The Water-Soluble Chitosan Derivative,N-Methylene Phosphonic Chitosan,Is an Effective Fungicide against the Phytopathogen Fusarium eumartii

Chitosan has been considered an environmental-friendly polymer. However, its use in agriculture has not been extended yet due to its relatively low solubility in water. N-Methylene phosphonic chitosan (NMPC) is a water-soluble derivative prepared by adding a phosphonic group to chitosan. This study demonstrates that NMPC has a fungicidal effect on the phytopathogenic fungus Fusarium solani f. sp. eumartii (F. eumartii) judged by the inhibition of F. eumartti mycelial growth and spore germination. NMPC affected fungal membrane permeability, reactive oxygen species production, and cell death. Also, this chitosan-derivative exerted antifungal effects against two other phytopathogens, Botrytis cinerea, and Phytophthora infestans. NMPC did not affect tomato cell viability at the same doses applied to these phytopathogens to exert fungicide action. In addition to water solubility, the selective biological cytotoxicity of NMPC adds value in its application as an antimicrobial agent in agriculture.     

Regional anesthesia for major vascular surgery.

The relative merits of general vs regional anesthesia for patients undergoing major vascular surgery has been the subject of debate over the past decade. Previous studies of regional vs general anesthesia often were deficient in experimental design and, therefore, did not produce definitive answers. Some of these deficiencies related to non-standardized, poorly conducted, and/or described general anesthetic techniques, nonstandardized methods of postoperative analgesia in the general anesthesia groups, and variations in preoperative cardiac status in the study groups. Furthermore, most studies did not conclusively demonstrate a cause and effect relationship between the proposed mechanisms of the beneficial effect of regional anesthesia and outcome. Recent studies, however, have claimed improvements in outcome following regional anesthesia in patients undergoing peripheral vascular procedures. The reported beneficial effects have included amelioration of the neuroendocrine stress response to surgery, improvement in pulmonary function, cardiovascular stability, enhancement of lower limb blood flow, reduction in the incidence of graft thrombosis, and a reduction in the thrombic response to surgery. Skeptics still question whether recent studies have the power to determine whether regional anesthesia decreases the incidence of cardiac and pulmonary complications following major vascular surgery. Furthermore, the issue of whether the beneficial effects of regional anesthesia on the incidence of graft thrombosis and the thrombotic response to surgery relating to intraoperative or postoperative regional anesthesia/analgesia, to regional anesthesia per se, or to the systemic effects of absorbed local anesthetics remains unresolved.     

Evaluating the Association between Anesthesia Type and Postoperative Complications for Patients Receiving Total Ankle Arthroplasty

BackgroundTotal ankle arthroplasty (TAA) is performed for ankle arthritis and there has been interest investigating which anesthetic method is the best choice in order to optimize perioperative outcomes. In this study, we compared postoperative complications after TAA for patients receiving either 1) general anesthesia alone or 2) general anesthesia plus regional anesthesia.MethodsPatients undergoing primary TAA from 2007 to 2018 were identified in a national database. Patients were stratified into 2 cohorts: general anesthesia and general anesthesia combined with regional anesthesia. In this analysis, 30-day wound, cardiac, pulmonary, renal, thromboembolic, and sepsis complications, as well mortality, postoperative transfusion, urinary tract infection, extended length of stay, and reoperation were assessed. Bivariate analyses and multivariable logistical regression were performed.ResultsOf 1,084 total patients undergoing TAA, 878 patients (81.0%) had general anesthesia and 206 (19.0%) had general anesthesia combined with regional anesthesia. Following adjustment, there were no increased risk of postoperative complications in the combined general and regional anesthesia group compared to those who only underwent general anesthesia.ConclusionCompared to general anesthesia alone, the addition of regional anesthesia to general anesthesia for TAA is not associated with increased risk of complications in the perioperative period. Level of Evidence: III     

Effects of spinal or general anesthesia on F₂-isoprostanes and isofurans during ischemia/reperfusion of the leg in patients undergoing knee replacement surgery

