Lymphocytopenia and Neutrophilia Deteriorate at the Lowest Oxygenation Index Timepoint in COVID-19 Patient

Objective: Coronavirus disease 2019 (COVID-19) spread throughout the world and caused hundreds of thousands of infected people to death. However, the pathogenesis of severe acute respiratory syndrome coronavirus-2 (SARS COV-2) is poorly understood. The objective of this study is to retrospectively explore the pathogenesis of COVID-19 from clinical laboratory findings, taking disease progression into account. Methods: A single-centered, retrospective study was carried out, which included moderate (n = 76) and severe COVID-19 cases (n = 22). The difference of laboratory findings from blood routine examination and hepatorenal function test were retrospectively evaluated between the state of moderate and severe. The disease progression was indicated by oxygenation index. Results: Age is a risk factor for disease progression from moderate to severe. Lymphocytopenia, neutrophilia, liver and kidney function decreasement occurred in severe patients on admission, compared with moderate patients. Lymphocytopenia and neutrophilia deteriorated at the lowest oxygenation index timepoint in the severe patients. And the oxygenation index was associated with ratio of lymphocyte and neutrophil in COVID-19 patients. Conclusions: Lymphocytopenia and neutrophilia, which deteriorate in the progression of severe patients, are the main pathogenesis of COVID-19. More measures need to be taken to control lymphocytopenia and neutrophilia in severe COVID-19. Oxygenation index presented potentiality as predictor on the progression of COVID-19.

Oxygen Radical Generation as an Index of Neurotoxic Damage

Biochemical, anatomical, and physiological characteristics of the brain make it especially vulnerable to insult. Specifically, some of these characteristics such as myelin and a high energy requirement provide for the introduction of free radical-induced insult. Recently, the biochemistry of free radicals has received considerable attention. It also has become increasingly suggestive that many drug and chemical-induced toxicities may be evoked via free radicals and oxidative stress. Major points addressed in this work are the regulation of neural-free radical generation by antioxidants and protective enzymes, xenobiotic-induced disruption of cerebral redox status, and specific examples of neurotoxic agent-induced alterations in free radicals as measured by the fluorescent probe dichlorofluorescein. This article considers that free radical mechanisms may contribute significantly to the properties of several diverse neurotoxic agents and proposes that free radicals may be common phenomena of neurotoxicity.

Effects of Early-stage Phased Rehabilitation Training on Acute Respiratory Distress Syndrome:A Systematic Review and Meta-analysis

[Objectives]To systematically evaluate the effects of early-stage phased rehabilitation training on the oxygenation index,ICU length of stay,duration of mechanical ventilation,and occurrence of complications(ventilator-associated pneumonia,pressure ulcers,delirium)in ARDS patients,thus contributing evidence for the clinical application of early-stage phased rehabilitation training.[Methods]The China National Knowledge Infrastructure(CNKI),Wanfang,and other databases were searched.Literature screening,data extraction,and systematic analysis of the included studies were performed using Revman software.[Results]Thirteen randomized controlled trials involving a total of 860 patients were included in this review.The results of the meta-analysis showed that compared to the traditional rehabilitation training group,the early-stage phased rehabilitation training group demonstrated a significant increase in the oxygenation index of ARDS patients[SMD=1.18,95%CI(1.01,1.35),P<0.01],with statistically significant differences.Furthermore,there were significant reductions in ICU length of stay[SMD=-0.70,95%CI(-0.90,-0.50),P<0.01],duration of mechanical ventilation[SMD=-1.15,95%CI(-1.36,-0.94),P<0.01],and occurrence of complications[OR=0.16,95%CI(0.10,0.26),P<0.01],all of which were statistically significant.[Conclusions]Early-stage phased pulmonary rehabilitation training for ARDS patients effectively improves the oxygenation index,shortens ICU length of stay and duration of mechanical ventilation,and reduces complications.These findings support the clinical application and promotion of early-stage phased rehabilitation training.

