Concern over the health effects of fine particles in the ambient environment led the U.S. Environmental Protection Agency to develop the first standard for PM2.5 （particulate matter less than 2.5 μm） in 1997. The P...Concern over the health effects of fine particles in the ambient environment led the U.S. Environmental Protection Agency to develop the first standard for PM2.5 （particulate matter less than 2.5 μm） in 1997. The Particle Technology Laboratory at the University of Minnesota has helped to establish the PM2.5 standard by developing many instruments and samplers to perform atmospheric measurements. In this paper, we review various aspects of PM2.5, including its measurement, source apportionment, visibility and health effects, and mitigation. We focus on PM2.s studies in China and where appropriate, compare them with those obtained in the U.S. Based on accurate PM2.5 sampling, chemical analysis, and source apportionment models, the major PM2.5 sources in China have been identified to be coal combustion, motor vehicle emissions, and industrial sources. Atmospheric visibility has been found to correlate well with PM2.s concentration. Sulfate, ammonium, and nitrate carried by PM2.s, commonly found in coal burning and vehicle emissions, are the dominant contributors to regional haze in China. Short-term exposure to PM2.s is strongly associated with the increased risk of morbidity and mortality from cardiovascular and respiratory diseases in China. The strategy for PMzs mitigation must be based on reducing the pollutants from the two primary sources of coal-fired power plants and vehicle emissions. Although conventional Particulate Emission Control Devices （PECD） such as electrostatic precipitators in Chinese coal-fired power plants are generally effective for large particles, most of them may not have high collection efficiency of PM2.5. Baghouse filtration is gradually incorporated into the PECD to increase the PM2.5 collection efficiency. By adopting stringent vehicle emissions standard such as Euro 5 and 6, the emissions from vehicles can be gradually reduced over the years. An integrative approach, from collaboration among academia, government, and industries, can effectively manage and mitigate the PM2.s p展开更多
Venous access devices are of pivotal importance for an increasing number of critically ill patients in a variety of disease states and in a variety of clinical settings(emergency, intensive care, surgery) and for diff...Venous access devices are of pivotal importance for an increasing number of critically ill patients in a variety of disease states and in a variety of clinical settings(emergency, intensive care, surgery) and for different purposes(fluids or drugs infusions, parenteral nutrition, antibiotic therapy, hemodynamic monitoring, procedures of dialysis/apheresis). However, healthcare professionals are commonly worried about the possible consequences that may result using a central venous access device(CVAD)(mainly, bloodstream infections and thrombosis), both peripherally inserted central catheters(PICCs) and centrally inserted central catheters(CICCs). This review aims to discuss indications, insertion techniques, and care of PICCs in critically ill patients. PICCs have many advantages over standard CICCs. First of all, their insertion is easy and safe-due to their placement into peripheral veins of the armand the advantage of a central location of catheter tip suitable for all osmolarity and p H solutions. Using the ultrasound-guidance for the PICC insertion, the risk of hemothorax and pneumothorax can be avoided, as wellas the possibility of primary malposition is very low. PICC placement is also appropriate to avoid post-procedural hemorrhage in patients with an abnormal coagulative state who need a CVAD. Some limits previously ascribed to PICCs(i.e., low flow rates, difficult central venous pressure monitoring, lack of safety for radio-diagnostic procedures, single-lumen) have delayed their start up in the intensive care units as common practice. Though, the recent development of power-injectable PICCs overcomes these technical limitations and PICCs have started to spread in critical care settings. Two important take-home messages may be drawn from this review. First, the incidence of complications varies depending on venous accesses and healthcare professionals should be aware of the different clinical performance as well as of the different risks associated with each type of CVAD(CICCs or PICCs). Second, an inapp展开更多
One-dimensional （1D） ZnO nanostructures have been studied intensively and extensively over the last decade not only for their remarkable chemical and physical properties, but also for their diverse current and futur...One-dimensional （1D） ZnO nanostructures have been studied intensively and extensively over the last decade not only for their remarkable chemical and physical properties, but also for their diverse current and future technological applications. This article gives a comprehensive overview of the progress that has been made within the context of 1D ZnO nanostructures synthesized via wet chemical methods. We will cover the synthetic methodologies and the corresponding growth mechanisms, various nanostructures grown, their doping and alloying, and position-controlled growth on substrates. Finally, we will review their functional properties in catalysis, hydrophobic surface modification, sensing, and electronic, optical, optoelectronic, and energy harvesting devices.展开更多
