Ventilatory and upper-airway resistance responses to upper-airway cooling and CO2 in anaesthetised rats

The effects of upper airway (UA) cool air and CO₂ on breathing and on laryngeal and supraglottic resistances were studied in anaesthetised rats breathing spontaneously through a tracheostomy. Warm, humidified air containing 0, 5 and 9–10% CO₂ and cool, room-humidity air were delivered at constant flow to either the isolated larynx to exit through a pharyngotomy or to the supraglottic UA to exit through the mouth and/or nose (nose open or sealed). Spontaneous tracheal airflow and UA airflows, temperatures and pressures were recorded. CO₂ had no effect on breathing but caused a slight increase in laryngeal resistance which was abolished by cutting the superior laryngeal nerves (SLN). Cool air caused a decrease in respiratory frequency and/or peak inspiratory flow when applied to the isolated larynx or to the supraglottic airway with the nose closed. These effects were abolished by SLN section. With the nose open, the ventilatory inhibition was not abolished by SLN section. Cool air also caused substantial decreases in laryngeal and supraglottic resistances which were attenuated by SLN section and which persisted following recurrent laryngeal nerve section. In conclusion, whilst UA cooling inhibits breathing and decreases UA resistances, UA CO₂ has minimal effects.     

Laser induced thermal injury of rabbit cornea and treatment with anti-inflammatory agents

A moderately severe thermal injury of the central cornea of 48 Dutch-belted rabbit eyes was produced with a carbon (CO₂) laser. The lesions were photographed with a slit lamp (SL) camera immediately following the injury and at 1, 2, 4, 7, 14, 21, 30 and 60 days after the exposure. Lesion size, opaqueness, and depth were graded clinically by SL biomicroscopy at the same intervals. No significant differences were found (p 0.05) between groups of eyes treated with flurbiprofen (0.03%), prednisolone acetate (1%), and vehicle control four-times-a-day for three weeks following injury. Additionally, eyes were studied histopathologically at 3 and 60 days following injury by light and transmission electron microscopy, and clinically at 30 and 60 days by endothelial specular microscopy. Important clinical and histopathological findings included coagulative necrosis of the corneal epithelium, epithelial sloughing, fusion of stromal collagen, stromal edema and inflammatory cell infiltration, stromal scar formation, corneal thinning, endothelial hyperplasia and metaplasia, fibrinous anterior chamber reaction with hypopyon, and retrocorneal fibrous membrane formation.     

Adequate Vitamin D Intake Cannot Be Achieved within Carbon Emission Limits Unless Food Is Fortified: A Simulation Study

This study applied linear programming using a Dutch “model diet” to simulate the dietary shifts needed in order to optimize the intake of vitamin D and to minimize the carbon footprint, considering the popularity of the diet. Scenarios were modelled without and with additional fortified bread, milk, and oil as options in the diets. The baseline diet provided about one fifth of the adequate intake of vitamin D from natural food sources and voluntary vitamin D-fortified foods. Nevertheless, when optimizing this diet for vitamin D, these food sources together were insufficient to meet the adequate intake required, unless the carbon emission and calorie intake were increased almost 3-fold and 2-fold, respectively. When vitamin D-fortified bread, milk, and oil were added as options to the diet, along with increases in fish consumption, and decreases in sugar, snack, and cake consumption, adequate intakes for vitamin D and other nutrients could be met within the 2000 kcal limits, along with a relatively unchanged carbon footprint. Achieving vitamin D goals while reducing the carbon footprint by 10% was only possible when compromising on the popularity of the diet. Adding vitamin D to foods did not contribute to the total carbon emissions. The modelling study shows that it is impossible to obtain adequate vitamin D through realistic dietary shifts alone, unless more vitamin D-fortified foods are a necessary part of the diet.     

