In this paper, an injection-seeded nanosecond optical parametric generation (OPG) using BBO crystal, which combines relatively low thresholds with a simple and compact configuration, was demonstrated. By seeding exter...In this paper, an injection-seeded nanosecond optical parametric generation (OPG) using BBO crystal, which combines relatively low thresholds with a simple and compact configuration, was demonstrated. By seeding externally with distributed feedback (DFB) diode laser at 1313 nm wavelength, pumped by 355 nm laser pulse, the maximum blue laser output power of 1.36 W at a rate of 100 Hz and with linewidth less than 0.13 nm were obtained, and the maximum optical to optical conversion efficiency was to 21.2%.展开更多
[Objectives]The research aimed to explore the determination method for content of total flavonoids from Paulownia fortunei flower.[Methods]Rutin was taken as control.By comparing absorption characteristics of total fl...[Objectives]The research aimed to explore the determination method for content of total flavonoids from Paulownia fortunei flower.[Methods]Rutin was taken as control.By comparing absorption characteristics of total flavonoids in NaNO_(2)-Al(NO_(3))_(3)-NaOH and AlCl_(3) chromogenic system,an appropriate method for the determination of total flavonoids from P.fortunei flower was screened,and the method was verified by methodology.On the basis of single factor experiment,the coloration time of the method was optimized by orthogonal experiment.[Results]NaNO_(2)-Al(NO_(3))_(3)-NaOH chromogenic system was more suitable for the determination of total flavonoids from P.fortunei flower,and the adding standard recovery was between 99.2%and 105.5%,and RSD was 2.18%,with better repeatability,precision,stability and accuracy.The optimized coloration time of NaNO_(2),Al(NO_(3))_(3) and NaOH was 6,6,and 10 min.Under the condition,average content of total flavonoids from P.fortunei flower was 3.78%,and RSD was 2.05%.[Conclusions]The optimized NaNO_(2)-Al(NO_(3))_(3)-NaOH chromogenic method is simple,rapid,and accurate,and could be used as a method for the determination of total flavonoids from P.fortunei flower.展开更多
Despite surgical improvements and pharmacological advances,management of late-stage gastric cancer patients,especially those with hepatic metastasis remains challenging[1–3].Although nationwide registry data from SEE...Despite surgical improvements and pharmacological advances,management of late-stage gastric cancer patients,especially those with hepatic metastasis remains challenging[1–3].Although nationwide registry data from SEER(Surveillance,Epidemiology,and End Results)[4]and the Nordic database[5]in Western countries have provided epidemiological information for patients with gastric cancer liver metastasis(GCLM),little is known about the detailed clinical characteristics.展开更多
An external frequency doubling electro-optically Q-switched neodymium-doped yttrium aluminum garnet (Nd:YAG) 473 nm blue laser was demonstrated. With absorbed pump energy of 48 mJ at 100 Hz repetition rate, about 2 mJ...An external frequency doubling electro-optically Q-switched neodymium-doped yttrium aluminum garnet (Nd:YAG) 473 nm blue laser was demonstrated. With absorbed pump energy of 48 mJ at 100 Hz repetition rate, about 2 mJ of 473 nm blue laser pulse energy was achieved by cascade frequency doubling. The second harmonic conversion efficiency was 64.5%, and overall optical-optical efficiency was 4.2%, respectively. The blue laser pulse width was less than 10 ns, and beam quality factor was less than 2.4.展开更多
A 222 nm all-solid-state far-ultraviolet C(UVC)pulse laser system based on an optical parametric oscillator(OPO)and second-harmonic generation(SHG)usingβ-Ba2BO4(BBO)crystals was demonstrated.Pumped by a Nd∶Y3Al5O12 ...A 222 nm all-solid-state far-ultraviolet C(UVC)pulse laser system based on an optical parametric oscillator(OPO)and second-harmonic generation(SHG)usingβ-Ba2BO4(BBO)crystals was demonstrated.Pumped by a Nd∶Y3Al5O12 laser with a repetition rate of 100 Hz at 355 nm,the maximum signal laser pulse energy of 1.22 mJ at 444 nm wavelength was obtained from the BBO-OPO system,corresponding to a conversion efficiency of 27.9%.The maximum output pulse energy of 164.9μJ at the 222 nm wavelength was successfully achieved,corresponding to an SHG conversion efficiency of 16.2%.Moreover,the tunable output wavelength of UVC light from 210 nm to 252.5 nm was achieved.展开更多