Optical waveguides are far more than mere connecting elements in integrated optical systems and circuits.Benefiting from their high optical confinement and miniaturized footprints,waveguide structures established base...Optical waveguides are far more than mere connecting elements in integrated optical systems and circuits.Benefiting from their high optical confinement and miniaturized footprints,waveguide structures established based on crystalline materials,particularly,are opening exciting possibilities and opportunities in photonic chips by facilitating their on-chip integration with different functionalities and highly compact photonic circuits.Femtosecond-laser-direct writing(FsLDW),as a true three-dimensional(3D)micromachining and microfabrication technology,allows rapid prototyping of on-demand waveguide geometries inside transparent materials via localized material modification.The success of FsLDW lies not only in its unsurpassed aptitude for realizing 3D devices but also in its remarkable material-independence that enables cross-platform solutions.This review emphasizes FsLDW fabrication of waveguide structures with 3D layouts in dielectric crystals.Their functionalities as passive and active photonic devices are also demonstrated and discussed.展开更多
Concentrations of Iron (Fe), As, and Cu in soil samples from the fields near the Baoshan Mine in Hunan Province, China, were analyzed and soil spectral reflectance was measured with an ASD FieldSpec FR spectroradiomet...Concentrations of Iron (Fe), As, and Cu in soil samples from the fields near the Baoshan Mine in Hunan Province, China, were analyzed and soil spectral reflectance was measured with an ASD FieldSpec FR spectroradiometer (Analytical Spectral Devices, Inc., USA) under laboratory condition. Partial least square regression (PLSR) models were constructed for predicting soil metal concentrations. The data pre-processing methods, first and second derivatives (FD and SD), baseline correction (BC), standard normal variate (SNV), multiplicative scatter correction (MSC), and continuum removal (CR), were used for the spectral reflectance data pretreatments. Then, the prediction results were evaluated by relative root mean square error (RRMSE) and coefficients of determination (R 2 ). According to the criteria of minimal RRMSE and maximal R 2 , the PLSR models with the FD pretreatment (RRMSE = 0.24, R 2 = 0.61), SNV pretreatment (RRMSE = 0.08, R 2 = 0.78), and BC-pretreatment (RRMSE = 0.20, R 2 = 0.41) were considered as the final models for predicting As, Fe, and Cu, respectively. Wavebands at around 460, 1 400, 1 900, and 2 200 nm were selected as important spectral variables to construct final models. In conclusion, concentrations of heavy metals in contaminated soils could be indirectly assessed by soil spectra according to the correlation between the spectrally featureless components and Fe; therefore, spectral reflectance would be an alternative tool for monitoring soil heavy metals contamination.展开更多
Background Different feasible and safe thrombectomy and distal protection devices have been used in clinical practice. The efficiency and safety of adjunct thrombectomy using Diver CE device （Invatec, Italy） versus ...Background Different feasible and safe thrombectomy and distal protection devices have been used in clinical practice. The efficiency and safety of adjunct thrombectomy using Diver CE device （Invatec, Italy） versus Guardwire Plus device （Medtronic, USA） before percutaneous coronary intervention （PCI） were compared in patients with acute inferior ST-segment-elevation myocardial infarction （STEMI） for less than 12 hours, thrombolysis in myocardial infarction （TIMI） flow grade 0 to 1, and total occlusion of the proximal right coronary artery （≥3 mm in diameter） in a prospective randomized single-center study. Methods The primary end point was the magnitude of ST-segment resolution （STR） （〉70%） measured immediately, 90 minutes and 6 hours after PCI, myocardial blush grade and slow flow or no-reflow. Secondary end points were left ventricular end-diastolic volume （LVEDV）, left ventricle ejection fraction （LVEF） and major adverse cardiac events （MACEs） including death, myocardial infarction, target vessel revascularization and stroke at 30 days. Results A total of 122 patients were equally divided into Diver CE group and Guardwire Plus group, which were comparable by age （（60±14） years vs （60±13） years）, male （82% vs 84%）, diabetes （31% vs 28%）, previous coronary artery disease （25% vs 23%）, onset-to-angiogram （（350±185） min vs （345±180） min）, and use of glycoprotein lib/llia inhibitor （11% vs 13%）. The magnitude of ST-segment resolution was similar in the two groups as ST-segment resolution 〉70% （57% vs 59%; P〉0.05）. Similar slow flow/no-reflow rates were observed in the Diver CE group （8%） and the Guardwire Plus group （7%）. TIMI flow grade 3 was obtained in 95% vs 97% patients, respectively （P〉0.05）. Myocardial blush grade 3 was similar （70% vs 72%; P〉0.05）. Thirty-day clinical outcome was comparable （LVEF, 0.54±0.12 vs 0.53 ±0.11; death, 3% vs 3%; myocardial infarction, 2% vs 0%; and target ves展开更多
