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Dendrobium officinale Kimura et Migo (D. officinale) is used as herbal medicine and new food resource in China, which is nontoxic and harmless, and can be used as common food. Polysaccharide as one of the main bioactive components in D. officinale, mainly composed of glucose and mannose (Manp: Glcp = 2.01:1.00-8.82:1.00), along with galactose, xylose, arabinose, and rhamnose in different molar ratios and types of glycosidic bonds. Polysaccharides of D. officinale exhibit a variety of biological effects, including immunomodulatory, anti-tumor, gastro-protective, hypoglycemic, anti-inflammatory, hepatoprotective, and vasodilating effects. This paper presents the extraction, purification, structural characteristics, bioactivities, structure-activity relationships and analyzes gaps in the current research on D. officinale polysaccharides. In addition, based on in vitro and in vivo experiments, the possible mechanisms of bioactivities of D. officinale polysaccharides were summarized. We hope that this work may provide helpful references and promising directions for further study and development of D. officinale polysaccharides.

The effect of anesthesia regimens on postoperative delirium after on-pump cardiac valve surgery is yet undetermined. This study aimed to evaluate the effect of volatile anesthesia compared with propofol-based total intravenous anesthesia (TIVA) on the occurrence of delirium after on-pump cardiac valve surgery.This randomized clinical trial was conducted at a university academic hospital in China, from February 2019 to January 2021. Patients scheduled for on-pump cardiac valve surgery or combined valve with coronary artery bypass grafting (CABG) surgeries were randomly assigned to receive anesthesia maintenance with either a volatile anesthetic (sevoflurane or desflurane) or propofol-based TIVA. The primary outcome was the incidence of delirium during the first 7 days after surgery, assessed using the confusion assessment method for the intensive care unit (ICU). The secondary outcomes included duration of delirium, subtypes of delirium, 30-day mortality, pain score, major morbidity (including cerebral infarction, respiratory failure, and pneumonia), duration of mechanical ventilation, and lengths of ICU and hospital stay. The statistical analysis of the primary outcome variable was by Pearson's χ 2 test.Among the 684 patients analyzed (mean age, 53.8 years; 381 [55.7%] women), 676 were assessed for the primary outcome. Postoperative delirium occurred in 63 of 337 (18.7%) patients receiving volatile anesthesia versus 76 of 339 (22.4%) patients receiving propofol-based TIVA (relative risk, 0.80; 95% confidence interval [CI], 0.55-1.16; P = .231). There were no significant differences between the groups in any of the secondary outcomes.Among patients undergoing on-pump cardiac valve surgery, anesthesia maintenance with a volatile agent did not result in significantly fewer occurrences of postoperative delirium than propofol-based TIVA.

Objective:To compare the embryo condition and clinical outcomes between patients with low and normal serum luteinizing hormone (LH) levels on the day after a single trigger of gonadotropin-releasing hormone agonist (GnRH-a). In patients with low LH levels we further analyzed the efficacy of human chorionic gonadotropin (HCG) to trigger ovulation.Methods:We retrospectively analyzed 957 infertile patients (tubal factor, ovulation disorders, male sperm factor, or unexplained infertility) who were treated with in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI)-assisted pregnancy at the Chengdu Xinan Gynecology Hospital from July 2017 to December 2020. Patients with sufficient GnRH-a single trigger and normal serum LH levels on the next day were used as the control group (n=906), and patients with low LH levels were set as the experimental group (n=51), of whom 10 received HCG retriggering. We analyzed the effects of low and normal LH levels, and the efficacy HCG retriggering in patients with low LH level on the embryo status and embryonic transplantation after cryopreservation outcome of patients.Results:There were no significant differences in egg yield, 2PN fertilization rate, excellent embryo rate, or live birth rate of frozen-thawed embryos between patients with low and normal LH levels after GnRH-a trigger. There was also no difference in patients with low LH levels who received HCG retriggering or not.Conclusion:The outcomes of patients with low LH levels on the day after GnRH-a administration were similar to those of patients with normal LH levels. The embryo status and live birth rate of frozen-thawed embryos in patients with low LH levels in the HCG retriggering and non-HCG retriggering groups are similar. When blood LH< 10 miu/ml was measured on the day after GnRH-a trigger, no special treatment was required, and there was no significant effect on embryonic and clinical outcomes. No blood LH test is required on the day following the trigger, which does not affect the outcome of in vitro fertilization.

