Currently,with the increasing tensionin doctor-patient relationship and medical disputes,it is of great practical importance to train medical students’communication skills in order to establisha harmonious doctor-pat...Currently,with the increasing tensionin doctor-patient relationship and medical disputes,it is of great practical importance to train medical students’communication skills in order to establisha harmonious doctor-patient relationship to improve the quality of clinical teaching.This paper emphasizes the importance of cultivation of communication skills in medical education and suggests ways to improve communication skills among medical students.展开更多
AIM： To clarify the prevalence of defensive medicine and the specific defensive medicine practices among gastroenterologists in Japan. METHODS： A survey of gastroenterologists in Hiroshima, Japan, was conducted by m...AIM： To clarify the prevalence of defensive medicine and the specific defensive medicine practices among gastroenterologists in Japan. METHODS： A survey of gastroenterologists in Hiroshima, Japan, was conducted by mail in March 2006. The number of gastroenterologists reporting defensive medicine behaviors or changes in their scope of practice and the reported defensive medicine practices, i.e., assurance and avoidance behaviors, were examined. RESULTS： A total of 131 （77%） out of 171 gastroenterologists completed the survey. Three （2%） respondents were sued, and most respondents （96%） had liability insurance. Nearly all respondents （98%） reported practicing defensive medicine. Avoidance behaviors, such as avoiding certain procedures or interventions and avoiding caring for high-risk patients, were very common （96%）. Seventy-five percent of respondents reported often avoiding certain procedures or interventions. However, seasoned gastroenterologists （those in practice for more than 20 years） adopted avoidance behaviors significantly less often than those in practice for less than 10 years. Assurance behaviors, i.e., supplying additional services of marginal or no medical value, were also widespread （91%）. Sixty-eight percent of respondents reported that they sometimes or often referred patients to other specialists unnecessarily. CONCLUSION： Defensive medicine may be highly prevalent among gastroenterologists throughout 3apan, with potentially serious implications regarding costs, access, and both technical and interpersonal quality of care.展开更多
AIM： To perform a long culture passage of H pylori without serum, taking into account its cytotoxicity and the presence of the probable new cytotoxic factor. METHODS： One sample of H pylon 60190 （ATCC 49503） was g...AIM： To perform a long culture passage of H pylori without serum, taking into account its cytotoxicity and the presence of the probable new cytotoxic factor. METHODS： One sample of H pylon 60190 （ATCC 49503） was grown on Brain Heart Infusion （BHI） agar containing 0.5% 2,6-di-O-methyl-β-cyclodextrin without any serum, being passaged 70-100 times every 3-4 d for approximately 2 h, while another sample of H pylori contained 70 mL/L fetal calf serum without 2,6-di-O- methyl-β-cyclodextrin. Their supernatant and extract after 16 h in culture were evaluated for changes in cell morphology and for cell viability using HeLa cells. Furthermore, the characteristics of the probable cytotoxic factor in the extract were examined on partial purification studies and its oytotoxicity was evaluated in various human cells. RESULTS： The supernatant and the extract of the bacterium grown on serum-free medium had strong cytotoxicity compared with those grown on serumcontaining medium. They irreversibly damaged HeLa cells without vacuolation that was altogether different from that of the bacterium when grown with serum. Their cytotoxicity was easily measured by cell viability assay. The probable cytotoxic factor partially purified and detected by chromatography had characteristics difference from that of vacuolating toxin and a broad cytotoxicity toward various cell lines. CONCLUSION： Serum-free long culture method of H pylorl makes its supernatant and its extract cytotoxic enough to be easily measured by cell viability assay. The probable cytotoxic factor has a unique characteristic and might be a new cytotoxin.展开更多
Medical models, or ＂phantoms,＂ have been widely used for medical training and for doctor-patient interactions. They are increasingly used for surgical planning, medical computational models, algorithm verification a...Medical models, or ＂phantoms,＂ have been widely used for medical training and for doctor-patient interactions. They are increasingly used for surgical planning, medical computational models, algorithm verification and validation, and medical devices development. Such new applications demand high-fidelity, patient-specific, tissue-mimicking medical phantoms that can not only closely emulate the geometric structures of human organs, but also possess the properties and functions of the organ structure. With the rapid advancement of three-dimensional （3D） printing and 3D bioprinting technologies, many researchers have explored the use of these additive manufacturing techniques to fabricate functional medical phantoms for various applications. This paper reviews the applications of these 3D printing and 3D bioprinting technologies for the fabrication of functional medical phantoms and bio-structures. This review specifically discusses the state of the art along with new developments and trends in 3D printed functional medical phantoms （i.e., tissue-mimicking medical phantoms, radiologically relevant medical phantoms, and physiological medical phantoms） and 3D bio-printed structures （i.e., hybrid scaffolding materials, convertible scaffolds, and integrated sensors） for regenerated tissues and organs.展开更多
