To investigate the influence of electric parameters and slag system on the solidification quality of electroslag ingot during electroslag remelting,different power supply modes,current strengths and remelting slag sys...To investigate the influence of electric parameters and slag system on the solidification quality of electroslag ingot during electroslag remelting,different power supply modes,current strengths and remelting slag systems were used to conduct electroslag remelting experiments on 304L austenitic stainless steel,and the macrostructure of electroslag ingots was analyzed.The results indicate that the depth of the metal pool decreases with the reduction of remelting frequency in the low frequency power supply mode.The effects of different power supply modes,such as low-frequency,direct current straight polarity(DCSP),and direct current reverse polarity(DCRP),on reducing the depth of the metal pool increase in that order.By reducing the remelting current strength in the same power supply mode,the depth of metal pool is reduced.When compared to the binary slag system of 70%CaF2+30%Al2O3,the ternary slag system of 60%CaF2+20%Al2O3+20%CaO is more effective in reducing the depth of the metal pool during remelting.Utilizing the 60%CaF2+20%Al2O3+20%CaO ternary slag system results in a shallower and flatter metal pool,with columnar crystal growth occurring closer to the axial crystal.This effect is observed for both low frequency and direct current(DC)power supply modes.展开更多
AIM: To address the microstructure and biomechanical changes of the sclera of rabbits after negative lens application by spectacle frame apparatus.METHODS: Five New Zealand rabbits of seven weeks post-natal were treat...AIM: To address the microstructure and biomechanical changes of the sclera of rabbits after negative lens application by spectacle frame apparatus.METHODS: Five New Zealand rabbits of seven weeks post-natal were treated with-8 D lens monocularly over the course of two weeks. Refractive errors and axial length(AXL) were measured at the 1 st, 7 th and 14 th days of the induction period. Ultrastructure of sclera was determined with electron microscopy. Biomechanical properties were tested by an Instron 5565 universal testing machine.RESULTS: Lens-induced(LI) eyes elongated more rapidly compared with fellow eyes with AXL values of 15.56±0.14 and 15.21±0.14 mm(P<0.01). Fibril diameter was significantly smaller in the LI eyes compared with control ones in the inner, middle, and outer layers(inner layer, 63.533 vs 76.467 nm; middle layer, 92.647 vs 123.984 nm; outer layer, 86.999 vs 134.257 nm, P<0.01, respectively). In comparison with control eyes, macrophage-like cells that engulfed fibroblasts, dilated endoplasmic reticulum, and vacuoles in fibroblasts were observed in the inner and middle stroma in the LI eyes. Ultimate stress and Young's modulus were lower in the LI eyes compared with those in the control eyes.CONCLUSION: Negative lens application alters eye growth, and results in axial elongation with changes in scleral ultrastructural and mechanical properties.展开更多
Testing the extreme weak gravitational forces between torsion pendulum and surrounding objects will indicate new physics which attracts many interests.In these measurements,the fiber alignment plays a crucial role in ...Testing the extreme weak gravitational forces between torsion pendulum and surrounding objects will indicate new physics which attracts many interests.In these measurements,the fiber alignment plays a crucial role in fulfilling high precision placement measurement,especially in measuring the deviation between the fiber and source mass or other objects.The traditional way of the fiber alignment requires to measure the component of the pendulum body and then transfer to the torsion fiber by some complicated calculations.A new method is reported here by using a CCD camera to get the projection image of the torsion fiber,which is a direct and no-contact measurement.Furthermore,the relative position change of the torsion fiber can also be monitored during the experiment.In our experiment,the alignment between the fiber and the center of the turntable has been operated as an example.Our result reaches the accuracy of several micrometers which is higher than the previous method.展开更多
