As one kind of key components with enormous quantities and diversities, the bent tube parts satisfy the increasing needs for lightweight and high-strength product from both materials and structure aspects. The bent tu...As one kind of key components with enormous quantities and diversities, the bent tube parts satisfy the increasing needs for lightweight and high-strength product from both materials and structure aspects. The bent tubes have been widely used in many high-end industries such as aviation, aerospace, shipbuilding, automobile, energy and health care. The tube bending has become one of the key manufacturing technologies for lightweight product forming. Via the analysis of bending characteristics and multiple defects, advances on exploring the common issues in tube bending are summarized regarding wrinkling instability at the intrados, wall thinning （cracking） at the extrados, springback phenomenon, cross-section deformation, forming limit and process/ tooling design/optimization. Some currently developed bending techniques are reviewed in terms of their advantages and limitations. Finally, in view of the urgent requirements of high-performance complex bent tube components with difficult-todeform and lightweight materials in aviation and aerospace fields, the development trends and corresponding challenges are presented for realizing the precise and high-efficiency tube bending deformation.展开更多
Gastroenteric tube feeding plays a major role in the management of patients with poor voluntary intake,chronic neurological or mechanical dysphagia or gut dysfunction,and patients who are critically ill.However,despit...Gastroenteric tube feeding plays a major role in the management of patients with poor voluntary intake,chronic neurological or mechanical dysphagia or gut dysfunction,and patients who are critically ill.However,despite the benefits and widespread use of enteral tube feeding,some patients experience complications.This review aims to discuss and compare current knowledge regarding the clinical application of enteral tube feeding,together with associated complications and special aspects.We conducted an extensive literature search on PubMed,Embase and Medline using index terms relating to enteral access,enteral feeding/nutrition,tube feeding,percutaneous endoscopic gastrostomy/jejunostomy,endoscopic nasoenteric tube,nasogastric tube,and refeeding syndrome.The literature showed common routes of enteral access to include nasoenteral tube,gastrostomy and jejunostomy,while complications fall into four major categories:mechanical,e.g.,tube blockage or removal;gastrointestinal,e.g.,diarrhea;infectious e.g.,aspiration pneumonia,tube site infection;and metabolic,e.g.,refeeding syndrome,hyperglycemia.Although the type and frequency of complications arising from tube feeding vary considerably according to the chosen access route,gastrointestinal complications are without doubt the most common.Complications associated with enteral tube feeding can be reduced by careful observance of guidelines,including those related to food composition,administration rate,portion size,food temperature and patient supervision.展开更多
Percutaneous endoscopic gastrostomy (PEG) is the preferred route of feeding and nutritional support in patients with a functional gastrointestinal system who require long-term enteral nutrition. Besides its well-known...Percutaneous endoscopic gastrostomy (PEG) is the preferred route of feeding and nutritional support in patients with a functional gastrointestinal system who require long-term enteral nutrition. Besides its well-known advantages over parenteral nutrition, PEG offers superior access to the gastrointestinal system over surgical methods. Considering that nowadays PEG tube placement is one of the most common endoscopic procedures performed worldwide, knowing its indications and contraindications is of paramount importance in current medicine. PEG tubes are sometimes placed inappropriately in patients unable to tolerate adequate oral intake because of incorrect and unrealistic understanding of their indications and what they can accomplish. Broadly, the two main indications of PEG tube placement are enteral feeding and stomach decompression. On the other hand, distal enteral obstruction, severe uncorrectable coagulopathy and hemodynamic instability constitute the main absolute contraindications for PEG tube placement in hospitalized patients. Although generally considered to be a safe procedure, there is the potential for both minor and major complications. Awareness of these potential complications, as well as understanding routine aftercare of the catheter, can improve the quality of care for patients with a PEG tube. These complications can generally be classified into three major categories: endoscopic technical difficulties, PEG procedure-related complications and late complications associated with PEG tube use and wound care. In this review we describe a variety of minor and major tube-related complications as well as strategies for their management and avoidance. Different methods of percutaneous PEG tube placement into the stomach have been described in the literature with the “pull” technique being the most common method. In the last section of this review, the reader is presented with a brief discussion of these procedures, techniques and related issues. Despite the mentioned PEG tube placeme展开更多
Bis-3-(triethoxysilyl)propyltetrasulfide(BTESPT) silane-rare earth cerium composite coatings on aluminum-tube were prepared at 60 °C by immersion method.The performance of composite coatings to protect the alumin...Bis-3-(triethoxysilyl)propyltetrasulfide(BTESPT) silane-rare earth cerium composite coatings on aluminum-tube were prepared at 60 °C by immersion method.The performance of composite coatings to protect the aluminum-tube against corrosion was investigated with potentiodynamic polarization curves,electrochemical impedance spectroscopy(EIS),and salt spray test(SST).The results of potentiodynamic polarization curves and EIS indicated that the self-corrosion current decreased by two orders of magnitude and the i...展开更多
