Medical devices are instruments and other tools that act on the human body to aid clinical diagnosis and disease treatment,playing an indispensable role in modern medicine.Nowadays,the increasing demand for personaliz...Medical devices are instruments and other tools that act on the human body to aid clinical diagnosis and disease treatment,playing an indispensable role in modern medicine.Nowadays,the increasing demand for personalized medical devices poses a significant challenge to traditional manufacturing methods.The emerging manufacturing technology of three-dimensional(3D)printing as an alternative has shown exciting applications in the medical field and is an ideal method for manufacturing such personalized medical devices with complex structures.However,the application of this new technology has also brought new risks to medical devices,making 3D-printed devices face severe challenges due to insufficient regulation and the lack of standards to provide guidance to the industry.This review aims to summarize the current regulatory landscape and existing research on the standardization of 3D-printed medical devices in China,and provide ideas to address these challenges.We focus on the aspects concerned by the regulatory authorities in 3D-printed medical devices,highlighting the quality system of such devices,and discuss the guidelines that manufacturers should follow,as well as the current limitations and the feasible path of regulation and standardization work based on this perspective.The key points of the whole process quality control,performance evaluation methods and the concept of whole life cycle management of 3D-printed medical devices are emphasized.Furthermore,the significance of regulation and standardization is pointed out.Finally,aspects worthy of attention and future perspectives in this field are discussed.展开更多
On the basis of expounding the corrosion mechanism of the stator hollow copper conductor in the water-cooling generator, methods of preventing corrosion of the stator hollow copper conductor in the wa-ter-cooling gene...On the basis of expounding the corrosion mechanism of the stator hollow copper conductor in the water-cooling generator, methods of preventing corrosion of the stator hollow copper conductor in the wa-ter-cooling generator through adjusting water quality of its cooling water have been proposed. For internal water cooling systems which are airtight, the corrosion of the hollow copper conductor can be prevented through keeping foreign oxygen and carbon dioxide from entering the system, and the amount of oxygen in the internal water can be lowered by blowing high purity nitrogen. For systems not airtight, the corrosion of the hollow copper conductor can be inhibited through lowering the amount of oxygen to some extent by sealing and increasing pH value by processing part of cooling water with bypass small flow sodium-type mix-bed.展开更多
The Venusian dayside ionosphere, similar to other planetary ionospheres, is produced primarily by ionization of its neutral upper atmosphere due to solar extreme ultraviolet (EUV) radiation. It has become clear that t...The Venusian dayside ionosphere, similar to other planetary ionospheres, is produced primarily by ionization of its neutral upper atmosphere due to solar extreme ultraviolet (EUV) radiation. It has become clear that the expansion of the ionosphere may be strongly controlled by the EUV level, as exhibited in data collected by the Pioneer Venus Orbiter (PVO) during one solar cycle (1978 1992). However, the EUV-dependence of the Venusian dayside ionopause altitude, which defines the outer boundary of the ionosphere, remains obscure because the PVO crossed the dayside ionopause only during the solar maximum;its periapsis lifted too high during the solar minimum. Recently, during the period 2006 2014, which included the longest and quietest solar minimum of the past several decades, Venus Express (VEX) provided measurements of the photoelectron boundary (PEB) over the northern high-latitude region. Since the photoelectron boundary is closely related to the ionopause, we have an opportunity to analyze the EUV effect on the dayside ionopause by combining PVO and VEX observations. We have evaluated and then reduced the orbit bias effect in data from both PVO and VEX, and then used the results to derive a relationship between solar EUV level and the dayside ionopause altitude. We find that the dayside ionopause altitude increases as the solar EUV level increases, which is consistent with theoretical expectations.展开更多
With the interdisciplinary convergence of biology,medicine and materials science,both research and clinical translation of biomaterials are progressing at a rapid pace.However,there is still a huge gap between applied...With the interdisciplinary convergence of biology,medicine and materials science,both research and clinical translation of biomaterials are progressing at a rapid pace.However,there is still a huge gap between applied basic research on biomaterials and their translational products-medical devices,where two significantly different perspectives and mindsets often work independently and non-synergistically,which in turn significantly increases financial costs and research effort.Although this gap is well-known and often criticized in the biopharmaceutical industry,it is gradually widening.In this article,we critically examine the developmental pipeline of biodegradable biomaterials and biomaterial-based medical device products.Then based on clinical needs,market analysis,and relevant regulations,some ideas are proposed to integrate the two different mindsets to guide applied basic research and translation of biomaterial-based products,from the material and technical perspectives.Cartilage repair substitutes are discussed here as an example.Hopefully,this will lay a strong foundation for biomaterial research and clinical translation,while reducing the amount of extra research effort and funding required due to the dissonance between innovative basic research and commercialization pipeline.展开更多