Tumor markers have been of vital importance in cancer diagnosis, treatment and monitoring. However, the sensitivity of current tumor markers for early diagnosis is low, reducing the clinical usefulness of tumor marker...Tumor markers have been of vital importance in cancer diagnosis, treatment and monitoring. However, the sensitivity of current tumor markers for early diagnosis is low, reducing the clinical usefulness of tumor markers. Quantum dots are new fluorescent nanoparticles with unique photophysical and chemical properties, thus having a great potential impact on the investigation of cancer pathogenesis, early diagnosis, targeted therapy, prognosis and monitoring, when combined with tumor markers. The current research is focused on the detection of specific tumor markers or molecules based on tangible carriers such as ceils and tissues. One of the most promising clinical applications would be to explore the potential of this highly sensitive labeling technique for the detecting and imagining tumor markers in serum and other body fluids, where some progresses have already been made recently. How to detect early cancer based solely on invisible carders would be the next step of quantum dots bio-probes in clinical use, so as to develop a new detection technique with greater sensitivity, specificity, rapidity and availability.展开更多
The progress of tissue-engineering technology has realized development of new therapies to treat various disorders by using cultured cells. Cell-and tissue-based therapies have been successfully applied to human patie...The progress of tissue-engineering technology has realized development of new therapies to treat various disorders by using cultured cells. Cell-and tissue-based therapies have been successfully applied to human patients, and several tissue-engineered products have been approved by the regulatory agencies and are commercially available. In the review article, we describe our experience of development and clinical application of cell sheet-based regenerative medicine.Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) have been shown to be useful for removal of gastrointestinal neoplasms with less invasiveness compared with open surgery, especially in esophageal surgery. However, postoperative inflammation and stenosis are major complications observed after intensive mucosal resection. Therefore, we have developed novel regenerative medicine to prevent such complications and promote wound healing of esophageal mucosa after EMR or ESD. Transplantable oral mucosal epithelial cell sheets were fabricated from patients' own oral mucosa. Immediately after EMR or ESD, fabricated autologous cell sheets were endoscopically transplanted to the ulcer sites. We performed a preclinical study with a canine model. In human clinical settings, cell culture and cell sheet fabrication were performed in clean rooms according to good manufacturing practice guidelines, and pharmaceutical drugs were used as supplements to culture medium in place of research regents used in animal study. We believe that cell-based regenerative medicine would be useful to improve quality of life of patients after EMR or ESD.展开更多
In order to improve the corrosion resistance of the Mg alloys, the superhydrophobic coatings on AZ31 Mg alloy wereprepared by a two-step process of micro-arc oxidation treatment and superhydrophobic treatment in stear...In order to improve the corrosion resistance of the Mg alloys, the superhydrophobic coatings on AZ31 Mg alloy wereprepared by a two-step process of micro-arc oxidation treatment and superhydrophobic treatment in stearic acid ethanol solution. Theeffects of voltages, frequencies and treatment time on the contact angle of the superhydrophobic treated sample were investigated.The results showed that with increasing the voltage, frequency and treatment time, all of the contact angles of the superhydrophobictreated sample increased first, and then decreased, reaching the maximum values at 350 V, 1000 Hz and 5 min, respectively. Theoptimal superhydrophobic coating was mainly composed of MgO and Mg2SiO4 phases, with the pore diameter of ～900 nm, thethickness of ～6.86 μm and the contact angle of 156.96°. The corrosion current density of the superhydrophobic AZ31 sampledecreased by three orders of magnitude, and the amount of hydrogen evolution decreased by 94.77% compared with that of the AZ31substrate sample.展开更多
