BMC Anesthesiol

No previous study investigated the dexmedetomidine-based opioid-free anesthesia (OFA) protocol in cardiac surgery. The main objective of this study was to evaluate the feasibility and the postoperative opioid-sparing effect of dexmedetomidine-based OFA in adult cardiac surgery patients. We conducted a single-centre and retrospective study including 80 patients above 18 years old who underwent on-pump cardiac surgery between November 2018 and February 2020. Patients were divided into two groups: OFA (lidocaine, ketamine, dexmedetomidine, MgSO4) or opioid-based anaesthesia (remifentanil and anti-hyperalgesic medications such as ketamine and/or MgSO4 and/or lidocaine at the discretion of the anesthesiologist). The primary endpoint was the total amount of opioid consumed in its equivalent of intravenous morphine during the first 48 postoperative hours. Secondary outcomes included perioperative hemodynamics, post-operative maximal pain at rest and during coughing and adverse outcomes. Data are expressed as median [interquartile range]. Patients in the OFA-group had a higher EuroSCORE II, with more diabetes, more dyslipidemia and more non-elective surgery but fewer smoking history. In the OFA group, the median loading dose of dexmedetomidine was 0.6 [0.4-0.6] μg.kg while the median maintenance dose was 0.11 μg.kg.h [0.05-0.20]. In 10 (25%) patients, dexmedetomidine was discontinued for a drop of mean arterial pressure below 55 mmHg. The median total amount of opioid consumed in its equivalent of intravenous morphine during the first 48 postoperative hours was lower in the OFA group (15.0 mg [8.5-23.5] versus 30.0 mg [17.3-44.3], p < 0.001). While no differences were seen with rest pain (2.0 [0.0-3.0] versus 0.5 [0.0-5.0], p = 0.60), the maximal pain score during coughing was lower in OFA group (3.5 [2.0-5.0] versus 5.5 [3.0-7.0], p = 0.04). In OFA group the incidence of atrial fibrillation (18% versus 40%, p = 0.03) and non-invasive ventilation use (25% versus 48%, p = 0.04) were lower. The incidence of bradycardia and the intraoperative use of norepinephrine were similar between both groups. Dexmedetomidine-based OFA in cardiac surgery patients is feasible and could be associated with a lower postoperative morphine consumption and better postoperative outcomes. Further randomized studies are required to confirm these promising results and determine the optimal associations, dosages, and infusion protocols during cardiac surgery

Research and Design of a Routing Protocol in Large-Scale Wireless Sensor Networks

无线传感器网络，作为全球未来十大技术之一，集成了传感器技术、嵌入式计算技术、分布式信息处理和自组织网技术，可实时感知、采集、处理、传输网络分布区域内的各种信息数据，在军事国防、生物医疗、环境监测、抢险救灾、防恐反恐、危险区域远程控制等领域具有十分广阔的应用前景。 本文研究分析了无线传感器网络的已有路由协议，并针对大规模的无线传感器网络设计了一种树状路由协议，它根据节点地址信息来形成路由，从而简化了复杂繁冗的路由表查找和维护，节省了不必要的开销，提高了路由效率，实现了快速有效的数据传输。 为支持此路由协议本文提出了一种自适应动态地址分配算——ADAR（AdaptiveDynamicAddre...As one of the ten high technologies in the future, wireless sensor network, which is the integration of micro-sensors, embedded computing, modern network and Ad Hoc technologies, can apperceive, collect, process and transmit various information data within the region. It can be used in military defense, biomedical, environmental monitoring, disaster relief, counter-terrorism, remote control of haz...学位：工学硕士院系专业：信息科学与技术学院通信工程系_通信与信息系统学号：2332007115216

On the use of the edge-on impact experiment to characterize damage of a bonded-polymer under impact loading

International audienc

Ultrasounds welding of nanocellulosic materials

International audienceThe interest for cellulose nanocrystals and nanofibrils is exponentially increased since last decade thanks to their industrialization. In addition to their low density, high aspect ratio, high stiffness and Young’s modulus and chemically reactive surface, this material is well known for its high specific surface. Thanks to these particular properties, cellulose nanomaterials can be used within a wide variety of applications. Coating is one of the promising applications for nanocellulose mainly for barrier applications in packaging. Indeed new bio-based but also high performance solutions are expected in food packaging. Unfortunately, up to now, high barrier solutions can be provided but they always require a layer of thermosealing polymer which is usually fossil based. These multilayer materials are also more complicate to handle when end of life is considered. One solution would be to propose cellulosic materials which could be welded easily. Except thermosealing, ultrasounds welding have been developed in plastic industry last years.This study is a proof of concept that nanocellulosic materials can be welded by ultrasounds. Several nanocellulosic materials were firstly designed and characterized, i.e. from classic cellulose nanocrystals and nanofibrils to functionalized CNC by esterification with lauric acid. Than model films were prepared and welded by ultrasounds. Process parameters were optimized and successful welding were obtained and mechanically characterized. These very positive results have been patented and open the doors for new solutions in welding of biobased materials

Ultrasounds welding of nanocellulosic materials

International audienceThe interest for cellulose nanocrystals and nanofibrils is exponentially increased since last decade thanks to their industrialization. In addition to their low density, high aspect ratio, high stiffness and Young’s modulus and chemically reactive surface, this material is well known for its high specific surface. Thanks to these particular properties, cellulose nanomaterials can be used within a wide variety of applications. Coating is one of the promising applications for nanocellulose mainly for barrier applications in packaging. Indeed new bio-based but also high performance solutions are expected in food packaging. Unfortunately, up to now, high barrier solutions can be provided but they always require a layer of thermosealing polymer which is usually fossil based. These multilayer materials are also more complicate to handle when end of life is considered. One solution would be to propose cellulosic materials which could be welded easily. Except thermosealing, ultrasounds welding have been developed in plastic industry last years.This study is a proof of concept that nanocellulosic materials can be welded by ultrasounds. Several nanocellulosic materials were firstly designed and characterized, i.e. from classic cellulose nanocrystals and nanofibrils to functionalized CNC by esterification with lauric acid. Than model films were prepared and welded by ultrasounds. Process parameters were optimized and successful welding were obtained and mechanically characterized. These very positive results have been patented and open the doors for new solutions in welding of biobased materials