Short-term prone positioning for severe acute respiratory distress syndrome after cardiopulmonary bypass:A case report and literature review

BACKGROUND Aortic dissection is a complex and dangerous cardiovascular disease,with many complications in the perioperative period,including severe acute respiratory distress syndrome(ARDS),which affects prognosis and increases mortality.Despite the effect of prone positioning(PP)in improving oxygenation in patients with severe ARDS,reports about PP early after cardiac surgery are few and such an opt-ion may be an issue in cardiac surgery patients because of the recent sternotomy.CASE SUMMARY A 40-year-old male patient diagnosed with acute type A aortic dissection on October 22,2021 underwent ascending artery replacement plus total aortic arch replacement plus stent elephant trunk implantation under cardiopulmonary bypass.Unfortunately,he developed ARDS on postoperative day 1.Despite comprehensive treatment with aggressive pulmonary protective ventilation,fluid management with continuous renal replacement therapy,the condition continued to deteriorate and rapidly progressed to severe ARDS with a minimum oxygenation index of 51.We are ready to implement salvage therapy,including PP and extracorporeal membrane oxygenation(ECMO).Due to the large amount of pericardial mediastinal and thoracic drainage after thoracotomy,ECMO may result in massive postoperative bleeding.Prolonged prone ventilation is often inappropriate after thoracotomy.Therefore,we chose short-term PP for<6 h.Finally,the oxygenation index greatly improved and the diffuse exudation in both lungs of the patient was significantly reduced with short-term prone positioning.CONCLUSION Intermittent short-term PP can improve early postoperative severe ARDS after acute aortic dissection.

Principles of Diagnosis and Treatment of Patients with Diagnosis of Covid-19 and Developing Viral Pneumonia

The article provides information on our achievements in the application of modern diagnostic methods and modern methods of treating patients with viral pneumonia,confirmed by covid-19.For this,statistical data of 2,000 patients were used.Of the 2,000 patients treated,920 were men,1,070 were women and 10 were children.Viral pneumonia-glaucoma syndrome in 1650 out of 2,000 patients with 10-20%damage;In 350,the diagnosis of viral pneumonia-frostbite syndrome with 50-85%damage,CRDS,respiratory failure was confirmed.Thus,50 out of 350 patients treated at the intensive care unit(ICU)out of 2,000 were intubated and connected to artificial ventilation.The research was carried out in 3 stages:I stage-admission to the intensive care unit;II stage-from the day of intubation to spontaneous breathing(7-14 days);and III stage-covers the period of extubation and recovery.The results of clinical,functional,hemodynamic and echocardiographic studies of the patients participating in the examination were analyzed.Also,the patients underwent bacteriological research studied the sensitivity to antibiotics.In addition,the composition of blood gases and the oxygenation index-Carrico were studied.

Research on Alkaline Filler Flame-Retarded Asphalt Pavement

Used as flame returdant of tunnel asphalt pavement, organic bromides produce a large amount of poisons and smoke in construction and flame retardation stage. The alkaline filler was found to replace mineral filler, and the flame- retarded asphalt mixtures were produced. Experimental results show that these asphalt mixtures are smoke restrained ; the performances and construction technology of asphalt pavement are not influenced; also the alkaline filler is of low-price. So this kind of flame-retarded asphalt mixtures is suitable for tunnel patement.

Heating Process of Thermosetting Insulation Materials for Buildings

Polyurethane （PU） and phenolic （PF） foams used for building isolation were analyzed by thermal gravity/differential thermal analysis to determine their pyrolysis behavior, including the decomposition point and the maximum reaction rate point. Besides, the shape deformations of PU and PF foams were observed, and their oxygen index and the calorific value in combustion were also studied. The results showed that the pyrolysis of both PU and PF can be divided into three stages from room temperature to 1 000 ℃ in the atmospheric air, with total mass loss of 94.345% for PF and 88.191% for PU, respectively. The oxygen index of PU and PF decreased with increasing the temperature and the duration of the heat treatment. With the temperature increasing, the calorific values of both materials were reduced remarkably. These results of the PU and PF could provide basic data of the thermal stability and fire safety design in the application of thermosetting insulation materials.

