Astrophysical ^{19}F(p,αγ)^{16}O Reaction in the Deepest Operational Underground Laboratory

Fluorine is one of the most interesting elements in nuclear astrophysics, where the ^{19}F(p,α)^{16}O reaction is of crucial importance for Galactic ^{19}F abundances and CNO cycle loss in first generation Population III stars. As a day-one campaign at the Jinping Underground Nuclear Astrophysics experimental facility, we report direct measurements of the essential ^{19}F(p,αγ)^{16}O reaction channel. The γ-ray yields were measured over E_{c.m.}=72.4-344  keV, covering the Gamow window; our energy of 72.4 keV is unprecedentedly low, reported here for the first time. The experiment was performed under the extremely low cosmic-ray-induced background environment of the China JinPing Underground Laboratory, one of the deepest underground laboratories in the world. The present low-energy S factors deviate significantly from previous theoretical predictions, and the uncertainties are significantly reduced. The thermonuclear ^{19}F(p,αγ)^{16}O reaction rate has been determined directly at the relevant astrophysical energies.

Corrosion comparison of free and roller surfaces of Fe70Si8B12Nb10 amorphous ribbon

The corrosion resistance of the free surface (FS) and roller surface (RS) of Fe₇₀Si₈B₁₂Nb₁₀ amorphous ribbon was systematically compared in simulated seawater (0.6 M NaCl). The electrochemical method and scanning electron microscopy showed that the FS corrosion resistance was higher than that of the RS. XPS etching and Mott–Schottky tests indicated that the passivation films on the FS and RS were divided into outer and inner layers. In the spinning process, the elements with a higher atomic mass tend to segregate toward the FS, while the elements with a lower atomic mass segregate toward the RS. These results provide data that can be used to improve the quality of melt spinning ribbons and to optimize the manufacturing of involved electric devices.

The two surfaces of the Fe₇₀Si₈B₁₂Nb₁₀ amorphous ribbon have very different corrosion resistances due to different structures.

Suppressing atomic diffusion with the Schwarz crystal structure in supersaturated Al-Mg alloys

High atomic diffusivity in metals enables substantial tuneability of their structure and properties by tailoring the diffusional processes, but this causes their customized properties to be unstable at elevated temperatures. Eliminating diffusive interfaces by fabricating single crystals or heavily alloying helps to address this issue but does not inhibit atomic diffusion at high homologous temperatures. We discovered that the Schwarz crystal structure was effective at suppressing atomic diffusion in a supersaturated aluminum-magnesium alloy with extremely fine grains. By forming these stable structures, diffusion-controlled intermetallic precipitation from the nanosized grains and their coarsening were inhibited up to the equilibrium melting temperature, around which the apparent across-boundary diffusivity was reduced by about seven orders of magnitude. Developing advanced engineering alloys using the Schwarz crystal structure may lead to useful properties for high-temperature applications.

[Detection of oropharyngeal sensory function in normal population]