General and spinal anesthesia are used extensively in orthopedic surgery. However, these methods of anesthesia may result in different amounts of oxygen being delivered to the patient. Ischemia/reperfusion injury after release of the tourniquet initiates free radical-mediated oxidative stress. F₂-isoprostanes are reliable markers of in vivo lipid peroxidation. However, under conditions of high oxygen tension, isofurans are formed. We aimed to compare plasma isofurans and F₂-isoprostanes in spinal versus general anesthesia in patients undergoing knee-replacement surgery in a randomized, blinded study. Thirty-nine patients were randomized to spinal (SA; n = 19) or general anesthesia (GA; n = 20). Blood was collected before anesthesia, and a tourniquet was then applied to the limb during surgery. After release of the tourniquet, blood samples were collected at 30 min, 2 h, and 24 h for measurement of plasma F₂-isoprostanes and isofurans by gas chromatography–mass spectrometry. The two groups were comparable in age and body mass index. Plasma F₂-isoprostanes were significantly lower in the GA patients compared with the SA patients (p = 0.045). In contrast, the GA patients had significantly elevated plasma isofurans (p = 0.032). Increased isofurans during GA compared with SA are likely to reflect increased oxidative stress due to elevated oxygen concentrations during GA. Further studies are required to assess the implications of these findings on perioperative outcomes.     

A coalescent dual process in a Moran model with genic selection, and the lambda coalescent limit

The genealogical structure of neutral populations in which reproductive success is highly-skewed has been the subject of many recent studies. Here we derive a coalescent dual process for a related class of continuous-time Moran models with viability selection. In these models, individuals can give birth to multiple offspring whose survival depends on both the parental genotype and the brood size. This extends the dual process construction for a multi-type Moran model with genic selection described in Etheridge and Griffiths (2009). We show that in the limit of infinite population size the non-neutral Moran models converge to a Markov jump process which we call the Λ-Fleming-Viot process with viability selection and we derive a coalescent dual for this process directly from the generator and as a limit from the Moran models. The dual is a branching-coalescing process similar to the Ancestral Selection Graph which follows the typed ancestry of genes backwards in time with real and virtual lineages. As an application, the transition functions of the non-neutral Moran and Λ-coalescent models are expressed as mixtures of the transition functions of the dual process.     

Discovery of multiple level heart-sound morphological variability resulting from changes in physiological states

Heart sounds carry information about the mechanical activity of the cardiovascular system. This information includes the specific physiological state of the subject, and short term variability related to the respiratory cycle. The interpretation of the sounds and extraction of changes in the physiological state, while monitoring short term variability is still an open problem and is the subject of this paper.We present a novel computational framework for analysis of data with multi-level variability, caused by externally induced changes. The framework presented includes an initial clustering of the first heart sound (S1) according to the morphology, and further aggregation of clusters into super-clusters. The clusters and super clusters are two methods of data segmentation, each reflecting a different level of variability in the data.The framework is applied to heart sounds recorded during laparoscopic surgeries of six patients. Procedures of this kind include anesthesia and abdominal insufflation, which together with the respiratory cycle, induce changes to the heart sound signal. We demonstrate a separation of the heart sound morphology according to different physiological states. The physiological states considered are the respiratory cycle, and the stages of the surgery. We achieve results of 90 ± 4% classification accuracy of heart beats to operation stages.The proposed framework is general and can be used to analyze data characterized by multi-level variability for various other (biomedical) applications.     

Hydrogels and electrospun nanofibrous scaffolds of N-methylene phosphonic chitosan as bioinspired osteoconductive materials for bone grafting

In this work, N-methylene phosphonic chitosan (NMPC) based hydrogels and electrospun nanofibrous scaffolds are reported with objective to obtain osteoconductive and osteoinductive matrixes for bone grafting applications. NMPC, a phosphorylated derivative of chitosan, is known to mimic the function of non collagenous phosphoproteins in providing nucleation sites for biomineralization. NMPC hydrogels were prepared by crosslinking between NMPC and genipin. A detailed investigation of physicochemical properties of NMPC solutions is also carried out in order to obtain beads free nanofibers. Both NMPC gels and nanofibers were further evaluated for their biomineralization potential and biocompatibility with human osteoblast like cells. Results indicated that hydrogels and nanofibrous scaffolds NMPC are biocompatible and significantly osteoinductive compared to tissue culture plate controls. However, cells seeded on nanofibrous scaffolds exhibited greater proliferation measured by MTT assay, and higher expression of early markers for osteogenic differentiation proving the superior applicability of nanofibrous scaffolds for bone grafting applications.     

