[Safety of modified T-piece resuscitator versus nasal cannula oxygen in electronic bronchoscopy for infants: a prospective randomized controlled study]. / 改良Tç»„åˆå¤è‹å™¨ä¸Žé¼»å¯¼ç®¡å¸æ°§ç”¨äºŽå©´å„¿ç”µå­æ”¯æ°”ç®¡é•œæ£€æŸ¥çš„å®‰å ¨æ€§æ¯”è¾ƒï¼šä¸€é¡¹å‰çž»æ€§éšæœºå¯¹ç §ç ”ç©¶.

OBJECTIVES: To optimize the oxygen therapy regimens for infants with pulmonary diseases during bronchoscopy. METHODS: A prospective randomized, controlled, and single-center clinical trial was conducted on 42 infants who underwent electronic bronchoscopy from July 2019 to July 2021. These infants were divided into a nasal cannula (NC) group and a modified T-piece resuscitator (TPR) group using a random number table. The lowest intraoperative blood oxygen saturation was recorded as the primary outcome, and intraoperative heart rate and respiratory results were recorded as the secondary outcomes. RESULTS: Compared with the NC group, the modified TPR group had a significantly higher level of minimum oxygen saturation during surgery and a significantly lower incidence rate of hypoxemia (P<0.05). In the modified TPR group, there were 6 infants with mild hypoxemia, 2 with moderate hypoxemia, and 1 with severe hypoxemia, while in the NC group, there were 3 infants with mild hypoxemia, 5 with moderate hypoxemia, and 9 with severe hypoxemia (P<0.05). The modified TPR group had a significantly lower incidence rate of intraoperative respiratory rhythm abnormalities than the NC group (P<0.05), but there was no significant difference in the incidence rate of arrhythmias between the two groups (P>0.05). CONCLUSIONS: Modified TPR can significantly reduce the risk of hypoxemia in infants with pulmonary diseases during electronic bronchoscopy, and TPR significantly decreases the severity of hypoxemia and the incidence of respiratory rhythm abnormalities compared with traditional NC.

[Clinical characteristics of children with Omicron variant infection in Chengdu area, China]. / 成都地区Omicronå˜å¼‚æ ªæ„ŸæŸ“å„¿ç«¥çš„ä¸´åºŠç‰¹å¾åˆ†æž.

OBJECTIVES: To investigate the clinical characteristics of children infected with the Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Chengdu of China. METHODS: A retrospective analysis was conducted for the clinical data of 226 children who were infected with the Omicron variant of SARS-Cov-2 and were isolated and treated in Chengdu Shelter Hospital from August 28 to September 21, 2022. According to the presence or absence of clinical symptoms, they were divided into two groups: asymptomatic group and mild symptomatic group. The two groups were compared in terms of clinical characteristics, diagnosis and treatment, and prognosis. RESULTS: Among the 226 children infected with the Omicron variant, 71 (31.4%) were asymptomatic and 155 (68.6%) had mild symptoms. Fever and cough were the most common clinical symptoms, with fever in 95 children (61.3%) and cough in 92 children (59.4%). Of all 226 children, 188 (83.2%) received coronavirus disease 2019 (COVID-19) vaccination. The time to nucleic acid clearance ranged from 6 to 26 days, with a nucleic acid clearance rate of 58.0% (131/226). There were no significant differences among different age groups in sex, early symptoms, clinical typing, nucleic acid re-positive rate, nucleic acid clearance rate, and length of hospital stay (P>0.05). There were no significant differences between the asymptomatic and mild symptomatic groups in age, sex, underlying diseases, COVID-19 vaccination, use of Lianhua Qingwen granules, nucleic acid clearance rate, nucleic acid re-positive rate, and length of hospital stay (P>0.05). CONCLUSIONS: Children infected with the Omicron variant of SARS-Cov-2 in Chengdu generally have mild clinical symptoms, mainly upper respiratory tract infection, which has little threat to the health of children of different ages, and children tend to have a good overall prognosis.

Electroacupuncture Alleviates Pain Responses and Inflammation in Collagen-Induced Arthritis Rats via Suppressing the TLR2/4-MyD88-NF-κB Signaling Pathway.

Results: EA intervention and OxPAPC injection could relieve mechanical allodynia and thermal hyperalgesia caused by CIA. Paw edema and pathological damage of synovium were significantly ameliorated after EA intervention and OxPAPC injection. Furthermore, EA intervention and OxPAPC injection markedly reduced the contents of serum TNF-α, IL-1ß, and IL-6, as well as the protein expression levels of synovial TLR2, TLR4, MyD88, and NF-κB p-p65. In particular, the expression of TLR2 and TLR4 on synovial fibroblasts and macrophages in synovium was significantly reduced by EA intervention. Conclusions: Repeated EA stimulation at ST36 and SP6 can effectively relieve joint pain and synovial inflammation caused by RA in CIA rats. The analgesic and anti-inflammatory effect of EA may be closely related to the inhibition of innate immune responses driven by the TLR2/4-MyD88-NF-κB signaling pathway in the synovium.

