[Objective] This study aimed to investigate the effects of different pretreat- ments on enzymatic saccharification of Miscanthus sinensis and improve reducing sugar yield in the enzymolysis process. [Method] M. sinens...[Objective] This study aimed to investigate the effects of different pretreat- ments on enzymatic saccharification of Miscanthus sinensis and improve reducing sugar yield in the enzymolysis process. [Method] M. sinensis was pretreated with 60Co y-ray irradiation and alkaline hydrogen peroxide, to analyze their effects on re- ducing sugar yield of enzymatic hydrolysis. [Result] After pretreatment with 400 kGy 60Co y-ray irradiation, reducing sugar yield in the enzymolysis process of M sinensis was 76.24 mg/g; after synergic pretreatment with 400 kGy 60Co y-ray irradiation and alkaline hydrogen peroxide, reducing sugar yield in the enzymolysis process of M. sinensis was 505.08 mg/g, which was improved by 5.6 times compared to that in pretreatment with 400 kGy 60Co y-ray irradiation. Based on process optimization, the optimal hydrolysis conditions were obtained： pretreatment temperature 30 ℃, NaOH concentration 1.2%, hydrogen peroxide concentration 2%, pretreatment time 6 h. [Conclusion] Synergic pretreatment with 60Co y-ray irradiation and alkaline hydrogen peroxide could significantly improve reducing sugar yield in the enzymolysis process of M. sinensis, which provided a new theoretical basis for preparing fuel ethanol with M. sinensis.展开更多
To extend the spectrum of lasers to the γ-ray range has been a dream for a long time for both nuclear and laser physi- cists. It means fantastic improvement of techniques, such as much more precise measurements of sp...To extend the spectrum of lasers to the γ-ray range has been a dream for a long time for both nuclear and laser physi- cists. It means fantastic improvement of techniques, such as much more precise measurements of space-time, holography for nanometer size or even smaller objects, and so on. There are various proposals for its realization, including those of using nuclear decay and condensed positronium decay,展开更多
Either sublinear or supralinear responses of dosimeters to y-ray can be described by a response function derived from statistical Poisson distribution.The characteristic parameters of the function determine linearity,...Either sublinear or supralinear responses of dosimeters to y-ray can be described by a response function derived from statistical Poisson distribution.The characteristic parameters of the function determine linearity, sublinearity and supralinearity in their responses. The experimental data of gamma dose-responses of alanine ESR dosimeters,film dosimeters, LiF(Mg, Cu, P) and LiF(Mg, Ti) thermoluminescence dosimeters are used to test the response function.展开更多
Objective： The aim of the study was to investigate the impact of 60Co y-ray on apoptosis, cell cycles and the expression of protein hypoxia-inducible factor-1α （HIF-1α） to Hep-2 cell line in the conditions of nor...Objective： The aim of the study was to investigate the impact of 60Co y-ray on apoptosis, cell cycles and the expression of protein hypoxia-inducible factor-1α （HIF-1α） to Hep-2 cell line in the conditions of normoxia and hypoxia. Methods： Hep-2 cell were divided into 2 groups： group A （normoxia） and group B （hypoxia）. All of the ceils were exposed to y-ray with dosage being 0, 1, 3, 5, 10, 20, and 40 Gy. Flow cytometry was used to measure the protein level of HIF-1α and to detect apoptosis and cell cycles. The protein level of HIF-1α was also determined by immunohistochemistry and Western blotting. Results： The protein level of HIF-1α in group B was significantly higher than that in group A. In group A, low doses （1-5 Gy） of y-ray had caused G0/G1 cell cycle arrest and high doses （10-40 Gy） had caused G2/M cell cycle arrest. In group B, without exposure of y-ray （0 Gy） had caused G0/G1 cell cycle arrest, all of the different dosage of y-ray could cause G2/M cell cycle arrest. The curve of apoptosis rate in group A was a parabola, the apoptotic rate was related to the dosage of y-ray in a dosage dependent manner. The peak was at the point of 5 Gy. The apoptosis rate in group A was significantly higher than that in group B. Conclusion： Different doses of y-ray could cause different cell cycles arrest then make different impact on apoptosis to Hep-2 ceil. The lower apoptosis rate in condition of hypoxia maybe has a relationship with G2/M cell cycle arrest. Up-regulated HIF-1α protein may be one of the reasons for G2/M cell cycle arrest.展开更多