Background Venous thromboembolism is known to be an important social and health care problem because of its high incidence among patients who undergo surgery. Studies on the mechanical prophylaxis of thromboembolism a...Background Venous thromboembolism is known to be an important social and health care problem because of its high incidence among patients who undergo surgery. Studies on the mechanical prophylaxis of thromboembolism after gynaecological pelvic surgery are few. The aim of our study was to evaluate the effect of mechanical thromboembolism prophylaxis after gynaecological pelvic surgery using a combination of graduated compression stockings （GCS） and intermittent pneumatic compression （IPC） or GCS alone. Methods The study was performed on 108 patients who were randomly assigned to two groups. The first group received GCS before the operation and IPC during the operation （IPC＋GCS group）, The second group received GCS before the operation （GCS group）. To analyze the effect of the preventive measures and the laboratory examination on the incidence of thrombosis and to compare the safety of these measures, the incidence of adverse reactions was assessed. Results The morbidity associated with DVT was 4.8% （5/104） in the IPC＋GCS group and 12.5% （14/112） in the GCS group. There were significant statistical differences between the two groups. There were no adverse effects in either group. Conclusions The therapeutic combination of GCS and prevention in high-risk patients undergoing gynaecological group.（No. ChiCTR-PRC-10000935）. IPC was more effective than GCS alone for thrombosis pelvic surgery, and there were no adverse effects in either展开更多
In this paper, a substrate removing technique in a silicon Mach–Zehnder modulator(MZM) is proposed and demonstrated to improve modulation bandwidth. Based on the novel and optimized traveling wave electrodes,the elec...In this paper, a substrate removing technique in a silicon Mach–Zehnder modulator(MZM) is proposed and demonstrated to improve modulation bandwidth. Based on the novel and optimized traveling wave electrodes,the electrode transmission loss is reduced, and the electro-optical group index and 50 Ω impedance matching are improved, simultaneously. A 2 mm long substrate removed silicon MZM with the measured and extrapolated 3 dB electro-optical bandwidth of >50 GHz and 60 GHz at the-8 V bias voltage is designed and fabricated.Open optical eye diagrams of up to 90 GBaud∕s NRZ and 56 GBaud∕s four-level pulse amplitude modulation(PAM-4) are experimentally obtained without additional optical or digital compensations. Based on this silicon MZM, the performance in a short-reach transmission system is further investigated. Single-lane 112 Gb∕s and 128 Gb∕s transmissions over different distances of 1 km, 2 km, and 10 km are experimentally achieved based on this high-speed silicon MZM.展开更多
Integrated photonics is attracting considerable attention and has found many applications in both classical and quantum optics,fulfilling the requirements for the ever-growing complexity in modern optical experiments ...Integrated photonics is attracting considerable attention and has found many applications in both classical and quantum optics,fulfilling the requirements for the ever-growing complexity in modern optical experiments and big data communication.Femtosecond(fs)laser direct writing(FLDW)is an acknowledged technique for producing waveguides(WGs)in transparent glass that have been used to construct complex integrated photonic devices.FLDW possesses unique features,such as three-dimensional fabrication geometry,rapid prototyping,and single step fabrication,which are important for integrated communication devices and quantum photonic and astrophotonic technologies.To fully take advantage of FLDW,considerable efforts have been made to produce WGs over a large depth with low propagation loss,coupling loss,bend loss,and highly symmetrical mode field.We summarize the improved techniques as well as the mechanisms for writing high-performance WGs with controllable morphology of cross-section,highly symmetrical mode field,low loss,and high processing uniformity and efficiency,and discuss the recent progress of WGs in photonic integrated devices for communication,topological physics,quantum information processing,and astrophotonics.Prospective challenges and future research directions in this field are also pointed out.展开更多
Lithium niobate(LN)has experienced significant developments during past decades due to its versatile properties,especially its large electro-optic(EO)coefficient.For example,bulk LN-based modulators with high speeds a...Lithium niobate(LN)has experienced significant developments during past decades due to its versatile properties,especially its large electro-optic(EO)coefficient.For example,bulk LN-based modulators with high speeds and a superior linearity are widely used in typical fiber-optic communication systems.However,with everincreasing demands for signal transmission capacity,the high power and large size of bulk LN-based devices pose great challenges,especially when one of its counterparts,integrated silicon photonics,has experienced dramatic developments in recent decades.Not long ago,high-quality thin-film LN on insulator(LNOI)became commercially available,which has paved the way for integrated LN photonics and opened a hot research area of LN photonics devices.LNOI allows a large refractive index contrast,thus light can be confined within a more compact