Research on the effect of the common flame retardant in reducing the flammability of the bitumen

The bituminous defect that the binder is flammable will bring road safety risk.Once it catches fires,large quantities of heat,smoke and poisonous gas are produced,released and spread quickly,which seriously hinder escape and rescue and harms heavily traffic safety.The common flame retardant system is used to modify the asphalt.Cone Calorimeter is adopted to evaluate the burning property of asphalt.The performance of the flame retardant is evaluated by limiting oxygen index and orthogonal design method.The paper analyzes the synergism of the asphalt and flame-retardant,and analyzes the effect of the flame on preventing the smoke to spread and demonstrates that the use of common flame retardants which is added into binder is good at reducing the flammability of the binder.This way can increase the safety of asphalt pavement when fire occurs in the tunnel.The study suggests that flame retardancy of asphalt can be evaluated by Limit Oxygen Index (LOI) and the flame retardancy property of asphalt has marked change according to the content of flame retardant.SB has perfect flame retardancy property,and ATH is better than MH in the effect of flame retardant.

Can Dexmedetomidine Improve Arterial Oxygenation and Intrapulmonary Shunt during One-lung Ventilation in Adults Undergoing Thoracic Surgery？ A Meta-analysis of Randomized, Placebo-controlled Trials

Background：One-lung ventilation （OLV） is a common ventilation technology during thoracic surgery that can cause serious clinical problems.We aimed to conduct a meta-analysis to compare oxygenation and intrapulmonary shunt during OLV in adults undergoing thoracic surgery with dexmedetomidine （Dex） versus placebo to assess the influence and safety of using Dex.Methods：Randomized controlled trials comparing lung protection in patients who underwent thoracic surgery with Dex or a placebo were retrieved from PubMed,EMBASE,MEDLINE,Cochrane Library,and China CNKI database.The following information was extracted from the paper：arterial oxygen partial pressure （PaO2）,PaO2/inspired oxygen concentration （PaO2/FiO2,oxygenation index [OI]）,intrapulmonary shunt （calculated as Qs/Qt）,mean arterial pressure （MAP）,heart rate （HR）,tumor necrosis factor-α （TNF-α）,interleukin （IL）-6,superoxide dismutase （SOD）,and malondialdehyde （MDA）.Results：Fourteen randomized controlled trials were included containing a total of 625 patients.Compared with placebo group,Dex significantly increased PaO2/FiO2 （standard mean difference [SMD] =0.98,95% confidence interval [CI] [0.72,1.23],P 〈 0.00001）.Besides,Qs/Qt （SMD=-1.22,95% CI [-2.20,-0.23],P =0.020）,HR （SMD=-0.69,95% CI [-1.20,0.17],P =0.009）,MAP （SMD=-0.44,95% CI [-0.84,0.04],P =0.030）,the concentrations ofTNF-α （SMD =-1.55,95% CI [-2.16,-0.95],P 〈0.001）,and IL-6 （SMD =-1.53,95% CI [-2.37,-0.70],P =0.0003） were decreased in the treated group,when compared to placebo group.No significant difference was found in MDA （SMD =-1.14,95% CI [-3.48,1.20],P =0.340） and SOD （SMD =0.41,95% CI [-0.29,1.10],P =0.250） between the Dex group and the placebo group.Funnel plots did not detect any significant publication bias.Conclusions：Dex may improve OI and reduce intrapulmonary shunt during OLV in adults undergoing thoracic surgery.However,this conclusion might be weakened by the limited number of pooled studies and patients.