Objective： The senile lung adenocarcinoma patients harboring an activating epidermal growth factor receptor （EGFR） mutation shows good and rapid response to EGFR tyrosine kinase inhibitors （TKIs）. Whether gefitin...Objective： The senile lung adenocarcinoma patients harboring an activating epidermal growth factor receptor （EGFR） mutation shows good and rapid response to EGFR tyrosine kinase inhibitors （TKIs）. Whether gefitinib combined with y-ray stereotactic body radiation therapy has better efficacy than gefitinib alone for senile lung adenocarcinoma patients with EGFR mutations as first-line regimen is still under investigation. Methods： The 42 senile lung adenocarcinoma patients with EGFR mutations were divided into 2 groups according to the therapy method. Group A was the 22 patients treated with gefitinib combined with y-ray stereotactic body radiation therapy （SBRT）. Group B was the 20 patients treated with gefitinib alone. All of the patients received gefitinib of 250 mg/d from the first day until disease progression or other reasons. The patients of Group A were treated with y-ray stereotactic body radiation therapy from the second day. Radiation fields included the primary lesions and the integration of lymph nodes. Dose curve of this group was 50%-80%. Encircled dose was 4.0-6.5 Gy per fraction and the range of total dose was 40-52 Gy. We treated the patients 8-12 times and treated five times every week. Results： All the patients were examined by enhanced double helix CT at the second month. The tumor response rate （RR） of group A was 81.8% （18/22）. Disease control rate （DCR） was 90.9% （20/22）. The median overall survival （OS） was 24.2 months （range 8-58 months ） and the progression-free survival （PFS） was 18.6 months. The overall 1-year survival rate was 72.3% （16/22） and 2-year survival rate was 54.5% （12/22）. The main side effects included skin rash and diarrhea. The RR of group B was 50.0 % （10/20）. DCR was 75.0% （15/20）. OS was 17.4 months （range 6-32 months ） and PFS was 12.1 months. The overall 1-year survival rate was 60.0% （12/20） and 2-year survival rate was 40.0% （8/20）. The main side effects included skin rash and diarrhea. The group A who were treated with gefitinib combined with y-ray stereotactic body radiation therapy had a higher short term therapeutic effects （RR） and long term therapeutic effects （OS） than group B who were treated with gefitinib alone respectively （81.8% vs 50.0%, P = 0.029 〈 0.05, x2 = 4.773 and 24.2 vs 17.4, P = 0.024 〈 0.05, X2 = 5.098）. Conclu. sion： Gefitinib combined with y-ray stereotactic body radiation therapy has better efficacy than gefitinib alone for senile lung adenocarcinoma patients with EGFR mutations as first-line regimen. The side affects are acceptable.展开更多
The objective of this work is to assess the radiation hazards associated gamma rays from building materials. Natural gamma rays activities of natural radionuclide represented mainly by three natural radioactive series...The objective of this work is to assess the radiation hazards associated gamma rays from building materials. Natural gamma rays activities of natural radionuclide represented mainly by three natural radioactive series ^238U, ^235U and ^232Th, and the primordial ^40K in the samples of building materials which consist of bricks, ceramics, marble and gypsum from different areas of eastern Algeria are measured using gamma ray spectrometry. The values of the activities of these radionuclides do not clearly reflect the radiation hazard associated with these materials. Therefore, the radium equivalent （Raeq） concentration is defined taking into account the effectiveness of these isotopes in creating the radiation hazard. Radium equivalent activities, external and internal hazard indices （Hex and Hin） are calculated from the activities of ^226Ra, ^232Th and ^40K for suitability of the materials.展开更多
Purpose Cosmic rays up to PeV energy are believed to be generated in our galaxy.γ-rays at 100TeV energies are important probe to identify PeVtrons.Besides,γ-rays contain additional information on the propagation of ...Purpose Cosmic rays up to PeV energy are believed to be generated in our galaxy.γ-rays at 100TeV energies are important probe to identify PeVtrons.Besides,γ-rays contain additional information on the propagation of the galactic cosmic rays.Methods Diffuseγ-rays originating from the Galactic plane from 20 to 200 TeV region are studied with early 160-day data collected by YangBaJing Hybrid Array(YBJ-HA),which is a hybrid array and consists of scintillation detectors and underground muon detectors.All-distance equi-zenith angle and time-swapping methods are used to analyze the number ofγ-rays excess.Result and conclusion Because of no significant observation onγ-ray emission,Helene's method is adopted to derive the 90%confidence level upper limits on the flux of diffuse galacticγ-rays.And the limit to the ratio of the flux ofγ-rays to CRs is obtained at the order of 10^(-4),which is the current best result at these energies.展开更多