麻醉方式对老年髋关节置换术患者的影响

目的:观察和比较腰硬联合麻醉与全麻对行择期髋关节置换术老年患者的生命体征、简易智力状况检查量表(Mini-mental State Examinatlon,MMSE)评分、认知功能障碍(postoperative cognitive dysfunction,POCD)发生率的影响。方法:选取2015年1月-2017年6月于我院行择期髋关节置换术的80例老年患者为研究对象,随机分为腰硬联合麻醉组和全麻组,每组各40例。全麻组患者术前应用全身麻醉,腰硬联合麻醉组患者术前应用腰硬联合麻醉。观察两组患者麻醉前后的生命体征、MMSE评分变化及POCD的发生情况。结果:腰硬联合麻醉组患者麻醉后收缩压(Systolic pressure,SP)、舒张压(diastolic pressure,DP)、心率(heart rate,HR)、呼吸频率(Respiratory rate,RR)均低于全麻组(P0.05),两组患者血氧饱和度(Pulse Oxygen Saturation,Sp O2)比较差异无统计学意义(P0.05)。腰硬联合麻醉组患者麻醉起效时间、运动阻滞恢复时间以及麻醉药用量均低于全麻组(P0.05)。术后6 h、24 h、72 h,腰硬联合麻醉组的MMSE评分均高于全麻组患者(P0.05)。术后1 d,全麻组的患者出现19例POCD,腰硬联合麻醉组出现4例,发生率显著低于全麻组(P0.05);两组在术后3 d的POCD发生率比较差异无统计学意义(P0.05)。结论:腰硬联合麻醉用于择期行髋关节置换术的老年患者具有良好的临床效果,麻醉起效快,缩短了完全阻滞时间,明显改善了患者的生命体征,降低术后认知功能障碍的发生,麻醉药物用量少。     

Effects of Pressure Support Ventilation Mode on Emergence Time and Intra-Operative Ventilatory Function: A Randomized Controlled Trial

We tested the hypothesis that pressure-support ventilation (PSV) allows a reduction in emergence time and laryngeal mask airway (LMA) removal time after general anesthesia compared to volume-controlled mechanical ventilation (CMV). Because spontaneous breathing (SB) is often used with LMA under general anesthesia, patients were allocated randomly to three groups (CMV, SB and PSV). Thirty-six consecutive ASA I–II patients scheduled for knee arthroscopic surgery under general anesthesia with a LMA and breathing throughout the ventilator circuit were included. Hemodynamic and ventilatory variables were recorded before and 10-min after general anesthesia-induction, at the surgical incision, at the end of anaesthetic drugs infusion and when the patient was totally awake (which defines emergence time). LMA removal time, drug consumption were recorded at the end of the surgical procedure. Leak fraction around the LMA was also evaluated. LMA removal time was significantly higher in the CMV-group (18±6 min) compared to both SB (8±4 min) and PSV (7±4 min, P<0.05) groups as well as for emergence time: CMV-group (32±12 min), SB (17±7 min) and PSV (13±6 min, P<0.05) groups. Total propofol consumption was significantly lower in the PSV-group (610±180 mg) than in both CMV (852±330 mg) and SB (734±246 mg, P<0.05) groups. Air leaks around the LMA was significantly higher in the CMV-group than in the SB and PSV groups (16% vs 3% and 7%, all P<0.05). In conclusion, in knee arthroscopic surgery, in comparison to CMV, PSV use during general anesthesia in unparalyzed patients decreases LMA removal time, propofol consumption and leaks around LMA while improving ventilatory variables without adverse effects.

