The diagnosis of bacterial infections remains a major challenge in medicine.Optical imaging of bacterial infection in living animals is usually conducted with genetic reporters such as lightemitting encymes or fluores...The diagnosis of bacterial infections remains a major challenge in medicine.Optical imaging of bacterial infection in living animals is usually conducted with genetic reporters such as lightemitting encymes or fluorescent proteins.However,there are many circumstances where genetic reporters are not applicable,and there is an urgent need for exogenous synthetic probes that can selectively target bacteria.Optical imaging of bacteria in vivo is much less developed than methods such as ndioimaging and MRI.Furthermore near infrared(NIR)dyes with emision wavelengths in the region of 650-900 rm can propagate through two or more centimeters of tissue and may enable deeper tisue imaging if sensitive detection techniques are employed.Here we constructed an antimicrobial peptide fragment UBI29-41-based near infrared fuorescent imaging probe.The probe is composed of UBI2941 conjugated to a near infraured dye ICG Der-02.UBI29-41 is a cationic antimicrobial peptide that targets the anionic surfaces of bacterial cells.The probe allows detection of Staphylococcus aureus infection(5×10^(7)cells)in a mouse local infection model using whole animal nearinfrared fuorescence imaging.Furthermore,we demonstrate that the UBI29-41-based imaging probe can selectively accumulate within bacteria.The significantly higher accumulation in bacterial infection suggests that UBI29-41-based imaging probe may be a promising imaging agent to detect bacterial infections.展开更多
In high voltage input DC-DC converter, auxiliary winding of isolation transformer is usually used to supply power for control circuit. Due to the wide-range of input voltage, the variable output voltage of auxiliary w...In high voltage input DC-DC converter, auxiliary winding of isolation transformer is usually used to supply power for control circuit. Due to the wide-range of input voltage, the variable output voltage of auxiliary winding will cause a series of problems, such as variable drive pulse amplitude, increased driver switching devices loss and drive transformer core saturation. This paper analyzes the influence of variable output voltage of auxiliary winding in detail. A novel method is proposed to solve the problem of large variation range of auxiliary winding output voltage, which is adding a buck converter between the auxiliary winding and the control circuit. A dual switch forward convert has been designed with 300 V - 800 V input and 24 V/5 A output. The results show that this method is effective by comparing the different results of using buck converter or not.展开更多
[Objective] The research aimed to screen out an efficient aniline-degrading strain and study its degradation characteristics. [Method] By domesticated enrichment culture, an efficient aniline-degrading strain named as...[Objective] The research aimed to screen out an efficient aniline-degrading strain and study its degradation characteristics. [Method] By domesticated enrichment culture, an efficient aniline-degrading strain named as DA-K was isolated from activated sludge sample collected from a chemical plant in Henan. DA-K could use aniline as the sole carbon and nitrogen sources. The strain was carried out physiological and biochemi- cal identification, and its biological degradation characteristics were studied. [ Result] DA-K strain was G - and red-shaped, and its colony color was off-white. It was initially determined as Acinetobacter sp. By measuring, the optimum growth temperature and pH for DA-K were respectively 30 ~C and 6.0. DA-K strain could grow well in inorganic salt medium with aniline of 2 500 mg/L. After shaking for 96 h under the conditions of pH 6.0, 30 ℃, 180 r/min and 1 000 mg/L of aniline, the degradation rate of the aniline by DA-K could reach nearly 80%. [ Conclusion] The DA-K strain had a higher aniline degradation efficiency and actual treatment capability of the aniline wastewater, which laid foundation for establishing gene engineerincl strain.展开更多
Neurotransmitters are increasingly recognized to play important roles in limiting anti-tumor immunity.N-acetyl-aspartyl-glutamate(NAAG)has been extensively studied in neurological disorders;however,its potential role ...Neurotransmitters are increasingly recognized to play important roles in limiting anti-tumor immunity.N-acetyl-aspartyl-glutamate(NAAG)has been extensively studied in neurological disorders;however,its potential role in restricting anti-tumor immunity has not been investigated.Here,we demonstrated that NAAG or its synthetase RimK-like family member B(RIMKLB)significantly disrupted anti-tumor immunity by rewiring the myeloid progenitor differentiation of polymorphonuclear myeloid-derived suppressor cells(PMN-MDSCs),which in turn promoted breast cancer growth and metastasis.Mechanistically,NAAG sustained the tumor immunosuppressive microenvironment by activating an NR2B-containing NMDA receptor(NR2B-NMDAR)-dependent p38-NOTCH1 axis,and subsequently stimulating tumor cell migration and invasion,as well as inducing PMN-MDSC differentiation and expansion.In mouse models,RIMKLB ablation or NMDAR inhibition enhanced the efficacy of anti-PD-1 therapy and suppressed tumor progression.An analysis of clinical samples revealed that high levels of NAAG and NR2B-NMDAR predicted a poor prognosis in TNBC patients.Collectively,our findings have uncovered a signaling role for tumor-derived NAAG beyond its classic function as a neurotransmitter that can be targeted pharmacologically to enhance immunotherapy against breast cancer.展开更多