Hepatoid carcinoma of the pancreas(HCP)is an extremely rare pancreatic cancer resembling hepatocellular carcinoma,a type of liver cancer(1).Most reports have shown that it has an aggressive behavior and is associated ...Hepatoid carcinoma of the pancreas(HCP)is an extremely rare pancreatic cancer resembling hepatocellular carcinoma,a type of liver cancer(1).Most reports have shown that it has an aggressive behavior and is associated with early metastasis.There is no standardized treatment for HCP due to its rarity,and the limited number of cases reported in the literature(2,3).However,treatment options for this type of rare cancer include surgery,chemotherapy,and radiation therapy,depending on the stage of the cancer.Nevertheless,the prognosis of HCP is poor.展开更多
Rapid large-area tissue imaging at the cellular resolution is important for clinical diagnosis.We present a probe-based confocal microendoscope(p CM)with a field-of-view(FOV)diameter over 500μm,lateral resolution of ...Rapid large-area tissue imaging at the cellular resolution is important for clinical diagnosis.We present a probe-based confocal microendoscope(p CM)with a field-of-view(FOV)diameter over 500μm,lateral resolution of 1.95μm,and outer diameter of 2.6 mm,compatible with the biopsy channel of conventional gastroscopes.Compared to a conventional p CM,our system's FOV increased by a factor of 4 while maintaining the probe size and cellular resolution—comparable to the FOV of Zeiss Axio Observer's 20×=0.8 numerical aperture objective lens.Ex vivo imaging of wide areas in healthy and diseased rat gastrointestinal tract tissues demonstrates the system's practicality.展开更多
SARS-CoV-2(severe acute respiratory syndrome coronavirus 2)has evolved many variants with stronger infectivity and immune evasion than the original strain,including Alpha,Beta,Gamma,Delta,Epsilon,Kappa,lota,Lambda,and...SARS-CoV-2(severe acute respiratory syndrome coronavirus 2)has evolved many variants with stronger infectivity and immune evasion than the original strain,including Alpha,Beta,Gamma,Delta,Epsilon,Kappa,lota,Lambda,and 21H strains.Amino acid mutations are enriched in the spike protein of SARS CoV-2.which plays a crucial role in cell infetion.However,the impact of these mutations on protein structure and function is unclear.Understanding the pathophysiology and pandemic feaures of these SARS-CoV-2 variants requires knowledge of the spike protein structures.Here,we obtained the spike protein structures of 10 main globally endemic SARS CoV-2 strains using AlphaFold2.The clustering analysis based on structural similarity revealed the unique features of the mainly pandemic SARS CoV-2 Delta variants.indicating that structural clusters can reflect the current characteristics of the epidemic more accurately than those based on the protein sequence.The analysis of the binding afinities of ACE2-RBD,antibody-NTD,and antibody-RBD complexes in the different variants revealed that the recognition of antibodies against SI NTD and RBD was decreased in the variants,especally the Delta variant compared with the original strain,which may induce the immune evasion of SARS-CoV-2 variants.Furthermore,by virtual screening the ZINC database against a high-accuracy predicted structure of Delta spike protein and experimental validation,we identified multiple compounds that target S1 NTD and RBD,which might contribute towards the development of clinical anti-SARS-CoV-2 medicines.Our findings provided a basic foundation for future in vitro and in vivo investigations that might speed up the development of potential therapies for the SARS-CoV-2 va riants.展开更多
A highly efficient laser system output at the H-β Fraunhofer line of 486.1 nm has been demonstrated. A high pulse energy single-frequency hybrid 1064 nm master oscillator power amplifier was frequency-tripled to achi...A highly efficient laser system output at the H-β Fraunhofer line of 486.1 nm has been demonstrated. A high pulse energy single-frequency hybrid 1064 nm master oscillator power amplifier was frequency-tripled to achieve355 nm laser pulses, which acted as the pump source of the beta barium borate nanosecond pulse optical parametric oscillator. With pump energy of 190 mJ, the laser system generated a maximum output of 62 mJ blue laser pulses at 486.1 nm, corresponding to conversion efficiency of 32.6%. The laser spectrum width was measured to be around 0.1 nm, being in conformity with the spectrum width of the solar Fraunhofer line.展开更多
