ObjectiveTo address the limitations of the current quality standard for Polygalae Radix（PR）， which relies on a single component for quality assessment and struggles to holistically control its intrinsic quality， by constructing a comprehensive quality evaluation system integrating "macro-characterization of chemical profile， synchronous quantification of multiple index components， and quantitative analysis of multi-components by single marker（QAMS） for key component groups". This study aims to facilitate the scientific revision of the quality standard for PR. MethodsHigh performance liquid chromatography（HPLC） characteristic chromatograms were established for 11 batches of PR medicinal materials（YZ）， 10 batches of PR decoction pieces（YP）， and 10 batches of licorice-processed PR decoction pieces（ZYZ）， followed by similarity evaluation and identification of common peaks. HPLC-QAMS was developed for xanthones（sibiricaxanthone B， polygalaxanthone Ⅺ， polygalaxanthone Ⅲ） in the characteristic chromatograms. Simultaneously， the external standard method（ESM） was used to determine the contents of the corresponding xanthones and 3，6'-disinapoyl sucrose in YZ， YP， and ZYZ， followed by multivariate statistical analysis and Spearman correlation analysis. ResultsThe similarity between the characteristic chromatograms of 31 batches of PR samples and the reference chromatogram was>0.9. A total of 13 common peaks were identified， and 10 of these peaks were characterized through reference standard comparison. The successfully constructed QAMS method showed that the relative correction factors（RCFs） of sibiricaxanthone B and polygalaxanthone Ⅺ to polygalaxanthone Ⅲ were 0.76 and 0.88， and their relative retention times（RRTs） were 0.85 and 0.97， respectively. The results calculated by the QAMS method showed no significant difference from those obtained by the ESM. According to the limit standard for polygalaxanthone Ⅲ in the 2020 edition of the Pharmacopoeia of the People's Republic of China（hereinafter referred to as the Chinese Pharmacopoeia）， the pass rate of 31 batches of samples was only 19.35%. Multivariate statistical analysis indicated certain compositional differences between different batches of YZ and YP， as well as between YP and ZYZ， with 3，6'-disinapoyl sucrose identified as the main differentiating component. Furthermore， correlation analysis revealed that the content of polygalaxanthone Ⅲ was positively correlated with the contents of sibiricaxanthone B and polygalaxanthone Ⅺ， but showed no association with the content of 3，6'-disinapoyl sucrose. ConclusionIt is recommended that the content limit for polygalaxanthone Ⅲ in YZ，YP and ZYZ be revised to not less than 0.07%， or the total content of polygalaxanthone Ⅲ， sibiricaxanthone B and polygalaxanthone Ⅺ be not less than 0.18%. The newly established triple quality control model of "holistic control via characteristic chromatograms， precise quantification of oligosaccharide esters， and efficient detection of xanthones by QAMS" provides a systematic and precise solution for quality evaluation of PR and similar Chinese herbal medicines.

BACKGROUND:Acupuncture at Xinshu(BL 15)can significantly improve cardiac function and protect myocardial cells in acute myocardial ischemia,but the effect and mechanism of thread embedding treatment at Xinshu(BL 15)on cardiac function in acute myocardial ischemia are yet unclear.Nuclear factor κB activation often appears as an intranuclear translocation of the P65 isoform,and activation of the nuclear factor κB signaling pathway is marked by elevated P65 levels.OBJECTIVE:To explore the effects of thread embedding pretreatment at Xinshu(BL 15)on cardiac function and the expression levels of interleukin-10,tumor necrosis factor-α,P65 genes and proteins in rats with acute myocardial ischemia.METHODS:Thirty-two male Sprague-Dawley rats were randomly divided into a blank group,a model group,a Xinshu(BL 15)acupoint group,and a non-meridian/non-acupoint group using a random number table method,with eight rats in each group.Rat models of acute myocardial ischemia were established in the latter three groups.The Xinshu(BL 15)acupoint group had thread embedding at Xinshu(BL 15)for 14 days,followed by subcutaneous injection of isoproterenol hydrochloride into the back to establish an acute myocardial ischemia rat model.The non-meridian/non-acupoint group had local thread embedding for 14 days,and the rest procedures were the same as above.In the model group,Xinshu(BL 15)was only marked,and the rest procedures were the same as above.In the