乳酸及降钙素原对一氧化碳中毒后迟发性脑病的预测价值

目的探讨检测血乳酸、降钙素原和联合检测对急性一氧化碳中毒后迟发性脑病(DEACMP)的预测价值。 方法随机抽取我院在急诊科收住院的ACMP患者70例,随访3个月,以其中发生DEACMP患者10例为DEACMP组,其余60例为非DEACMP组,随机抽取同期笔者医院40例健康体检者为对照组。对患者立即行动脉血Lac和血清PCT检测,并计算Lac和PCT诊断DEACMP的灵敏度、特异度。 结果DEACMP组血Lac和PCT检测值均明显高于非DEACMP和对照组,差异有统计学意义(采用秩和检验,P<0.05);检测异常率亦明显高于非DEACMP组及对照组,差异有统计学意义(采用χ²检验,P<0.05)。Lac和PCT升高预测DEACMP的敏感度均为90.0% ,特异度分别为50.0%和65.0% ,准确性分别为55.7%和68.6%。联合检测时若其中1个指标为阳性时即预测DEACMP发病,则联合检测的敏感度为100.0%,特异度为41.7%,阳性预测值为21.7%,阴性预测值为100.0%,准确性为71.4%。 结论DEACMP患者早期动脉血Lac和PCT均明显升高,PCT诊断价值优于Lac,联合检测较单项指标检测对DEACMP发病预测价值更理想。     

阻塞性呼吸睡眠暂停综合征与中枢呼吸驱动

目的阐明不同浓度的CO     

氯化钛白氧化反应器壁结疤机理

利用预燃烧直管反应器,研究氯化钛白氧化反应器内的结疤机理。氧化反应器内结疤支要起因子氧化过程生成的超细TiO2颗粒在反应器壁的沉积和烧结,反应器壁面温度越高结疤速率越快。当反应器壁面温度较低时,靠近壁面为ＴiO2颗粒堆结层,而告气体相主体的疤层发生了部分烧结。反应温度升高、反应物浓度增大时,结疤速度增大;壁面状态对结疤速率影响不大。     

金红石型钛白粉表面包覆氧化铝的形态及机理

探讨了以H2SO4和CH2OHCH2Cl为酸解介质时,氯化法金红石型钛白粉表面包铝的行为及形态特征。利用正交实验研究了包膜过程中,熟化pH、熟化时间以及温度对包铝钛白粉白度的影响。氯化法金红石型钛白粉浆在pH为10时,Zeta电位最大,在水中达到最佳分散,利用H2OHCH2Cl作为酸解介质时,浆液中的均相成核得到显著抑制,钛白粉表面的包膜质量得到明显改善。以稀硫酸作为酸解介质时,随熟化温度升高和熟化时间的延长,钛白粉包覆效果明显改善,白度值明显升高。     

A capnography and transcutaneous CO2 profile of bariatric patients during early postoperative period after opioid-sparing anesthesia

BackgroundNoninvasive monitoring of partial pressure of carbon dioxide can be accomplished indirectly with capnography (P_ETCO₂) or with transcutaneous carbon dioxide monitoring (P_TCCO₂). The use of capnography has been shown to offer an advantage over pulse oximetry alone in the early detection of adverse respiratory events when supplemental oxygen is administered. Furthermore, capnography allows for the monitoring of various respiratory measures, including end-tidal carbon dioxide, respiratory rate, tidal volume, and changes in breathing patterns. Transcutaneous CO₂ also closely approximates arterial CO₂ values, but is not as easy to monitor for prolonged periods. The purpose of this study was to examine the usefulness of capnography and of transcutaneous carbon dioxide monitoring in patients recovering from obesity surgery at high risk of developing postoperative obstructive sleep apnea.MethodsIn a prospective observational study, 64 bariatric surgery patients at risk of developing obstructive sleep apnea were monitored in the postanesthesia care unit (PACU) with either capnography alone (31 patients) or capnography plus transcutaneous carbon dioxide monitoring (33 additional patients) every 3–5 minutes for the duration of their recovery. Primary endpoints included end-tidal and transcutaneous carbon dioxide, peripheral oxygen saturation, respiratory rate, pain scores, and incidence of adverse respiratory events.ResultsAlthough no adverse pulmonary events were observed, capnography detected several patients who experienced short periods of respiratory apnea while maintaining pulse oximetry readings within normal limits. Transcutaneous values were slow to change and averaged 4.5 ± 5.5 mm Hg (P < .05) higher than corresponding end-tidal measurements.ConclusionsThese results indicate the capabilities of both these noninvasive techniques for postoperative monitoring. Capnography acutely monitors changes in respiration, whereas transcutaneous monitoring more accurately reflects arterial CO₂ levels.     

