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
The accurate measurement on the compressibility and thermal expansion coefficients of density standard liquid at 2329kg/m3（DSL-2329） plays an important role in the quality control for silicon single crystal manufact...The accurate measurement on the compressibility and thermal expansion coefficients of density standard liquid at 2329kg/m3（DSL-2329） plays an important role in the quality control for silicon single crystal manufacturing. A new method is developed based on hydrostatic suspension principle in order to determine the two coefficients with high measurement accuracy. Two silicon single crystal samples with known density are immersed into a sealed vessel full of DSL-2329. The density of liquid is adjusted with varying liquid temperature and static pressure, so that the hydrostatic suspension of two silicon single crystal samples is achieved. The compression and thermal expansion coefficients are then calculated by using the data of temperature and static pressure at the suspension state. One silicon single crystal sample can be suspended at different state, as long as the liquid temperature and static pressure function linearly according to a certain mathematical relationship. A hydrostatic suspension experimental system is devised with the maximal temperature control error ±50 μK; Silicon single crystal samples can be suspended by adapting the pressure following the PID method. By using the method based on hydrostatic suspension principle, the two key coefficients can be measured at the same time, and measurement precision can be improved due to avoiding the influence of liquid surface tension. This method was further validated experimentally, where the mixture of 1, 2, 3-tribromopropane and 1,2-dibromoethane is used as DSL-2329. The compressibility and thermal expansion coefficients were measured, as 8.5′10–4 K–1 and 5.4′10–10 Pa–1, respectively.展开更多
The treatment of RECl3.xH2O （RE = Ho, Er, Tm, Yb, Lu; x = 3-4） with sodium diethyldithiocarbamate （NaEtEdtc-3H2O） and 1,10-phenanthroline hydrate （o-phen.H2O） in absolute ethanol yielded five ternary solid compl...The treatment of RECl3.xH2O （RE = Ho, Er, Tm, Yb, Lu; x = 3-4） with sodium diethyldithiocarbamate （NaEtEdtc-3H2O） and 1,10-phenanthroline hydrate （o-phen.H2O） in absolute ethanol yielded five ternary solid complexes RE（EtEdtC）a（phen）. IR spectra of the complexes showed that RE^3＋ coordinated to two sulfur atoms in NaEt2dtc and two nitrogen atoms in o-phen. The constant-volume energies of combustion of the complexes have been determined by a precise rotating-bomb calorimeter at 298.15 K. The standard enthalpies of combustion and standard enthalpies of formation were calculated.展开更多
Three-dimensional(3D)printing technology,as a novel technical method,can convert conventional computed tomography(CT)or magnetic resonance imaging(MRI)scans to computer-aided design files and develop a 2D spatial stru...Three-dimensional(3D)printing technology,as a novel technical method,can convert conventional computed tomography(CT)or magnetic resonance imaging(MRI)scans to computer-aided design files and develop a 2D spatial structure into a 3D imaging structure.In recent years,the technology has been widely used in numerous areas,including head and neck surgery,orthopedics,and bio-medicinal research.This article uses examples of 3D printed tumor models to develop Response Evaluation Criteria In Solid Tumors(RECIST)standards to evaluate the changes in tumors.RECIST standard is currently recognized as the standard for assessment of chemotherapy.Under the RECIST standard,changes occurring in tumors before and after the surgery,are evaluated.The assessment depends upon a CT evaluation of the changes in the lesions with the largest diameters.In addition,the disease progression and stability of remission is also assessed.Three-dimensional printing technology is more intuitive in the evaluation of changes to human tumors following chemotherapy and targeted therapy.However,a few reports are available.展开更多
The 3rd Generation Partnership Project (3GPP) initiated its Long Term Evolution (LTE) standardization work to retain its technology and standard advantages in the field of mobile communications. A series of advanced t...The 3rd Generation Partnership Project (3GPP) initiated its Long Term Evolution (LTE) standardization work to retain its technology and standard advantages in the field of mobile communications. A series of advanced technologies and novel concepts related to the physical layer (Layer 1),air interface protocol structure layer (Layer 2) and network architecture are adopted. Solutions to Voice over IP (VoIP) and Multimedia Broadcast/Multicast Service (MBMS) are in the optimization process. 3GPP LTE has achieved the design goals of high data rate,low latency and an all-packet basis.展开更多