Background The current clinical practice regarding intraoperative ventilation management in non-cardiothoracic surgical setting among anesthesia providers in China is unclear. Methods We developed a 25-question anonymous survey which was distributed to anesthesia departments from 81 tertiary/university hospitals in China between August 2021 and September 2021. Information including participant characteristics, ventilatory settings, and opinions on lung-protective ventilation were obtained by electronic survey. Results were reported descriptively. Results The survey was completed by 1089 anesthesiologists from 57 institutions (70% institution response rate). The vast majority of respondents (1010/1089; 92.7%)used low tidal volume (6–8 ml kg − 1) ventilation. About three quarters (840/1089; 77.1%) utilized positive end-expiratory pressure, and most anesthesiologists set positive end-expiratory pressure of 1–5 cmH2O in either laparoscopic (639/840; 76.1%) or non-laparoscopic surgery (736/840; 87.6%). The majority of respondents (921/1089; 84.6%) performed alveolar recruitment maneuver intraoperatively. Approximate 20% of respondents routinely implemented lung-protective ventilation with bundles of low tidal volume, positive end-expiratory pressure, and alveolar recruitment maneuver. Conclusions We found that heterogeneity exists between individual practices regarding intraoperative ventilation management in the setting of non-cardiothoracic surgery, indicating the potential knowledge-practice gap among Chinese anesthesiologists. Trial registration number: ChiCTR2100047653; Registration date: June 21, 2021 Registry URL: Chictr.org.cn.

Edible and medicinal mushrooms are extensively cultivated and commercially consumed around the world. However, green mold disease (causal agent

The purpose of this study was to evaluate the effect of volatile anesthesia and propofol-based total intravenous anesthesia (TIVA) on postoperative pulmonary complications (PPCs) among patients undergoing cardiac surgery.Parallel-group, randomized controlled trial.Single-center tertiary care hospital.Five hundred twenty-four patients undergoing cardiac surgery with cardiopulmonary bypass.The patients were assigned randomly (1:1) to receive anesthesia maintenance with a volatile anesthetic (sevoflurane or desflurane) or propofol-based TIVA.The primary outcome was a composite of postoperative pulmonary complications within the first 7 postoperative days. The PPCs occurred in 118 of 262 patients (45.0%) in the volatile anesthesia group compared with 105 of 262 patients (40.1%) in the propofol-based intravenous anesthesia group (relative risk: 1.17 [95% CI 0.96-1.42], p = 0.123). There were no significant differences in the severity of PPCs within 7 days postoperatively, the occurrence and severity grade of PPCs within 30 days, the incidence of hypoxia, and 30-day mortality.In adult patients undergoing cardiac surgery with cardiopulmonary bypass, general anesthesia with a volatile anesthetic compared with propofol-based TIVA had not reduced pulmonary complications within the first 7 days after surgery.

The internal behaviors of carriers in InGaAsP single-junction solar cell are investigated by using electroluminescence (EL) measurements. Two emission peaks can be observed in current-dependent electroluminescence spectra at low temperatures, and carrier localization exists for both peaks under low excitation. The trends of power index α extracted from excitation-dependent EL spectra at different temperatures imply that there exists a competition between Shockley–Read–Hall recombination and Auger recombination. Auger recombination becomes dominant at high temperatures, which is probably responsible for the lower current density of InGaAsP solar cell. Besides, the anomalous “S-shape” tendency with the temperature of band-edge peak position can be attributed to potential fluctuation and carrier redistribution, demonstrating delocalization, transfer, and redistribution of carriers in the continuum band-edge. Furthermore, the strong reduction of activation energy at high excitations indicates that electrons and holes escaped independently, and the faster-escaping carriers are holes.