[Value of metagenomic next-generation sequencing in children with hemophagocytic syndrome with central nervous system involvement]. / å®åŸºå› ç»„äºŒä»£æµ‹åºåœ¨ä¼´æœ‰ä¸­æž¢ç¥žç»ç³»ç»Ÿå—ç´¯å„¿ç«¥å™¬è¡€ç»†èƒžç»¼åˆå¾ä¸­çš„åº”ç”¨ä»·å€¼.

OBJECTIVES: To study the value of metagenomic next-generation sequencing (mNGS) in detecting intracranial Epstein-Barr virus (EBV) infection in children with hemophagocytic syndrome (HPS) with central nervous system involvement. METHODS: A retrospective analysis was performed for the cerebrospinal fluid mNGS results of 30 HPS children with central nervous system involvement, which were compared with the results of cerebrospinal fluid EBV-DNA detection and serum EBV antibody profile. The change in serum EBV-DNA copy number after treatment was used to evaluate the efficacy of targeted therapy. RESULTS: The positive rate of EBV in cerebrospinal fluid determined by mNGS was significantly higher than that of EBV-DNA in cerebrospinal fluid (100% vs 10%, P<0.001) and had no significant difference from the positive rate of serum EBV antibody profile (100% vs 93%, P>0.05). The median number of sequences determined by mNGS was 2 400, and serum EBV-DNA copy number before treatment was moderately positively correlated with the number of EBV sequences (rs=0.693, P<0.001). The multiple linear regression analysis showed that the number of sequences determined by mNGS in cerebrospinal fluid increased with the increase in serum EBV-DNA copy number before treatment (P<0.05). CONCLUSIONS: EBV-associated HPS often results in EBV-infected viral encephalitis, and mNGS can significantly increase the detection rate of EBV in cerebrospinal fluid, which may help with clinical diagnosis.

[Analysis of the Characteristics of the Outcomes of Job-Transfer Subspecialty Training Program in Pediatrics in Sichuan].

Objective: To discuss the characteristics of physician trainee outcomes after completion of the job-transfer subspecialty training in pediatrics, a program designed to increase the number of pediatricians, in Sichuan Province and to provide countermeasures for alleviating the shortage of pediatricians. Methods: We collected with questionnaire surveys information on changes in the workload and salaries experienced by physicians who completed the job-transfer subspecialty training program in pediatrics between February 2017 and May 2020 in Sichuan Province. Then, we compared the characteristics of physicians who successful became pediatricians and those who did no. Results: A total of 208 physicians completed the job-transfer subspecialty training program in pediatrics. Among them, 178, accounting for 85.6%, completed the questionnaire survey, and 120, accounting for 67.4%, had a background in other subspecialties than pediatrics. The majority (>90%) of physicians who participated in the training program came from secondary or lower levels of hospitals from the cities and prefectures all over Sichuan Province. In this study, we found that the rate of successful job transfer from being a physician to being a pediatrician in Sichuan Province in the past four years was 85.0% (102/120), with the year-by-year results being 88.2% (15/17) in 2017, 72.7% (16/22) in 2018, 86.7% (39/45) in 2019, and 94.% (32/34) in 2020. There was no significant difference between physicians who had successful job transfer and became pediatricians and those who failed to do so in terms of gender, age, hospital level, specialization prior to the job transfer, whether or not the hospital had a pediatrics department, amount of support for the pediatrics department, whether or not the physician was working at a new hospital after the job transfer, salaries, and changes of responsibilities during COVID-19 (all P>0.05). There was significant difference in the change of workload after completion of the training program between physicians who had successful job transfer and became pediatricians and those who failed to do so ( χ 2=9.037, P=0.003), and 78.4% of the trainees stated that their workload had increased after the job transfer. There was a moderate correlation between successful job transfer and changes in workload after the transfer (|Phi[ψ] |=0.729). Conclusions: The policy of government-supported job-transfer subspecialty training in pediatrics has played an active and important role in the swift resolution of the shortage of pediatricians. However, finding the root cause of and addressing the problem of the overwhelming workload of pediatricians remain challenging issues to be resolved.

[Effects of transcutaneous auricular vagus nerve stimulation on bone and cartilage destruction in rats with rheumatoid arthritis].