The aim of this work was to study the influence of the processing route on the microstructural constituents,hardness andtribological(wear and friction)behavior of Ti6Al4V biomedical alloy.In this sense,three different...The aim of this work was to study the influence of the processing route on the microstructural constituents,hardness andtribological(wear and friction)behavior of Ti6Al4V biomedical alloy.In this sense,three different processing routes were studied:conventional casting,hot pressing and selective laser melting.A comprehensive metallurgical,mechanical and tribologicalcharacterization was performed by X-ray diffraction analysis,Vickers hardness tests and reciprocating ball-on-plate wear tests ofTi6Al4V/Al2O3sliding pairs.The results showed a great influence of the processing route on the microstructural constituents andconsequent differences on hardness and wear performance.The highest hardness and wear resistance were obtained for Ti6Al4Valloy produced by selective laser melting,due to a markedly different cooling rate that leads to significantly different microstructurewhen compared to hot pressing and casting.This study assesses and confirms that selective laser melting is potential to producecustomized Ti6Al4V implants with improved wear performance.展开更多
A number of congenital and acquired disorders require esophageal tissue replacement.Various surgical techniques,such as gastric and colonic interposition,are standards of treatment,but frequently complicated by stenos...A number of congenital and acquired disorders require esophageal tissue replacement.Various surgical techniques,such as gastric and colonic interposition,are standards of treatment,but frequently complicated by stenosis and other problems.Regenerative medicine approaches facilitate the use of biological constructs to replace or regenerate normal tissue function.We review the literature of esophageal tissue engineering,discuss its implications,compare the methodologies that have been employed and suggest possible directions for the future.Medline,Embase,the Cochrane Library,National Research Register and ClinicalTrials.gov databases were searched with the following search terms:stem cell and esophagus,esophageal replacement,esophageal tissue engineering,esophageal substitution.Reference lists of papers identified were also examined and experts in this field contacted for further information.All full-text articles in English of all potentially relevant abstracts were reviewed.Tissue engineering has involved acellular scaffolds that were either transplanted with the aim of being repopulated by host cells or seeded prior to transplantation.When acellular scaffolds were used to replace patch and short tubular defects they allowed epithelial and partial muscular migration whereas when employed for long tubular defects the results were poor leading to an increased rate of stenosis and mortality.Stenting has been shown as an effective means to reduce stenotic changes and promote cell migration,whilst omental wrapping to induce vascularization of the construct has an uncertain benefit.Decellularized matrices have been recently suggested as the optimal choice for scaffolds,but smart polymers that will incorporate signalling to promote cell-scaffold interaction may provide a more reproducible and available solution.Results in animal models that have used seeded scaffolds strongly suggest that seeding of both muscle and epithelial cells on scaffolds prior to implantation is a prerequisite for complete esophageal replacement.Novel approaches need to be designed to allow for peristalsis and vascularization in the engineered esophagus.Although esophageal tissue engineering potentially offers a real alternative to conventional treatments for severe esophageal disease,important barriers remain that need to be addressed.展开更多
The increasing shortage of donors and the adverse effects of immunosuppression have restricted the impact of solid organ transplantation.Despite the initial promising developments in xenotransplantation,roadblocks sti...The increasing shortage of donors and the adverse effects of immunosuppression have restricted the impact of solid organ transplantation.Despite the initial promising developments in xenotransplantation,roadblocks still need to be overcome and this form of organ support remains a long way from clinical practice.While hepatocyte transplantation may be effectively correct metabolic defects,it is far less effective in restoring liver function than liver transplantation.Tissue engineering,using extracellular matrix scaffolds with an intact but decellularized vascular network that is repopulated with autologous or allogeneic stem cells and/or adult cells,holds great promise for the treatment of failure of organs within gastrointestinal tract,such as endstage liver disease,pancreatic insufficiency,bowel failure and type 1 diabetes.Particularly in the liver field,where there is a significant mortality of patients awaiting transplant,human bioengineering may offer a source of readily available organs for transplantation.The use of autologous cells will mitigate the need for long term immunosuppression thus removing a major hurdle in transplantation.展开更多