blank group,Xinshu(BL 15)was only marked,and then an equal amount of physiological saline was injected subcutaneously into the back.After 24 hours of modeling,electrocardiogram and cardiac ultrasound were performed.Abdominal aorta blood was extracted for detection of serum creatine kinase and creatine kinase isoenzyme levels using enzyme-linked immunosorbent assay.Subsequently,the rats were euthanized and samples were collected.Hematoxylin-eosin and TUNEL staining were used to observe the pathological changes of myocardial tissue and the apoptosis of myocardial cells.Real-time fluorescence quantitative PCR(RT-qPCR)and western blot were used to detect the mRNA and protein expression of tumor necrosis factor-α,interleukin-10,and P65 in myocardial tissue respectively.RESULTS AND CONCLUSION:(1)Electrocardiogram:Compared with the blank group,the model group,non-meridian/non-acupoint group,and Xinshu(BL 15)acupoint group had significantly elevated ST segment in lead Ⅱ of the electrocardiogram.(2)Cardiac ultrasound:Compared with the model group,the Left ventricular end-systolic dimension in the Xinshu(BL 15)acupoint group were significantly reduced(P＜0.05),while left ventricular ejection fraction and left ventricular fractional shortening rate were significantly increased(P＜0.05).(4)Serum creatine kinase and creatine kinase isoenzyme:Compared with the model group,the Xinshu(BL 15)acupoint group showed a significant decrease in serum creatine kinase and creatine kinase isoenzyme levels(P＜0.05).(4)Hematoxylin-eosin staining:Compared with the model group,the arrangement of myocardial fibers in the Xinshu(BL 15)acupoint group was basically neat,with less edema and a small amount of inflammatory cell infiltration.(5)TUNEL staining:Compared with the model group,the fluorescence intensity of myocardial cell apoptosis in the Xinshu(BL 15)acupoint group was significantly reduced,and its apoptosis rate was significantly reduced(P＜0.05).(6)RT-qPCR and western blot:Compared with the model group,the myocardial tissue interleukin-10 level in the Xinshu(BL 15)acupoint group was significantly increased(P＜0.05),while tumor necrosis factor-α and P65 levels were significantly decreased(P＜0.05).These findings indicate that thread embedding pretreatment at Xinshu(BL 15)can improve cardiac function in rats with acute myocardial ischemia,and its mechanism of action may be related to the inhibition of the activation of the nuclear factor-κB signaling pathway.

BACKGROUND:Acupuncture at Xinshu(BL 15)can significantly improve cardiac function and protect myocardial cells in acute myocardial ischemia,but the effect and mechanism of thread embedding treatment at Xinshu(BL 15)on cardiac function in acute myocardial ischemia are yet unclear.Nuclear factor κB activation often appears as an intranuclear translocation of the P65 isoform,and activation of the nuclear factor κB signaling pathway is marked by elevated P65 levels.OBJECTIVE:To explore the effects of thread embedding pretreatment at Xinshu(BL 15)on cardiac function and the expression levels of interleukin-10,tumor necrosis factor-α,P65 genes and proteins in rats with acute myocardial ischemia.METHODS:Thirty-two male Sprague-Dawley rats were randomly divided into a blank group,a model group,a Xinshu(BL 15)acupoint group,and a non-meridian/non-acupoint group using a random number table method,with eight rats in each group.Rat models of acute myocardial ischemia were established in the latter three groups.The Xinshu(BL 15)acupoint group had thread embedding at Xinshu(BL 15)for 14 days,followed by subcutaneous injection of isoproterenol hydrochloride into the back to establish an acute myocardial ischemia rat model.The non-meridian/non-acupoint group had local thread embedding for 14 days,and the rest procedures were the same as above.In the model group,Xinshu(BL 15)was only marked,and the rest procedures were the same as above.In the blank group,Xinshu(BL 15)was only marked,and then an equal amount of physiological saline was injected subcutaneously into the back.After 24 hours of modeling,electrocardiogram and cardiac ultrasound were performed.Abdominal aorta blood was extracted for detection of serum creatine kinase and creatine kinase isoenzyme levels using enzyme-linked immunosorbent assay.Subsequently,the rats were euthanized and samples were collected.Hematoxylin-eosin and TUNEL staining were used to observe the pathological changes of myocardial tissue and the apoptosis of myocardial cells.Real-time fluorescence quantitative PCR(RT-qPCR)and western blot were used to detect the mRNA and protein expression of tumor necrosis factor-α,interleukin-10,and P65 in myocardial tissue respectively.RESULTS AND CONCLUSION:(1)Electrocardiogram:Compared with the blank group,the model group,non-meridian/non-acupoint group,and Xinshu(BL 15)acupoint group had significantly elevated ST segment in lead Ⅱ of the electrocardiogram.