Trial Registration

Controlled-Trials.com ISRCTN17382426     

全身麻醉和硬膜外麻醉对老年骨科手术患者术后短期 认知功能的影响

目的：探讨全身麻醉和硬膜外麻醉对老年骨科手术患者术后短期认知功能的影响。方法：按随机数字方式将2010 年3 月至 2013 年5 月收治的全麻骨科手术老年患者64 例分为两组,全身麻醉组（32 例）给予全身麻醉进行手术,硬膜外麻醉组（32 例）给 予硬膜外麻醉进行手术,对比分析两组观察麻醉前后动脉血压与心率,睁眼、拔管及应答时间,术后6、12、24、72 h的MMSE 评分 差异,并统计术后POCD的发生情况。结果：两组的年龄、体重、麻醉时间、受教育时间、出血量等一般临床资料均无明显差异（P＞ 0.05）;两组麻醉前、麻醉后术前、手术0.5h 及手术结束时动脉血压和心率差异均不显著（P＞0.05）;全身麻醉组的睁眼、拔管及应 答时间分别为（30.3 ± 10. 5）min、（30.3 ± 7.8）min、（33.2 ± 9.6）min;膜外麻醉组的睁眼、拔管及应答时间分别为（30.6 ± 11.6）min、 （30.1± 6.6）min、（34.3 ± 8.5）min,两组差异不显著（P＞0.05）;全身麻醉组麻醉前MMSE 评分为29.2 ± 1.5,而膜外麻醉组麻醉前 MMSE 评分为29.1 ± 1.0,差异不显著（P＞0.05）;麻醉后,两组的MMSE 评分均出现先减少后恢复的变化,膜外麻醉组麻醉后 24h 时的MMSE 评分28.7 ± 1.0 明显高于全身麻醉组的27.3 ± 0.8（t=5.491,P=0.000<0.05）;全身麻醉组麻醉后6h 和12hPOCD 的发生率均明显高于膜外麻醉组的（P<0.05）,而两组在麻醉后24h 开始POCD的发生率无明显差异（P＞0.05）。结论：全身麻醉 对老年骨科手术患者术后短期认知功能的影响明显大于硬膜外麻醉。     

糖尿病患者外科手术麻醉的临床研究与探讨

目的:研究与探讨糖尿病患者外科手术麻醉的安全性和有效性。方法:糖尿病外科手术患者262例。其中急性胆囊炎64例,胃穿孔52例,化脓性阑尾炎71例,阑尾穿孔弥漫性腹膜炎各63例,外伤性脾破裂12例。采用硬膜外麻醉146例,全身麻醉116例。结果:所有患者均手术顺利,麻醉平稳,麻醉手术过程中血糖水平较术前均有不同程度升高,按升高的血糖量适当增加胰岛素用量,血糖控制在10-12mmol/L,尿酮体(-),无糖尿病酮症酸中毒、高渗性非酮症性高血糖昏迷及低糖症发生。术毕均及时清醒,拔管,血糖水平较平稳。结论:急诊糖尿病患者手术时采用硬膜外麻醉对血糖影响小于全麻。     

Effect of dexmedetomidine-induced anesthesia on the postoperative cognitive function of elder patients after laparoscopic ovarian cystectomy

ObjectiveTo investigate the effect of dexmedetomidine at maintenance dose on the postoperative function of elder patients after general anesthesia for laparoscopic ovarian cystectomy.MethodsWe enrolled a total of 96 elder patients who were admitted to this hospital for laparoscopic ovarian cystectomy under general anesthesia between March 2015 and March 2017, and divided them into two groups, Group A (n = 48) and B (n = 48). Patients in both groups received the same methods for anesthesia induction and maintenance drugs. At the beginning of operation, patients in Group A received the intravenous injection of dexmedetomidine (0.8 μg/kg) followed by maintenance dose [0.5 μg/(kg h)] to the end of operation, while those in Group B underwent intravenous injection of 0.9% normal saline at the same rate, during which blood pressure, heart rate, oxyhemoglobin saturation and dosage of anesthetics at T1 (5 min after being delivered into the operation room), T2 (immediately after anesthesia induction), T3 (immediately after intubation), T4 (immediately after operation), T5 (immediately after end of operation) and T6 (immediately after extubation). Then, the levels of NSE, IL-6, CRP and HMGB1 were compared between two groups at 24 h before the operation, at the end, 24 h, 3 d and 7 d after operation. Besides, we also compared the postoperative cognitive functions and incidence of adverse reactions at 1 d before, 1, 2, 3 and 7 d after operation through MOCA scales.ResultsAt T3, T4 and T6, comparisons of the average arterial pressure and heart rate showed that the differences between the two groups had statistical significance (p < .05). At the end of operation, and at 24 h, 3 d and 7 d after operation, we found that the levels of IL-6 and CRP in patients of two groups were all significantly elevated when compared with those before operation; at the end of operation and at 24 h and 3 d after operation, the levels of IL-6 and CRP in the Group B were higher than those in the Group A, and the differences had statistical significance (p < .05). At the end of operation and at 24 h and 3 d after operation, the levels of NSE and HMGB1 in two group were higher than those before operation, and a more significant elevation was identified in Group B with statistically significant differences (p < .05); at 7 d after operation, a decreasing trend was found in the level of HMGB1, which, however, remained higher than the preoperative level, and the level in Group B was still higher than that in Group A with statistically significant differences (p < .05). At 2 d after operation, we found that the scores of MOCA in the Group B were remarkably decreased in comparison with the scores in Group A with a statistically significant difference (p < .05). Moreover, the incidence rate of postoperative cognitive dysfunction (POCD) in the Group A was significantly lower than that in the Group B, and the difference had statistical significance (p < .05).ConclusionDexmedetomidine can ameliorate the postoperative cognitive functions of elder patients who received the laparoscopic ovarian cystectomy under general anesthesia, and effectively decrease the incidence rate of POCD without any obvious or severe adverse reaction. Thus, it can serve as a kind of adjuvant drug for general anesthesia in clinical practice.     