We calculate numerically the hydrodynamic evolution of a γ-ray burst fireball. The results show that refluence will emerge during fireball expansion due to negative-pressure effect. The refluence will collide with ou...We calculate numerically the hydrodynamic evolution of a γ-ray burst fireball. The results show that refluence will emerge during fireball expansion due to negative-pressure effect. The refluence will collide with outward fluid, then shock wave will form. Electrons moving between the inward and outward fluid shells can be accelerated to 104–105 MeV by one order Femi-type acceleration with high efficiency after several collisions. Radiation of electrons with such high energy may be the observed γray bursts.展开更多
This work provides an approach to determine the efficiency of T-ray detectors with a good accuracy in order to determine the concentrations of either naturally occurring or artificially prepared radionuclides. This ap...This work provides an approach to determine the efficiency of T-ray detectors with a good accuracy in order to determine the concentrations of either naturally occurring or artificially prepared radionuclides. This approach is based on the efficiency transfer formula （ET）, the effective solid angles, the self- absorptions of the source matrix, the attenuation by the source container and the detector housing materials on the detector efficiency. The experimental calibration process was done using radioactive （Cylindrical ＆ Marinelli） sources, in different dimensions, that contain aqueous 152Eu radionuclide. The comparison point to a fine agreement between the experimental measured and calculated efficiencies for the （NaI ＆ HPGe） detectors using volumetric radioactive sources.展开更多
Cross-section data of the^(185)Re(n,2n)^(184)mRe,^(185)Re(n,2n)^(184)gRe,^(185)Re(n,α)182m1+m2+gTa,^(187)Re(n,2n)^(186)g,(m)Re,^(187)Re(n,α)^(184)Ta,and^(187)Re(n,p)^(187)W reactions were measured at four neutron en...Cross-section data of the^(185)Re(n,2n)^(184)mRe,^(185)Re(n,2n)^(184)gRe,^(185)Re(n,α)182m1+m2+gTa,^(187)Re(n,2n)^(186)g,(m)Re,^(187)Re(n,α)^(184)Ta,and^(187)Re(n,p)^(187)W reactions were measured at four neutron energies,namely 13.5,14.1,14.4,and 14.8 MeV,by means of the activation technique,relative to the reference cross-section values of the 93Nb(n,2n)92mNb reaction.The neutrons were generated from the T(d,n)4He reaction at the K-400 Neutron Generator at China Academy of Engineering Physics.The inducedγactivities were measured using a high-resolutionγ-ray spectrometer equipped with a coaxial high-purity germanium detector.The excitation functions of the six above-mentioned nuclear reactions at neutron energies from the threshold to 20 MeV were calculated by adopting the nuclear theoretical model program system Talys-1.9 with the relevant parameters properly adjusted.The measured cross sections were analyzed and compared with previous experiments conducted by other researchers,and with the evaluated data of BROND-3.1,ENDF/B-VIII.0,JEFF-3.3,and the theoretical values based on Talys-1.9.The new measured results agree with those of previous experiments and the theoretical excitation curve at the corresponding energies.The theoretical excitation curves based on Talys-1.9 generally match most of experimental data well.展开更多
基金Supported by National High Technology Research and Development Program of China(863 Program)(2012AA101804)~~
文摘[Objective] This study aimed to investigate the effects of different pretreat- ments on enzymatic saccharification of Miscanthus sinensis and improve reducing sugar yield in the enzymolysis process. [Method] M. sinensis was pretreated with 60Co y-ray irradiation and alkaline hydrogen peroxide, to analyze their effects on re- ducing sugar yield of enzymatic hydrolysis. [Result] After pretreatment with 400 kGy 60Co y-ray irradiation, reducing sugar yield in the enzymolysis process of M sinensis was 76.24 mg/g; after synergic pretreatment with 400 kGy 60Co y-ray irradiation and alkaline hydrogen peroxide, reducing sugar yield in the enzymolysis process of M. sinensis was 505.08 mg/g, which was improved by 5.6 times compared to that in pretreatment with 400 kGy 60Co y-ray irradiation. Based on process optimization, the optimal hydrolysis conditions were obtained： pretreatment temperature 30 ℃, NaOH concentration 1.2%, hydrogen peroxide concentration 2%, pretreatment time 6 h. [Conclusion] Synergic pretreatment with 60Co y-ray irradiation and alkaline hydrogen peroxide could significantly improve reducing sugar yield in the enzymolysis process of M. sinensis, which provided a new theoretical basis for preparing fuel ethanol with M. sinensis.