Cancer is a major threat to public health in the 21st century because it is one of the leading causes of death worldwide.The mechanisms of carcinogenesis,cancer invasion,and metastasis remain unclear.Thus,the developm...Cancer is a major threat to public health in the 21st century because it is one of the leading causes of death worldwide.The mechanisms of carcinogenesis,cancer invasion,and metastasis remain unclear.Thus,the development of a novel approach for cancer detection is urgent,and real-time monitoring is crucial in revealing its underlying biological mechanisms.With the optical and chemical advantages of quantum dots(QDs),QD-based nanotechnology is helpful in constructing a biomedical imaging platform for cancer behavior study.This review mainly focuses on the application of QD-based nanotechnology in cancer cell imaging and tumor microenvironment studies both in vivo and in vitro,as well as the remaining issues and future perspectives.展开更多
Rare-earth doped upconversion nanophosphors(UCNPs), which convert low energy near-infrared(NIR) photons into high energy photons such as ultraviolet, visible light and NIR light, have found various applications in opt...Rare-earth doped upconversion nanophosphors(UCNPs), which convert low energy near-infrared(NIR) photons into high energy photons such as ultraviolet, visible light and NIR light, have found various applications in optical bioimaging. In this review article, we summarize recent advances in the synthesis and applications of UCNPs achieved by us and other groups in the past few years. The approaches for the synthesis of UCNPs are presented,with an emphasis on the role of green chemistry in the advancement of this field, followed by a focused overview on their latest applications in optical bioimaging from subcellular structures through cells to living animals. Challenges and opportunities for the use of UCNPs in biomedical diagnosis and therapy are discussed.展开更多
Objectives:The study aimed to explore the experiences of nursing undergraduates participating in a simulation-centred educational program in hospice care in Macao,China.Methods:This descriptive qualitative study was b...Objectives:The study aimed to explore the experiences of nursing undergraduates participating in a simulation-centred educational program in hospice care in Macao,China.Methods:This descriptive qualitative study was based on the data collected through semi-structured individual interviews.Seventeen nursing undergraduates in Macao,China who attended the simulation-centred program in hospice care participated in this qualitative from November to December 2020.This program included three parts:introduction to hospice care(2 h),management of terminal symptoms(10 h),and hospice situation simulations(6 h).The interview data were analyzed using qualitative content analysis.Results:This study revealed two themes and six sub-themes.Theme 1 was developing competencies in caring for dying patients and their families,which included four subcategories of sensitivity to patients’needs,knowledge of hospice care,skills of symptom control and comfort supply,and communication skills.Theme 2 was improving the ability to self-care and support colleagues,which included two subcategories of reflection on life and death and sharing and supporting among colleagues.Conclusion:This program improved the competency of nursing undergraduates in hospice care and participants’learning experience was good.展开更多
In addition to squamous cell carcinoma,the incidence of Barrett's esophagus with high-grade dysplasia and esophageal adenocarcinoma is rapidly increasing worldwide.Unfortunately,the current standard of care for es...In addition to squamous cell carcinoma,the incidence of Barrett's esophagus with high-grade dysplasia and esophageal adenocarcinoma is rapidly increasing worldwide.Unfortunately,the current standard of care for esophageal pathology involves resection of the affected tissue,sometimes involving radical esophagectomy.Without exception,these procedures are associated with a high morbidity,compromised quality of life,and unacceptable mortality rates.Regenerative medicine approaches to functional tissue replacement include the use of biological and synthetic scaffolds to promote tissue remodeling and growth.In the case of esophageal repair,extracellular matrix(ECM) scaffolds have proven to be effective for the reconstruction of small patch defects,anastomosis reinforcement,and the prevention of stricture formation after endomucosal resection(EMR).More so,esophageal cancer patients treated with ECM scaffolds have shown complete restoration of a normal,functional,and disease-free epithelium after EMR.These studies provide evidence that a regenerative medicine approach may enable aggressive resection of neoplastic tissue without the need for radical esophagectomy and its associated complications.展开更多
文摘Currently,with the increasing tensionin doctor-patient relationship and medical disputes,it is of great practical importance to train medical students’communication skills in order to establisha harmonious doctor-patient relationship to improve the quality of clinical teaching.This paper emphasizes the importance of cultivation of communication skills in medical education and suggests ways to improve communication skills among medical students.