OBJECTIVE: To observe the alleviating effect of transcutaneous auricular vagus nerve stimulation (taVNS) on articular cartilage and bone destruction in rats with collagen-induced arthritis (CIA), and explore the cellular and molecular mechanisms of taVNS against rheumatoid arthritis (RA). METHODS: The male SD rats were randomly divided into normal control group (n=12), model group (n=12), and taVNS group (n=12). The CIA rat model was established by multi-point injection of emulsion prepared from type Ⅱ bovine collagen and Freund's incomplete adjuvant into the root of rat tail. The rats in the taVNS group were treated with taVNS at bilateral auricular conchae, 30 min per time, once a day, for consecutive 28 d. The cartilage destruction of the ankle joint was observed by safranin O-fast green staining, the production of osteoclasts in the joint tissue by tartrate-resistant acid phosphatase (TRAP) staining, and the bone erosion by X-ray and Micro-CT imaging. The protein expression levels of matrix metalloproteinase (MMP)-1, MMP-3, MMP-13, receptor activator of nuclear factor-κB ligand (RANKL), and osteoprotegerin (OPG) in the synovial tissues were detected by Western blot. RESULTS: Compared with the normal control group, the CIA rats presented with typical RA symptoms and elevated arthritis index (AI,P<0.05). After intervention with taVNS, the AI remarkably declined in comparison with that in the model group (P<0.05). Compared with the control group, the model group displayed loss of cartilage matrix in the ankle joint, thinned cartilage layer, obvious cartilage damage, and increased number of osteo-clasts in the joint (P<0.01); the imaging results showed bone loss and three-dimensional structural destruction of ankle joint and aggravated bone erosion (P<0.01); the expression levels of MMP-1, MMP-3 and MMP-13, and RANKL/OPG ratio were significantly elevated in the synovial tissue of ankle joint (P<0.01, P<0.05), while the expression level of OPG was decreased (P<0.05). Compared with the model group, taVNS resulted in relatively intact cartilage layer of ankle joint, alleviated cartilage destruction, decreased number of osteoclasts (P<0.01), improved bone erosion, loss, and three-dimensional structural destruction (P<0.01), and diminished MMP-1, MMP-3, and MMP-13 expression and RANKL/OPG ratio in the synovial tissue of ankle joint (P<0.05, P<0.01), while the expression level of OPG was increased (P<0.05). CONCLUSION: taVNS effectively relieves bone and cartilage destruction in CIA rats, which might be related to its efficacy in reducing the production of osteoclasts in joint tissues and down-regulating the expression levels of MMP-1, MMP-3 and MMP-13, and RANKL/OPG ratio.

[Clinical Study on Early Extubation and Sequential Non-Invasive Respiratory Support for Children with Acute Respiratory Failure Receiving Invasive Mechanical Ventilation].

Objective: To explore the treatment outcome of the strategy of early extubation and then switching to non-invasive mechanical ventilation in children with acute respiratory failure, and the safety and feasibility of using the strategy to replace traditional methods. Methods: A total of 102 children, aged between 1 month to 14 years old, who had acute respiratory failure and were admitted to the pediatric ICU of West China Second University Hospital, Sichuan University between January 2019 and December 2020 were enrolled and randomly assigned to treatment group 1 (n=55) and treatment group 2 (n=47). In addition, 53 children who had the same condition in the 12 month prior to the beginning of the study were included in the control group. In the two treatment groups, the patients were extubated first, and then weaned off the ventilator. In group 1, when the patient met the invasive-non-invasive switching criteria, the tracheal tube was pulled out and non-invasive bi-level positive airway pressure (BiPAP) ventilation was used for respiratory support. In group 2, high-flow nasal cannula (HFNC) oxygen therapy was used for respiratory support. The traditional progressive weaning method was adopted for the control group (extubing and weaning were performed at the same time). The incidence of ventilator-associated pneumonia (VAP) during the period of tracheal intubation was compared and the mortality of the two groups was evaluated from the point when the patients were recruited. At the time of extubation in the treatment groups and extubation plus weaning in the control group, the pressure support levels, or PC above PEEP, intubation time, sequential time (between 2 treatment groups only), weaning failure rate, and the incidence of laryngeal edema and nasal pressure ulcer were compared. Results: The subjects of the study were predominantly infants (93 cases, 60%) and young children (31 cases, 20%). Among the 155 cases, 82 (53%) were male. There was no statistical difference in age distribution or gender among the groups. There was no significant difference in the clinical indicators among the three groups before tracheal intubation. At the time of extubation, the PC above PEEP in the two treatment groups was higher than that in the control group, and higher in group 1 than that of group 2, the difference being statistically significant (P<0.05). The intubation time of the two treatment groups was shorter than that of the control group, and shorter in group 1 than that of group 2 (P<0.05). The sequential time of group 2 was shorter than that of group 1 (P<0.05). The extubation failure rate and the incidence of VAP in the two treatment groups were lower than those in the control group, and there was no statistically significant difference between the two treatment groups. The incidence of nasal pressure ulcers in group 1 was higher than that in the other two groups (P<0.05). There was 1 death in treatment group 1, and no deaths in treatment group 2 or the control group. There was no significant difference in mortality or the incidence of laryngeal edema after extubation in the three groups. Conclusion: Early extubation and then switching to non-invasive mechanical ventilation can be well tolerated by the patients, and can be used in clinical practice as an effective weaning method for children with acute respiratory failure.