As China’s first asteroid exploration mission,the TianWen-2 spacecraft mainly focuses on surface sampling on the near-Earth asteroid 2016 HO3.Different from the usual sampling strategy of releasing a small lander or ...As China’s first asteroid exploration mission,the TianWen-2 spacecraft mainly focuses on surface sampling on the near-Earth asteroid 2016 HO3.Different from the usual sampling strategy of releasing a small lander or ejecting a projectile,the whole TianWen-2 spacecraft will be controlled to achieve touchdown and sampling.However,sampling on a low-gravity regolith-covered surface with unknown physical properties is particularly challenging and risky.In order to successfully implement an in situ exploration,a comprehensive understanding and evaluation of spacecraft dynamics and control behavior during sampling is essential for system design.In this paper,a system-level simulation method for the interaction between the spacecraft and the regolith surface is proposed.The discrete element method is adopted for the simulation of granular material dynamics.Parametric comparisons with test data from microgravity low-speed intrusion drop-tower experiments are implemented to calibrate and verify the physical parameters of the discrete element method simulation model.An explicit multibody dynamics model of the spacecraft is developed to describe dynamic characteristics such as orbit and attitude motion,solar array vibration,and sampler deformation.Finally,numerical simulations of the interaction between granular dynamics,multibody dynamics,and control are performed to study the dynamics and control behaviors of TianWen-2 sampling on an asteroid regolith surface.展开更多
The embryonic mesoderm comprises heterogeneous cell subpopulations with distinct lineage biases.It is unclear whether a bias for the human hematopoietic lineage emerges at this early developmental stage.In this study,...The embryonic mesoderm comprises heterogeneous cell subpopulations with distinct lineage biases.It is unclear whether a bias for the human hematopoietic lineage emerges at this early developmental stage.In this study,we integrated single-cell transcriptomic analyses of human mesoderm cells from embryonic stem cells and embryos,enabling us to identify and define the molecular features of human hematopoietic mesoderm(HM)cells biased towards hematopoietic lineages.We discovered that BMP4 plays an essential role in HM specification and can serve as a marker for HM cells.Mechanistically,BMP4 acts as a downstream target of HDAC1,which modulates the expression of BMP4 by deacetylating its enhancer.Inhibition of HDAC significantly enhances HM specification and promotes subsequent hematopoietic cell differentiation.In conclusion,our study identifies human HM cells and describes new mechanisms for human hematopoietic development.展开更多
Flow and heat transfer characteristics of slot jets impingement to a cylindrical convex surface are numerically investigated.Suitable turbulence models have been determined through comparison with the experimental dat...Flow and heat transfer characteristics of slot jets impingement to a cylindrical convex surface are numerically investigated.Suitable turbulence models have been determined through comparison with the experimental data.Flow structures are described and impingement heat transfer characteristics are discussed.The effects of Re,H/B and D/B on single-slot jets impingement heat transfer are analyzed and heat transfer characteristics of multiple-slot jets are investigated.The results show that:Gas flows along the convex surface and boundary layer separation occurs in both single and multiple-slot jets impingement.A maximum stagnation Nu appears at H/B=8 and the local Nu decreases with increasing H/B in the region far away from the stagnation.The Nu in the stagnation region decreases with increasing D/B but the Nu is nearly the same in the region far away from the stagnation.Pressure gradient is an important factor on heat transfer enhancement.Correlations of the Num for single-slot,double-slot and quadric-slot jets impinging on a convex surface are obtained.It indicates the effects of Re and D/B on Num could become more important in less slot jets impingement.展开更多
基金The authors are grateful to Natural Science Foun-dation Committee of China(NSFC 81220108012,81171395,81071194,81000666,30970776,30672015,30800257 and 31050110123)the Ministry of Science and Technology(2009ZX09310-004)the Pri-ority Academic Program Development of Jiangsu Higher Education Institutions for their financial support.