Objective: To study the oropharyngeal sensory function by Current Perception Threshold(CPT) detection, to explore the detection method of oropharyngeal sensory function in normal population, and to analyze the possible influencing factors. Methods: Fifty-eight normal subjects were included prospectively in this study. Age, gender, body mass index (BMI) were collected. The age of the subjects ranged from 20 to 76 (43.27±13.52) years old. There were 34 females with 17 in childbearing period and 17 in menopause; and 24 males were included.In all the cases, 6 cases were in low BMI, 39 cases were in normal BMI, 10 cases were overweight and 3 cases were suffering from obesity. The CPT system of Neurometer was used to stimulate bilateral palatoglossal arch and tongue base.The current used was 2000 Hz, 250 Hz and 5 Hz respectively.The function of type Aβ, Aδ and C sensory nerve fibers were tested and the CPT values were recorded.The values were inversely proportional to pharyngeal sensation function.To evaluate the oropharyngeal sensory function of the subjects, the CPT values of each frequency at each testing point were compared. SPSS 25.0 software was used for statistical analysis. Results: The CPT value of palatoglossal arch was significantly lower than that of tongue base (t=-2.58,-2.65,-2.54,-2.47,-2.37,-2.77,P<0.05), 2 000 Hz>250 Hz>5 Hz, and there was no significant difference between left and right sides(t=-0.03,-0.51,-0.49,0.06,-0.16,0.13,P>0.05). The CPT value of male was slightly higher than that of female (t=0.92,1.55,0.27,0.78,1.44,1.26,0.35,0.77,1.27,0.24,0.78,0.96,P>0.05). The CPT values of women in childbearing period were significantly less than those in menopausal women (t=-3.90,-3.64,-2.14,-4.20,-4.28,-4.28,-3.52,-4.46,-3.41,-3.63,-4.66,-2.86,P<0.05). The CPT value increased with age, and the values of all frequency of 20 to 30 years old group was significantly lower than those of subjects over 40 years old at each point (The t values of bilateral palatoglossal arch at 2 000 Hz were -5.57,-6.22,-10.18,-11.00;the t values of bilateral palatoglossal arch at 250 Hz were -6.39,-8.79,-6.39,-15.61;the t values of bilateral palatoglossal arch at 5 Hz were -7.09, -5.57, -9.26, -15.23;the t values of tongue base at 2 000 Hz were -3.11,-3.88,-7.60,-8.55;the t values of tongue base at 250 Hz were -6.31,-10.59,-8.52,-10.60;the t values of tongue baseat 5 Hz were -6.69,-5.09,-8.70,-7.07,P<0.05).The values at all frequencies and testing points of 30-40 years old group were significantly lower than those of all subjects over 60 years old (The t values of bilateral palatoglossal arch at 2 000 Hz were -10.91,-12.42;the t values of bilateral palatoglossal arch at 250 Hz were -6.25,-10.87;the t values of bilateral palatoglossal arch at 5 Hz were -5.53,-11.01;the t values of tongue base at 2 000 Hz were -8.62,-10.12;the t values of tongue base at 250 Hz were -6.89,-7.82;the t values of tongue base at 5 Hz were -6.13,-6.48,P<0.05). Conclusions: CPT can be used to evaluate oropharyngeal sensory function. The sensitivity of tongue base is lower than that of palatoglossal arch, there is no significant difference in oropharyngeal sensory function between male and female,between left and right sides. There are many factors influencing oropharyngeal sensory function. Age, hormone level changes may affect the sensitivity of oropharyngeal sensory function.

[Correlation between preoperative inflammatory biomarkers and postoperative pneumonia or long-term prognosis in patients with esophageal cancer after neoadjuvant therapy]

Objective: To examine the correlation between neutrophil-lymphocyte ratio (NLR), lymphocyte-monocyte ratio (LMR) and neutrophil-monocyte ratio (NMR) for postoperative pneumonia or long-term overall survival in patients with esophageal cancer after neoadjuvant therapy. Methods: The clinical data of 137 patients, including 111 males and 26 females, with the age of (M(QR))61(10) years (range: 45 to 75 years), undergoing radical resection of esophageal cancer after neoadjuvant therapy admitted at Department of Thoracic Surgery, West China Hospital from January 2016 to May 2019 were analyzed retrospectively. The blood routine one or two days before surgery and the occurrence of pneumonia after surgery were collected via hospital information system. The absolute count of neutrophils, lymphocytes and monocytes was recorded, to calculate NLR, LMR and NMR. The survival of patients was recorded systematically via follow-up. In the first part, the influencing factors of postoperative inflammation were analyzed, to group the patients into two groups according to the occurrence of postoperative pneumonia. χ2 test, t-test or rank-sum test were conducted for inter-group comparison. In the second part, cutoff values of inflammatory biomarkers were obtained with the receiver operating characteristic (ROC) curve and grouped, with postoperative pneumonia as endpoint criteria. Independent factors correlated with postoperative pneumonia were determined through univariate and multivariate Logistic regression analysis. In the third part, the analysis on prognosis factors was carried on, with the survival as endpoint criteria. Cutoff values of inflammatory biomarkers were obtained with X-Tile software and grouped. The survival analysis was carried on with univariate and multivariate Cox proportional hazards regression model, and the Kaplan-Meier curve was drawn finally. The results of survival analysis were verified by Log-rank test. Results: Median follow-up time was 614 (299) days (range: 382 to 1 612 days). Cutoff values of NLR, LMR, and NMR obtained via the ROC curve were 3.0, 3.9, and 6.2, respectively. According to the multivariate Logistic regression analysis, NLR>3.0 (OR=2.740, 95% CI: 1.221 to 6.152, P=0.015) and LMR>3.9 (OR=0.140, 95% CI: 0.022 to 0.890, P=0.037) were independent prognosis factors for postoperative pneumonia in patients with esophageal cancer after neoadjuvant therapy. Cutoff values of NLR, LMR, and NMR obtained with X-Tile software were 3.3, 4.2, and 7.2, respectively. Through multivariate Cox proportional risk regression analysis, late tumor ypTNM staging (8th AJCC) (HR=2.087, 95% CI:1.079 to 4.038, P=0.029), poor pathologic response (HR=2.251, 95% CI: 1.117 to 4.538, P=0.023), and LMR>4.2 (HR=0.347, 95% CI: 0.127 to 0.946, P=0.039) could be independent prognosis factors for overall survival. Kaplan-Meier survival analysis indicated that the overall survival of patients with LMR ≤4.2 was worse (P=0.002), with the 1-year overall survival rate of 82.9%, and the 1-year overall survival rate of patients with LMR>4.2 was 94.6%. Conclusion: Preoperative LMR ≤3.9 and NLR>3.0 can be considered as independent prognosis factors for postoperative pneumonia, while LMR≤4.2 as one of independent prognosis factors for overall survival.