基金supported by the National Natural Science Foundation of China(Grant No.10875003)
文摘To extend the spectrum of lasers to the γ-ray range has been a dream for a long time for both nuclear and laser physi- cists. It means fantastic improvement of techniques, such as much more precise measurements of space-time, holography for nanometer size or even smaller objects, and so on. There are various proposals for its realization, including those of using nuclear decay and condensed positronium decay,
文摘Either sublinear or supralinear responses of dosimeters to y-ray can be described by a response function derived from statistical Poisson distribution.The characteristic parameters of the function determine linearity, sublinearity and supralinearity in their responses. The experimental data of gamma dose-responses of alanine ESR dosimeters,film dosimeters, LiF(Mg, Cu, P) and LiF(Mg, Ti) thermoluminescence dosimeters are used to test the response function.
文摘Objective： The aim of the study was to investigate the impact of 60Co y-ray on apoptosis, cell cycles and the expression of protein hypoxia-inducible factor-1α （HIF-1α） to Hep-2 cell line in the conditions of normoxia and hypoxia. Methods： Hep-2 cell were divided into 2 groups： group A （normoxia） and group B （hypoxia）. All of the ceils were exposed to y-ray with dosage being 0, 1, 3, 5, 10, 20, and 40 Gy. Flow cytometry was used to measure the protein level of HIF-1α and to detect apoptosis and cell cycles. The protein level of HIF-1α was also determined by immunohistochemistry and Western blotting. Results： The protein level of HIF-1α in group B was significantly higher than that in group A. In group A, low doses （1-5 Gy） of y-ray had caused G0/G1 cell cycle arrest and high doses （10-40 Gy） had caused G2/M cell cycle arrest. In group B, without exposure of y-ray （0 Gy） had caused G0/G1 cell cycle arrest, all of the different dosage of y-ray could cause G2/M cell cycle arrest. The curve of apoptosis rate in group A was a parabola, the apoptotic rate was related to the dosage of y-ray in a dosage dependent manner. The peak was at the point of 5 Gy. The apoptosis rate in group A was significantly higher than that in group B. Conclusion： Different doses of y-ray could cause different cell cycles arrest then make different impact on apoptosis to Hep-2 ceil. The lower apoptosis rate in condition of hypoxia maybe has a relationship with G2/M cell cycle arrest. Up-regulated HIF-1α protein may be one of the reasons for G2/M cell cycle arrest.
基金Supported by a grant from the Clinical Medicine Sciences Foundation of Jiangsu University(No.JLY20080085)
文摘Objective： The senile lung adenocarcinoma patients harboring an activating epidermal growth factor receptor （EGFR） mutation shows good and rapid response to EGFR tyrosine kinase inhibitors （TKIs）. Whether gefitinib combined with y-ray stereotactic body radiation therapy has better efficacy than gefitinib alone for senile lung adenocarcinoma patients with EGFR mutations as first-line regimen is still under investigation. Methods： The 42 senile lung adenocarcinoma patients with EGFR mutations were divided into 2 groups according to the therapy method. Group A was the 22 patients treated with gefitinib combined with y-ray stereotactic body radiation therapy （SBRT）. Group B was the 20 patients treated with gefitinib alone. All of the patients received gefitinib of 250 mg/d from the first day until disease progression or other reasons. The patients of Group A were treated with y-ray stereotactic body radiation therapy from the second day. Radiation fields included the primary lesions and the integration of lymph nodes. Dose curve of this group was 50%-80%. Encircled dose was 4.0-6.5 Gy per fraction and the range of total dose was 40-52 Gy. We treated the patients 8-12 times and treated five times every week. Results： All the patients were examined by enhanced double helix CT at the second month. The tumor response rate （RR） of group A was 81.8% （18/22）. Disease control rate （DCR） was 90.9% （20/22）. The median overall survival （OS） was 24.2 months （range 8-58 months ） and the progression-free survival （PFS） was 18.6 months. The overall 1-year survival rate was 72.3% （16/22） and 2-year survival rate was 54.5% （12/22）. The main side effects included skin rash and diarrhea. The RR of group B was 50.0 % （10/20）. DCR was 75.0% （15/20）. OS was 17.4 months （range 6-32 months ） and PFS was 12.1 months. The overall 1-year survival rate was 60.0% （12/20） and 2-year survival rate was 40.0% （8/20）. The main side effects included skin rash and diarrhea. The group A who were treated with gefitinib combined with y-ray stereotactic body radiation therapy had a higher short term therapeutic effects （RR） and long term therapeutic effects （OS） than group B who were treated with gefitinib alone respectively （81.8% vs 50.0%, P = 0.029 〈 0.05, x2 = 4.773 and 24.2 vs 17.4, P = 0.024 〈 0.05, X2 = 5.098）. Conclu. sion： Gefitinib combined with y-ray stereotactic body radiation therapy has better efficacy than gefitinib alone for senile lung adenocarcinoma patients with EGFR mutations as first-line regimen. The side affects are acceptable.