Value of heparin-binding protein in the diagnosis of severe infection in children: a prospective study. / è‚ç´ ç»“åˆè›‹ç™½å¯¹å„¿ç«¥é‡ç—‡æ„ŸæŸ“è¯Šæ–­ä»·å€¼çš„å‰çž»æ€§ç ”ç©¶.

OBJECTIVES: To study the value of heparin-binding protein (HBP) in the diagnosis of severe infection in children. METHODS: This study was a prospective observational study. The medical data of children who were admitted to the pediatric intensive care unit due to infection from January 2019 to January 2020 were collected. According to the diagnostic criteria for severe sepsis and sepsis, the children were divided into a severe sepsis group with 49 children, a sepsis group with 82 children, and a non-severe infection group with 33 children. The three groups were compared in terms of related biomarkers such as plasma HBP, serum C-reactive protein, serum procalcitonin, and platelet count. The receiver operating characteristic (ROC) curve was plotted to investigate the value of plasma HBP level in the diagnosis of severe infection (including severe sepsis and sepsis). RESULTS: The severe sepsis and sepsis groups had a significantly higher plasma HBP level on admission than the non-severe infection group (P<0.05). Compared with the sepsis and non-severe groups, the severe sepsis group had significantly higher serum levels of C-reactive protein and procalcitonin and a significantly lower platelet count (P<0.05). Plasma HBP level had an area under the ROC curve of 0.590 in determining severe infection, with a sensitivity of 38.0% and a specificity of 82.4% (P<0.05). CONCLUSIONS: There is an increase in plasma HBP level in children with severe infection, and plasma HBP level has a lower sensitivity but a higher specificity in the diagnosis of severe infection and can thus be used as one of the markers for the judgment of severe infection in children.

Effectiveness of azithromycin mass drug administration on trachoma: a systematic review.

BACKGROUNDS: Azithromycin mass drug administration (MDA) is a key part of the strategy for controlling trachoma. This systematic review aimed to comprehensively summarize the present studies of azithromycin MDA on trachoma; provide an overview of the impact of azithromycin MDA on trachoma in different districts; and explore the possible methods to enhance the effectiveness of azithromycin MDA in hyperendemic districts. METHODS: PubMed, Embase, the Cochrane Central Register of Controlled Trials, Web of Science, and ClinicalTrials.gov were searched up to February 2021 with no language restriction. Studies reporting the effect of azithromycin MDA on trachoma were included. Mathematical modeling studies, animal studies, case reports, and reviews were excluded. The trachomatous inflammation-follicular (TF) <5.0% was used to judge the effect of azithromycin MDA on eliminating trachoma as a public health problem. Two researchers independently conducted the selection process and risk of bias assessment. RESULTS: A total of 1543 studies were screened, of which 67 studies including 13 cluster-randomized controlled trials and 54 non-randomized studies were included. The effect of azithromycin MDA on trachoma was closely related to the baseline prevalence in districts. For the districts with baseline prevalence between 5.0% and 9.9%, a single round of MDA achieved a TF <5.0%. For the districts with baseline between 10.0% and 29.9%, annual MDA for 3 to 5 years reduced TF <5.0%. However, for the districts with high level of baseline prevalence (TF >30.0%), especially with baseline TF >50.0%, annual MDA was unable to achieve the TF <5.0% even after 5 to 7 years of treatment. Quarterly MDA is more effective in controlling trachoma in these hyperendemic districts. CONCLUSIONS: Azithromycin MDA for controlling trachoma depends on the baseline prevalence. The recommendation by the World Health Organization that annual MDA for 3 to 5 years in the districts with TF baseline >10.0% is not appropriate for all eligible districts.

[Effect of electroacupuncture on articular morphological changes and serum inflammatory factors and synovial MMPs in collagen-induced arthritis rats].