[Relationship of quality and duration of sleep with hypertension among adults in Guangzhou]

Objective: To explore the relationship of sleep quality and sleep duration with hypertension among adults aged 30-79 years old in Guangzhou. Methods: According to multi-stage stratified cluster sampling, 12 747 residents aged 30-79 years old were sampled and surveyed in Guangzhou from January 2018 to March 2019. Data on general demographic characteristics, sleep quality, sleep duration and hypertension were collected through questionnaire survey, the Pittsburgh sleep quality index (PSQI) and physical examination. Multivariate logistic regression models were used to analyze the putative association between sleep quality, sleep duration and hypertension. Restrictive cubic spline curve was used to draw the dose-response relationship curve between sleep quality, sleep time and hypertension. Results: The mean age of the subjects was (52.68±12.17) years, the prevalence of hypertension was 36.6% (4 664/12 747), the average score of PSQI was (4.70±2.88), and the average sleep time was (7.00±1.32) hours. The prevalence of hypertension was positively associated with the PSQI score. Compared to the subjects with a score less than 3, OR (95%CI) of hypertension with a PSQI score of 3-5, 5-8, ≥9 were 1.14 (1.02-1.27), 1.17 (1.03-1.34), 1.41 (1.21-1.64), respectively. The relationship between sleep duration and hypertension appeared U-shaped. Compared with 6 to 8 hours sleep duration, both sleep duration<6 hours with OR(95%CI) of 1.27(1.12-1.43) or >8 hours with OR(95%CI) of 1.20(1.05-1.38) was associated with hypertension. Conclusion: Both poor sleep quality, longer or shorter sleep duration were responsible for increased risk of cognitive impairment in older Chinese.

[Timing of food introduction to the infant diet and risk of food allergy: a systematic review and Meta-analysis]