文摘AIM： To clarify the prevalence of defensive medicine and the specific defensive medicine practices among gastroenterologists in Japan. METHODS： A survey of gastroenterologists in Hiroshima, Japan, was conducted by mail in March 2006. The number of gastroenterologists reporting defensive medicine behaviors or changes in their scope of practice and the reported defensive medicine practices, i.e., assurance and avoidance behaviors, were examined. RESULTS： A total of 131 （77%） out of 171 gastroenterologists completed the survey. Three （2%） respondents were sued, and most respondents （96%） had liability insurance. Nearly all respondents （98%） reported practicing defensive medicine. Avoidance behaviors, such as avoiding certain procedures or interventions and avoiding caring for high-risk patients, were very common （96%）. Seventy-five percent of respondents reported often avoiding certain procedures or interventions. However, seasoned gastroenterologists （those in practice for more than 20 years） adopted avoidance behaviors significantly less often than those in practice for less than 10 years. Assurance behaviors, i.e., supplying additional services of marginal or no medical value, were also widespread （91%）. Sixty-eight percent of respondents reported that they sometimes or often referred patients to other specialists unnecessarily. CONCLUSION： Defensive medicine may be highly prevalent among gastroenterologists throughout 3apan, with potentially serious implications regarding costs, access, and both technical and interpersonal quality of care.
文摘AIM： To perform a long culture passage of H pylori without serum, taking into account its cytotoxicity and the presence of the probable new cytotoxic factor. METHODS： One sample of H pylon 60190 （ATCC 49503） was grown on Brain Heart Infusion （BHI） agar containing 0.5% 2,6-di-O-methyl-β-cyclodextrin without any serum, being passaged 70-100 times every 3-4 d for approximately 2 h, while another sample of H pylori contained 70 mL/L fetal calf serum without 2,6-di-O- methyl-β-cyclodextrin. Their supernatant and extract after 16 h in culture were evaluated for changes in cell morphology and for cell viability using HeLa cells. Furthermore, the characteristics of the probable cytotoxic factor in the extract were examined on partial purification studies and its oytotoxicity was evaluated in various human cells. RESULTS： The supernatant and the extract of the bacterium grown on serum-free medium had strong cytotoxicity compared with those grown on serumcontaining medium. They irreversibly damaged HeLa cells without vacuolation that was altogether different from that of the bacterium when grown with serum. Their cytotoxicity was easily measured by cell viability assay. The probable cytotoxic factor partially purified and detected by chromatography had characteristics difference from that of vacuolating toxin and a broad cytotoxicity toward various cell lines. CONCLUSION： Serum-free long culture method of H pylorl makes its supernatant and its extract cytotoxic enough to be easily measured by cell viability assay. The probable cytotoxic factor has a unique characteristic and might be a new cytotoxin.
文摘Medical models, or ＂phantoms,＂ have been widely used for medical training and for doctor-patient interactions. They are increasingly used for surgical planning, medical computational models, algorithm verification and validation, and medical devices development. Such new applications demand high-fidelity, patient-specific, tissue-mimicking medical phantoms that can not only closely emulate the geometric structures of human organs, but also possess the properties and functions of the organ structure. With the rapid advancement of three-dimensional （3D） printing and 3D bioprinting technologies, many researchers have explored the use of these additive manufacturing techniques to fabricate functional medical phantoms for various applications. This paper reviews the applications of these 3D printing and 3D bioprinting technologies for the fabrication of functional medical phantoms and bio-structures. This review specifically discusses the state of the art along with new developments and trends in 3D printed functional medical phantoms （i.e., tissue-mimicking medical phantoms, radiologically relevant medical phantoms, and physiological medical phantoms） and 3D bio-printed structures （i.e., hybrid scaffolding materials, convertible scaffolds, and integrated sensors） for regenerated tissues and organs.