The challenges brought by broadband wireless access technologies to cellular mobile communication technologies speed up the study and standardization of 3G evolution technologies that support higher data rates. Both t...The challenges brought by broadband wireless access technologies to cellular mobile communication technologies speed up the study and standardization of 3G evolution technologies that support higher data rates. Both the 3GPP and the 3GPP2 have launched research programs on the study and standardization of the emerging 3G evolution technologies. The Long Term Evolution (LTE) program of 3GPP has made progress in key technical indexes of air interface, wireless network architecture and high-level protocols. At the same time, the Air Interface Evolution (AIE) program of 3GPP2 has made study achievements in the formulation of air interface standards for Layer 2 and upper layers, as well as for the physical layer.展开更多
Only ZTE can deliver end-to-end equipment for all 3G standards-WCDMA, CDMA2000, TD-SCDMA and WiMAX. Our WCDMA solutions are used in 30 countries and regions, and our CDMA systems are used by 120 operators in more than...Only ZTE can deliver end-to-end equipment for all 3G standards-WCDMA, CDMA2000, TD-SCDMA and WiMAX. Our WCDMA solutions are used in 30 countries and regions, and our CDMA systems are used by 120 operators in more than 70 countries.展开更多
Only ZTE can deliver end-to-end equipment for all 3G standards-WCDMA, CDMA2000, TD-SCDMA and WiMAX. Our WCDMA solutions are used in 30 countries and regions,
General Administration of Quality Supervision,Inspection and Quarantine of P.R.China and Standardization Administration of China have approved the following 163 national standards and 81 national reference materials.
From the discussion above, the 3G choice of China is difficult to makerapidly because of multiple complicated factors. Either delay or impulsion will be costly. So theChinese government regulators need intensive and c...From the discussion above, the 3G choice of China is difficult to makerapidly because of multiple complicated factors. Either delay or impulsion will be costly. So theChinese government regulators need intensive and careful study on key factors before making a rightdecision. But the following policy trends can be inferred: (1)The regulator will not use the auctionlike Europe to issue 3G licenses; (2)Three 3G standards will co-exist in China mobile market withmultiple 3G services competition; (3)The 3G licenses schedule of China will inevitably be associatedwith the market demand and standard mature.展开更多
[Objectives]To establish the quality standard of Nardostachys jatamansi Herba.[Methods]The characters and microscopical identification of N.jatamansi Herba were carried out.The contents of moisture,total ash,acid-inso...[Objectives]To establish the quality standard of Nardostachys jatamansi Herba.[Methods]The characters and microscopical identification of N.jatamansi Herba were carried out.The contents of moisture,total ash,acid-insoluble ash and extract were determined according to the relevant methods of the Chinese Pharmacopoeia(2020 edition).Using chlorogenic acid and 3,5-O-dicaffeoylquinic acid as quality control indexes,TLC and HPLC methods were established for qualitative and quantitative determination,and HPLC fingerprints were established.[Results]The characteristics of character identification,microscopic identification and thin layer identification were obvious.The moisture content ranged from 2.7%to 7.8%,with an average value of 5.4%.The total ash content ranged from 6.7%to 16.2%,with an average of 11.0%.The acid-insoluble ash content ranged from 0.7%to 8.5%,with an average of 3.6%.Extractives content ranged from 20.9%to 34.4%,with an average of 29.7%.Chlorogenic acid content was between 0.45%and 1.30%,with an average value of 0.77%.The content of 3,5-O-dicaffeoylquinic acid ranged from 0.18%to 0.58%,with an average of 0.31%.The similarity of each batch was between 0.930 and 0.994,indicating that the quality of medicinal materials from different producing areas was stable.[Conclusions]The quality standard of N.jatamansi Herba was established,which could provide quality control basis for rational,comprehensive and efficient utilization of N.jatamansi DC.resources and clinical use.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.