Experimental techniques based on SR facilities have emerged with the development of synchrotron radiation(SR)sources.Accordingly,detector miniaturization has become significant for the development of SR experimental t...Experimental techniques based on SR facilities have emerged with the development of synchrotron radiation(SR)sources.Accordingly,detector miniaturization has become significant for the development of SR experimental techniques.In this study,the miniaturization of a detector was achieved by coupling a commercial silicon PIN photodiode(SPPD)into a beamstop,aiming for it not only to acquire X-ray absorption fine structure(XAFS)spectra,but also to protect the subsequent two-dimensional detector from high-brilliance X-ray radiation damage in certain combination techniques.This mini SPPD detector coupled to a beamstop was used as the rear detector in both the conventional sampling scheme and novel high-frequency(HF)sampling scheme to collect the transmission XAFS spectra.Traditional ion chambers were also used to collect the transmission XAFS spectra,which were used as the reference.These XAFS spectra were quantitatively analyzed and compared;the results demonstrated that the XAFS spectra collected by this SPPD in both the conventional sampling scheme and HF sampling scheme are feasible.This study provides a new detector-selection scheme for the acquisition of the quick-scanning XAFS(QXAFS)and HF sampling XAFS spectra.The SPPD detector presented in this study can partially meet the requirements of detector miniaturization.展开更多
Dear editor,Lactic acidosis is a commonly encountered condition in the emergency department,and the most common causes of lactic acidosis are hypoperfusion and hypoxia induced by sepsis.A number of other diseases can ...Dear editor,Lactic acidosis is a commonly encountered condition in the emergency department,and the most common causes of lactic acidosis are hypoperfusion and hypoxia induced by sepsis.A number of other diseases can also cause hyperlactatemia,such as hematological malignancies,which can sometimes be life-threatening.Treatment of hyperlactatemia is largely dependent on underlying conditions.Therefore,an accurate diagnosis is important,and prompt treatment could be lifesaving.Despite the advances in medical sciences,lactic acidosis and malignancy have been linked only in a small number of cases,[1]and hypoglycemia and dyslipidemia were rare findings.We report a case of an elderly woman who had persistent lactic acidosis and hypoglycemia with dyslipidemia and was finally diagnosed with B-cell lymphoma.The aim of this case is to highlight the importance of considering hematological malignancies when presented with persistent lactic acidosis and identify a diagnosis for appropriate and timely treatment.展开更多
Biodegradable poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)/graphene nanosheet (GNS) composites were prepared via a solution-casting method at low GNS loadings in this work. Transmission electron microscopy reve...Biodegradable poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)/graphene nanosheet (GNS) composites were prepared via a solution-casting method at low GNS loadings in this work. Transmission electron microscopy revealed that a fine dispersion of GNSs was achieved in the PHBV matrix. The thermal properties of the nanocomposites were investigated by thermogravimetric analysis, and the results showed that the thermal stability of PHBV was significantly improved with a very low loading of GNSs. Nonisothermal melts crystallization behavior, spherulitic morphology and crystal structure of neat PHBV and the PHBV/GNSs nanocomposites were investigated, and the experimental results indicated that crystallization behavior of PHBV was enhanced by the presence of GNSs due to the heterogeneous nucleation effect; however, the two-dimensional (2D) GNSs might restrict the mobility of the PHBV chains in the process of crystal growing. Dynamic mechanical analysis studies showed that the storage modulus of the PHBV/GNSs nanocomposites was greatly improved.展开更多
Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)(PHBV)/chitin nanocrystals(CNC) composite scaffolds were synthesized by the salt leaching and thermally induced phase separation(TIPS) technique.The scaffolds have porous st...Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)(PHBV)/chitin nanocrystals(CNC) composite scaffolds were synthesized by the salt leaching and thermally induced phase separation(TIPS) technique.The scaffolds have porous structures with macro-pores(100-300 μm in diameters) and micro-pores(10μm).The surface characteristics of the scaffolds were characterized by X-ray photoelectron spectroscopy(XPS) and static water contact angle measurement,and the mechanical properties were investigated by a compression test.Human adipose-derived stem cells(hADSCs) were seeded onto the PHBV/CNC scaffolds and in vitro cell culture results showed that the composite scaffolds enhanced the hADSCs adhesion,which implies that the material may have potential application in tissue engineering.展开更多
To the Editor:A 64-year-old Chinese man(65 kg)with fever and lymphadenopathy was admitted to the hematology department of the Peking University First Hospital.Before admission,he had had intermittent fever for the pas...To the Editor:A 64-year-old Chinese man(65 kg)with fever and lymphadenopathy was admitted to the hematology department of the Peking University First Hospital.Before admission,he had had intermittent fever for the past 3 months with a body temperature high of 38.5°C.He had no accompanying discomfort and his temperature sometimes dropped to normal without drugs.One month before admission,he found several palpable enlarged cervical lymph nodes.Upon admission,a lymph node biopsy was conducted and the pathological diagnosis showed a nodular sclerosis,a subtype of classical Hodgkin lymphoma.展开更多
Flexible,breathable and lightweight electronic textiles hold great promise to change the ways we intact with electronics.Electrical connections among functional components are indispensable for system integrations of ...Flexible,breathable and lightweight electronic textiles hold great promise to change the ways we intact with electronics.Electrical connections among functional components are indispensable for system integrations of electronic textiles.However,it remains challenging to achieve mechanically and electrically robust connections to fully integrate with interwoven architecture and weaving process of textiles.Here,we reported a seamlessly-integrated textile electric circuit by weaving conductive fibers with self-connecting capacity at the interwoven points.Selfconnecting conductive fibers(SCFs)were prepared by coating modified polyurethane conductive composites onto nylon fibers.Electrical connections were achieved at interwoven points in less than 5 s once the weft and warp SCFs were woven together,due to the designed dynamic bonds of aromatic disulfide metathesis and hydrogen bonds in the modified polyurethane(MPU).The self-connecting point was electrically stable(varied by less than 6.7%in electrical resistance)to withstand repeated deformations of bending,pressing and even folding.Such a selfconnecting strategy could be generalized to weave full-textile electronics capable of receiving signals and displaying with enhanced interfacial stability,offering a new way to unify fabrication of electronics and weaving of textiles.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant Nos.52074002,52174289)Natural Science Foundation of Anhui Province(Grant No.2208085J37)。
文摘To investigate the influence of electric parameters and slag system on the solidification quality of electroslag ingot during electroslag remelting,different power supply modes,current strengths and remelting slag systems were used to conduct electroslag remelting experiments on 304L austenitic stainless steel,and the macrostructure of electroslag ingots was analyzed.The results indicate that the depth of the metal pool decreases with the reduction of remelting frequency in the low frequency power supply mode.The effects of different power supply modes,such as low-frequency,direct current straight polarity(DCSP),and direct current reverse polarity(DCRP),on reducing the depth of the metal pool increase in that order.By reducing the remelting current strength in the same power supply mode,the depth of metal pool is reduced.When compared to the binary slag system of 70%CaF2+30%Al2O3,the ternary slag system of 60%CaF2+20%Al2O3+20%CaO is more effective in reducing the depth of the metal pool during remelting.Utilizing the 60%CaF2+20%Al2O3+20%CaO ternary slag system results in a shallower and flatter metal pool,with columnar crystal growth occurring closer to the axial crystal.This effect is observed for both low frequency and direct current(DC)power supply modes.