structure.Together with other properties of LN,such as nonlinear/acousto-optic/pyroelectric effects,various kinds of high-performance integrated LN devices can be demonstrated.A comprehensive summary of advances in LN photonics is provided.As LN photonics has experienced several decades of development,our review includes some of the typical bulk LN devices as well as recently developed thin film LN devices.In this way,readers may be inspired by a complete picture of the evolution of this technology.We first introduce the basic material properties of LN and several key processing technologies for fabricating photonics devices.After that,various kinds of functional devices based on different effects are summarized.Finally,we give a short summary and perspective of LN photonics.We hope this review can give readers more insight into recent advances in LN photonics and contribute to the further development of LN related research.展开更多
Single-walled carbon nanotube(SWNT)thin film electrodes have been printed on flexible substrates and cloth fabrics by using SWNT inks and an off-the-shelf inkjet printer,with features of controlled pattern geometry(0....Single-walled carbon nanotube(SWNT)thin film electrodes have been printed on flexible substrates and cloth fabrics by using SWNT inks and an off-the-shelf inkjet printer,with features of controlled pattern geometry(0.4-6 cm^(2)),location,controllable thickness(20-200 nm),and tunable electrical conductivity.The as-printed SWNT films were then sandwiched together with a piece of printable polymer electrolyte to form flexible and wearable supercapacitors,which displayed good capacitive behavior even after 1,000 charge/discharge cycles.Furthermore,a simple and efficient route to produce ruthenium oxide(RuO_(2))nanowire/SWNT hybrid films has been developed,and it was found that the knee frequency of the hybrid thin film electrodes can reach 1,500 Hz,which is much higher than the knee frequency of the bare SWNT electrodes(~158 Hz).In addition,with the integration of RuO_(2) nanowires,the performance of the printed SWNT supercapacitor was significantly improved in terms of its specific capacitance of 138 F/g,power density of 96 kW/kg,and energy density of 18.8 Wh/kg.The results indicate the potential of printable energy storage devices and their significant promise for application in wearable energy storage devices.展开更多
Improper flow control devices in a multi-strand tundish can cause some problems, for example, liquid steel cannot reach every nozzle at the same time and the liquid steel in nozzles far away from the entry zone has a ...Improper flow control devices in a multi-strand tundish can cause some problems, for example, liquid steel cannot reach every nozzle at the same time and the liquid steel in nozzles far away from the entry zone has a lower temperature. The water model experiment of a six-strand tundish of Tianjin Iron ＆ Steel Co. Ltd. was performed, a new ＂U＂ type baffle was obtained, and its parameters were defined by perpendicular analysis. The ＂U＂ baffle can not only improve those imperfections, but also prolong the residence time of nonmetallic inclusions, which is good for their flotation and separation.展开更多
There are now numerous emerging flexible and wearable sensing technologies that can perform a myriad of physical and physiological measurements.Rapid advances in developing and implementing such sensors in the last se...There are now numerous emerging flexible and wearable sensing technologies that can perform a myriad of physical and physiological measurements.Rapid advances in developing and implementing such sensors in the last several years have demonstrated the growing significance and potential utility of this unique class of sensing platforms.Applications include wearable consumer electronics,soft robotics,medical prosthetics,electronic skin,and health monitoring.In this review,we provide a state-ofthe-art overview of the emerging flexible and wearable sensing platforms for healthcare and biomedical applications.We first introduce the selection of flexible and stretchable materials and the fabrication of sensors based on these materials.We then compare the different solid-state and liquid-state physical sensing platforms and examine the mechanical deformation-based working mechanisms of these sensors.We also highlight some of the exciting applications of flexible and wearable physical sensors in emerging healthcare and biomedical applications,in particular for artificial electronic skins,physiological health monitoring and assessment,and therapeutic and drug delivery.Finally,we conclude this review by offering some insight into the challenges and opportunities facing this field.展开更多
With a large number of researches being conducted on two?dimen?sional(2D) materials, their unique properties in optics, electrics, mechanics, and magnetics have attracted increasing attention. Accordingly, the idea of...With a large number of researches being conducted on two?dimen?sional(2D) materials, their unique properties in optics, electrics, mechanics, and magnetics have attracted increasing attention. Accordingly, the idea of combining distinct functional 2D materials into heterostructures naturally emerged that pro?vides unprecedented platforms for exploring new physics that are not accessible in a single 2D material or 3D heterostructures. Along with the rapid development of controllable, scalable, and programmed synthesis techniques of high?quality 2D heterostructures, various heterostructure devices with extraordinary performance have been designed and fabricated, including tunneling transistors, photodetectors, and spintronic devices. In this review, we present a summary of the latest progresses in fabrications, properties, and applications of di erent types of 2D heterostruc?tures, followed by the discussions on present challenges and perspectives of further investigations.展开更多