老年骨科全麻患者术后麻醉恢复室谵妄的影响因素分析及防范措施

目的:分析老年骨科全麻患者术后麻醉恢复室谵妄的影响因素,并探讨相关防范措施。方法:选取2018年7月-2020年6月期间我院收治的200例老年骨科全麻患者,收集患者的临床资料。根据其术后麻醉恢复室是否出现谵妄分为观察组(术后发生谵妄)和对照组(术后未发生谵妄),分析术后麻醉恢复室谵妄的影响因素。结果:200例老年骨科全麻患者中,发生术后谵妄的患者83例,发生率为41.50%(83/200)。单因素分析结果显示,老年骨科全麻患者术后麻醉恢复室谵妄与年龄、合并其它基础疾病、吸烟史、术前血糖、术前血红蛋白、术前红细胞压积、手术类型、术中失血量、电解质紊乱有关(P<0.05),而与性别、体质量指数(BMI)、Zung焦虑自评量表(SAS)评分、术前总蛋白、抑郁自评量表(SDS)评分、血钾、手术时间无关(P>0.05)。多因素Logistic回归分析结果显示:年龄>75岁、合并其它基础疾病、术前血红蛋白<12g/dl、术中失血量≥200 mL、电解质紊乱均为老年骨科全麻患者术后发生谵妄的危险因素(P<0.05)。结论:引起老年骨科全麻患者术后麻醉恢复室谵妄的危险因素较多,包括年龄、合并其它基础疾病、术前血红蛋白、术中失血量、电解质紊乱等,临床应采取必要的防范措施,合理制定手术方案,以降低患者术后谵妄的发生率。     

骨质疏松性椎体压缩骨折经皮椎体后凸成形术中应用不同麻醉方式对疼痛阈值的影响

摘要 目的：探究骨质疏松性椎体压缩骨折经皮椎体后凸成形术中应用不同麻醉方式对疼痛阈值的影响。方法：选择120例接受经皮椎体后凸成形术治疗的骨质疏松性椎体压缩骨折患者,并将其随机分为全身麻醉组（n=40）、局部麻醉组（n=40）和硬膜外麻醉组（n=40）。对比分析三组麻醉效果、不同时间点疼痛阈值（VAS值）、疼痛总分（PRI）与疼痛强度（PPI）、温度疼痛阈值和电疼痛阈值以及采取自控镇痛、止痛药的情况。结果：全身麻醉组患者麻醉优良率为95.00 %,局部麻醉组患者麻醉优良率为87.50 %,硬膜外麻醉组患者麻醉优良率为92.50 %。三组患者麻醉效果比较,全身麻醉组显著优于局部麻醉组和硬膜外麻醉组（P<0.05）。随着麻醉时间的延长,硬膜外麻醉组患者在麻醉后的VAS值、PRI和PPI值、温度疼痛阈值和电疼痛阈值均显著低于全身麻醉组和局部麻醉组患者（P<0.05）。全身麻醉组采取其他方式进行止痛的概率为1.67 %,局部麻醉组为30.00 %,硬膜外麻醉组为2.50 %,差异有统计学意义（P<0.05）。结论：硬膜外麻醉方式对骨质疏松性椎体压缩骨折经皮椎体后凸成形术的麻醉效果和镇痛效果较全身麻醉和局部麻醉效果好,值得临床推广使用。     

Meta-analysis of randomized controlled trials on the efficacy of thoracic epidural anesthesia in preventing atrial fibrillation after coronary artery bypass grafting