OBJECTIVE: To observe the effect of electroacupuncture (EA) of "Zusanli"(ST36) and "Sanyinjiao"(SP6) on serum TNF-α, IL-1ß, and IL-6 and expression of synovial matrimetalloproteinases (MMPs) and articular morphology in collagen-induced arthritis (CIA) rats, so as to explore its mechanisms underlying relief of arthritis. METHODS: Thirty male SD rats were randomly divided into normal control, CIA model and EA groups (n=10 rats per group). The arthritis model was induced by multi-point intradermal injection of bovine type Ⅱ collagen emulsion. EA (2 Hz/100 Hz, 1 mA) was applied to bilateral ST36 and SP6 for 30 min, once a day for 28 days. The hind-limb paw volume was measured and the arthritis index (AI) score given according to the swelling degree, rigidity and deformity of the ankle joint (0-4 points). After EA intervention, the morphological damage of the affected ankle joints was revealed by H.E. staining, safranin O-fast green staining, and tartrate-resistant acid phosphatase (TRAP) staining, separately. The levels of serum TNF-α, IL-1ß, and IL-6 were measured by ELISA, and the expression levels of MMP-1, MMP-3, MMP-13, and receptor activator of nuclear factor Kappa B ligand (RANKL) in the synovial tissue were detected by Western blot. RESULTS: Compared with the normal control group, the paw volume, AI score, TRAP-revealed number of osteoclasts, contents of serum TNF-α, IL-1ß and IL-6, and expression levels of MMP-1, MMP-3, MMP-13 and RANKL proteins were significantly increased in the model group (P<0.01, P<0.05). Following the intervention, the paw volume, AI score, number of osteoclasts, contents of serum TNF- α, IL-1ß and IL-6, and expression levels of MMP-1, MMP-3, MMP-13 and RANKL proteins were significantly decreased in the EA group (P<0.05, P<0.01) in contrast to the model group. H.E. and safranin O-fast green staining showed rough articular cartilage surface with thinned cartilage layer, obvious hyperplasia of the synovial tissue with many inflammatory cells, and serious damage and degradation of the cartilage matrix in the model group, these situations were relatively milder in the EA group. CONCLUSION: EA of ST36 and SP6 can reduce the articular damage in collagen-induced arthritis rats, which is associated with its function in reducing inflammatory response and down-regulating the expression of synovial MMP-1, MMP-3, MMP-13 and RANKL proteins.

[Clinical features and antibiotic sensitivity of invasive pneumococcal disease versus noninvasive pneumococcal disease in children].

OBJECTIVE: To analyze the clinical data of children with invasive pneumococcal disease (IPD) or noninvasive pneumococcal disease (NIPD), and to provide a reference for clinical diagnosis and treatment. METHODS: A retrospective analysis was performed on the medical data and the drug susceptibility test results of isolated strains of 518 children who were hospitalized due to Streptococcus pneumoniae (SP) infection from January 2013 to December 2017. According to the location of the isolated strains, the children were divided into an IPD group with 35 children and an NIPD group with 483 children. RESULTS: The children with IPD had a median age of 2.2 years, and the children aged ≤5 years accounted for 80.0%. For the children with IPD, the main type of infection was meningitis which was observed in 19 children (54.3%), and the most common underlying disease was hematological malignancy in 8 children (22.9%); 14 children (40.0%) were admitted to the pediatric intensive care unit (PICU), 18 children (51.4%) experienced complications, and 8 children (22.9%) died. For the children with NIPD, the median age was 1.2 years; the main type of infection was pneumonia in 429 children (88.8%), and the most common underlying disease was congenital heart disease in 60 children (12.4%); 60 children (12.4%) were admitted to the PICU, 102 children (21.1%) experienced complications, and 11 children (2.3%) died. The IPD group had significantly higher incidence rate of complications, PICU admission rate, and mortality rate than the NIPD group (P < 0.01). The invasive SP strains had a significantly lower susceptibility rate to penicillin than noninvasive SP strains (68.6% vs 94.2%, P < 0.01). CONCLUSIONS: SP infection is common in children under 5 years of age, and the children with underlying diseases including hematological malignancy are at high risk for IPD. Although the complication rate, PICU admission rate, and mortality rate of NIPD children are lower than those of IPD children, they still cannot be ignored. Penicillin may be used as an empirical treatment for children with NIPD, but not for those with IPD.

Treatment of particle/gas partitioning using level III fugacity models in a six-compartment system.

In this paper, two level III fugacity models are developed and applied using an environmental system containing six compartments, including air, aerosols, soil, water, suspended particulate matters (SPMs), and sediments, as a "unit world". The first model, assumes equilibrium between air and aerosols and between water and SPMs. These assumptions lead to a four-fugacity model. The second model removes these two assumptions leading to a six-fugacity model. The two models, compared using four PBDE congeners, BDE-28, -99, -153, and -209, with a steady flux of gaseous congeners entering the air, lead to the following conclusions. 1. When the octanol-air partition coefficient (KOA) is less than 1011.4, the two models produce similar results; when KOA > 1011.4, and especially when KOA > 1012.5, the model results diverge significantly. 2. Chemicals are in an imposed equilibrium in the four-fugacity model, but in a steady state and not necessary an equilibrium in the six-fugacity model, between air and aerosols. 3. The results from the six-fugacity model indicate an internally consistent system with chemicals in steady state in all six compartments, whereas the four-fugacity model presents an internally inconsistent system where chemicals are in equilibrium but not a steady state between air and aerosols. 4. Chemicals are mass balanced in air and aerosols predicted by the six-fugacity model but not by the four-fugacity model. If the mass balance in air and aerosols is achieved in the four-fugacity model, the condition of equilibrium between air and aerosols will be no longer valid.