文摘Concern over the health effects of fine particles in the ambient environment led the U.S. Environmental Protection Agency to develop the first standard for PM2.5 （particulate matter less than 2.5 μm） in 1997. The Particle Technology Laboratory at the University of Minnesota has helped to establish the PM2.5 standard by developing many instruments and samplers to perform atmospheric measurements. In this paper, we review various aspects of PM2.5, including its measurement, source apportionment, visibility and health effects, and mitigation. We focus on PM2.s studies in China and where appropriate, compare them with those obtained in the U.S. Based on accurate PM2.5 sampling, chemical analysis, and source apportionment models, the major PM2.5 sources in China have been identified to be coal combustion, motor vehicle emissions, and industrial sources. Atmospheric visibility has been found to correlate well with PM2.s concentration. Sulfate, ammonium, and nitrate carried by PM2.s, commonly found in coal burning and vehicle emissions, are the dominant contributors to regional haze in China. Short-term exposure to PM2.s is strongly associated with the increased risk of morbidity and mortality from cardiovascular and respiratory diseases in China. The strategy for PMzs mitigation must be based on reducing the pollutants from the two primary sources of coal-fired power plants and vehicle emissions. Although conventional Particulate Emission Control Devices （PECD） such as electrostatic precipitators in Chinese coal-fired power plants are generally effective for large particles, most of them may not have high collection efficiency of PM2.5. Baghouse filtration is gradually incorporated into the PECD to increase the PM2.5 collection efficiency. By adopting stringent vehicle emissions standard such as Euro 5 and 6, the emissions from vehicles can be gradually reduced over the years. An integrative approach, from collaboration among academia, government, and industries, can effectively manage and mitigate the PM2.s p
文摘Venous access devices are of pivotal importance for an increasing number of critically ill patients in a variety of disease states and in a variety of clinical settings(emergency, intensive care, surgery) and for different purposes(fluids or drugs infusions, parenteral nutrition, antibiotic therapy, hemodynamic monitoring, procedures of dialysis/apheresis). However, healthcare professionals are commonly worried about the possible consequences that may result using a central venous access device(CVAD)(mainly, bloodstream infections and thrombosis), both peripherally inserted central catheters(PICCs) and centrally inserted central catheters(CICCs). This review aims to discuss indications, insertion techniques, and care of PICCs in critically ill patients. PICCs have many advantages over standard CICCs. First of all, their insertion is easy and safe-due to their placement into peripheral veins of the armand the advantage of a central location of catheter tip suitable for all osmolarity and p H solutions. Using the ultrasound-guidance for the PICC insertion, the risk of hemothorax and pneumothorax can be avoided, as wellas the possibility of primary malposition is very low. PICC placement is also appropriate to avoid post-procedural hemorrhage in patients with an abnormal coagulative state who need a CVAD. Some limits previously ascribed to PICCs(i.e., low flow rates, difficult central venous pressure monitoring, lack of safety for radio-diagnostic procedures, single-lumen) have delayed their start up in the intensive care units as common practice. Though, the recent development of power-injectable PICCs overcomes these technical limitations and PICCs have started to spread in critical care settings. Two important take-home messages may be drawn from this review. First, the incidence of complications varies depending on venous accesses and healthcare professionals should be aware of the different clinical performance as well as of the different risks associated with each type of CVAD(CICCs or PICCs). Second, an inapp
文摘One-dimensional （1D） ZnO nanostructures have been studied intensively and extensively over the last decade not only for their remarkable chemical and physical properties, but also for their diverse current and future technological applications. This article gives a comprehensive overview of the progress that has been made within the context of 1D ZnO nanostructures synthesized via wet chemical methods. We will cover the synthetic methodologies and the corresponding growth mechanisms, various nanostructures grown, their doping and alloying, and position-controlled growth on substrates. Finally, we will review their functional properties in catalysis, hydrophobic surface modification, sensing, and electronic, optical, optoelectronic, and energy harvesting devices.