纳米碳与吲哚菁绿导航腹腔镜胃癌根治术淋巴结清扫的对比性研究

目的对比纳米碳与吲哚菁绿(ICG)在腹腔镜胃癌根治术淋巴结清扫方面的优劣性。方法回顾性分析2016年1月至2019年12月接受腹腔镜胃癌根治术的167例患者资料,根据所使用的示踪剂种类,分为纳米碳组130例、ICG组37例,应用GraphPad Prism 8.0统计软件进行分析,围术期指标及淋巴结清扫数目等计量资料以(±s)表示,采用独立t检验;术后并发症、二次手术率等计数指标比较采用χ²检验,P<0.05为差异有统计学意义。结果两种示踪剂对不同病理分期胃癌的淋巴结清扫效果差异无统计学意义。在各种胃癌根治术式中,淋巴结分拣均有助于提高淋巴结总检出数。纳米碳组较ICG组更有助于提高根治性全胃切除术第5站淋巴结的清扫数目(P=0.02)、根治性近端胃切除术第1站淋巴结的清扫数目(P=0.03)以及根治性远端胃淋巴结的总清扫数目(P=0.03)。在提高淋巴结检出率方面,两种示踪剂差异无统计学意义。结论纳米碳与吲哚菁绿在不同病理分期中的总体淋巴结清扫效果差异无统计学意义。无论使用何种示踪剂,均提倡淋巴结分拣。纳米碳较吲哚菁绿更有助于提高根治性全胃第5站淋巴结的清扫数、根治性近端胃第1站淋巴结的清扫数以及根治性远端胃淋巴结的总清扫数目。     

Effective improvements to the live-attenuated Newcastle disease virus vaccine by polyethylenimine-based biomimetic silicification

Live and killed vaccines impart a significant role in preventing of Newcastle disease (ND) in China. Vaccine efficacy could be ameliorated by improving vaccine-induced cellular immunity and antibody persistency. Previous studies substantiated the potency of silicon dioxide (SiO₂) in the control-release of drugs and as a vaccine adjuvant, and polyethylenimine (PEI) merits as a mucosal adjuvanticity with electro-positivity. The present study employed SiO₂ and PEI to prepare biomimetic silicon mineralized nanoparticle G7M@SiO₂-PEI and microparticle (SiO₂ + PEI)@G7M vaccines of G7M, a candidate for live attenuated vaccine of genotype VII Newcastle disease virus (NDV). The zeta potential experiment confirmed the significant increase in the average zeta potential of the nanoparticle G7M@SiO₂-PEI and microparticle (SiO₂ + PEI)@G7M relative to G7M before mineralization. The results of RT-qPCR revealed more than 99% mineralization efficiency of the G7M@SiO₂-PEI and (SiO₂ + PEI)@G7M. The morphology detected by transmission electron microscopy reported that the diameters of G7M@SiO₂-PEI were similar to those of G7M, while for (SiO₂ + PEI)@G7M, it was about five times larger than that of G7M. Silicon was detected on the surface of both mineralization particles, except for G7M, as observed from the elemental distribution detected by elemental mapping and energy dispersive X-ray spectrogram. Indirect immunofluorescence assays validated that mineralization virus have replicated ability in BHK-21F cells. In vivo experiments revealed higher than 5.50 log₂ of antibody in nanoparticles G7M@SiO₂-PEI group until 10-week post-vaccination, and significant proliferation of antigen-specific CD3⁺CD4⁺ in nanoparticles G7M@SiO₂-PEI immunized group corroborated improved cellular immune responses. Vaccines provided full protection to the immunized chickens, whereas all the chickens receiving mock immunizations succumbed to the disease. Overall, our study concluded the efficacy of biomimetic mineralization of live attenuated vaccine in nanoparticles to improve humoral and cellular immune responses.