A single-resonant low-threshold type-Iβ-Ba_(2)BO_(4)(BBO) optical parametric oscillator (OPO) with tunable output from 410 nm to 630 nm at 5 k Hz repetition rate is reported.By taking the noncollinear phase matching ...A single-resonant low-threshold type-Iβ-Ba_(2)BO_(4)(BBO) optical parametric oscillator (OPO) with tunable output from 410 nm to 630 nm at 5 k Hz repetition rate is reported.By taking the noncollinear phase matching method,low-threshold OPO operation could be obtained compared with the configuration of collinear phase matching,and the maximum optical–optical conversion efficiency of 11.8%was achieved at 500 nm wavelength when 0.4 m J pump pulse energy was applied.When the noncollinearity angle was preset at 1.6°,4.8°,and 6.3°,a continuously tuning output with a total spectral range of 220 nm was successfully obtained by adjusting the phase matching angle of the BBO crystal.展开更多
One fast simulation method using Markov chains was introduced to simulate angular,energy,and temporal characteristics of pulsed laser beam propagation underwater.Angular dispersion of photons with a different number o...One fast simulation method using Markov chains was introduced to simulate angular,energy,and temporal characteristics of pulsed laser beam propagation underwater.Angular dispersion of photons with a different number of collisions was calculated based on scattering function and the state transition matrix of Markov chains.Temporal distribution and energy on the receiving plane were obtained,respectively,by use of a novel successive layering model and receiving ratio.The validity of this method was verified by comparing it with the Monte Carlo ray tracing(MCRT)method.The simulation results were close to those obtained by MCRT but were less time consuming and had smoother curves.展开更多
文摘In this paper, an injection-seeded nanosecond optical parametric generation (OPG) using BBO crystal, which combines relatively low thresholds with a simple and compact configuration, was demonstrated. By seeding externally with distributed feedback (DFB) diode laser at 1313 nm wavelength, pumped by 355 nm laser pulse, the maximum blue laser output power of 1.36 W at a rate of 100 Hz and with linewidth less than 0.13 nm were obtained, and the maximum optical to optical conversion efficiency was to 21.2%.
基金Jiangsu Innovation Training Program for College Students(202114541009Y).
文摘[Objectives]The research aimed to explore the determination method for content of total flavonoids from Paulownia fortunei flower.[Methods]Rutin was taken as control.By comparing absorption characteristics of total flavonoids in NaNO_(2)-Al(NO_(3))_(3)-NaOH and AlCl_(3) chromogenic system,an appropriate method for the determination of total flavonoids from P.fortunei flower was screened,and the method was verified by methodology.On the basis of single factor experiment,the coloration time of the method was optimized by orthogonal experiment.[Results]NaNO_(2)-Al(NO_(3))_(3)-NaOH chromogenic system was more suitable for the determination of total flavonoids from P.fortunei flower,and the adding standard recovery was between 99.2%and 105.5%,and RSD was 2.18%,with better repeatability,precision,stability and accuracy.The optimized coloration time of NaNO_(2),Al(NO_(3))_(3) and NaOH was 6,6,and 10 min.Under the condition,average content of total flavonoids from P.fortunei flower was 3.78%,and RSD was 2.05%.[Conclusions]The optimized NaNO_(2)-Al(NO_(3))_(3)-NaOH chromogenic method is simple,rapid,and accurate,and could be used as a method for the determination of total flavonoids from P.fortunei flower.
基金This work was supported by the National Natural Science Foundation of China(81972790)the Beijing Nova Program(Z181100006218011).
文摘Despite surgical improvements and pharmacological advances,management of late-stage gastric cancer patients,especially those with hepatic metastasis remains challenging[1–3].Although nationwide registry data from SEER(Surveillance,Epidemiology,and End Results)[4]and the Nordic database[5]in Western countries have provided epidemiological information for patients with gastric cancer liver metastasis(GCLM),little is known about the detailed clinical characteristics.