(2)Cardiac ultrasound:Compared with the model group,the Left ventricular end-systolic dimension in the Xinshu(BL 15)acupoint group were significantly reduced(P＜0.05),while left ventricular ejection fraction and left ventricular fractional shortening rate were significantly increased(P＜0.05).(4)Serum creatine kinase and creatine kinase isoenzyme:Compared with the model group,the Xinshu(BL 15)acupoint group showed a significant decrease in serum creatine kinase and creatine kinase isoenzyme levels(P＜0.05).(4)Hematoxylin-eosin staining:Compared with the model group,the arrangement of myocardial fibers in the Xinshu(BL 15)acupoint group was basically neat,with less edema and a small amount of inflammatory cell infiltration.(5)TUNEL staining:Compared with the model group,the fluorescence intensity of myocardial cell apoptosis in the Xinshu(BL 15)acupoint group was significantly reduced,and its apoptosis rate was significantly reduced(P＜0.05).(6)RT-qPCR and western blot:Compared with the model group,the myocardial tissue interleukin-10 level in the Xinshu(BL 15)acupoint group was significantly increased(P＜0.05),while tumor necrosis factor-α and P65 levels were significantly decreased(P＜0.05).These findings indicate that thread embedding pretreatment at Xinshu(BL 15)can improve cardiac function in rats with acute myocardial ischemia,and its mechanism of action may be related to the inhibition of the activation of the nuclear factor-κB signaling pathway.

Objective:To describe the safety of using the Chinese-made robotic laparoscopic surgery system for laparoscopic sacrocolpopexy in the treatment of severe pelvic organ prolapse.Methods:A pilot descriptive clinical study was conducted, enrolling 16 severe pelvic organ prolapse patients at Peking University First Hospital from April 2023 to January 2024. Patients who consented to participate in this study underwent laparoscopic sacrocolpopexy for severe pelvic organ prolapse using Chinese-made robotic laparoscopic surgery system. Preoperative clinical basic data and perioperative data of the patients were collected, summarizing the data on perioperative bleeding and complications, and reviewed the surgical learning experience. The evaluation indicators related to the learning experience included: (1) efficiency evaluation: including equipment docking time, total surgery time, suturing time, mechanical arm operation time and hysterectomy time, which were timed and recorded during surgery; (2) equipment operability evaluation: including equipment operation task load assessment and intraoperative operation feeling score. The cumulative sum analysis method was used to quantify surgery time and fit the learning curve.Results:Sixteen patients were successfully enrolled and underwent surgery, including total hysterectomy with bilateral salpingo-oophorectomy or salpingectomy plus sacrocolpopexy, or sacrocolpopexy alone (for one case without uterus). The age of 16 cases was (56.7±7.6) years (ranged from 44 to 67 years), with body mass index of (25.4±2.5) kg/m2. Concurrent procedures included anterior vaginal wall repair in 12 cases (12/16), posterior vaginal wall repair in 13 cases (13/16), tension-free vaginal tape obturator system in 1 case (1/16), and recto-uterine pouch hernia repair in 4 cases (4/16). The total surgery time was (355.8±91.1) minutes, with docking time at (6.7±4.9) minutes, robotic operative time at (267.6±81.4) minutes, robotic suturing time at (155.6±53.9) minutes, and hysterectomy time at (112.0±45.3) minutes. Learning curve analysis revealed inflection points at 6 cases for total surgery time ( P<0.001, R2=0.944) and robotic operative time ( P<0.001, R2=0.982), 5 cases for docking time ( P<0.001, R2=0.989), and 6 cases for robotic suturing time ( P<0.001, R2=0.907). Hysterectomy time had an inflection point at 5 cases ( P=0.023, R2=0.700). Median blood loss was 30 ml (range: 10-1 000 ml), with severe bleeding in one patient (1/16). No conversions to open surgery or laparoscopy occurred, and no severe perioperative or postoperative complications were reported. Conclusion:The Chinese-made robotic laparoscopic surgery system demonstrates excellent short-time safety and ease of operation for laparoscopic sacrocolpopexy.