基金Supported by the Science and Technology Commission of Shanghai Municipality(No.134119a5100)
文摘AIM: To address the microstructure and biomechanical changes of the sclera of rabbits after negative lens application by spectacle frame apparatus.METHODS: Five New Zealand rabbits of seven weeks post-natal were treated with-8 D lens monocularly over the course of two weeks. Refractive errors and axial length(AXL) were measured at the 1 st, 7 th and 14 th days of the induction period. Ultrastructure of sclera was determined with electron microscopy. Biomechanical properties were tested by an Instron 5565 universal testing machine.RESULTS: Lens-induced(LI) eyes elongated more rapidly compared with fellow eyes with AXL values of 15.56±0.14 and 15.21±0.14 mm(P<0.01). Fibril diameter was significantly smaller in the LI eyes compared with control ones in the inner, middle, and outer layers(inner layer, 63.533 vs 76.467 nm; middle layer, 92.647 vs 123.984 nm; outer layer, 86.999 vs 134.257 nm, P<0.01, respectively). In comparison with control eyes, macrophage-like cells that engulfed fibroblasts, dilated endoplasmic reticulum, and vacuoles in fibroblasts were observed in the inner and middle stroma in the LI eyes. Ultimate stress and Young's modulus were lower in the LI eyes compared with those in the control eyes.CONCLUSION: Negative lens application alters eye growth, and results in axial elongation with changes in scleral ultrastructural and mechanical properties.
基金the National Natural Science Foundation of China(Grant No.11305057).
文摘Testing the extreme weak gravitational forces between torsion pendulum and surrounding objects will indicate new physics which attracts many interests.In these measurements,the fiber alignment plays a crucial role in fulfilling high precision placement measurement,especially in measuring the deviation between the fiber and source mass or other objects.The traditional way of the fiber alignment requires to measure the component of the pendulum body and then transfer to the torsion fiber by some complicated calculations.A new method is reported here by using a CCD camera to get the projection image of the torsion fiber,which is a direct and no-contact measurement.Furthermore,the relative position change of the torsion fiber can also be monitored during the experiment.In our experiment,the alignment between the fiber and the center of the turntable has been operated as an example.Our result reaches the accuracy of several micrometers which is higher than the previous method.
基金supported by the National Key R&D Program of China(Nos.2017YFA0403000 and 2017YFA0403100).
文摘Experimental techniques based on SR facilities have emerged with the development of synchrotron radiation(SR)sources.Accordingly,detector miniaturization has become significant for the development of SR experimental techniques.In this study,the miniaturization of a detector was achieved by coupling a commercial silicon PIN photodiode(SPPD)into a beamstop,aiming for it not only to acquire X-ray absorption fine structure(XAFS)spectra,but also to protect the subsequent two-dimensional detector from high-brilliance X-ray radiation damage in certain combination techniques.This mini SPPD detector coupled to a beamstop was used as the rear detector in both the conventional sampling scheme and novel high-frequency(HF)sampling scheme to collect the transmission XAFS spectra.Traditional ion chambers were also used to collect the transmission XAFS spectra,which were used as the reference.These XAFS spectra were quantitatively analyzed and compared;the results demonstrated that the XAFS spectra collected by this SPPD in both the conventional sampling scheme and HF sampling scheme are feasible.This study provides a new detector-selection scheme for the acquisition of the quick-scanning XAFS(QXAFS)and HF sampling XAFS spectra.The SPPD detector presented in this study can partially meet the requirements of detector miniaturization.
文摘Dear editor,Lactic acidosis is a commonly encountered condition in the emergency department,and the most common causes of lactic acidosis are hypoperfusion and hypoxia induced by sepsis.A number of other diseases can also cause hyperlactatemia,such as hematological malignancies,which can sometimes be life-threatening.Treatment of hyperlactatemia is largely dependent on underlying conditions.Therefore,an accurate diagnosis is important,and prompt treatment could be lifesaving.Despite the advances in medical sciences,lactic acidosis and malignancy have been linked only in a small number of cases,[1]and hypoglycemia and dyslipidemia were rare findings.We report a case of an elderly woman who had persistent lactic acidosis and hypoglycemia with dyslipidemia and was finally diagnosed with B-cell lymphoma.The aim of this case is to highlight the importance of considering hematological malignancies when presented with persistent lactic acidosis and identify a diagnosis for appropriate and timely treatment.