Background To determine whether maintaining ventilation during cardiopulmonary bypass (CPB) with a different fraction of inspired oxygen (FiO2) had an impact on the occurrence of postoperative pulmonary complications (PPCs). Methods A total of 413 adult patients undergoing elective cardiac surgery with CPB were randomly assigned into three groups: 138 in the NoV group (received no mechanical ventilation during CPB), 138 in the LOV group (received a tidal volume (VT) of 3–4 ml/kg of ideal body weight with the respiratory rate of 10–12 bpm, and the positive end-expiratory pressure of 5–8 cmH2O during CPB; the FiO2 was 30%), and 137 in the HOV group (received the same ventilation parameters settings as the LOV group while the FiO2 was 80%). Results The primary outcomes were the incidence and severity of PPCs during hospitalization. The composite incidence of PPCs did not significantly differ between the NoV (63%), LOV (49%) and HOV (57%) groups (P = 0.069). And there was also no difference regarding the incidence of PPCs between the non-ventilation (NoV) and ventilation (the combination of LOV and HOV) groups. The LOV group was observed a lower proportion of moderate and severe pulmonary complications (grade ≥ 3) than the NoV group (23.1% vs. 44.2%, P = 0.001). Conclusion Maintaining ventilation during CPB did not reduce the incidence of PPCs in patients undergoing cardiac surgery. Trial registration: Chinese Clinical Trial Registry ChiCTR1800015261. Prospectively registered 19 March 2018. http://www.chictr.org.cn/showproj.aspx?proj=25982

BackgroundPostoperative pulmonary complications (PPCs) are the most common perioperative complications following surgical site infection (SSI). They prolong the hospital stay and increase health care costs. A lung-protective ventilation strategy is considered better practice in abdominal surgery to prevent PPCs. However, the role of the inspiratory oxygen fraction (FiO2) in the strategy remains disputed. Previous trials have focused on reducing SSI by increasing the inhaled oxygen concentration but higher FiO2(80%) was found to be associated with a greater incidence of atelectasis and mortality in recent research. The trial aims at evaluating the effect of different FiO2added to the lung-protective ventilation strategy on the incidence of PPCs during general anesthesia for abdominal surgery.Methods and designPROtective Ventilation with a low versus high Inspiratory Oxygen fraction trial (PROVIO) is a single-center, prospective, randomized controlled trial planning to recruit 252 patients undergoing abdominal surgery lasting for at least 2 h. The patients will be randomly assigned to (1) a low-FiO2(30% FiO2) group and (2) a high-FiO2(80% FiO2) group in the lung-protective ventilation strategy. The primary outcome of the study is the occurrence of PPCs within the postoperative 7 days. Secondary outcomes include the severity grade of PPCs, the occurrence of postoperative extrapulmonary complications and all-cause mortality within the postoperative 7 and 30 days.DiscussionThe PROVIO trial assesses the effect of low versus high FiO2added to a lung-protective ventilation strategy on PPCs for abdominal surgery patients and the results should provide practical approaches to intraoperative oxygen management.Trial registrationwww.ChiCTR.org.cn, identifier:ChiCTR18 00014901. Registered on 13 February 2018.

Background The effect of general anesthetics (propofol and volatile anesthetics) on pulmonary outcome after lung resection surgery with one-lung ventilation (OLV) is yet undetermined. We evaluated the effect of intravenous anesthesia (propofol) and volatile anesthesia (sevoflurane or desflurane) regimens on postoperative pulmonary complications (PPCs) in patients undergoing lung resection surgery. Methods This prospective, randomized controlled trial enrolled 555 adult patients scheduled for lung resection surgery with OLV. Participants were randomized to 1 of 3 general anesthetic regimens (propofol, sevoflurane, or desflurane). Standard anesthesia and ventilation protocols were followed in all groups. The primary outcome was a composite of PPCs in the first 7 postoperative days. Secondary outcomes included the severity of PPCs and major postoperative complications classification. Intergroup difference in the primary outcome was assessed for significance using the Pearson χ2 test. Results Of 837 patients who were assessed for eligibility, 555 were randomized and 545 were analyzed. One hundred and seventy-nine patients were assigned to the propofol group, 182 in the sevoflurane group, and 184 in the desflurane group. The incidence of PPCs did not differ between the combined volatile anesthetics (sevoflurane and desflurane) group and the propofol group (21.9% vs 24.0%; odds ratio, 0.89; 95% confidence interval, 0.58-1.35; P = .570). The PPCs grade and Clavien-Dindo scores did not differ significantly across groups. Conclusions In patients undergoing lung resection surgery with OLV, general anesthesia with volatile anesthetics (sevoflurane or desflurane) did not reduce PPCs compared with propofol. No difference in secondary outcomes was observed.