Objective To analyze the efficacy of CT-guided alcohol ablation of splanchnic nerve block(SNB)in the treatment of pain in patients with pancreatic cancer,and to discuss the related factors influencing the effectiveness in treating pancreatic cancer pain.Methods The clinical data of patients with pancreatic cancer pain,who was unable to receive surgery and underwent CT-guided SNB at Hai'an People's Hospital from June 2018 to September 2023,were retrospectively analyzed.According to postoperative one-month VAS pain score and the used dosage of opioids,the improvement of pain was assessed.Logistic regression analysis was used to evaluate the demographic characteristics,tumor features,and pain-related factors so as to determine the predictive factors for effective analgesia after SNB,and the survival outcomes were compared between the patients with effective SNB analgesia and the patients with ineffective SNB analgesia.Results A total of 133 patients were included in this analysis.One week after SNB,74.4％of patients achieved effective pain relief,and one month after the procedure,54.9％of patients experienced effective pain relief.One month after treatment,multivariate logistic regression analysis showed that the diabetes(OR=0.637,95％CI=0.397-0.876,P=0.034),serum CA199(OR=1.531,95％CI=1.030-2.370,P=0.042),serum MMP-1(OR=0.703,95％CI=0.457-0.983,P=0.038),preoperative ECOG score(OR=2.693,95％CI=1.234-6.609,P=0.021),and preoperative daily morphine consumption(OR=2.797,95％CI=1.148-6.695,P=0.019)were the independent predictive factors for achieving a good analgesic efficacy after SNB.Patients with poor analgesic outcomes after SNB had a significantly lower median survival time when compared to patients with good analgesic outcomes(82 days vs 149 days,P＜0.05).No serious SNB-related adverse events occurred.Conclusion For the treatment of refractory pancreatic cancer pain,CT-guided SNB is clinically safe and effective.The diabetes,ECOG score,serum MMP-1 level,CA199 level,and preoperative daily used dosage of opioids are the independent predictive factors for the efficacy of CT-guided SNB in treating pancreatic cancer pain.

Objective:To evaluate the efficacy and safety of nebulized inhalation of recombinant human interferon (IFN) α1b injection in the treatment of respiratory syncytial virus (RSV) associated lower respiratory tract infections (pneumonia and bronchiolitis) in children.Methods:A randomized, double-blind, parallel, placebo-controlled add-on design was used.Children with pneumonia or bronchiolitis aged 2 months to 5 years who tested positive for RSV antigen within 72 hours of onset from 30 clinical trial sites including Beijing Children′s Hospital, Capital Medical University between February 2021 and December 2022 were included in this study and randomly divided into 2 groups at a ratio of 1∶1 based on a stratified-block method.Both groups received basic treatments such as cough control, asthma relieving, expectorant treatment, fever reduction, oxygen therapy, etc.The experimental group received additional nebulized inhalation of IFN α1b injection at a dose of 2.0 μg/(kg·time), twice a day.The control group received nebulized inhalation of placebo twice a day.Clinical efficacy was evaluated based on indicators such as the duration of clinical symptoms and signs, and the Kaplan-Meier method was used to calculate the median and 95% CI of the duration of clinical symptoms and signs.The Log-rank test was used to compared data between groups.Safety was assessed through the incidence of adverse reactions and laboratory tests, and the Chi-square test was used to analyze the difference between groups. Results:There were 123 children in the experimental group and 122 children in the control group.The median durations of all the 5 clinical symptoms and signs [including shortness of breath, wheezing, dyspnea (visible retractions), decreased transcutaneous oxygen saturation, and abnormal mental state] in the experimental group after treatment were slightly shortened than those in the control group [2.7 d(95% CI: 1.9-3.0 d)] vs.[2.9 d(95% CI: 2.6-3.6 d), P=0.027].The improvement in dyspnea (retractions) was especially pronounced in the experimental group, with a relief rate of 50.0% (0, 100%) on the first day of administration[compared with 0 (0, 50.0%) in the control group ( Z=2.002, P=0.025)].The median duration of dyspnea in the experimental group was nearly 1 day shorter than that in the control group [1.0 d(95% CI: 0.7-1.7 d) vs.1.8 d(95% CI: 1.0-2.5 d), P=0.046].There were no significant difference in hospital stay [6.0(5.0, 8.0) d vs.6.5(5.0, 8.0) d, Z=0.675, P=0.500], oxygen therapy duration [32.0(14.0, 96.3) h vs.39.0 (24.0, 83.2) h, Z=0.094, P=0.925], the recovery rate from clinical symptoms during treatment [(105/106, 99.1%) vs.