ABSTRACT: BACKGROUND: Postoperative atrial fibrillation (POAF) is one of the most common complications in patients undergoing coronary artery bypass grafting (CABG). The goal of this meta-analysis was to evaluate the efficacy of thoracic epidural anesthesia (TEA) in preventing POAF in adult patients undergoing CABG. METHODS: MEDLINE and EMBASE were searched to identify randomized controlled trails in adult patients undergoing CABG who were randomly assigned to receive general anesthesia plus thoracic epidural anesthesia (GA + TEA) or general anesthesia only (GA). Two authors independently extracted data using a standardized Excel file. The primary outcome measure was the incidence of POAF. We used DerSimonian-Laird random-effects models to compute summary risk ratios with 95 % confidence intervals. RESULTS: Five studies involving 540 patients met our inclusion criteria. No significant difference in the incidence of POAF was observed between the two groups (risk ratio, 0.61; 95 % confidence interval, 0.33 to 1.12; P = 0.11), with significant heterogeneity among the studies (I2 = 73 %, P = 0.005). Sensitivity analyses by primary endpoint, methodological quality and surgical technique yielded similar results. CONCLUSIONS: The limited evidence suggests that TEA shows no beneficial efficacy in preventing POAF in adult patients undergoing CABG. However, the results of this meta-analysis should be interpreted with caution due to significant heterogeneity of the studies included. Thus, the potential infuence of TEA on the incidence of atrial fibrillation following CABG warrants further investigation.     

全身麻醉和硬膜外麻醉对老年骨科手术患者术后短期认知功能的影响

目的：探讨全身麻醉和硬膜外麻醉对老年骨科手术患者术后短期认知功能的影响。方法：按随机数字方式将2010年3月至2013年5月收治的全麻骨科手术老年患者64例分为两组,全身麻醉组（32例）给予全身麻醉进行手术,硬膜外麻醉组（32例）给予硬膜外麻醉进行手术,对比分析两组观察麻醉前后动脉血压与心率,睁眼、拔管及应答时间,术后6、12、24、72h的MMSE评分差异,并统计术后POCD的发生情况。结果：两组的年龄、体重、麻醉时间、受教育时间、出血量等一般临床资料均无明显差异（P〉0．05）;两组麻醉前、麻醉后术前、手术0．5h及手术结束时动脉血压和心率差异均不显著（P〉0．05）;全身麻醉组的睁眼、拔管及应答时间分别为（30．3±10．5）min、（30.3±7．8）min、（33．2±9．6）min;膜外麻醉组的睁眼、拔管及应答时间分别为（30．6±11．6）min、（30．1±6．6）min、（34.3±8．5）min,两组差异不显著（P〉0．05）;全身麻醉组麻醉前MMSE评分为29．2±1．5,而膜外麻醉组麻醉前MMSE评分为29．1±1．0,差异不显著（P〉0．05）;麻醉后,两组的MMSE评分均出现先减少后恢复的变化,膜外麻醉组麻醉后24h时的MMSE评分28．7±1．0明显高于全身麻醉组的27．3±0．8（t=-5．491,P=0．000〈0．05）;全身麻醉组麻醉后6h和12hPOCD的发生率均明显高于膜外麻醉组的（P〈0．05）,而两组在麻醉后24h开始POCD的发生率无明显差异（P〉0．05）。结论：全身麻醉对老年骨科手术患者术后短期认知功能的影响明显大于硬膜外麻醉。     

不同麻醉方法对肝癌手术患者炎性细胞因子基因表达的影响

目的:探讨不同麻醉方法对肝癌手术患者外周血炎性细胞因子基因表达的影响。方法:选择肝癌手术患者48例,随机分为单纯全麻和全麻复合硬膜外麻醉两组,在麻醉前和麻醉后4h抽取静脉血,Trizol法抽提RNA,RT-PCR检测IL-1β、IL-6、IL-8的TNF-α的mRNA表达水平。结果:麻醉前两组患者间外周血炎性细胞因子基因表达无差别,麻醉4h后全麻组外周血IL-1β、IL-6、IL-8的mRNA表达水平显著升高(P<0.05),并高于联合组(P<0.05)。结论:不同麻醉方法对细胞因子的分泌会产生不同的影响,单纯全麻将增强肝癌手术病人外周血炎性细胞因子基因的表达。     