Cyber-physical systems (CPS) is a next-generation intelligent system that realizes close integration of computing, communication and physical elements based on environmental perception. The interaction between information technology and the physical world makes CPS vulnerable to various malicious attacks and damage Its security. The paper designs a sensor attack detection method based on fusion interval and historical measurement. The method first builds different fault models for different sensors, and uses system dynamics equations to integrate historical measurements into the attack detection method. Different aspects of sensor measurement are analyzed. In addition, the use of historical measurement and fusion interval solves the problem of whether there is a failure when the measurements of two sensors intersect. The core idea of this method is to use the paired inconsistent relationship between sensors to detect and identify attacks .

Background Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), involves multiple organs. Testicular involvement is largely unknown. Objective To determine the pathological changes and whether SARS-CoV-2 can be detected in the testes of deceased COVID-19 patients. Design, setting, and participants Postmortem examination of the testes from 12 COVID-19 patients was performed using light and electron microscopy, and immunohistochemistry for lymphocytic and histiocytic markers. Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the virus in testicular tissue. Outcome measurements and statistical analysis Seminiferous tubular injury was assessed as none, mild, moderate, or severe according to the extent of tubular damage. Leydig cells in the interstitium were counted in ten 400× microscopy fields. Results and limitations Microscopically, Sertoli cells showed swelling, vacuolation and cytoplasmic rarefaction, detachment from tubular basement membranes, and loss and sloughing into lumens of the intratubular cell mass. Two, five, and four of 11 cases showed mild, moderate, and severe injury, respectively. The mean number of Leydig cells in COVID-19 testes was significantly lower than in the control group (2.2 vs 7.8, p, Take Home Message We found significant injury in the testes of coronavirus disease 2019 (COVID-19) patients. However, the virus was not detected in the testes in the majority of cases. These findings can provide evidence-based guidance for sperm donation and inform management strategies to mitigate the risk of testicular injury during the COVID-19 disease course.

Four coordination polymers, [CuCl(cptpy)·2H2O]n (1), [Mn2Cl2(cptpy)2(phdat)H2O]n (2) and [Ln(cptpy)3]n (Ln = La (3), Pr (4)) (Hcptpy = 4'-(4-carboxyphenyl)-2,2':6',2''-terpyridine, phdat = 2,4-diamino-6-phenyl-triazine) have been hydrothermally synthesized and characterized by IR spectra, X-ray single-crystal diffraction, powder X-ray diffraction (PXRD), elemental analyses and thermogravimetric analyses (TGA). Compounds 1, 3 and 4 exhibit 2D or 3D structures comprising 1D linear chain connected by π…π stacking interactions. While, compound 2 contains two kinds of 1D chains, of which one is a linear chain and the other is a ladder chain, and further extends to 3D structure by π…π stacking and hydrogen bonding interactions. The electrochemical analysis shows that compound 1 has good catalytic activities for the reductions of both NaNO2 and H2O2, and is a potential catalytic material. Magnetic analysis indicates that compound 2 exhibits antiferromagnetic behavior.