文摘The diagnosis of bacterial infections remains a major challenge in medicine.Optical imaging of bacterial infection in living animals is usually conducted with genetic reporters such as lightemitting encymes or fluorescent proteins.However,there are many circumstances where genetic reporters are not applicable,and there is an urgent need for exogenous synthetic probes that can selectively target bacteria.Optical imaging of bacteria in vivo is much less developed than methods such as ndioimaging and MRI.Furthermore near infrared(NIR)dyes with emision wavelengths in the region of 650-900 rm can propagate through two or more centimeters of tissue and may enable deeper tisue imaging if sensitive detection techniques are employed.Here we constructed an antimicrobial peptide fragment UBI29-41-based near infrared fuorescent imaging probe.The probe is composed of UBI2941 conjugated to a near infraured dye ICG Der-02.UBI29-41 is a cationic antimicrobial peptide that targets the anionic surfaces of bacterial cells.The probe allows detection of Staphylococcus aureus infection(5×10^(7)cells)in a mouse local infection model using whole animal nearinfrared fuorescence imaging.Furthermore,we demonstrate that the UBI29-41-based imaging probe can selectively accumulate within bacteria.The significantly higher accumulation in bacterial infection suggests that UBI29-41-based imaging probe may be a promising imaging agent to detect bacterial infections.
文摘In high voltage input DC-DC converter, auxiliary winding of isolation transformer is usually used to supply power for control circuit. Due to the wide-range of input voltage, the variable output voltage of auxiliary winding will cause a series of problems, such as variable drive pulse amplitude, increased driver switching devices loss and drive transformer core saturation. This paper analyzes the influence of variable output voltage of auxiliary winding in detail. A novel method is proposed to solve the problem of large variation range of auxiliary winding output voltage, which is adding a buck converter between the auxiliary winding and the control circuit. A dual switch forward convert has been designed with 300 V - 800 V input and 24 V/5 A output. The results show that this method is effective by comparing the different results of using buck converter or not.
基金Supported by National Transgene Special Project, China(2008ZX2008005-001)Major Public Project in Henan Province,China (091100910500)
文摘[Objective] The research aimed to screen out an efficient aniline-degrading strain and study its degradation characteristics. [Method] By domesticated enrichment culture, an efficient aniline-degrading strain named as DA-K was isolated from activated sludge sample collected from a chemical plant in Henan. DA-K could use aniline as the sole carbon and nitrogen sources. The strain was carried out physiological and biochemi- cal identification, and its biological degradation characteristics were studied. [ Result] DA-K strain was G - and red-shaped, and its colony color was off-white. It was initially determined as Acinetobacter sp. By measuring, the optimum growth temperature and pH for DA-K were respectively 30 ~C and 6.0. DA-K strain could grow well in inorganic salt medium with aniline of 2 500 mg/L. After shaking for 96 h under the conditions of pH 6.0, 30 ℃, 180 r/min and 1 000 mg/L of aniline, the degradation rate of the aniline by DA-K could reach nearly 80%. [ Conclusion] The DA-K strain had a higher aniline degradation efficiency and actual treatment capability of the aniline wastewater, which laid foundation for establishing gene engineerincl strain.
基金supported by the National Key Research and Development Program of China(2023YFC2506400 and 2020YFA0112300)the National Natural Science Foundation of China(82230103,82073267,W2431054,81930075,and 82372689)+2 种基金“Ten Thousand Plan”-National High-Level Talents Special Support Plan(WR-YK5202101)Program for Outstanding Leading Talents in Shanghai,Program for Outstanding Medical Academic Leader in Shanghai(2019LJ04)Program of Shanghai Academic/Technology Research Leader(20XD1400700)。
文摘Neurotransmitters are increasingly recognized to play important roles in limiting anti-tumor immunity.N-acetyl-aspartyl-glutamate(NAAG)has been extensively studied in neurological disorders;however,its potential role in restricting anti-tumor immunity has not been investigated.Here,we demonstrated that NAAG or its synthetase RimK-like family member B(RIMKLB)significantly disrupted anti-tumor immunity by rewiring the myeloid progenitor differentiation of polymorphonuclear myeloid-derived suppressor cells(PMN-MDSCs),which in turn promoted breast cancer growth and metastasis.Mechanistically,NAAG sustained the tumor immunosuppressive microenvironment by activating an NR2B-containing NMDA receptor(NR2B-NMDAR)-dependent p38-NOTCH1 axis,and subsequently stimulating tumor cell migration and invasion,as well as inducing PMN-MDSC differentiation and expansion.In mouse models,RIMKLB ablation or NMDAR inhibition enhanced the efficacy of anti-PD-1 therapy and suppressed tumor progression.An analysis of clinical samples revealed that high levels of NAAG and NR2B-NMDAR predicted a poor prognosis in TNBC patients.Collectively,our findings have uncovered a signaling role for tumor-derived NAAG beyond its classic function as a neurotransmitter that can be targeted pharmacologically to enhance immunotherapy against breast cancer.