基金the grants from the New-Century Excellent Talents Sup-porting Program of the Ministry of Education of China (No. NCET-04-0669)the Foundation for the Author of National Excellent Doctoral Dis-sertation of China (No. 200464)+2 种基金the Wuhan Innovation Study Project (No. 20066002054)the Natural Science Foundation of China (No. 20675058)the Science Fund for Creative Research Groups (No. 20621502), NSFC.
文摘Tumor markers have been of vital importance in cancer diagnosis, treatment and monitoring. However, the sensitivity of current tumor markers for early diagnosis is low, reducing the clinical usefulness of tumor markers. Quantum dots are new fluorescent nanoparticles with unique photophysical and chemical properties, thus having a great potential impact on the investigation of cancer pathogenesis, early diagnosis, targeted therapy, prognosis and monitoring, when combined with tumor markers. The current research is focused on the detection of specific tumor markers or molecules based on tangible carriers such as ceils and tissues. One of the most promising clinical applications would be to explore the potential of this highly sensitive labeling technique for the detecting and imagining tumor markers in serum and other body fluids, where some progresses have already been made recently. How to detect early cancer based solely on invisible carders would be the next step of quantum dots bio-probes in clinical use, so as to develop a new detection technique with greater sensitivity, specificity, rapidity and availability.
基金Supported by The Formation of Innovation Center for Fusion of Advanced Technologies in the Special Coordination Funds for Promoting ScienceTechnology from the Ministry of Education, Culture, Sports, Science, and Technology, Japan
文摘The progress of tissue-engineering technology has realized development of new therapies to treat various disorders by using cultured cells. Cell-and tissue-based therapies have been successfully applied to human patients, and several tissue-engineered products have been approved by the regulatory agencies and are commercially available. In the review article, we describe our experience of development and clinical application of cell sheet-based regenerative medicine.Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) have been shown to be useful for removal of gastrointestinal neoplasms with less invasiveness compared with open surgery, especially in esophageal surgery. However, postoperative inflammation and stenosis are major complications observed after intensive mucosal resection. Therefore, we have developed novel regenerative medicine to prevent such complications and promote wound healing of esophageal mucosa after EMR or ESD. Transplantable oral mucosal epithelial cell sheets were fabricated from patients' own oral mucosa. Immediately after EMR or ESD, fabricated autologous cell sheets were endoscopically transplanted to the ulcer sites. We performed a preclinical study with a canine model. In human clinical settings, cell culture and cell sheet fabrication were performed in clean rooms according to good manufacturing practice guidelines, and pharmaceutical drugs were used as supplements to culture medium in place of research regents used in animal study. We believe that cell-based regenerative medicine would be useful to improve quality of life of patients after EMR or ESD.
基金Project(51101085)supported by the National Natural Science Foundation of ChinaProject(2016BAB206109)supported by the Natural Science Foundation of Jiangxi Province,China+6 种基金Project(BK20151291)supported by the Natural Science Foundation of Jiangsu Province,ChinaProject(BRA2015377)supported by the 333 Project of Jiangsu Province,ChinaProject(20151BBG70039)supported by the Science and Technology Support Plan of Jiangxi Province,ChinaProject(GJJ150721)supported by the Science and Technology Project of Jiangxi Province Education Department,ChinaProject(HAG201601)supported by the Foundation of Huaian Science and Technology,ChinaProject(HAC2015026)supported by the Huaian International Cooperation Program,ChinaProject(jr1416)supported by the Foundation of Jiangsu Provincial Key Laboratory for Interventional Medical Devices,China
文摘In order to improve the corrosion resistance of the Mg alloys, the superhydrophobic coatings on AZ31 Mg alloy wereprepared by a two-step process of micro-arc oxidation treatment and superhydrophobic treatment in stearic acid ethanol solution. Theeffects of voltages, frequencies and treatment time on the contact angle of the superhydrophobic treated sample were investigated.The results showed that with increasing the voltage, frequency and treatment time, all of the contact angles of the superhydrophobictreated sample increased first, and then decreased, reaching the maximum values at 350 V, 1000 Hz and 5 min, respectively. Theoptimal superhydrophobic coating was mainly composed of MgO and Mg2SiO4 phases, with the pore diameter of ～900 nm, thethickness of ～6.86 μm and the contact angle of 156.96°. The corrosion current density of the superhydrophobic AZ31 sampledecreased by three orders of magnitude, and the amount of hydrogen evolution decreased by 94.77% compared with that of the AZ31substrate sample.