Objective: To evaluate the relationship between the timing of complementary feeding for infants and the occurrence of food allergy. Methods: The PubMed, Cochrane Library, China National Knowledge Infrastructure (CNKI), and WanFang Data database were searched for randomized controlled trials (RCTs) about the effects of early introduction of complementary foods in infants on the occurrence of food allergy. Papers published from the establishment of the databases to December 31, 2019 were extracted. The quality of the selected literature was evaluated using the risk-of-bias (ROB) tools in the Cochrane Handbook, and the RevMan 5.3 software was used for meta-analysis. For the complementary food analyzed in a few reports in literature, a systematic review was conducted. Results: A total of 8 RCTs were extracted, and the systematic review and Meta-analysis were carried out according to food types. The results of Meta-analysis showed that compared with late introduction (after 6 months of age), early introduction (before 6 months of age) of eggs (RR=0.60, 95%CI 0.46-0.79) could reduce the risk of egg allergy in infants. The subgroup analysis of the six studies about eggs demonstrated that in infants with a prior or family history of allergic diseases, the introduction of eggs before 6 months of age was associated with reduced risk of egg allergy (RR=0.55, 95%CI 0.40-0.75), and the introduction of raw eggs (RR=0.67, 95%CI 0.49-0.93) and small amount of eggs (equivalent to weekly protein 0-4 g) (RR=0.55, 95%CI 0.36-0.85) before 6 months of age were also associated with reduced risk of egg allergy. In addition, egg supplementation during 4-6 months of age reduced the occurrence of egg allergy compared with supplementation before 4 months of age (RR=0.58, 95%CI 0.43-0.78). The systematic review found no conclusive relationship between early peanut introduction and peanut allergy, nor the correlation between early cow's milk protein introduction and cow's milk protein allergy (P>0.05). Conclusion: Early introduction (before 6 months of age) of eggs in infants' complementary foods can prevent infant egg allergy, but the limitations of the study need to be considered.

{Cu8} Cluster-Sandwiched Polyoxotungstates and Their Polymers: Syntheses, Structures, and Properties

Four inorganic-organic hybrid octa-Cu cluster sandwiched polyoxotungstates (POTs), [Cu₈(H₂O)₂(en)₄(B-α-H₂SiW₉O₃₄)₂] (1), [Cu₈(H₂O)₂(en)₄(B-α-H₂GeW₉O₃₄)₂] (2), K₂[Cu₈(en)₄(B-α-HSiW₉O₃₄)₂]·6H₂O (3), and K₂[Cu₈(en)₄(B-α-HGeW₉O₃₄)₂]·2H₂O (4) (en = ethylenediamine), were hydrothermally made and characterized by single-crystal X-ray diffraction, infrared spectra, powder X-ray diffraction, and thermogravimetric analysis, respectively. Structure analysis reveals that the polyoxoanion of 1/2 is a discrete dimer built by two trivalent Keggin [B-α-XW₉O₃₄]^10- (X = Si/Ge) fragments and one octa-Cu cluster, whereas 3 and 4 display a two-dimensional network built by octa-Cu-sandwiched POT units via substitution of coordinated water on polyanions of 1 and 2 and further expand into a three-dimensional framework via K cation bridges. Ultraviolet-visible diffuse reflectance spectra reveal that 1-4 are potential semiconductor materials. Moreover, its visible light-driven catalytic H₂ evolution activity, electrochemical properties, catalysis for oxygenation reactions of thioethers, and magnetic behaviors have been investigated in detail.

Rapid-flow expulsion maneuver in subglottic secretion clearance to prevent ventilator-associated pneumonia: a randomized controlled study

Background

Following endotracheal intubation, clearing secretions above the endotracheal tube cuff decreases the incidence of ventilator-associated pneumonia (VAP); therefore, subglottic secretion drainage (SSD) is widely advocated. Our group developed a novel technique to remove the subglottic secretions, the rapid-flow expulsion maneuver (RFEM). The objective of this study was to explore the effectiveness and safety of RFEM compared with SSD.

Methods

This study was a single-center, prospective, randomized and controlled trial, conducted at Respiratory Intensive Care Unit (ICU) of Beijing Chao-Yang Hospital, a university-affiliated tertiary hospital. The primary outcome was the incidence of VAP, assessed for non-inferiority.

Results

Patients with an endotracheal tube allowing drainage of subglottic secretions (n = 241) were randomly assigned to either the RFEM group (n = 120) or SSD group (n = 121). Eleven patients (9.17%) in the RFEM group and 13 (10.74%) in the SSD group developed VAP (difference, − 1.59; 95% confidence interval [CI] [− 9.20 6.03]), as the upper limit of 95% CI was not greater than the pre-defined non-inferiority limit (10%), RFEM was declared non-inferior to SSD. There were no statistically significant differences in the duration of mechanical ventilation, ICU mortality, or ICU length of stay and costs between groups. In terms of safety, no accidental extubation or maneuver-related barotrauma occurred in the RFEM group. The incidence of post-extubation laryngeal edema and reintubation was similar in both groups.