Bone morphogenetic protein(BMP),belongs to transforming growth factor-b(TGF-b)superfamily except BMP-1.Implanting BMP into muscular tissues induces ectopic bone formation at the site of implantation,which provides opp...Bone morphogenetic protein(BMP),belongs to transforming growth factor-b(TGF-b)superfamily except BMP-1.Implanting BMP into muscular tissues induces ectopic bone formation at the site of implantation,which provides opportunity for the treatment of bone defects.Recombinant human BMP-2(rhBMP-2)has been used clinically,but the lack of standard methods for quantifying rhBMP-2 biological activity greatly hindered the progress of commercialization.In this article,we describe an in vitro rhBMP-2 quantification method,as well as the data analyzation pipeline through logistic regression in RStudio.Previous studies indicated that alkaline phosphatase(ALP)activity of C2C12 cells was significantly increased when exposed to rhBMP-2,and showed dose-dependent effects in a certain concentration range of rhBMP-2.Thus,we chose to quantify ALP activity as an indicator of rhBMP-2 bioactivity in vitro.A sigmoid relationship between the ALP activity and concentration of rhBMP-2 was discovered.However,there are tons of regression models for such a non-linear relationship.It has always been a major concern for researchers to choose a proper model that not only fit data accurately,but also have parameters representing practical meanings.Therefore,to fit our rhBMP-2 quantification data,we applied two logistic regression models,three-parameter log-logistic model and four-parameter log-logistic model.The four-parameter log-logistic model(adj-R2>0.98)fits better than three-parameter log-logistic model(adj-R2>0.75)for the sigmoid curves.Overall,our results indicate rhBMP-2 quantification in vitro can be accomplished by detecting ALP activity and fitting four-parameter log-logistic model.Furthermore,we also provide a highly adaptable R script for any additional logistic models.展开更多
基金the National Natural Science Foundation of China(No.81827804,U1909218)the Science Fund for Creative Research Groups of the National Natural Science Foundation of China(No.T2121004).
文摘Medical devices are instruments and other tools that act on the human body to aid clinical diagnosis and disease treatment,playing an indispensable role in modern medicine.Nowadays,the increasing demand for personalized medical devices poses a significant challenge to traditional manufacturing methods.The emerging manufacturing technology of three-dimensional(3D)printing as an alternative has shown exciting applications in the medical field and is an ideal method for manufacturing such personalized medical devices with complex structures.However,the application of this new technology has also brought new risks to medical devices,making 3D-printed devices face severe challenges due to insufficient regulation and the lack of standards to provide guidance to the industry.This review aims to summarize the current regulatory landscape and existing research on the standardization of 3D-printed medical devices in China,and provide ideas to address these challenges.We focus on the aspects concerned by the regulatory authorities in 3D-printed medical devices,highlighting the quality system of such devices,and discuss the guidelines that manufacturers should follow,as well as the current limitations and the feasible path of regulation and standardization work based on this perspective.The key points of the whole process quality control,performance evaluation methods and the concept of whole life cycle management of 3D-printed medical devices are emphasized.Furthermore,the significance of regulation and standardization is pointed out.Finally,aspects worthy of attention and future perspectives in this field are discussed.
文摘On the basis of expounding the corrosion mechanism of the stator hollow copper conductor in the water-cooling generator, methods of preventing corrosion of the stator hollow copper conductor in the wa-ter-cooling generator through adjusting water quality of its cooling water have been proposed. For internal water cooling systems which are airtight, the corrosion of the hollow copper conductor can be prevented through keeping foreign oxygen and carbon dioxide from entering the system, and the amount of oxygen in the internal water can be lowered by blowing high purity nitrogen. For systems not airtight, the corrosion of the hollow copper conductor can be inhibited through lowering the amount of oxygen to some extent by sealing and increasing pH value by processing part of cooling water with bypass small flow sodium-type mix-bed.