Three novel inorganic–organic hybrid materials [Co(btp)2(W5O16)(H2O)]n (1), [Cd3(btp)6(PW12O40)2(H2O)6·6H2O]n (2), and [Ag3(btp)2(PMo12O40)·1.5H2O]n (3) (btp = 2,6-bis(1,2,4-triazol-1-yl)pyridine) have been hydrothermally synthesized and characterized by IR spectroscopy, single-crystal X-ray diffraction, powder X-ray diffraction (PXRD), elemental analysis and thermal gravimetric analysis (TGA). The most striking structure feature of compound 1 is a 3D polycatenation framework, interpenetrated by a 2D 4-connected sql topology layer and a 3D 6-connected rob topology framework. Compound 2 exhibits a rare meso-helices 3D network with different chiralities crossing coexistence. Compound 3 also holds a 3D framework formed by linking terminal oxygen atoms of [α-PMo12O40]3− anions and silver ions in a 2D metal–organic layer. Compound 1 displays antiferromagnetic behavior. The luminescence, electrochemical and photocatalytic properties of compounds 1–3 have also been investigated. Compound 3 exhibits significant electrochemical activity for the reduction of H2O2 while compounds 1 and 2 show efficient photocatalytic activities for the degradation of Rhodamine B (RhB). Furthermore, the three compounds display luminescence behaviors in the solid state.

As a new online education model, MOOC has the characteristics of large-scale, online, open and interactive. More and more college students become MOOC learners. The paper conducts a case study on the basic computer culture course based on computational thinking, constructs the teaching design pattern and corresponding design template of the university computer course under the MOOC environment, and provides the theoretical framework and practical guidance for the related research of the micro-curricular under the MOOC environment.

Three novel compounds, [Ni4(1,4-ndc)3(OH)2(H2O)2·2.5H2O]n (1), {[Mn2(1,4-ndc)2(OAc)](C5MIm)·0.5H2O}n (2), and {[Co3(1,4-ndc)4(H2O)4](C5MIm)2·2H2O}n (3), were hydro-/solvothermally prepared with the corresponding acetate, 1,4-H2ndc (1,4-H2ndc = 1,4-naphthalenedicarboxylic acid) and different auxiliaries such as C5MImBr (C5MImBr = 1-pentyl-3-methylimidazolium bromide) or 2,4-diamino-6-methyl-1,3,5-triazine. Compound 1 composes of one three-dimensional (3D) network, where one rare nickel chain is constructed through NiII ions bridged by μ3-OH– groups, μ3-η2:η1 and μ2-η1:η1 carboxyl groups from 1,4-ndc2– groups as well as coordination water molecules. In compound 2, MnII ions are connected by μ4-η1:η1:η1:η1 1,4-ndc2– groups and μ2-η1:η1 acetate radicals, forming a 3D framework. For compound 3, a [Co3(CO2)4(H2O)4] unit is observed, which is further bridged by μ2-η1:η0:η1:η0 and μ4-η1:η1:η1:η1 1,4-ndc2– groups and ultimately results in forming a 3D structure. It demonstrates compounds 1–3 can be noted as pcu, l...

Four new isostructural lanthanide coordination polymers [Ln(Hcit)(H2O)2·2H2O]n (H4cit = citric acid) (Ln = Sm (1), Gd (2), Er (3), Nd (4)) have been synthesized under hydrothermal method by using citric acid, melamine as well as Sm(NO3)3·6H2O (1), Gd(NO3)3·6H2O (2), Er(NO3)3·6H2O (3), Nd(NO3)3·6H2O (4), and structurally characterized by FT-IR, thermogravimetric analyses (TGA), powder X-ray diffraction (PXRD), elemental analyses and X-ray single-crystal diffraction. The X-ray single-crystal diffraction analyses demonstrated that Hcit3- ligand adopt the rare coordination mode to connect the metal atoms of complexes 1–4 by chelating carboxyl group, single coordinated carboxyl group and hydroxyl group, forming left-handed and right-handed helical chains, which are further connected to 2D layer structures by Ln–O bonds. Furthermore, complex 1 displayed good fluorescence at solid state; complexes 1 and 3 exhibited antiferromagnetic behaviors, while complex 2 displayed ferromagnetic behavior.