基金financial support from National Natural Science Foundation of China(No.61775120).
文摘Optical waveguides are far more than mere connecting elements in integrated optical systems and circuits.Benefiting from their high optical confinement and miniaturized footprints,waveguide structures established based on crystalline materials,particularly,are opening exciting possibilities and opportunities in photonic chips by facilitating their on-chip integration with different functionalities and highly compact photonic circuits.Femtosecond-laser-direct writing(FsLDW),as a true three-dimensional(3D)micromachining and microfabrication technology,allows rapid prototyping of on-demand waveguide geometries inside transparent materials via localized material modification.The success of FsLDW lies not only in its unsurpassed aptitude for realizing 3D devices but also in its remarkable material-independence that enables cross-platform solutions.This review emphasizes FsLDW fabrication of waveguide structures with 3D layouts in dielectric crystals.Their functionalities as passive and active photonic devices are also demonstrated and discussed.
基金Project supported by the National Natural Science Foundation of China (No. 40571130)the Natural Science Foundation of Shanghai, China (No. 07ZR14032)
文摘Concentrations of Iron (Fe), As, and Cu in soil samples from the fields near the Baoshan Mine in Hunan Province, China, were analyzed and soil spectral reflectance was measured with an ASD FieldSpec FR spectroradiometer (Analytical Spectral Devices, Inc., USA) under laboratory condition. Partial least square regression (PLSR) models were constructed for predicting soil metal concentrations. The data pre-processing methods, first and second derivatives (FD and SD), baseline correction (BC), standard normal variate (SNV), multiplicative scatter correction (MSC), and continuum removal (CR), were used for the spectral reflectance data pretreatments. Then, the prediction results were evaluated by relative root mean square error (RRMSE) and coefficients of determination (R 2 ). According to the criteria of minimal RRMSE and maximal R 2 , the PLSR models with the FD pretreatment (RRMSE = 0.24, R 2 = 0.61), SNV pretreatment (RRMSE = 0.08, R 2 = 0.78), and BC-pretreatment (RRMSE = 0.20, R 2 = 0.41) were considered as the final models for predicting As, Fe, and Cu, respectively. Wavebands at around 460, 1 400, 1 900, and 2 200 nm were selected as important spectral variables to construct final models. In conclusion, concentrations of heavy metals in contaminated soils could be indirectly assessed by soil spectra according to the correlation between the spectrally featureless components and Fe; therefore, spectral reflectance would be an alternative tool for monitoring soil heavy metals contamination.
文摘Background Different feasible and safe thrombectomy and distal protection devices have been used in clinical practice. The efficiency and safety of adjunct thrombectomy using Diver CE device （Invatec, Italy） versus Guardwire Plus device （Medtronic, USA） before percutaneous coronary intervention （PCI） were compared in patients with acute inferior ST-segment-elevation myocardial infarction （STEMI） for less than 12 hours, thrombolysis in myocardial infarction （TIMI） flow grade 0 to 1, and total occlusion of the proximal right coronary artery （≥3 mm in diameter） in a prospective randomized single-center study. Methods The primary end point was the magnitude of ST-segment resolution （STR） （〉70%） measured immediately, 90 minutes and 6 hours after PCI, myocardial blush grade and slow flow or no-reflow. Secondary end points were left ventricular end-diastolic volume （LVEDV）, left ventricle ejection fraction （LVEF） and major adverse cardiac events （MACEs） including death, myocardial infarction, target vessel revascularization and stroke at 30 days. Results A total of 122 patients were equally divided into Diver CE group and Guardwire Plus group, which were comparable by age （（60±14） years vs （60±13） years）, male （82% vs 84%）, diabetes （31% vs 28%）, previous coronary artery disease （25% vs 23%）, onset-to-angiogram （（350±185） min vs （345±180） min）, and use of glycoprotein lib/llia inhibitor （11% vs 13%）. The magnitude of ST-segment resolution was similar in the two groups as ST-segment resolution 〉70% （57% vs 59%; P〉0.05）. Similar slow flow/no-reflow rates were observed in the Diver CE group （8%） and the Guardwire Plus group （7%）. TIMI flow grade 3 was obtained in 95% vs 97% patients, respectively （P〉0.05）. Myocardial blush grade 3 was similar （70% vs 72%; P〉0.05）. Thirty-day clinical outcome was comparable （LVEF, 0.54±0.12 vs 0.53 ±0.11; death, 3% vs 3%; myocardial infarction, 2% vs 0%; and target ves
文摘Background Venous thromboembolism is known to be an important social and health care problem because of its high incidence among patients who undergo surgery. Studies on the mechanical prophylaxis of thromboembolism after gynaecological pelvic surgery are few. The aim of our study was to evaluate the effect of mechanical thromboembolism prophylaxis after gynaecological pelvic surgery using a combination of graduated compression stockings （GCS） and intermittent pneumatic compression （IPC） or GCS alone. Methods The study was performed on 108 patients who were randomly assigned to two groups. The first group received GCS before the operation and IPC during the operation （IPC＋GCS group）, The second group received GCS before the operation （GCS group）. To analyze the effect of the preventive measures and the laboratory examination on the incidence of thrombosis and to compare the safety of these measures, the incidence of adverse reactions was assessed. Results The morbidity associated with DVT was 4.8% （5/104） in the IPC＋GCS group and 12.5% （14/112） in the GCS group. There were significant statistical differences between the two groups. There were no adverse effects in either group. Conclusions The therapeutic combination of GCS and prevention in high-risk patients undergoing gynaecological group.（No. ChiCTR-PRC-10000935）. IPC was more effective than GCS alone for thrombosis pelvic surgery, and there were no adverse effects in either