Slopes and intercepts from log-log correlations of gas/particle quotient and octanol-air partition coefficient (vapor-pressure) for semi-volatile organic compounds: I. Theoretical analysis.

Gas/particle partitioning governs the transport and fate of semi-volatile organic compounds (SVOCs) released to the atmosphere. The partition quotient of SVOCs, KP, is related to their subcooled liquid vapor pressure (logKP = mp logPL + bp) and to their octanol-air partition coefficient (logKP = mo logKOA + bo). Previous theory predicts that -mp and mo should be close to, or equal to 1 based on the assumption that gas- and particle-phases are at equilibrium in the atmosphere. Here, we develop analytical equations to calculate mo and bo as functions of logKOA and mp and bp as functions of logPL. We find that experimental, analytical, or statistical artifacts and other reported factors are not the leading causes for deviations of the slopes, mp and mo, from -1 and 1, respectively. Rather, it is the inherent parameter, KOA, that determines mo and bo, and equivalently, PL is the major parameter determining mp and bp, and such deviations are evidence that equilibrium is an inappropriate assumption. In contrast, the actual steady-state between gas and particle phases of SVOCs leads that their -mp and mo should range from 0 to 1, implying that equilibrium is a reasonable assumption only when -mp and mo are larger than 0.49. To illustrate these points, we provide a detailed discussion of the global atmospheric transport of polybrominated diphenyl ethers (PBDEs) with emphasis on Polar Regions where low air temperatures favor a special steady-state, where their slopes mp and mo can reach 0, indicating a constant value of logKP (-1.53).

Slopes and intercepts from log-log correlations of gas/particle quotient and octanol-air partition coefficient (vapor-pressure) for semi-volatile organic compounds: II. Theoretical predictions vs. monitoring.

The logarithm of gas/particle (G/P) partition quotient (logKP) has been found to have a linear relationship with logKOA (octanol-air partition coefficient) with slope mo and intercept bo and logPL (subcooled liquid vapor pressure) with slope mp and intercept bp. In the sister paper of the present work, analytical equations to predict the slope mo and intercept bo based on logKOA and predict the slope mp and intercept bp based on logPL are developed using steady state theory. In this work, the equations are evaluated using world-wide monitoring data (262 pairs for mo and bo values and 292 pairs for mp and bp values produced from more than 10,000 monitiring data worldwide) for selected seven groups of semi-volatile organic compounds (SVOCs), including polybrominated diphenyl ethers (PBDEs), polychlorinated dibenzo-p-dioxins and polychorinated dibenzofurans (PCDD/Fs), polyclorinated biphenyl (PCBs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated naphthalenes (PCNs), organochlorinated pesticides (OCPs), novel brominated flame retardants (NBFRs), and other selected halogenated flame retardants. The slopes and intercepts predicted by the steady state equations reproduce the trends observed in monitoring regression results for the seven SVOC groups, with 44.4% of the variation of monitoring mo values accounted for by logKOA and 48.2% of the variation of monitoring mp values accounted for by logPL. Theoretically, the values of mo can be any value between 0 and 1 dependent on the values of KOA, and are not constrained to 1 as in equilibrium theory. Likewise, the values of mp can be any value between 0 and -1 dependent on the values of PL, and not constrained to -1 predicted by the equilibrium theory. The influence of sampling artifacts on the G/P partitioning of SVOCs has most likely been overemphasized by the equilibrium theory. Thus, the equilibrium approach should be abandoned in favor of the steady state approach for calculating the G/P partition quotients for SVOCs with high KOA values (>1011.38) or low PL values (<10-4.92).

New equation to predict size-resolved gas-particle partitioning quotients for polybrominated diphenyl ethers.