(96/101, 95.0%)], and recurrence rate [(0/106, 0) vs.(2/101, 2.0%)] between the 2 groups (all P>0.05).However, the above-mentioned four indicators in the experimental group showed a trend of clinical benefits.The quantitative virus detection results showed that the RSV viral load in both groups decreased after treatment compared to before treatment.After 2 days of treatment, the decline rate of RSV viral load from the baseline was 0.90 lg copies/(mL·d) in the experimental group and 0.25 lg copies/(mL·d)in the control group, with a statistically significant difference ( P<0.05).Furthermore, there was no statistically significant difference in the incidence of adverse reactions between the 2 groups ( P>0.05).Importantly, no drug-related serious adverse reactions occurred in both groups. Conclusions:The nebulized inhalation therapy of IFN α1b demonstrates efficacy and safety in treating pediatric RSV associated lower respiratory tract infections.It particularly offers outstanding clinical therapeutic value for severe children.

Atherosclerosis is the most common cause of ischemic stroke. Antiplatelet aggregation is considered as the effective treatment for atherosclerotic ischemic stroke. Ticagrelor is a novel P2Y12 receptor antagonist, which has the advantages as rapid onset, strong effect, no need for liver metabolism activation and reversible platelet inhibition. Studies have confirmed that ticagrelor has a better therapeutic effect on ischemic stroke patients who are resistant to clopidogrel; especially in dual antiplatelet therapy, patients used ticagrelor have lower stroke risk and severe hemorrhage risk does not increase in these patients. This article reviews the recent advances in mechanism of ticagrelor and its application in acute ischemic stroke, with the aim of providing references for clinical application of ticagrelor.

The integration of traditional Chinese and Western medicine is a crucial contemporary medical model widely utilized today.Modern medicine is intricately linked to"data"and"calculation".The key to the high-quality development of integrated Chinese and Western medicine is to realise the in-depth integration of information technology and modern medicine,including tackling the three major scientific problems(algorithm establishment,queue creation and data quality),introducing laws and policies,fostering cross-innovation talents in integrated Chinese and Western medicine,and regulating standards.At the same time,adhering to the principle of integrity and innovation,and being firm in cultural self-confidence are important factors in promoting the healthy,rapid and sustainable development of the cause of integrative Chinese and Western medicine and traditional Chinese medicine.

ObjectiveTo investigate the application of the novel inflammatory factor adsorption column CA280 combined with low-dose plasma exchange （LPE） in patients with acute-on-chronic liver failure （ACLF）. MethodsA prospective cohort study was designed， and a total of 93 ACLF patients who were admitted to The Ninth Hospital of Nanchang from June 2023 to January 2025 were enrolled and randomly divided into DPMAS+LPE group with 50 patients and CA280+LPE group with 43 patients. In addition to comprehensive medical treatment， the patients in the DPMAS+LPE group received DPMAS and LPE treatment， and those in the CA280+LPE group received CA280 and LPE treatment. The two groups were observed in terms of routine blood test results， liver function parameters， renal function markers， electrolytes， coagulation function parameters， cytokines， adverse events， and 28-day prognosis before surgery （baseline）， during surgery （DPMAS or CA280）， and after surgery （after sequential LPE treatment）. The paired t-test was used for comparison of normally distributed continuous data before and after treatment within each group， and the independent-samples t test was used for comparison between groups； the Wilcoxon signed-rank test was used for comparison of non-normally distributed continuous data before and after treatment within each group， and the Mann-Whitney U test was used for comparison between groups. The chi-square test or the Fisher’s exact test was used for comparison of categorical data between groups， and the Spearman test was used for correlation analysis. ResultsAfter CA280 treatment， the ACLF patients had significant reductions in the levels of cytokines （IL-6， IL-8， IL-10， TNF-α， and IFN-γ）， liver function parameters （ALT， AST， ALP， TBil， DBil， Alb， and glutathione