文摘In this paper, a substrate removing technique in a silicon Mach–Zehnder modulator(MZM) is proposed and demonstrated to improve modulation bandwidth. Based on the novel and optimized traveling wave electrodes,the electrode transmission loss is reduced, and the electro-optical group index and 50 Ω impedance matching are improved, simultaneously. A 2 mm long substrate removed silicon MZM with the measured and extrapolated 3 dB electro-optical bandwidth of >50 GHz and 60 GHz at the-8 V bias voltage is designed and fabricated.Open optical eye diagrams of up to 90 GBaud∕s NRZ and 56 GBaud∕s four-level pulse amplitude modulation(PAM-4) are experimentally obtained without additional optical or digital compensations. Based on this silicon MZM, the performance in a short-reach transmission system is further investigated. Single-lane 112 Gb∕s and 128 Gb∕s transmissions over different distances of 1 km, 2 km, and 10 km are experimentally achieved based on this high-speed silicon MZM.
基金This work was financially supported by the National Key R&D Program of China(2020YFB1805900)the National Natural Science Foundation of China(U20A20211,51902286,61775192,61905215,and 51772270)Open Funds of the State Key Laboratory of High Field Laser Physics,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,and the Fundamental Research Funds for the Central Universities.The authors declare no competing financial interest.
文摘Integrated photonics is attracting considerable attention and has found many applications in both classical and quantum optics,fulfilling the requirements for the ever-growing complexity in modern optical experiments and big data communication.Femtosecond(fs)laser direct writing(FLDW)is an acknowledged technique for producing waveguides(WGs)in transparent glass that have been used to construct complex integrated photonic devices.FLDW possesses unique features,such as three-dimensional fabrication geometry,rapid prototyping,and single step fabrication,which are important for integrated communication devices and quantum photonic and astrophotonic technologies.To fully take advantage of FLDW,considerable efforts have been made to produce WGs over a large depth with low propagation loss,coupling loss,bend loss,and highly symmetrical mode field.We summarize the improved techniques as well as the mechanisms for writing high-performance WGs with controllable morphology of cross-section,highly symmetrical mode field,low loss,and high processing uniformity and efficiency,and discuss the recent progress of WGs in photonic integrated devices for communication,topological physics,quantum information processing,and astrophotonics.Prospective challenges and future research directions in this field are also pointed out.
基金the National Research Foundation,Singapore,under its Competitive Research Programme(CRP Award No.NRF-CRP24-2020-0003)This work was also supported by the program for HUST Academic Frontier Youth Team(2018QYTD08)This work was partially supported by A*STAR(Agency for Science,Technology and Research),Singapore,under the RIE2020 Advanced Manufacturing and Engineering(AME)IAF-PP Grant,No.A19B3a0008
文摘Lithium niobate(LN)has experienced significant developments during past decades due to its versatile properties,especially its large electro-optic(EO)coefficient.For example,bulk LN-based modulators with high speeds and a superior linearity are widely used in typical fiber-optic communication systems.However,with everincreasing demands for signal transmission capacity,the high power and large size of bulk LN-based devices pose great challenges,especially when one of its counterparts,integrated silicon photonics,has experienced dramatic developments in recent decades.Not long ago,high-quality thin-film LN on insulator(LNOI)became commercially available,which has paved the way for integrated LN photonics and opened a hot research area of LN photonics devices.LNOI allows a large refractive index contrast,thus light can be confined within a more compact structure.Together with other properties of LN,such as nonlinear/acousto-optic/pyroelectric effects,various kinds of high-performance integrated LN devices can be demonstrated.A comprehensive summary of advances in LN photonics is provided.As LN photonics has experienced several decades of development,our review includes some of the typical bulk LN devices as well as recently developed thin film LN devices.In this way,readers may be inspired by a complete picture of the evolution of this technology.We first introduce the basic material properties of LN and several key processing technologies for fabricating photonics devices.After that,various kinds of functional devices based on different effects are summarized.Finally,we give a short summary and perspective of LN photonics.We hope this review can give readers more insight into recent advances in LN photonics and contribute to the further development of LN related research.