Conclusions

RFEM is effective and safe, with non-inferiority compared to SSD in terms of the incidence of VAP. RFEM could be an alternative method in first-line treatment of respiratory ICU patients.

Trial registration This study has been registered on ClinicalTrials.gov (Registration Number: NCT02032849, https://clinicaltrials.gov/ct2/show/NCT02032849); registered on January 2014

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-021-00887-5.

[Effects and mechanisms of polycaprolactone-cellulose acetate nanofiber scaffold loaded with rat epidermal stem cells on wound healing of full-thickness skin defects in rats]

Objective: To explore the effects and mechanisms of polycaprolactone-cellulose acetate (PCL-CA) nanofiber scaffold loaded with rat epidermal stem cells (ESCs) on wound healing of full-thickness skin defects in rats. Methods: The experiment research method was applied. The primary ESCs were isolated from 1-3 d old Sprague-Dawley (SD) rats (undefined gender) by rapid adherent method and cultured by rapid adherent method. ESCs of the first passage were used for the subsequent experiments after the positive expressions of integrin β₁ and cytokeratin 19 (CK19) in primary cells were identified respectively by flow cytometey and immunofluorescence method. PCL-CA nanofiber scaffolds with polycaprolactone and cellulose acetate as components were prepared by electrospinning technique. The topological structure of the nanofiber scaffolds was determined and the diameter of 25 fibers was measured by scanning electron microscope. The constructed PCL-CA nanofiber scaffolds were used as the culture substrate for ESCs, which were cultured in keratinocytes (KCs) medium to construct ESCs-nanofiber scaffold complex (hereinafter referred to as ESCs scaffold). After 3 days of culture, the morphology of ESCs in the scaffold and their relationship was observed by scanning electron microscopy. The ESCs in ESCs scaffold were set as PCL-CA nanofiber scaffold group, and the ESCs cultured with KCs medium in culture dishes coated with type Ⅳ collagen were set as type Ⅳ collagen group. Western blotting was used to detect the protein expression level of CK19 in ESCs in the two groups after 3 days of culture (n=3). The protein expressions of CK19 and proliferating nuclear antigen (PCNA) in ESCs in the two groups were detected by immunofluorescence method after 7 days of culture. A circular full-thickness skin wound of about 2 cm in diameter was prepared on both left and right sides of the back of 15 male SD rats aged 6-8 weeks. The rats were then equally divided into blank control group without implantation, scaffold alone group implanted with PCL-CA nanofiber scaffold, and ESCs scaffold group implanted with ESCs scaffold which were constructed after 3 days of culture according to the random number table. The percentage of wound areas on post injury day (PID) 3, 7, 14, and 21 was calculated (n=5). The new skin tissue at the wound edge was collected on PID 21, the wound healing quality was evaluated by Masson staining, and the protein expression levels of Notch1, Jagged1, and Hes1, which are key proteins of Notch signaling pathway, were detected by Western blotting (n=3). Data were statistically analyzed with one-way analysis of variance, one-way analysis of variance, analysis of variance for repeated measurement, independent sample t test, and Bonferroni correction. Results: The constructed PCL-CA nanofiber scaffolds had a porous, mesh-like, and multilayered three-dimensional structure, in which the surface of the fibers was smooth and non-porous, and the fiber diameter was (383±24) nm. The ESCs in ESCs scaffold showed intact cellular structures and were tightly attached to the scaffold after 3 days of culture. The cells were interconnected and fully extended on the surface of the scaffold to form a membrane. After 3 days of culture, the protein expression level of CK19 of ESCs in PCL-CA nanofiber scaffold group was significantly higher than that in type Ⅳ collagen group (t=24.56, P<0.01). After 7 days of culture, compared with those in type Ⅳ collagen group, there was no significant change in the proportion of PCNA positive cells of ESCs in PCL-CA nanofiber scaffold group, while the proportion of CK19 positive cells was higher. On PID 3, 7, 14, and 21, the percentages of wound areas of rats in ESCs scaffold group were (78.0±1.8)%, (40.9±2.0)%, (17.9±1.1)%, and (5.0±1.0)%, respectively, which were significantly lower than (84.2±1.9)%, (45.4±2.6)%, (21.8±1.7)%, and (10.1±1.1)% in blank control group (t=5.42, 3.09, 4.33, 7.58, P<0.05 or P<0.01) and (82.7±1.2)%, (44.8±2.0)%, (22.4±2.4)%, and (10.3±2.4)% in scaffold alone group (t=4.98, 3.11, 3.84, 4.57, P<0.05 or P<0.01), while the percentages of wound areas of rats between blank control group and scaffold alone group were similar (t=1.47, 0.39, 0.47, 0.22, P>0.05). On PID 21, the layer of new skin at the wound edge of rats in each group was intact; compared with that in blank control group or scaffold alone group, the new skin tissue at the wound edge of rats in ESCs scaffold group had more orderly collagen arrangement; the scaffolds in the new skin at the wound edge of rats were completely degraded in ESCs scaffold group and scaffold alone group. On PID 21, the protein expression levels of Notch1, Jagged1, and Hes1 in the new skin tissue at the wound edge of rats in scaffold alone group were similar to those in blank control group (t=1.70, 1.94, 0.18, P>0.05), while the protein expression levels of Notch1, Jagged1, and Hes1 in the new skin tissue at the wound edge of rats in ESCs scaffold group were significantly higher than those in scaffold alone group (t=13.31, 22.07, 20.71, P<0.01). Conclusions: PCL-CA nanofiber scaffolds can inhibit the differentiation of ESCs of rats without affecting their proliferation in vitro. ESCs scaffolds constructed through using PCL-CA nanofiber scaffolds as the carrier to culture ESCs of rats can significantly promote the wound healing of full-thickness skin defects in rats, and the mechanism may be related to the activation of Notch signaling pathway.