reductase）， and the renal function marker urea nitrogen （all P<0.05）， and in terms of coagulation function parameters， there were significant increases in prothrombin time， activated partial thromboplastin time （APTT）， thrombin time， and international normalized ratio （INR） and significant reductions in prothrombin activity （PTA） and fibrinogen （FIB） （all P<0.05）. Compared with the DPMAS+LPE group， the CA280+LPE group showed better improvements in the serum cytokines IL-8 （Z=-2.63， P=0.009）， IL-10 （Z=-3.94， P<0.001）， and TNF-α （Z=-1.53， P=0.023）， and the two artificial liver support systems had a similar effect in improving liver function （ALT， AST， GGT， GR， TBil， and DBil） （all P >0.05）， but the CA280+LPE group showed a significantly greater reduction in Alb （Z=-2.08， P=0.037）. CA280+LPE was more effective in reducing uric acid （Z=-2.97， P=0.003）. Compared with DPMAS+LPE， CA280+LPE treatment resulted in a significant reduction in INR （Z=-4.01， P<0.001）， a significant increase in APTT （Z=-2.53， P=0.011）， and significant greater increases in PTA （Z=-6.28， P<0.001） and FIB （Z=-3.93， P<0.001）. There were no significant differences in the incidence rates of adverse reactions and the rate of improvement at discharge between the two groups （all P>0.05）. The Spearman correlation analysis showed that IL-6 was significantly correlated with WBC （r=0.22， P=0.042）， TBil （r=0.29， P=0.005）， and FIB （r=-0.33， P=0.003）； IL-8 was positively correlated with APTT （r=0.37， P<0.001） and INR （r=0.25， P=0.013）； TNF-α was significantly correlated with WBC （r=0.40， P<0.001） and TBil （r=0.34， P<0.001）. ConclusionCompared with DPMAS， CA280 combined with LPE can effectively clear proinflammatory cytokines and improve liver function in ACLF patients， but it has a certain impact on Alb and coagulation function. This regimen provides a new option for the individualized treatment of ACLF and can improve the short-term prognosis of patients， but further studies are needed to verify its long-term efficacy.

With the continuous advancement and innovation in medical equipment technology, the transition between high-flow oxygen therapy, non-invasive ventilation, and invasive ventilation can be easily achieved by adjusting the ventilation mode of ventilators. During the weaning phase for tracheotomized patients, it is necessary to disconnect the ventilator circuit, change the ventilator mode, and gradually extend the weaning time to achieve complete ventilator liberation. During the weaning process, due to patients' excessive dependence on the ventilator, there may be situations where respiratory endpoints and Y-connectors of the ventilator are reconnected for invasive ventilation. However, during the weaning process, the Y-connector and expiratory end connectors are exposed to the air, which cannot ensure the tightness of the ventilator circuit, easily increasing the probability of ventilator circuit contamination and subsequently the risk of ventilator-associated pneumonia (VAP). To overcome these issues, the research team of department of critical care medicine of Zhongda Hospital Southeast University has designed a ventilator circuit interface protective device for weaning and has obtained a National Utility Model Patent of China (ZL 2023 2 1453385.8). The main body of the protective device is a Y-connector plug, consisting of multiple components, including a sealing piece, a protective cover, a sealing plug, an interface 1 (connects with the patient's tracheal tube), an interface 2 (connects with the respiratory branch of the ventilator), and an interface 3 (connects with the expiratory branch of the ventilator), featuring a unique design and easy operation. During the patient's weaning training process, the interface 1 and interface 2 is disconnected from the patient's tracheal tube and respiratory branch, respectively. The interface 1 is plugged with a stopper, and the interface 2 is covered with a protective cover to ensure the tightness of the expiratory branch and Y-connector of the ventilator. During the period when the patient is using the ventilator, the protective cover and plug are removed, and connecting them together ensures the tightness of the device itself, reducing the incidence of VAP caused by ventilator circuit contamination, avoiding nosocomial infections, and shortening the prolonged use of invasive ventilation, increased complication rate, extended hospital stay, and increased medical cost associated with weaning.
Humans ; Ventilator Weaning/methods* ; Equipment Design ; Ventilators, Mechanical ; Respiration, Artificial/instrumentation* ; Pneumonia, Ventilator-Associated/prevention & control*