基金We acknowledge financial support from the National Science Foundation(Nos.CCF 0726815 and CCF 0702204).
文摘Single-walled carbon nanotube(SWNT)thin film electrodes have been printed on flexible substrates and cloth fabrics by using SWNT inks and an off-the-shelf inkjet printer,with features of controlled pattern geometry(0.4-6 cm^(2)),location,controllable thickness(20-200 nm),and tunable electrical conductivity.The as-printed SWNT films were then sandwiched together with a piece of printable polymer electrolyte to form flexible and wearable supercapacitors,which displayed good capacitive behavior even after 1,000 charge/discharge cycles.Furthermore,a simple and efficient route to produce ruthenium oxide(RuO_(2))nanowire/SWNT hybrid films has been developed,and it was found that the knee frequency of the hybrid thin film electrodes can reach 1,500 Hz,which is much higher than the knee frequency of the bare SWNT electrodes(~158 Hz).In addition,with the integration of RuO_(2) nanowires,the performance of the printed SWNT supercapacitor was significantly improved in terms of its specific capacitance of 138 F/g,power density of 96 kW/kg,and energy density of 18.8 Wh/kg.The results indicate the potential of printable energy storage devices and their significant promise for application in wearable energy storage devices.
文摘Improper flow control devices in a multi-strand tundish can cause some problems, for example, liquid steel cannot reach every nozzle at the same time and the liquid steel in nozzles far away from the entry zone has a lower temperature. The water model experiment of a six-strand tundish of Tianjin Iron ＆ Steel Co. Ltd. was performed, a new ＂U＂ type baffle was obtained, and its parameters were defined by perpendicular analysis. The ＂U＂ baffle can not only improve those imperfections, but also prolong the residence time of nonmetallic inclusions, which is good for their flotation and separation.
文摘There are now numerous emerging flexible and wearable sensing technologies that can perform a myriad of physical and physiological measurements.Rapid advances in developing and implementing such sensors in the last several years have demonstrated the growing significance and potential utility of this unique class of sensing platforms.Applications include wearable consumer electronics,soft robotics,medical prosthetics,electronic skin,and health monitoring.In this review,we provide a state-ofthe-art overview of the emerging flexible and wearable sensing platforms for healthcare and biomedical applications.We first introduce the selection of flexible and stretchable materials and the fabrication of sensors based on these materials.We then compare the different solid-state and liquid-state physical sensing platforms and examine the mechanical deformation-based working mechanisms of these sensors.We also highlight some of the exciting applications of flexible and wearable physical sensors in emerging healthcare and biomedical applications,in particular for artificial electronic skins,physiological health monitoring and assessment,and therapeutic and drug delivery.Finally,we conclude this review by offering some insight into the challenges and opportunities facing this field.
基金supported by NSF of China (Grant No. 61775241)partly by the Innovation-driven Project (Grant No. 2017CX019)the funding support from the Australian Research Council (ARC Discovery Projects, DP180102976)
文摘With a large number of researches being conducted on two?dimen?sional(2D) materials, their unique properties in optics, electrics, mechanics, and magnetics have attracted increasing attention. Accordingly, the idea of combining distinct functional 2D materials into heterostructures naturally emerged that pro?vides unprecedented platforms for exploring new physics that are not accessible in a single 2D material or 3D heterostructures. Along with the rapid development of controllable, scalable, and programmed synthesis techniques of high?quality 2D heterostructures, various heterostructure devices with extraordinary performance have been designed and fabricated, including tunneling transistors, photodetectors, and spintronic devices. In this review, we present a summary of the latest progresses in fabrications, properties, and applications of di erent types of 2D heterostruc?tures, followed by the discussions on present challenges and perspectives of further investigations.