Gas/particle (G/P) partition quotients of semi-volatile organic compounds (SVOCs) for bulk air have been widely discussed in experimental and theoretical contexts, but research on size-resolved G/P partition quotients (KPi) are scarce and limited in scope. To investigate G/P partition behavior of polybrominated diphenyl ethers (PBDEs) for size-segregated particles in the atmosphere, 396 individual size-segregated particulate samples (36 batches × 11 size-ranges), and 108 pairs of concurrent gaseous and bulk particulate samples were collected in Harbin, China. A steady-state equation based on bulk particles is derived to determine G/P partition quotients of PBDEs for size-segregated particles, which depends on the organic matter contents of size-segregated particles (fOMi). This equation can well predict KPi with knowledge of bulk partition quotient (KPS), ambient temperature, and fOMi, the results of which match well with monitoring data in Harbin and other published data collected in Shanghai and Guangzhou of China and Thessaloniki of Greece, and remedies a defect of over-estimate KPi for high-brominated PBDEs by the previous equation. In particular, the new equation contributes to obtaining the PBDEs concentrations in all atmospheric phase from partial phase, then provides a credible path to evaluate healthy exposure dose from the airborne PBDEs, by co-utilization with exposure models.

Modeling gas/particle partitioning of polybrominated diphenyl ethers (PBDEs) in the atmosphere: A review.

Gas/particle (G/P) partitioning of semi-volatile organic compounds (SVOCs) such as polybrominated diphenyl ethers (PBDEs), is an important atmospheric process due to its significance in governing atmospheric fate, wet/dry deposition, and long-range atmospheric transport. In this article, eight models published to predict the G/P partitioning of PBDEs are reviewed. These eight models are used to calculate the G/P partitioning quotient and particulate phase fraction of selected PBDE congeners. A comparison of the predicted results from the eight models with monitoring data published by several research groups worldwide leads to the following conclusions: 1) when the values of the logarithm of the octanol-air partition coefficient (logKOA) fall below 11.4 (the first threshold value, logKOA1), all 8 models perform well in predicting the G/P partitioning of PBDEs in the atmosphere, and 2) when logKOA is >11.4, and especially above 12.5 (the second threshold value, logKOA2), the Li-Ma-Yang model, a steady-state model developed based on wet and dry deposition of the particles (Li et al., Atmos. Chem. Phys. 2015; 15:1669-1681), shows the best performance with highest conformity to the measurements for selected PBDEs (94.4 ± 1.6% data points within ±1 log unit). Overall, the Li-Ma-Yang model appears to capture the most important factors that affect the partitioning of PBDEs between gaseous and particular phases in the atmosphere.

Gas/particle partitioning of semi-volatile organic compounds in the atmosphere: Transition from unsteady to steady state.

We derive differential equations to determine the kinetics of gas/particle partitioning of semi-volatile organic compounds (SVOCs). These equations model the transient states from initiation of sorption to particles (non-steady state) through the establishment of steady state. Two hypothetical scenarios are examined: (1) exchange of SVOCs between gas- and particle-phases alone; and (2) both gas/particle partitioning and wet and dry deposition of particles. The differential equations show that, under Scenario 1, a steady state is reached as an equilibrium between gas- and particle-phases, whereas under Scenario 2, the attained steady state is not in equilibrium. Our model shows that SVOCs in atmosphere where particle deposition is occurring reach a steady non-equilibrium state sooner than they would reach equilibrium under Scenario 1. We infer that SVOCs in the atmosphere will reach steady state instead of equilibrium between gaseous and particulate phases in circumstances where wet and dry deposition of particles cannot be neglected. In addition, our study indicates that the time for SVOCs to reach steady state in the atmosphere is fast, most likely within minutes or hours, suggesting that SVOCs are in steady or quasi-steady state in the atmosphere. Our analysis also reveals that gas/particle partitioning and particle deposition of SVOCs are dependent on each other.

Gas/particle partitioning of PAHs based on equilibrium-state model and steady-state model.

The gas/particle (G/P) partitioning (KP) behavior is an important factor for the environmental fate of PAHs in atmosphere. Based on large database of log KP, equilibrium-state and steady-state models were applied for the comprehensive study with the G/P partitioning of PAHs, including the Harner-Bidleman (H-B) model, the Dachs-Eisenreich (D-E) model, and the Li-Ma-Yang (L-M-Y) model. For different sites, the trend of regression between log KP and log KOA was same, however, the slopes and intercepts were different. No obvious difference was observed between northern Chinese cities and southern Chinese cities. For congeners and aromatic rings of PAHs, the difference was much more obvious for the regressions, slopes and intercepts. The prediction of the D-E model and the H-B model matched well for the regression of the 4-rings and 5-rings PAHs, with >80% of monitoring data points in the range of ±1 log unit. The L-M-Y model only predicted well with the measurement for 4-rings PAHs with special values of log KOA. For different ranges of log KOA, the difference with the regression between log KP and log KOA was also obvious. Compared with our measurement, if 1 order of magnitude difference with log KP values between prediction and measurement was considered, the H-B model, the D-E model and the L-M-Y model can be only used when the log KOA in the ranges from 7.65 to 13.7, 6.88 to 13.5, and 7.65 to 11.7, respectively. Therefore, further studies with prediction models should be conducted for the G/P partitioning of PAHs. The results of this study provided new insights into the research field of the G/P partitioning of SVOCs.