Ecological Assessment of Oxygen Balance:A Case Study of China’s Natural Oxygen Bars

Ecological assessment plays a vital role in sustainable development of the environment,and thus exploration of specific and integrated ecological assessment methods has become a critical task.In this study,based on the concept of oxygen balance and by accommodating both natural factors and socioeconomic elements,we establish an oxygen(O_(2))balance index(OBI),i.e.,the ratio of the O_(2)production from the ecosystem to the O_(2)consumption by human behavior,based on the net primary productivity(NPP),fuel consumption,gross domestic production(GDP),population data,and so on.The results show that the spatial distributions of OBI in China are intimately correlated to the regional vegetation and socioeconomic development.The estimated OBI values are then validated by statistical data from 27 counties in China,and it is found that the OBI reflects the ecological environment status well.Moreover,the average OBI values derived from 190 natural oxygen bars in China reveal extreme imbalance between O_(2)production and consumption in highly developed regions,especially in the cities,in contrast to good O_(2)balance in areas with high-quality ecological status and less industrialization.The findings from this study have quantitatively captured the regional ecological quality,providing guidance for sustainable natural and socioeconomic developments in local areas of China.

SYNTHESIS AND CHARACTERIZATION OF POLYBENZOXAZINE CONTAINING PHOSPHORUS

The novel benzoxazine monomer containing phosphorus has been synthesized based on multifianctional amine route from bis（4-aminophenyl）phenylphosphate, p-cresol and formaldehyde. Subsequently, the benzoxazine monomer was thermo-cured into polybenzoxazine containing phosphorus. The chemical structures were identified by nuclear magnetic resonance （NMR）, Fourier transform infrared spectroscopy （FT-IR）. The curing reaction was monitored by differential scanning calorimetry （DSC） and FT-IR. The thermal and flame-retardant properties of obtained polybenzoxazine were evaluated by dynamic mechanical thermal analysis （DMA）, thermal gravimetric analysis （TGA） and oxygen index meter, respectively. The results show that the novel polybenzoxazine has high limiting oxygen index （38.1） and glass transition temperature （232℃）.

OPTICALLY ACTIVE AND FLAME-RETARDANT POLY(AMIDE-IMIDE)S BASED ON PHOSPHINE OXIDE MOIETY AND N,N′-(PYROMELLITOYL)BIS-L-AMINO ACID IN THE MAIN CHAIN:SYNTHESIS AND CHARACTERIZATION

Six new optically active and flame-retardant poly（amide-imide）s PAls 5a-5f containing phosphine oxide moiety as a flame-retardant unit in the main chain were synthesized from direct polycondensation reaction of six chiral N,N＇-（pyromellitoyl）-bis-L-amino acid 3a-3f with bis（3-aminophenyl）phenyl phosphine oxide 4 in a medium consisting of N-methyl-2-pyrrolidone （NMP）, triphenyl phosphite （TPP）, calcium chloride （CaCl2） and pyridine. The polymerization reactions produced a series of optically active poly（amide-imide）s with good yield and good inherent viscosity of 0.34-0.70 dLg^-1. The resulted polymers were fully characterized by means of FTIR and ^1H-NMR spectroscopy, gel permeation chromatography （GPC）, elemental analyses, inherent viscosity and solubility tests. Thermal properties and flameretardant behavior of the PAIs 5a-5f were investigated using thermal gravimetric analysis （TGA and DTG） and limiting oxygen index （LOI）. Data obtained by thermal analysis （TGA and DTG） revealed that these polymers showed good thermal stability. Furthermore, high char yield in TGA and good LOI values indicated that the resulting polymers were capable of exhibiting good flame retardant properties. N,N＇-（pyromellitoyl）-bis-L-amino acids 3a-3f were prepared in quantitative yields by the condensation reaction of pyromellitic dianhydride （1,2,4,5-benzenetetracarboxylicacid-1,2,4,5-dianhydride） 1 with L-alanine 2a, L-valine 2b, L-leucine 2c, L-isoleucine 2d, L-phenyl alanine 2e and L-2-aminobutyric acid 2f in acetic acid solution.