基金supported by the National Key Research and Development Program of China(No.2016YFC1400902)
文摘An external frequency doubling electro-optically Q-switched neodymium-doped yttrium aluminum garnet (Nd:YAG) 473 nm blue laser was demonstrated. With absorbed pump energy of 48 mJ at 100 Hz repetition rate, about 2 mJ of 473 nm blue laser pulse energy was achieved by cascade frequency doubling. The second harmonic conversion efficiency was 64.5%, and overall optical-optical efficiency was 4.2%, respectively. The blue laser pulse width was less than 10 ns, and beam quality factor was less than 2.4.
基金supported by the National Natural Science Foundation of China(21835003,91833304,21422402,21604043,21674050,and 62004106)the National Key Basic Research Program of China(973 Program,2014CB648300 and 2017YFB0404501)+10 种基金the Natural Science Foundation of Jiangsu Province(BK20160888 and BE2019120)the Program for Jiangsu Specially-Appointed Professor(RK030STP15001)the Six Talent Peaks Project of Jiangsu Province(TD-XCL-009)the 333 Project of Jiangsu Province(BRA2017402)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(20KJB140005)China Postdoctoral Science Foundation(2020M671553)the NUPT“1311 Project”Scientific Foundation(NY217169,NY215062,NY215107,and NY217087)the Leading Talent of Technological Innovation of National Ten-Thousands Talents Program of China,the Excellent Scientific and Technological Innovative Teams of Jiangsu Higher Education Institutions(TJ217038)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(SJCX21-0297)the Synergetic Innovation Center for Organic Electronics and Information Displays,and the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
基金supported by the Natural Science Foundation of Shanghai(No.19YF1453600)the Key Task Project in Scientific and Technological Research on Social Development of Shanghai(No.20dz1206502)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA22000000)the Major Program of the National Natural Science Foundation of China(No.61991453).
文摘A 222 nm all-solid-state far-ultraviolet C(UVC)pulse laser system based on an optical parametric oscillator(OPO)and second-harmonic generation(SHG)usingβ-Ba2BO4(BBO)crystals was demonstrated.Pumped by a Nd∶Y3Al5O12 laser with a repetition rate of 100 Hz at 355 nm,the maximum signal laser pulse energy of 1.22 mJ at 444 nm wavelength was obtained from the BBO-OPO system,corresponding to a conversion efficiency of 27.9%.The maximum output pulse energy of 164.9μJ at the 222 nm wavelength was successfully achieved,corresponding to an SHG conversion efficiency of 16.2%.Moreover,the tunable output wavelength of UVC light from 210 nm to 252.5 nm was achieved.
文摘Hepatoid carcinoma of the pancreas(HCP)is an extremely rare pancreatic cancer resembling hepatocellular carcinoma,a type of liver cancer(1).Most reports have shown that it has an aggressive behavior and is associated with early metastasis.There is no standardized treatment for HCP due to its rarity,and the limited number of cases reported in the literature(2,3).However,treatment options for this type of rare cancer include surgery,chemotherapy,and radiation therapy,depending on the stage of the cancer.Nevertheless,the prognosis of HCP is poor.
基金National Key Research and Development Program of China(2017YFC0110002,2016YFA0201403)National Natural Science Foundation of China(61890952)Major Special Science and Technology Project of Hainan Province(ZDKJ202006)。
文摘Rapid large-area tissue imaging at the cellular resolution is important for clinical diagnosis.We present a probe-based confocal microendoscope(p CM)with a field-of-view(FOV)diameter over 500μm,lateral resolution of 1.95μm,and outer diameter of 2.6 mm,compatible with the biopsy channel of conventional gastroscopes.Compared to a conventional p CM,our system's FOV increased by a factor of 4 while maintaining the probe size and cellular resolution—comparable to the FOV of Zeiss Axio Observer's 20×=0.8 numerical aperture objective lens.Ex vivo imaging of wide areas in healthy and diseased rat gastrointestinal tract tissues demonstrates the system's practicality.
基金supported by the Shanghai Municipal Science and_Technology Major Project(2017SHZDZX01)NaturalScienceFoundationof,China(32070679,U1804284,and 81871055)+2 种基金the National Key R&D Program.of China(2019YFA0905400,2017YFC0908105,and 2021YFC2702103)Taishan Scholar Program of Shandong Province(tsqn201812153)and Natural Science Foundation of Shandong Province(ZR2019YQ14).