基金supported by the National Natural Science Foundation of China (41525016, 41525015, 41661164034, 41621063)the National Important Basic Research Project (2011CB811405)supported by the Thousand Young Talents Program of China
文摘The Venusian dayside ionosphere, similar to other planetary ionospheres, is produced primarily by ionization of its neutral upper atmosphere due to solar extreme ultraviolet (EUV) radiation. It has become clear that the expansion of the ionosphere may be strongly controlled by the EUV level, as exhibited in data collected by the Pioneer Venus Orbiter (PVO) during one solar cycle (1978 1992). However, the EUV-dependence of the Venusian dayside ionopause altitude, which defines the outer boundary of the ionosphere, remains obscure because the PVO crossed the dayside ionopause only during the solar maximum;its periapsis lifted too high during the solar minimum. Recently, during the period 2006 2014, which included the longest and quietest solar minimum of the past several decades, Venus Express (VEX) provided measurements of the photoelectron boundary (PEB) over the northern high-latitude region. Since the photoelectron boundary is closely related to the ionopause, we have an opportunity to analyze the EUV effect on the dayside ionopause by combining PVO and VEX observations. We have evaluated and then reduced the orbit bias effect in data from both PVO and VEX, and then used the results to derive a relationship between solar EUV level and the dayside ionopause altitude. We find that the dayside ionopause altitude increases as the solar EUV level increases, which is consistent with theoretical expectations.
基金This work was supported by the National Natural Science Foundation of China grant(81772334).
文摘With the interdisciplinary convergence of biology,medicine and materials science,both research and clinical translation of biomaterials are progressing at a rapid pace.However,there is still a huge gap between applied basic research on biomaterials and their translational products-medical devices,where two significantly different perspectives and mindsets often work independently and non-synergistically,which in turn significantly increases financial costs and research effort.Although this gap is well-known and often criticized in the biopharmaceutical industry,it is gradually widening.In this article,we critically examine the developmental pipeline of biodegradable biomaterials and biomaterial-based medical device products.Then based on clinical needs,market analysis,and relevant regulations,some ideas are proposed to integrate the two different mindsets to guide applied basic research and translation of biomaterial-based products,from the material and technical perspectives.Cartilage repair substitutes are discussed here as an example.Hopefully,this will lay a strong foundation for biomaterial research and clinical translation,while reducing the amount of extra research effort and funding required due to the dissonance between innovative basic research and commercialization pipeline.
基金This work was supported by the China National keypoint research and invention program of the thirteenth(Project ID:2016YFC1102304).
文摘Bone morphogenetic protein(BMP),belongs to transforming growth factor-b(TGF-b)superfamily except BMP-1.Implanting BMP into muscular tissues induces ectopic bone formation at the site of implantation,which provides opportunity for the treatment of bone defects.Recombinant human BMP-2(rhBMP-2)has been used clinically,but the lack of standard methods for quantifying rhBMP-2 biological activity greatly hindered the progress of commercialization.In this article,we describe an in vitro rhBMP-2 quantification method,as well as the data analyzation pipeline through logistic regression in RStudio.Previous studies indicated that alkaline phosphatase(ALP)activity of C2C12 cells was significantly increased when exposed to rhBMP-2,and showed dose-dependent effects in a certain concentration range of rhBMP-2.Thus,we chose to quantify ALP activity as an indicator of rhBMP-2 bioactivity in vitro.A sigmoid relationship between the ALP activity and concentration of rhBMP-2 was discovered.However,there are tons of regression models for such a non-linear relationship.It has always been a major concern for researchers to choose a proper model that not only fit data accurately,but also have parameters representing practical meanings.Therefore,to fit our rhBMP-2 quantification data,we applied two logistic regression models,three-parameter log-logistic model and four-parameter log-logistic model.The four-parameter log-logistic model(adj-R2>0.98)fits better than three-parameter log-logistic model(adj-R2>0.75)for the sigmoid curves.Overall,our results indicate rhBMP-2 quantification in vitro can be accomplished by detecting ALP activity and fitting four-parameter log-logistic model.Furthermore,we also provide a highly adaptable R script for any additional logistic models.