基金Supported by National Natural Science Foundation of China(Grant No.51105347)National Key Technology R&D Program of Ministry of Science and Technology of China(Grant No.2011BAI02B03)
文摘The accurate measurement on the compressibility and thermal expansion coefficients of density standard liquid at 2329kg/m3（DSL-2329） plays an important role in the quality control for silicon single crystal manufacturing. A new method is developed based on hydrostatic suspension principle in order to determine the two coefficients with high measurement accuracy. Two silicon single crystal samples with known density are immersed into a sealed vessel full of DSL-2329. The density of liquid is adjusted with varying liquid temperature and static pressure, so that the hydrostatic suspension of two silicon single crystal samples is achieved. The compression and thermal expansion coefficients are then calculated by using the data of temperature and static pressure at the suspension state. One silicon single crystal sample can be suspended at different state, as long as the liquid temperature and static pressure function linearly according to a certain mathematical relationship. A hydrostatic suspension experimental system is devised with the maximal temperature control error ±50 μK; Silicon single crystal samples can be suspended by adapting the pressure following the PID method. By using the method based on hydrostatic suspension principle, the two key coefficients can be measured at the same time, and measurement precision can be improved due to avoiding the influence of liquid surface tension. This method was further validated experimentally, where the mixture of 1, 2, 3-tribromopropane and 1,2-dibromoethane is used as DSL-2329. The compressibility and thermal expansion coefficients were measured, as 8.5′10–4 K–1 and 5.4′10–10 Pa–1, respectively.
基金[This work was financially supported by the Natural Science Foundation of China (No. 20171036), the Natural Science Foundation of Shaanxi Province (Nos. 01JK229, FF02328 and 05JK291) and Postgraduate Foundation of China.]
文摘The treatment of RECl3.xH2O （RE = Ho, Er, Tm, Yb, Lu; x = 3-4） with sodium diethyldithiocarbamate （NaEtEdtc-3H2O） and 1,10-phenanthroline hydrate （o-phen.H2O） in absolute ethanol yielded five ternary solid complexes RE（EtEdtC）a（phen）. IR spectra of the complexes showed that RE^3＋ coordinated to two sulfur atoms in NaEt2dtc and two nitrogen atoms in o-phen. The constant-volume energies of combustion of the complexes have been determined by a precise rotating-bomb calorimeter at 298.15 K. The standard enthalpies of combustion and standard enthalpies of formation were calculated.
基金Supported by a grant from the National Natural Science Foundation of China(No.81702622)。
文摘Three-dimensional(3D)printing technology,as a novel technical method,can convert conventional computed tomography(CT)or magnetic resonance imaging(MRI)scans to computer-aided design files and develop a 2D spatial structure into a 3D imaging structure.In recent years,the technology has been widely used in numerous areas,including head and neck surgery,orthopedics,and bio-medicinal research.This article uses examples of 3D printed tumor models to develop Response Evaluation Criteria In Solid Tumors(RECIST)standards to evaluate the changes in tumors.RECIST standard is currently recognized as the standard for assessment of chemotherapy.Under the RECIST standard,changes occurring in tumors before and after the surgery,are evaluated.The assessment depends upon a CT evaluation of the changes in the lesions with the largest diameters.In addition,the disease progression and stability of remission is also assessed.Three-dimensional printing technology is more intuitive in the evaluation of changes to human tumors following chemotherapy and targeted therapy.However,a few reports are available.