A testing technique to investigate the tensile behavior of propellant representative material

Propellants are energetic materials abundantly used to generate the propulsion of rockets, projectiles, or other objects. A wide range of stress-state and strain-rate has to be considered in view of predicting the mechanical behaviour of this material over its different life cycles. Propellant materials are usually studied through the use of propellant representative materials (PRM) when studied in a university laboratory. In the present work an experimental device was developed to investigate the dynamic tensile response of a PRM material. This device is based on the use of a pendulum that is employed to dynamically load the PRM sample on one end. The sample is attached to an instrumented Hopkinson bar on the other end. The data processing of Hopkinson bar point measurements combined to DIC (digital-imagecorrelation) measurements allows the stress and strain levels in the sample to be characterised. Finally these experimental results can be used to enhance the constitutive modelling of PRM materials

A testing technique to investigate the tensile behavior of propellant representative material

International audienc

Feasibility and postoperative opioid sparing effect of an opioid-free anaesthesia in adult cardiac surgery: a retrospective study

International audienceBackground: No previous study investigated the dexmedetomidine-based opioid-free anesthesia (OFA) protocol in cardiac surgery. The main objective of this study was to evaluate the feasibility and the postoperative opioid-sparing effect of dexmedetomidine-based OFA in adult cardiac surgery patients.Methods: We conducted a single-centre and retrospective study including 80 patients above 18 years old who underwent on-pump cardiac surgery between November 2018 and February 2020. Patients were divided into two groups: OFA (lidocaine, ketamine, dexmedetomidine, MgSO4) or opioid-based anaesthesia (remifentanil and anti-hyperalgesic medications such as ketamine and/or MgSO4 and/or lidocaine at the discretion of the anesthesiologist). The primary endpoint was the total amount of opioid consumed in its equivalent of intravenous morphine during the first 48 postoperative hours. Secondary outcomes included perioperative hemodynamics, post-operative maximal pain at rest and during coughing and adverse outcomes. Data are expressed as median [interquartile range].Results: Patients in the OFA-group had a higher EuroSCORE II, with more diabetes, more dyslipidemia and more non-elective surgery but fewer smoking history. In the OFA group, the median loading dose of dexmedetomidine was 0.6 [0.4-0.6] μg.kg- 1 while the median maintenance dose was 0.11 μg.kg- 1.h- 1 [0.05-0.20]. In 10 (25%) patients, dexmedetomidine was discontinued for a drop of mean arterial pressure below 55 mmHg. The median total amount of opioid consumed in its equivalent of intravenous morphine during the first 48 postoperative hours was lower in the OFA group (15.0 mg [8.5-23.5] versus 30.0 mg [17.3-44.3], p < 0.001). While no differences were seen with rest pain (2.0 [0.0-3.0] versus 0.5 [0.0-5.0], p = 0.60), the maximal pain score during coughing was lower in OFA group (3.5 [2.0-5.0] versus 5.5 [3.0-7.0], p = 0.04). In OFA group the incidence of atrial fibrillation (18% versus 40%, p = 0.03) and non-invasive ventilation use (25% versus 48%, p = 0.04) were lower. The incidence of bradycardia and the intraoperative use of norepinephrine were similar between both groups.Conclusion: Dexmedetomidine-based OFA in cardiac surgery patients is feasible and could be associated with a lower postoperative morphine consumption and better postoperative outcomes. Further randomized studies are required to confirm these promising results and determine the optimal associations, dosages, and infusion protocols during cardiac surgery

ASAIO J

Peripheral venoarterial extracorporeal membrane oxygenation (VA-ECMO) is increasingly being used in patients suffering from refractory cardiogenic shock (CS). Although considered life-saving, peripheral VA-ECMO may also be responsible for intracardiac hemodynamic changes, including left ventricular overload and dysfunction. Venoarterial extracorporeal membrane oxygenation may also increase myocardial wall stress and stroke work, possibly affecting the cellular cardioprotective and apoptosis signaling pathways, and thus the infarct size. To test this hypothesis, we investigated the effects of increasing the peripheral VA-ECMO blood flow (25-100% of the baseline cardiac output) on systemic and cardiac hemodynamics in a closed-chest CS model. Upon completion of the experiment, the hearts were removed for assessment of infarct size, histology, apoptosis measurements, and phosphorylation statuses of p38 and protein Kinase B (Akt), and extracellular signal-regulated kinase mitogen-activated protein kinases (ERK-MAPK). Peripheral VA-ECMO restored systemic perfusion but induced a significant and blood flow-dependent increase in left ventricular preload and afterload. Venoarterial extracorporeal membrane oxygenation did not affect infarct size but significantly decreased p38-MAPK phosphorylation and cardiac myocyte apoptosis in the border zone

Fixing method

A method for fixing a first surface to a second surface. The method comprises depositing a first layer of nanocellulose on the first surface; bringing the first layer of nanocellulose into contact with the second surface or with a second layer of nanocellulose deposited on the second surface; and fixing the first layer of nanocellulose to the second surface, the second surface containing cellulose, or to the second layer of nanocellulose by a step of ultrasonic welding, which results in a first zone comprising the first layer of nanocellulose, where the first surface is fixed to the second surface, and a second zone around the first zone, where the first surface is not fixed to the second surface