The Cu(I)/phosphoric acid (PA) dual-catalyzed radical aminoperfluoroalkylation and aminodifluoromethylation of alkenes with commercially available fluoroalkylsulfonyl chlorides as the radical source is described. Functionalized α-tertiary pyrrolidines bearing four types of fluoroalkyl groups are obtained with moderate to excellent yields. The introduction of a Cu(I)/phosphoric acid dual catalytic system and the use of silver carbonate as a key additive to inhibit the side hydroamination reaction caused by the in situ generated HCl are crucial for the transformation.

The hot deformation behavior of TC27 titanium alloy at the temperatures of 900-1150 °C and the strain rate of 0.01-10 s-1, the height reduction of 70%, was investigated in the isothermal compression test to identify the optimal extrusion parameters. The processing-map of TC27 titanium alloy was constructed based on dynamic materials model (DMM) and principle of Prasad*s instability. The conclusion shows that temperature and strain rate of deformation had a great influence on flow stress. At the beginning of deformation, the flow stress increased quickly with the augment of true strain and decreased slowly after flow stress reaching to the maximum value. Finally, flow stress tended to relatively stable condition. The flow stress decreased with the increase of temperature and increased with the increase of strain rate. The TC27 titanium alloy was sensitive to temperature and strain rate. Processing-map exhibited two peak efficiencies of power dissipation; one peak was 49% at 900°C/0.01 s-1, which dynamic recovery occured. The other peak was also 49% at 1050 °C /0.01s-1, which dynamic recrystallization occured in the domain. Besides, there were two instability areas in the processing-map which should be avoided during the extrusion. Therefore, in order to obtain the satisfactory properties, the parameters that 1050 °C and 0.01 s-1 were selected in the extrusion.

The compounds [Co(e,a-cis-1,4-chdc)(phdat)]n (1) and [Cd(e,a-cis-1,4-chdc)(phdat)]n (2) have been synthesized under hydrothermal method by using 1,4-cyclohexanedicarboxylic acid (1,4-H2chdc), 2,4-diamino-6-phenyl-1,3,5-triazine (phdat) as well as CoCl2·6H2O, CdCl2·2.5H2O respectively and characterized by IR spectra, X-ray single-crystal diffraction, powder X-ray single-crystal diffraction (PXRD), elemental analyses and thermogravimetric analyses (TGA). The results show the compounds 1 and 2 are isomorphous and exhibit paddle-wheel dinuclear Co2(CO2)4/Cd2(CO2)4 units, which are further connected to 1D chain structures by μ4:η1:η1:η1:η1 1,4-chdc2– ligands and extended into a 3D structures via different hydrogen bonding and π…π stacking interactions. Furthermore, compound 1 exhibits antiferromagnetic behavior and compound 2 displays luminescent behavior at solid state.

Background There is no consensus on the ventilation management during cardiopulmonary bypass (CPB), and the anesthesiologists or the surgeons usually ventilate the lungs with different ventilation strategies or keep them static. Better outcomes are more likely to occur when the ventilation is administered during CPB according to the existing literatures. However, the use of high fraction of inspired oxygen (FiO2) is debatable in cardiac surgery. And the potential effects of strategies combining low tidal volume (VT) ventilation with different FiO2 during CPB on postoperative pulmonary complications (PPCs) are unclear. Design The VONTCPB trial is a single-center, prospective, double-blinded, randomized, controlled trial. We are going to recruit total 420 elective cardiac surgery patients with median sternotomy under CPB, who will be equally randomized into three different ventilation strategy groups: NoV, LOV and HOV. (1) The NoV group receives no mechanical ventilation during CPB; (2) the LOV group receives a low VT of 3-4 ml/kg of ideal body weight (IBW) with the respiratory rate (RR) of 10–12 acts/min, and the positive end-expiratory pressure (PEEP) of 5–8 cmH2O during CPB; the FiO2 is 30%; (3) the HOV group receives a low VT of 3-4 ml/kg of IBW with the RR of 10–12 acts/min, and the PEEP of 5–8 cmH2O during CPB; the FiO2 is 80%. The primary endpoints are the incidence of the composite of PPCs and the PPCs score. The secondary endpoints refer to the incidence of the oxygenation index (PaO2/FiO2 ratio)