基金supported by the National Natural Science Foundation of China(Grant No.U24B2048).
文摘As China’s first asteroid exploration mission,the TianWen-2 spacecraft mainly focuses on surface sampling on the near-Earth asteroid 2016 HO3.Different from the usual sampling strategy of releasing a small lander or ejecting a projectile,the whole TianWen-2 spacecraft will be controlled to achieve touchdown and sampling.However,sampling on a low-gravity regolith-covered surface with unknown physical properties is particularly challenging and risky.In order to successfully implement an in situ exploration,a comprehensive understanding and evaluation of spacecraft dynamics and control behavior during sampling is essential for system design.In this paper,a system-level simulation method for the interaction between the spacecraft and the regolith surface is proposed.The discrete element method is adopted for the simulation of granular material dynamics.Parametric comparisons with test data from microgravity low-speed intrusion drop-tower experiments are implemented to calibrate and verify the physical parameters of the discrete element method simulation model.An explicit multibody dynamics model of the spacecraft is developed to describe dynamic characteristics such as orbit and attitude motion,solar array vibration,and sampler deformation.Finally,numerical simulations of the interaction between granular dynamics,multibody dynamics,and control are performed to study the dynamics and control behaviors of TianWen-2 sampling on an asteroid regolith surface.
基金supported by the CAMS Innovation Fund for Medical Sciences(2021-I2M-1-073,2021-I2M-1-040,2022-I2M-JB-015)the National Key Research and Development Program of China(2021YFA1100703,2021YFA1103000)+2 种基金Haihe Laboratory of Cell Ecosystem Innovation Fund(22HHXBSS00031)the National Natural Science Foundation of China(82125003,32271161,82200141)Tianjin Municipal Science and Technology Commission Grant(20JCYBJC00240,22ZXSYSY00010,22JCQNJC01270)。
文摘The embryonic mesoderm comprises heterogeneous cell subpopulations with distinct lineage biases.It is unclear whether a bias for the human hematopoietic lineage emerges at this early developmental stage.In this study,we integrated single-cell transcriptomic analyses of human mesoderm cells from embryonic stem cells and embryos,enabling us to identify and define the molecular features of human hematopoietic mesoderm(HM)cells biased towards hematopoietic lineages.We discovered that BMP4 plays an essential role in HM specification and can serve as a marker for HM cells.Mechanistically,BMP4 acts as a downstream target of HDAC1,which modulates the expression of BMP4 by deacetylating its enhancer.Inhibition of HDAC significantly enhances HM specification and promotes subsequent hematopoietic cell differentiation.In conclusion,our study identifies human HM cells and describes new mechanisms for human hematopoietic development.
文摘Flow and heat transfer characteristics of slot jets impingement to a cylindrical convex surface are numerically investigated.Suitable turbulence models have been determined through comparison with the experimental data.Flow structures are described and impingement heat transfer characteristics are discussed.The effects of Re,H/B and D/B on single-slot jets impingement heat transfer are analyzed and heat transfer characteristics of multiple-slot jets are investigated.The results show that:Gas flows along the convex surface and boundary layer separation occurs in both single and multiple-slot jets impingement.A maximum stagnation Nu appears at H/B=8 and the local Nu decreases with increasing H/B in the region far away from the stagnation.The Nu in the stagnation region decreases with increasing D/B but the Nu is nearly the same in the region far away from the stagnation.Pressure gradient is an important factor on heat transfer enhancement.Correlations of the Num for single-slot,double-slot and quadric-slot jets impinging on a convex surface are obtained.It indicates the effects of Re and D/B on Num could become more important in less slot jets impingement.