基金Foundation items： National Natural Science Foundation of China （50905144） State Key Laboratory of Materials Processing and Die ＆ Mould Technology, Huazhong University of Science and Technology （09-10）+2 种基金 NPU Foundation for Fundamental Research （JC201028） Fund of the State Key Laboratory of Solidification Processing in NWPU, Natural Science Basic Research Plan in Shaanxi Province （2011JQ6004） ＂111＂ Project （B08040）
文摘As one kind of key components with enormous quantities and diversities, the bent tube parts satisfy the increasing needs for lightweight and high-strength product from both materials and structure aspects. The bent tubes have been widely used in many high-end industries such as aviation, aerospace, shipbuilding, automobile, energy and health care. The tube bending has become one of the key manufacturing technologies for lightweight product forming. Via the analysis of bending characteristics and multiple defects, advances on exploring the common issues in tube bending are summarized regarding wrinkling instability at the intrados, wall thinning （cracking） at the extrados, springback phenomenon, cross-section deformation, forming limit and process/ tooling design/optimization. Some currently developed bending techniques are reviewed in terms of their advantages and limitations. Finally, in view of the urgent requirements of high-performance complex bent tube components with difficult-todeform and lightweight materials in aviation and aerospace fields, the development trends and corresponding challenges are presented for realizing the precise and high-efficiency tube bending deformation.
文摘Gastroenteric tube feeding plays a major role in the management of patients with poor voluntary intake,chronic neurological or mechanical dysphagia or gut dysfunction,and patients who are critically ill.However,despite the benefits and widespread use of enteral tube feeding,some patients experience complications.This review aims to discuss and compare current knowledge regarding the clinical application of enteral tube feeding,together with associated complications and special aspects.We conducted an extensive literature search on PubMed,Embase and Medline using index terms relating to enteral access,enteral feeding/nutrition,tube feeding,percutaneous endoscopic gastrostomy/jejunostomy,endoscopic nasoenteric tube,nasogastric tube,and refeeding syndrome.The literature showed common routes of enteral access to include nasoenteral tube,gastrostomy and jejunostomy,while complications fall into four major categories:mechanical,e.g.,tube blockage or removal;gastrointestinal,e.g.,diarrhea;infectious e.g.,aspiration pneumonia,tube site infection;and metabolic,e.g.,refeeding syndrome,hyperglycemia.Although the type and frequency of complications arising from tube feeding vary considerably according to the chosen access route,gastrointestinal complications are without doubt the most common.Complications associated with enteral tube feeding can be reduced by careful observance of guidelines,including those related to food composition,administration rate,portion size,food temperature and patient supervision.
文摘Percutaneous endoscopic gastrostomy (PEG) is the preferred route of feeding and nutritional support in patients with a functional gastrointestinal system who require long-term enteral nutrition. Besides its well-known advantages over parenteral nutrition, PEG offers superior access to the gastrointestinal system over surgical methods. Considering that nowadays PEG tube placement is one of the most common endoscopic procedures performed worldwide, knowing its indications and contraindications is of paramount importance in current medicine. PEG tubes are sometimes placed inappropriately in patients unable to tolerate adequate oral intake because of incorrect and unrealistic understanding of their indications and what they can accomplish. Broadly, the two main indications of PEG tube placement are enteral feeding and stomach decompression. On the other hand, distal enteral obstruction, severe uncorrectable coagulopathy and hemodynamic instability constitute the main absolute contraindications for PEG tube placement in hospitalized patients. Although generally considered to be a safe procedure, there is the potential for both minor and major complications. Awareness of these potential complications, as well as understanding routine aftercare of the catheter, can improve the quality of care for patients with a PEG tube. These complications can generally be classified into three major categories: endoscopic technical difficulties, PEG procedure-related complications and late complications associated with PEG tube use and wound care. In this review we describe a variety of minor and major tube-related complications as well as strategies for their management and avoidance. Different methods of percutaneous PEG tube placement into the stomach have been described in the literature with the “pull” technique being the most common method. In the last section of this review, the reader is presented with a brief discussion of these procedures, techniques and related issues. Despite the mentioned PEG tube placeme
基金supported by the Provincial Natural Science Foundation of Hunan Province (04JJ30817)
文摘Bis-3-(triethoxysilyl)propyltetrasulfide(BTESPT) silane-rare earth cerium composite coatings on aluminum-tube were prepared at 60 °C by immersion method.The performance of composite coatings to protect the aluminum-tube against corrosion was investigated with potentiodynamic polarization curves,electrochemical impedance spectroscopy(EIS),and salt spray test(SST).The results of potentiodynamic polarization curves and EIS indicated that the self-corrosion current decreased by two orders of magnitude and the i...