基金supported by FTC through the projects PTDC/EMS-TEC/5422/2014 and EXCL/EMS-TEC/ 0460/2012the grant SFRH/BPD/112111/2015+1 种基金supported by FCT with the reference project UID/EEA/04436/2013by FEDER funds through the COMPETE 2020-Programa Operacional Competitividade e Internacionalizacao (POCI) with the reference project POCI-01-0145FEDER-006941.
文摘The aim of this work was to study the influence of the processing route on the microstructural constituents,hardness andtribological(wear and friction)behavior of Ti6Al4V biomedical alloy.In this sense,three different processing routes were studied:conventional casting,hot pressing and selective laser melting.A comprehensive metallurgical,mechanical and tribologicalcharacterization was performed by X-ray diffraction analysis,Vickers hardness tests and reciprocating ball-on-plate wear tests ofTi6Al4V/Al2O3sliding pairs.The results showed a great influence of the processing route on the microstructural constituents andconsequent differences on hardness and wear performance.The highest hardness and wear resistance were obtained for Ti6Al4Valloy produced by selective laser melting,due to a markedly different cooling rate that leads to significantly different microstructurewhen compared to hot pressing and casting.This study assesses and confirms that selective laser melting is potential to producecustomized Ti6Al4V implants with improved wear performance.
文摘A number of congenital and acquired disorders require esophageal tissue replacement.Various surgical techniques,such as gastric and colonic interposition,are standards of treatment,but frequently complicated by stenosis and other problems.Regenerative medicine approaches facilitate the use of biological constructs to replace or regenerate normal tissue function.We review the literature of esophageal tissue engineering,discuss its implications,compare the methodologies that have been employed and suggest possible directions for the future.Medline,Embase,the Cochrane Library,National Research Register and ClinicalTrials.gov databases were searched with the following search terms:stem cell and esophagus,esophageal replacement,esophageal tissue engineering,esophageal substitution.Reference lists of papers identified were also examined and experts in this field contacted for further information.All full-text articles in English of all potentially relevant abstracts were reviewed.Tissue engineering has involved acellular scaffolds that were either transplanted with the aim of being repopulated by host cells or seeded prior to transplantation.When acellular scaffolds were used to replace patch and short tubular defects they allowed epithelial and partial muscular migration whereas when employed for long tubular defects the results were poor leading to an increased rate of stenosis and mortality.Stenting has been shown as an effective means to reduce stenotic changes and promote cell migration,whilst omental wrapping to induce vascularization of the construct has an uncertain benefit.Decellularized matrices have been recently suggested as the optimal choice for scaffolds,but smart polymers that will incorporate signalling to promote cell-scaffold interaction may provide a more reproducible and available solution.Results in animal models that have used seeded scaffolds strongly suggest that seeding of both muscle and epithelial cells on scaffolds prior to implantation is a prerequisite for complete esophageal replacement.Novel approaches need to be designed to allow for peristalsis and vascularization in the engineered esophagus.Although esophageal tissue engineering potentially offers a real alternative to conventional treatments for severe esophageal disease,important barriers remain that need to be addressed.
文摘The increasing shortage of donors and the adverse effects of immunosuppression have restricted the impact of solid organ transplantation.Despite the initial promising developments in xenotransplantation,roadblocks still need to be overcome and this form of organ support remains a long way from clinical practice.While hepatocyte transplantation may be effectively correct metabolic defects,it is far less effective in restoring liver function than liver transplantation.Tissue engineering,using extracellular matrix scaffolds with an intact but decellularized vascular network that is repopulated with autologous or allogeneic stem cells and/or adult cells,holds great promise for the treatment of failure of organs within gastrointestinal tract,such as endstage liver disease,pancreatic insufficiency,bowel failure and type 1 diabetes.Particularly in the liver field,where there is a significant mortality of patients awaiting transplant,human bioengineering may offer a source of readily available organs for transplantation.The use of autologous cells will mitigate the need for long term immunosuppression thus removing a major hurdle in transplantation.