全身麻醉复合硬膜外麻醉与全身麻醉对老年腹部肿瘤手术患者的影响

目的:探究全身麻醉复合硬膜外麻醉与全身麻醉对老年腹部肿瘤手术患者影响。方法:选择2015年10月-2018年10月于我院进行手术治疗的老年腹部肿瘤患者96例,随机分为两组,每组48例患者。其中,对照组患者给予全身麻醉,研究组患者联合硬膜外麻醉,对比两组患者的麻醉指标、围术期指标、应激激素指标、肺功能指标和不同时间点血清NSE、S100β浓度的变化。结果:研究组患者的瑞芬太尼用量、异丙酚用量、苏醒时间、拔管时间均显著少于(短于)对照组(P<0.05);对照组患者术后肾上腺素、去甲肾上腺素、皮质醇等指标水平均比术前显著升高(P<0.05);研究组患者术后的去甲肾上腺素水平显著高于术前(P<0.05),但肾上腺素、皮质醇与术前无显著性差异(P<0.05);随着治疗时间推移,两组患者手术1 h时、手术时2 h时、术毕时血清NSE、S100β浓度呈逐渐升高趋势,且研究组患者以上指标均明显低于对照组(P<0.05);对照组患者术后的(MVV-VE)/FEV1、MVV/FEV1指标水平均比术前显著降低(P<0.05);RV/TLC水平比术前显著升高(P<0.05);但研究组患者术后的(MVV-VE)/FEV1、MVV/FEV1、RV/TLC等指标与术前无显著差异(P>0.05)。结论:与全身麻醉相比,全身麻醉复合硬膜外麻醉可更有效改善老年腹部肿瘤患者手术指标,并控制机体应激反应和降低麻醉过程对脑部的损伤,且对其肺功能影响较小。     

Estimation of Quasi-Stiffness of the Human Knee in the Stance Phase of Walking

Biomechanical data characterizing the quasi-stiffness of lower-limb joints during human locomotion is limited. Understanding joint stiffness is critical for evaluating gait function and designing devices such as prostheses and orthoses intended to emulate biological properties of human legs. The knee joint moment-angle relationship is approximately linear in the flexion and extension stages of stance, exhibiting nearly constant stiffnesses, known as the quasi-stiffnesses of each stage. Using a generalized inverse dynamics analysis approach, we identify the key independent variables needed to predict knee quasi-stiffness during walking, including gait speed, knee excursion, and subject height and weight. Then, based on the identified key variables, we used experimental walking data for 136 conditions (speeds of 0.75–2.63 m/s) across 14 subjects to obtain best fit linear regressions for a set of general models, which were further simplified for the optimal gait speed. We found R² > 86% for the most general models of knee quasi-stiffnesses for the flexion and extension stages of stance. With only subject height and weight, we could predict knee quasi-stiffness for preferred walking speed with average error of 9% with only one outlier. These results provide a useful framework and foundation for selecting subject-specific stiffness for prosthetic and exoskeletal devices designed to emulate biological knee function during walking.     

Estimation of Quasi-Stiffness and Propulsive Work of the Human Ankle in the Stance Phase of Walking

Characterizing the quasi-stiffness and work of lower extremity joints is critical for evaluating human locomotion and designing assistive devices such as prostheses and orthoses intended to emulate the biological behavior of human legs. This work aims to establish statistical models that allow us to predict the ankle quasi-stiffness and net mechanical work for adults walking on level ground. During the stance phase of walking, the ankle joint propels the body through three distinctive phases of nearly constant stiffness known as the quasi-stiffness of each phase. Using a generic equation for the ankle moment obtained through an inverse dynamics analysis, we identify key independent parameters needed to predict ankle quasi-stiffness and propulsive work and also the functional form of each correlation. These parameters include gait speed, ankle excursion, and subject height and weight. Based on the identified form of the correlation and key variables, we applied linear regression on experimental walking data for 216 gait trials across 26 subjects (speeds from 0.75–2.63 m/s) to obtain statistical models of varying complexity. The most general forms of the statistical models include all the key parameters and have an R² of 75% to 81% in the prediction of the ankle quasi-stiffnesses and propulsive work. The most specific models include only subject height and weight and could predict the ankle quasi-stiffnesses and work for optimal walking speed with average error of 13% to 30%. We discuss how these models provide a useful framework and foundation for designing subject- and gait-specific prosthetic and exoskeletal devices designed to emulate biological ankle function during level ground walking.