[Electroacupuncture alleviated incisional neck pain possibly by suppressing TNF-α expression and increasing IL-4/IL-4 receptor signaling in cervical dorsal part of spinal cord in incisio-nal neck pain rats].

OBJECTIVE: To observe the effect of electroacupuncture (EA) on incisional pain and expression of tumor necrosis factor-α (TNF-α), interleukin-10 (IL-10) and interleukin-4 (IL-4) of cervical dorsal part of spinal cord in rats with incisional neck pain, so as to explore its analgesic mechanisms. METHODS: Eighty-four male SD rats were randomly divided into normal control, model, EA-Futu(LI18) and EA-Zusanli(ST36)-Yanglingquan(GB34, EA-ST36-GB34) groups (n=21 in each group). The incisional neck pain model was established by making a longitudinal incision along the bilateral cervical thyroid regions and repeated mechanical separation stimulation. For rats of the EA groups, EA (2 Hz/100 Hz, 1 mA) was applied to bilateral LI18 or ST36-GB34 for 30 min/ time during the surgery, and 20 and 44 h after surgery, respectively. The thermal pain threshold (TPT) of the incisional region was detected. The immunoactivity of TNF-α and IL-10 of the dorsal portion of the cervical spinal cord (C2-C5) was detected by immunofluorescence, and the expression of TNF-α, IL-10, IL-4 and IL-4 receptor (IL-4R) mRNAs was determined by quantitative real-time PCR. RESULTS: Compared with the normal group, the TPT of the incisional area was significantly decreased at 4, 24 and 48 h after neck-incision (P<0.05), the levels of TNF-α mRNA, IL-10 mRNA and TNF-α IL-10 immunoactivity at 24 h were remarkably increased (P<0.05), and the expression of IL-4R mRNA was considerably decreased at 24 h in the model group (P<0.05). Following EA intervention, the TPT, and expression levels of IL-4 mRNA and IL-4R mRNA were significantly increased at 24 h after surgery in the EA-LI18 group relevant to the model group (P<0.05), while the expression level of TNF-α(coexpressed with microgliacytes) in the EA-LI18 group, and TNF-α mRNA expression at 24 h in both EA-LI18 and EA-ST36-GB34 groups, as well as the expression of IL-10 and IL-10 mRNA at 24 h in both EA-LI18 and EA-ST36-GB34 groups were significantly decreased (P<0.05). The effect of EA LI18 was significantly superior to that of EA ST36-GB34 in up-regulating TPT and expression of IL-4 mRNA and IL-4R mRNA at 24 h (P<0.05). CONCLUSION: EA of LI18 has an analgesic effect in incisional neck pain rats, which may be related to its effect in down-regulating the expression of TNF-α, IL-10 and promoting IL-4 /IL-4R signaling in dorsal portions of the cervical spinal cord. The analgesic effect of EA LI18 is better than that of EA ST36-GB34.

[High-risk factors for early failure of high-flow nasal cannula oxygen therapy in children].

OBJECTIVE: To determine the high-risk factors for early failure of high-flow nasal cannula (HFNC) oxygen therapy in children with acute respiratory insufficiency (ARI). METHODS: The clinical data of 123 children with ARI were reviewed who received HFNC oxygen therapy in the pediatric intensive care unit from January to June, 2018. The children who did not require an upgrade of respiratory support during hospitalization and were successfully weaned from HFNC were classified as HFNC success group (69 cases). Of the remaining children (54 cases) who required an upgrade of their respiratory support during hospitalization, those that needed to upgrade their respiratory support within 48 hours of receiving HFNC were classified as early HFNC failure group (46 cases). Risk factors for early failure of HFNC were determined using multivariate logistic regression analysis. RESULTS: The incidence rates of shock, sepsis, intracranial hypertension syndrome, and multiple organ dysfunction syndrome were significantly higher in the early HFNC failure group than in the HFNC success group (P<0.05). Before implementation of respiratory support, the early HFNC failure group had significantly lower Glasgow coma score, pH value, and oxygenation index and significantly higher Pediatric Risk of Mortality (PRISM) score and PaCO2/PaO2 ratio than the HFNC success group (P<0.05). Multivariate logistic regression analysis showed that PRISM score >4.5 and PaCO2/PaO2 ratio >0.64 were independent risk factors for early HFNC failure (OR=5.535 and 9.089 respectively; P<0.05). CONCLUSIONS: Pediatric ARI patients with PRISM score >4.5 or PaCO2/PaO2 ratio >0.64 have relatively high risk of early HFNC failure.