文摘SARS-CoV-2(severe acute respiratory syndrome coronavirus 2)has evolved many variants with stronger infectivity and immune evasion than the original strain,including Alpha,Beta,Gamma,Delta,Epsilon,Kappa,lota,Lambda,and 21H strains.Amino acid mutations are enriched in the spike protein of SARS CoV-2.which plays a crucial role in cell infetion.However,the impact of these mutations on protein structure and function is unclear.Understanding the pathophysiology and pandemic feaures of these SARS-CoV-2 variants requires knowledge of the spike protein structures.Here,we obtained the spike protein structures of 10 main globally endemic SARS CoV-2 strains using AlphaFold2.The clustering analysis based on structural similarity revealed the unique features of the mainly pandemic SARS CoV-2 Delta variants.indicating that structural clusters can reflect the current characteristics of the epidemic more accurately than those based on the protein sequence.The analysis of the binding afinities of ACE2-RBD,antibody-NTD,and antibody-RBD complexes in the different variants revealed that the recognition of antibodies against SI NTD and RBD was decreased in the variants,especally the Delta variant compared with the original strain,which may induce the immune evasion of SARS-CoV-2 variants.Furthermore,by virtual screening the ZINC database against a high-accuracy predicted structure of Delta spike protein and experimental validation,we identified multiple compounds that target S1 NTD and RBD,which might contribute towards the development of clinical anti-SARS-CoV-2 medicines.Our findings provided a basic foundation for future in vitro and in vivo investigations that might speed up the development of potential therapies for the SARS-CoV-2 va riants.
基金supported by the National Key Research and Development Program of China(No.2016YFC1400902)the National Key Scientific Instrument and Equipment Development Project(No.2013YQ120343)+1 种基金the Scientific Innovation Fund of Chinese Academy of Sciences(No.CXJJ-16S014)the Development Program of China(No.2014AA093301)
文摘A highly efficient laser system output at the H-β Fraunhofer line of 486.1 nm has been demonstrated. A high pulse energy single-frequency hybrid 1064 nm master oscillator power amplifier was frequency-tripled to achieve355 nm laser pulses, which acted as the pump source of the beta barium borate nanosecond pulse optical parametric oscillator. With pump energy of 190 mJ, the laser system generated a maximum output of 62 mJ blue laser pulses at 486.1 nm, corresponding to conversion efficiency of 32.6%. The laser spectrum width was measured to be around 0.1 nm, being in conformity with the spectrum width of the solar Fraunhofer line.
基金This work was supported by the Natural Science Foundation of Shanghai(No.19YF1453600)the Key Task Project in Scientific and Technological Research on Social Development of Shanghai(No.20dz1206502)+2 种基金the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)(No.2018SDKJ0102)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA22000000)the Major Program of the National Natural Science Foundation of China(No.61991453)。
文摘A single-resonant low-threshold type-Iβ-Ba_(2)BO_(4)(BBO) optical parametric oscillator (OPO) with tunable output from 410 nm to 630 nm at 5 k Hz repetition rate is reported.By taking the noncollinear phase matching method,low-threshold OPO operation could be obtained compared with the configuration of collinear phase matching,and the maximum optical–optical conversion efficiency of 11.8%was achieved at 500 nm wavelength when 0.4 m J pump pulse energy was applied.When the noncollinearity angle was preset at 1.6°,4.8°,and 6.3°,a continuously tuning output with a total spectral range of 220 nm was successfully obtained by adjusting the phase matching angle of the BBO crystal.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (No. XDA22000000)the Ministry of Science and Technology of China (No. 2014AA093301)+1 种基金the Laboratory for Regional Oceanography and Numerical Modeling, Qingdao National Laboratory for Marine Science and Technology (No. 2017B04)the Natural Science Foundation of Shanghai (No. 19YF1453600)
文摘One fast simulation method using Markov chains was introduced to simulate angular,energy,and temporal characteristics of pulsed laser beam propagation underwater.Angular dispersion of photons with a different number of collisions was calculated based on scattering function and the state transition matrix of Markov chains.Temporal distribution and energy on the receiving plane were obtained,respectively,by use of a novel successive layering model and receiving ratio.The validity of this method was verified by comparing it with the Monte Carlo ray tracing(MCRT)method.The simulation results were close to those obtained by MCRT but were less time consuming and had smoother curves.