ClyA enhances LPS-induced IL-1β secretion in human macrophages through TLR4 and NLRP3 signaling

Lipopolysaccharide (LPS) plays an important role in tumor suppression by activating macrophages. After macrophages activation, a trail of cytokines was secreted, including IL-1β. Previous studies reported that the anti-tumor function of IL-1β is concentration-dependent, and increasing the level of IL-1β will enhance its anti-tumor effect. Cytolysin A (ClyA), a member of the protein family called pore-forming toxins (PFTs), is secreted by Gram-negative bacteria, which has a potential role in enhancing the secretion of IL-1β. In this study, the function of Cytolysin A was evaluated by investigating its ability to induce innate immune responses in macrophages and the signaling pathway(s) involved in LPS-induced production of IL-1β. The production of IL-1β was highly enhanced when the macrophages were treated with LPS and ClyA together. The production of IL-1β was regulated by TLR4-MyD88-IL-1β pathway and NLRP3-ASC-Caspase1-IL1β pathway. By treating the colon cancer cell line CT26 with the conditioned medium, the proliferation of CT26 cells was inhibited and the apoptosis of CT26 cells was increased. In conclusion, this study indicated that ClyA enhances the production of IL-1β induced by LPS in human macrophages. The proliferation of CT26 cells was inhibited and the apoptosis was increased when being treated with the macrophage-conditioned media, which provides a feasible treatment for colon tumor.

Association of waist circumstance with long-term all-cause mortality and cardiac death in patients with a pacemaker

Funding Acknowledgements

Type of funding sources: None.

Objective

To explore the association of abdominal obesity with long-term prognosis in patients with a pacemaker.

Methods

Patients in the Summit study were enrolled and divided into groups according to baseline waist circumference: with obesity, normal, and lean. Regular follow-up was performed. The primary endpoint was all-cause mortality, and the secondary endpoint was cardiac death.

Results

In total, 492 patients were included in the analysis. The average baseline waist circumference was 84.2 ± 12.7 cm, and abdominal obesity was observed in 37.6% of patients. During a mean follow-up of 67.2 ± 17.5 months,71 all-cause mortality (14.40%) and 24 cardiac death (4.87%) events occurred. All-cause mortality was associated with higher waist circumference (87.6 versus 83.6 cm, P = 0.014), but not body mass index (23.6 versus 23.5, P= 0.930). Multivariate Cox analysis showed compared with patients with abdominal obesity, lean patients had a significant survival benefit in both all-cause mortality (HR 0.188, 95%CI 0.070-0.505, P = 0.001) and cardiac death (HR 0.097, 95% CI 0.012-0.792, P = 0.029).