基金supported by the Ningbo Natural Science Foundation (Nos. 2010A610193 and 2011A610116)the Program for Ningbo Innovative Research Team (2009B21008)the Ningbo Key Lab of Polymer Materials(No. 2010A22001)
文摘Biodegradable poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)/graphene nanosheet (GNS) composites were prepared via a solution-casting method at low GNS loadings in this work. Transmission electron microscopy revealed that a fine dispersion of GNSs was achieved in the PHBV matrix. The thermal properties of the nanocomposites were investigated by thermogravimetric analysis, and the results showed that the thermal stability of PHBV was significantly improved with a very low loading of GNSs. Nonisothermal melts crystallization behavior, spherulitic morphology and crystal structure of neat PHBV and the PHBV/GNSs nanocomposites were investigated, and the experimental results indicated that crystallization behavior of PHBV was enhanced by the presence of GNSs due to the heterogeneous nucleation effect; however, the two-dimensional (2D) GNSs might restrict the mobility of the PHBV chains in the process of crystal growing. Dynamic mechanical analysis studies showed that the storage modulus of the PHBV/GNSs nanocomposites was greatly improved.
基金Ministry of Science and Technology of the People's Republic of China(No.1106)Ningbo Science Foundation (No.2011A610116)+1 种基金National Key Basic Research Program of China(973,No.2014CB643305)the China Postdoctoral Science Foundation Funded Project(No.2012T50564) for financial support
文摘Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)(PHBV)/chitin nanocrystals(CNC) composite scaffolds were synthesized by the salt leaching and thermally induced phase separation(TIPS) technique.The scaffolds have porous structures with macro-pores(100-300 μm in diameters) and micro-pores(10μm).The surface characteristics of the scaffolds were characterized by X-ray photoelectron spectroscopy(XPS) and static water contact angle measurement,and the mechanical properties were investigated by a compression test.Human adipose-derived stem cells(hADSCs) were seeded onto the PHBV/CNC scaffolds and in vitro cell culture results showed that the composite scaffolds enhanced the hADSCs adhesion,which implies that the material may have potential application in tissue engineering.
基金supported by the Municipal Science Technology Commission(No.Z191100006619026)。
文摘To the Editor:A 64-year-old Chinese man(65 kg)with fever and lymphadenopathy was admitted to the hematology department of the Peking University First Hospital.Before admission,he had had intermittent fever for the past 3 months with a body temperature high of 38.5°C.He had no accompanying discomfort and his temperature sometimes dropped to normal without drugs.One month before admission,he found several palpable enlarged cervical lymph nodes.Upon admission,a lymph node biopsy was conducted and the pathological diagnosis showed a nodular sclerosis,a subtype of classical Hodgkin lymphoma.
基金financially supported by the National Natural Science Foundation of China(Nos.22175042,52122310,22075050 and 22105045)Science and Technology Commission of Shanghai Municipality(Nos.20JC1414902,21511104900 and 19QA1400800)Shanghai Municipal Education Commission(No.2017-01-07-00-07-E00062)。
文摘Flexible,breathable and lightweight electronic textiles hold great promise to change the ways we intact with electronics.Electrical connections among functional components are indispensable for system integrations of electronic textiles.However,it remains challenging to achieve mechanically and electrically robust connections to fully integrate with interwoven architecture and weaving process of textiles.Here,we reported a seamlessly-integrated textile electric circuit by weaving conductive fibers with self-connecting capacity at the interwoven points.Selfconnecting conductive fibers(SCFs)were prepared by coating modified polyurethane conductive composites onto nylon fibers.Electrical connections were achieved at interwoven points in less than 5 s once the weft and warp SCFs were woven together,due to the designed dynamic bonds of aromatic disulfide metathesis and hydrogen bonds in the modified polyurethane(MPU).The self-connecting point was electrically stable(varied by less than 6.7%in electrical resistance)to withstand repeated deformations of bending,pressing and even folding.Such a selfconnecting strategy could be generalized to weave full-textile electronics capable of receiving signals and displaying with enhanced interfacial stability,offering a new way to unify fabrication of electronics and weaving of textiles.