文摘The 3rd Generation Partnership Project (3GPP) initiated its Long Term Evolution (LTE) standardization work to retain its technology and standard advantages in the field of mobile communications. A series of advanced technologies and novel concepts related to the physical layer (Layer 1),air interface protocol structure layer (Layer 2) and network architecture are adopted. Solutions to Voice over IP (VoIP) and Multimedia Broadcast/Multicast Service (MBMS) are in the optimization process. 3GPP LTE has achieved the design goals of high data rate,low latency and an all-packet basis.
基金National "863"Program of China (No. 2005AA123410)
文摘The challenges brought by broadband wireless access technologies to cellular mobile communication technologies speed up the study and standardization of 3G evolution technologies that support higher data rates. Both the 3GPP and the 3GPP2 have launched research programs on the study and standardization of the emerging 3G evolution technologies. The Long Term Evolution (LTE) program of 3GPP has made progress in key technical indexes of air interface, wireless network architecture and high-level protocols. At the same time, the Air Interface Evolution (AIE) program of 3GPP2 has made study achievements in the formulation of air interface standards for Layer 2 and upper layers, as well as for the physical layer.
文摘Only ZTE can deliver end-to-end equipment for all 3G standards-WCDMA, CDMA2000, TD-SCDMA and WiMAX. Our WCDMA solutions are used in 30 countries and regions, and our CDMA systems are used by 120 operators in more than 70 countries.
文摘Only ZTE can deliver end-to-end equipment for all 3G standards-WCDMA, CDMA2000, TD-SCDMA and WiMAX. Our WCDMA solutions are used in 30 countries and regions,
文摘General Administration of Quality Supervision,Inspection and Quarantine of P.R.China and Standardization Administration of China have approved the following 163 national standards and 81 national reference materials.
文摘From the discussion above, the 3G choice of China is difficult to makerapidly because of multiple complicated factors. Either delay or impulsion will be costly. So theChinese government regulators need intensive and careful study on key factors before making a rightdecision. But the following policy trends can be inferred: (1)The regulator will not use the auctionlike Europe to issue 3G licenses; (2)Three 3G standards will co-exist in China mobile market withmultiple 3G services competition; (3)The 3G licenses schedule of China will inevitably be associatedwith the market demand and standard mature.
基金Supported by National Key R&D Plan Project (2018YFC1708005)Application Foundation Project of Sichuan Provincial Department of Science and Technology (20YYJC3299)Special Fund for Basic Scientific Research Business Expenses of Central Universities of Southwest Minzu University (2020NGD01).
文摘[Objectives]To establish the quality standard of Nardostachys jatamansi Herba.[Methods]The characters and microscopical identification of N.jatamansi Herba were carried out.The contents of moisture,total ash,acid-insoluble ash and extract were determined according to the relevant methods of the Chinese Pharmacopoeia(2020 edition).Using chlorogenic acid and 3,5-O-dicaffeoylquinic acid as quality control indexes,TLC and HPLC methods were established for qualitative and quantitative determination,and HPLC fingerprints were established.[Results]The characteristics of character identification,microscopic identification and thin layer identification were obvious.The moisture content ranged from 2.7%to 7.8%,with an average value of 5.4%.The total ash content ranged from 6.7%to 16.2%,with an average of 11.0%.The acid-insoluble ash content ranged from 0.7%to 8.5%,with an average of 3.6%.Extractives content ranged from 20.9%to 34.4%,with an average of 29.7%.Chlorogenic acid content was between 0.45%and 1.30%,with an average value of 0.77%.The content of 3,5-O-dicaffeoylquinic acid ranged from 0.18%to 0.58%,with an average of 0.31%.The similarity of each batch was between 0.930 and 0.994,indicating that the quality of medicinal materials from different producing areas was stable.[Conclusions]The quality standard of N.jatamansi Herba was established,which could provide quality control basis for rational,comprehensive and efficient utilization of N.jatamansi DC.resources and clinical use.