Conclusions

Waist circumference was associated with long-term all-cause mortality and cardiac death. Baseline waist circumference less than 80 cm for men and less than 75 cm for women had a significant survival benefit.

The transcription factors of tall fescue in response to temperature stress

Tall fescue (Festuca arundinacea) is an important grass species worldwide, but temperature stress severely affects its distribution and yield. Transcription factors (TFs), as the master switches in sophisticated regulatory networks, play essential roles in plant growth development and abiotic stress responses. In this study, the comparative transcriptome analysis was performed to explore the commonalities and differences in the response of TFs to the heat (40 °C), cold (10 °C) and control (22 °C) conditions. A total of 877 TF genes belonging to 35 families were identified. Most of them (784) were differentially expressed genes (DEG), indicating TF genes actively responded to temperature stress. The expression of bZIP and GTF family members was up-regulated when exposed to both heat and cold, but conversely, the expression of the most WRKY and NAC families members decreased. The HSF and GTE families and DREB2B were up-regulated upon heat, while bHLH, MYB, HD-ZIP and ERF families were elevated under cold stress. The TFs involved in 'Plant hormone signal transduction', 'Plant-pathogen interaction', 'Circadian rhythm' play major roles in responding to temperature stresses. The results showed the temperature threats up-regulated the expression of stress tolerance-related genes, and down-regulated those genes associated with growth and disease resistance, indicating TFs exert crucial roles in plant adaptation to an adverse environment. This study profiled the responsive pattern of TFs to temperature stresses, partially explained the mechanism of adaptations of cold-season forage crops and screened many candidate stress-tolerant TF genes.

[Psychoactive substances use in men who have sex with men in China: an internet based survey]

Objective: To assess the prevalence of psychoactive substances use in men who have sex with men (MSM) and its related risk factors. Methods: From July to December 2019, MSM in 6 provinces were recruited from social MSM organizations in communities. The inclusion criteria were male, age ≥18 years, having had sex with men or male homosexuality, voluntary participation and informed consent. Data collected through an anonymous self-filled online questionnaire including socio-demographic characteristics, sexual behavior and psychoactive substance use. Multivariate logistic regression was performed to examine factors correlated with psychoactive substances use. Results: A total of 2 616 MSM were included in the study. Overall, 32.2% (841/2 616) of MSM had ever used at least one psychoactive substances, of whom 92.4% (777/841) were Rush users and 14.4% (121/841) were multi drug users. Rush and tryptamine were used the most (79.7%,98/121). After adjusting the influence of province, factors associated with psychoactive substances use included age <35 years (<25: OR=1.28, 95%CI: 1.02-1.61; 25-34: OR= 1.34, 95%CI: 1.08-1.67) , active sexual role preference (OR=1.47, 95%CI: 1.22-1.77), having non-regular partners in last sex (OR=1.21, 95%CI: 1.01-1.45) and use of tobacco products in the past 6 months (OR=1.29, 95%CI: 1.06-1.56). Conclusions: Psychoactive substances like Rush are popular among MSM, especially in the younger ones. MSM who played active sexual role, had non-regular sex partners and used tobacco also reported higher level of psychoactive substance use. Our findings suggest the urgent need for precise and comprehensive interventions to control the use of psychoactive substances and related hazards in young MSM.

PASP: Property analysis and simulation package for materials

We have developed a software package, namely, PASP (Property Analysis and Simulation Package for materials), to analyze the structural, electronic, magnetic, and thermodynamic properties of complex condensed matter systems. Our package integrates several functionalities including symmetry analysis, global structure searching methods, effective Hamiltonian methods, and Monte Carlo simulation methods. In conjunction with first-principles calculations, PASP has been successfully applied to diverse physical systems. In this paper, we give a brief introduction to its main features and underlying theoretical formulism. Some typical applications are provided to demonstrate the usefulness, high efficiency, and reliability of PASP. We expect that further developments will make PASP a general-purpose tool for material simulation and property calculation of condensed matters.