Background: Postoperative pulmonary complications (PPCs) is the most common perioperative complication following surgical site infection (SSI), which prolongs the hospital stay and increases health care cost. Lung-protective ventilation strategy is considered better practice in abdominal surgery to prevent PPCs. However, the role of inspiratory oxygen fraction (FiO₂) in the strategy remains disputable. Previous trials have focused on reducing SSI by increasing inhaled oxygen concentration but higher FiO₂ (80%) was found to be associated with a greater incidence of atelectasis and mortality in recent researches. The trial aims at evaluating the effect of different FiO₂ added to lung-protective ventilation strategy on the incidence of PPCs during general anesthesia for abdominal surgery. Methods: PROtective Ventilation with a low versus high Inspiratory Oxygen fraction trial（PROVIO）is a single-center, prospective, randomized, controlled trial planning to recruit 252 patients undergoing abdominal surgery lasting for at least 2 hours. The patients will be randomly assigned to (1) a low FiO₂ (30% FiO₂) group and (2) a high FiO₂ (80% FiO₂) group in lung-protective ventilation strategy. The primary outcome of the study is the occurrence of PPCs within the postoperative 7 days. Secondary outcomes include the severity grade of PPCs, the occurrence of postoperative extrapulmonary complications and all-cause mortality within the postoperative 7 and 30 days. Discussion: PROVIO trial assesses the effect of low versus high FiO₂ added to lung-protective ventilation strategy on PPCs for abdominal surgery patients and the results will provide practical approaches to intraoperative oxygen management. Trial registration number: Registered at www.ChiCTR.org.cn on 13 February 2018 with identifier no. ChiCTR18 00014901. Keywords: Postoperative pulmonary complications, Lung-protective ventilation, Fraction of inspired oxygen, Abdominal surgery.

A new coordination polymer, {[Mn(HPIDC)(H 2 O)]·2H 2 O} n ( 1 ) (H 3 PIDC = 2-(pyridin-4-yl)-1 H -imidazole-4,5-dicarboxylic acid), has been obtained by hydrothermal method and structurally characterized by X-ray single crystal diffraction, elemental analysis and thermogravimetric analysis (TGA). X-ray single crystal diffraction reveals that compound 1 crystallizing in acentric Pna 2 1 space group, exhibits an ultimate racemic three-dimension framework with rare noninterpenetrated (10,3)-d (or utp) topology due to the alternate array of left- and right-handed helixes. Moreover, compound 1 also features ferroelectric, nonlinear optical (NLO) and antiferromagnetic behaviors.

A 10-week experiment was conducted to estimate the effects of graded levels of histidine on growth performance, digested enzymes activities, erythrocyte osmotic fragility and hypoxia-tolerance of juvenile grass carp Ctenopharyngodon idella. Six isonitrogenous (38%) and isoenergetic semi-purified diets containing casein and gelatin with graded levels of histidine (0.45, 0.72, 1.02, 1.28, 1.55, 1.78 g 100 g − 1 DM) were formulated. Each diet was assigned to triplicate groups of 30 fish (3.68 ± 0.01) for each tank. The highest weight gain (WG, %), final body weight (FBW, g) and specific growth rate (SGR) were recorded when histidine level was 1.02% of the diet. Whole body protein and muscle protein were not significantly affected by the histidine level ( P > 0.05). Muscle histidine content was linearly increased along with the dietary histidine increasing ( P − 1 ) exhibited highest erythrocyte osmotic fragility ( P P Statement of relevance The present study determined optimum dietary histidine requirement for juvenile grass carp and the data goes to 1.21% of the diet, corresponding to 3.2% of dietary protein. We also found that juvenile grass carp fed with histidine deficiency diet not only limited their growth performance, but also exhibited higher erythrocyte osmotic fragility, lower hypoxia-tolerance and antioxidant enzyme activities. Digested enzyme activities were also significantly affected by the dietary histidine levels. Thus, it is important to meet histidine requirement when commercial diets are formulated for this species.