基金supported by the Academic Award for Excellent Ph.D.Candidates Funded by the Ministry of Education of China(No.5052011303014)the National Natural Science Foundation of China(No.81171396)+1 种基金the Science Fund for Creative Research Groups of the National Natural Science Foundation of China(Nos.20621502 and 20921062)the Fundamental Research Funds for the Central Universities of Ministry of Education of China(No.4103005).
文摘Cancer is a major threat to public health in the 21st century because it is one of the leading causes of death worldwide.The mechanisms of carcinogenesis,cancer invasion,and metastasis remain unclear.Thus,the development of a novel approach for cancer detection is urgent,and real-time monitoring is crucial in revealing its underlying biological mechanisms.With the optical and chemical advantages of quantum dots(QDs),QD-based nanotechnology is helpful in constructing a biomedical imaging platform for cancer behavior study.This review mainly focuses on the application of QD-based nanotechnology in cancer cell imaging and tumor microenvironment studies both in vivo and in vitro,as well as the remaining issues and future perspectives.
基金Supported by the National Key Research and Development Program of China(2016YFA0201701/2016YFA0201700)the Beijing Natural Science Foundation(2182051)+2 种基金the National Natural Science Foundation of China(21622601)the Fundamental Research Funds for the Central Universities of China(BUCTRC201601)the "111" project of China(B14004)
文摘Rare-earth doped upconversion nanophosphors(UCNPs), which convert low energy near-infrared(NIR) photons into high energy photons such as ultraviolet, visible light and NIR light, have found various applications in optical bioimaging. In this review article, we summarize recent advances in the synthesis and applications of UCNPs achieved by us and other groups in the past few years. The approaches for the synthesis of UCNPs are presented,with an emphasis on the role of green chemistry in the advancement of this field, followed by a focused overview on their latest applications in optical bioimaging from subcellular structures through cells to living animals. Challenges and opportunities for the use of UCNPs in biomedical diagnosis and therapy are discussed.
基金This research received the sponsor from the Academic Research Funding of Macao Polytechnic University(No.RP/ESS 02/2018).
文摘Objectives:The study aimed to explore the experiences of nursing undergraduates participating in a simulation-centred educational program in hospice care in Macao,China.Methods:This descriptive qualitative study was based on the data collected through semi-structured individual interviews.Seventeen nursing undergraduates in Macao,China who attended the simulation-centred program in hospice care participated in this qualitative from November to December 2020.This program included three parts:introduction to hospice care(2 h),management of terminal symptoms(10 h),and hospice situation simulations(6 h).The interview data were analyzed using qualitative content analysis.Results:This study revealed two themes and six sub-themes.Theme 1 was developing competencies in caring for dying patients and their families,which included four subcategories of sensitivity to patients’needs,knowledge of hospice care,skills of symptom control and comfort supply,and communication skills.Theme 2 was improving the ability to self-care and support colleagues,which included two subcategories of reflection on life and death and sharing and supporting among colleagues.Conclusion:This program improved the competency of nursing undergraduates in hospice care and participants’learning experience was good.
基金Supported by Award Number T32EBO01026-08,from the National Institute of Biomedical Imaging and Bioengineering, in part
文摘In addition to squamous cell carcinoma,the incidence of Barrett's esophagus with high-grade dysplasia and esophageal adenocarcinoma is rapidly increasing worldwide.Unfortunately,the current standard of care for esophageal pathology involves resection of the affected tissue,sometimes involving radical esophagectomy.Without exception,these procedures are associated with a high morbidity,compromised quality of life,and unacceptable mortality rates.Regenerative medicine approaches to functional tissue replacement include the use of biological and synthetic scaffolds to promote tissue remodeling and growth.In the case of esophageal repair,extracellular matrix(ECM) scaffolds have proven to be effective for the reconstruction of small patch defects,anastomosis reinforcement,and the prevention of stricture formation after endomucosal resection(EMR).More so,esophageal cancer patients treated with ECM scaffolds have shown complete restoration of a normal,functional,and disease-free epithelium after EMR.These studies provide evidence that a regenerative medicine approach may enable aggressive resection of neoplastic tissue without the need for radical esophagectomy and its associated complications.