文摘The objective of this work is to assess the radiation hazards associated gamma rays from building materials. Natural gamma rays activities of natural radionuclide represented mainly by three natural radioactive series ^238U, ^235U and ^232Th, and the primordial ^40K in the samples of building materials which consist of bricks, ceramics, marble and gypsum from different areas of eastern Algeria are measured using gamma ray spectrometry. The values of the activities of these radionuclides do not clearly reflect the radiation hazard associated with these materials. Therefore, the radium equivalent （Raeq） concentration is defined taking into account the effectiveness of these isotopes in creating the radiation hazard. Radium equivalent activities, external and internal hazard indices （Hex and Hin） are calculated from the activities of ^226Ra, ^232Th and ^40K for suitability of the materials.
基金supported by National Natural Science Foundation of China under grant:11635011,11761141001,11873005,11765019,11963004
文摘Purpose Cosmic rays up to PeV energy are believed to be generated in our galaxy.γ-rays at 100TeV energies are important probe to identify PeVtrons.Besides,γ-rays contain additional information on the propagation of the galactic cosmic rays.Methods Diffuseγ-rays originating from the Galactic plane from 20 to 200 TeV region are studied with early 160-day data collected by YangBaJing Hybrid Array(YBJ-HA),which is a hybrid array and consists of scintillation detectors and underground muon detectors.All-distance equi-zenith angle and time-swapping methods are used to analyze the number ofγ-rays excess.Result and conclusion Because of no significant observation onγ-ray emission,Helene's method is adopted to derive the 90%confidence level upper limits on the flux of diffuse galacticγ-rays.And the limit to the ratio of the flux ofγ-rays to CRs is obtained at the order of 10^(-4),which is the current best result at these energies.
文摘We calculate numerically the hydrodynamic evolution of a γ-ray burst fireball. The results show that refluence will emerge during fireball expansion due to negative-pressure effect. The refluence will collide with outward fluid, then shock wave will form. Electrons moving between the inward and outward fluid shells can be accelerated to 104–105 MeV by one order Femi-type acceleration with high efficiency after several collisions. Radiation of electrons with such high energy may be the observed γray bursts.
文摘This work provides an approach to determine the efficiency of T-ray detectors with a good accuracy in order to determine the concentrations of either naturally occurring or artificially prepared radionuclides. This approach is based on the efficiency transfer formula （ET）, the effective solid angles, the self- absorptions of the source matrix, the attenuation by the source container and the detector housing materials on the detector efficiency. The experimental calibration process was done using radioactive （Cylindrical ＆ Marinelli） sources, in different dimensions, that contain aqueous 152Eu radionuclide. The comparison point to a fine agreement between the experimental measured and calculated efficiencies for the （NaI ＆ HPGe） detectors using volumetric radioactive sources.
基金Supported by National Natural Science Foundation of China(11605099,11575090)。
文摘Cross-section data of the^(185)Re(n,2n)^(184)mRe,^(185)Re(n,2n)^(184)gRe,^(185)Re(n,α)182m1+m2+gTa,^(187)Re(n,2n)^(186)g,(m)Re,^(187)Re(n,α)^(184)Ta,and^(187)Re(n,p)^(187)W reactions were measured at four neutron energies,namely 13.5,14.1,14.4,and 14.8 MeV,by means of the activation technique,relative to the reference cross-section values of the 93Nb(n,2n)92mNb reaction.The neutrons were generated from the T(d,n)4He reaction at the K-400 Neutron Generator at China Academy of Engineering Physics.The inducedγactivities were measured using a high-resolutionγ-ray spectrometer equipped with a coaxial high-purity germanium detector.The excitation functions of the six above-mentioned nuclear reactions at neutron energies from the threshold to 20 MeV were calculated by adopting the nuclear theoretical model program system Talys-1.9 with the relevant parameters properly adjusted.The measured cross sections were analyzed and compared with previous experiments conducted by other researchers,and with the evaluated data of BROND-3.1,ENDF/B-VIII.0,JEFF-3.3,and the theoretical values based on Talys-1.9.The new measured results agree with those of previous experiments and the theoretical excitation curve at the corresponding energies.The theoretical excitation curves based on Talys-1.9 generally match most of experimental data well.
