Systematic experiments about the antitumor effects of low energy laser irradiation combined with the traditional antitumor medicine of cyclophosphamide were conducted using the experimental model of mouse S180 ascite...Systematic experiments about the antitumor effects of low energy laser irradiation combined with the traditional antitumor medicine of cyclophosphamide were conducted using the experimental model of mouse S180 ascites sarcoma.The three groups of tumor bearing mice were irradiated upon the inner corners with the dosages of 11 00,14 67 and 22 00 J·cm -2 LELI respectively,and injected with CYT intraperitoneally to observe the changes of the survival time,the ascites growth speed,and the kinetic changes of immune functions.The survival times of the three groups of CYT/LELI combination were obviously longer than those of the tumor and CYT control groups.Correspondingly,the amounts of ascites,tumor cells densities and total tumor cells in CYT/LELI groups decreased significantly,while the death ratio of the tumor cells increased.Comparatively,the group of 22 00 J·cm -2 LELI combined with CYT showed the most ideal antitumor effects,and the life prolongation ratio was up to 53 20%.展开更多
Physical and chemical phenomena of low-energy ion irradiation on solid surfaces have been studied systematically for many years, due to the wide applications in surface modification, ion implantation and thin-film gro...Physical and chemical phenomena of low-energy ion irradiation on solid surfaces have been studied systematically for many years, due to the wide applications in surface modification, ion implantation and thin-film growth. Recently the bombardment of nano-scale materials with low-energy ions gained much attention. Comared to bulk materials, nano-scale materials show different physical and chemical properties. In this article, we employed molecular dynamics simulations to study the damage caused by low-energy ion irradiation on copper nanowires. By simulating the ion bombardment of 5 different incident energies, namely, 1 keV, 2 keV, 3 keV, 4 keV and 5 keV, we found that the sputtering yield of the incident ion is linearly proportional to the energies of incident ions. Low-energy impacts mainly induce surface damage to the nanowires, and only a few bulk defects were observed. Surface vacancies and adatoms accumulated to form defect clusters on the surface, and their distribution are related to the type of crystal plane, e.g. surface vacancies prefer to stay on （100） plane, while adatoms prefer （110） plane. These results reveal that the size effect will influence the interaction between low-energy ion and nanowire.展开更多
<strong>Objective: </strong>Utilizing VISIA skin tester to quantitatively evaluate the effect of low energy far-infrared irradiation on healthy people’s facial skin. <strong>Methods:</strong> ...<strong>Objective: </strong>Utilizing VISIA skin tester to quantitatively evaluate the effect of low energy far-infrared irradiation on healthy people’s facial skin. <strong>Methods:</strong> 60 volunteers were selected in hospital from September 2019 to June 2020, and the total score of face, skin spots, texture, wrinkles and pores were observed before and after low energy far-infrared irradiation treatment with VISIA skin tester. <strong>Results:</strong> After 2 weeks of low energy far-infrared irradiation treatment, the total skin score of volunteers increased significantly (P < 0.01). In the itemized statistics, the moisture value, stain value and wrinkle value increased significantly (P < 0.05). <strong>Conclusion:</strong> Low energy far-infrared irradiation can significantly improve the facial skin quality of healthy people.展开更多
Ever since the low energy N+ ion beam has been accepted that the mutation effects of ionizing radiation are attributed mainly to direct or indirect damage to DNA. Evidences based on naked DNA irradiation in support of...Ever since the low energy N+ ion beam has been accepted that the mutation effects of ionizing radiation are attributed mainly to direct or indirect damage to DNA. Evidences based on naked DNA irradiation in support of a mutation spectrum appears to be consistent, but direct proof of such results in vivo are limited. Using mutS, dam and/or dcm defective Eschericha coli imitator strains, an preliminary experimental system on induction of in vivo mutation spectra of low energy N+ ion beam has been established in this study. It was observed that the mutation rates of rifampicin resistance induced by N+ implantation were quite high, ranging from 9.2 x 10~8 to 4.9× 10~5 at the dosage of 5.2×1014 ions/cm2. Strains all had more than 90-fold higher mutation rate than its spontaneous mutation rate determined by this method. It reveals that base substitutions involve in induction of mutation of low energy nitrogen ion beam implantation. The mutation rates of mutator strains were nearly 500-fold (GM2929), 400-fold (GM5864) and 6-fold larger than that of AB1157. The GM2929 and GM5864 both lose the ability of repair DNA mismatch damage by virtue of both dam and dcm pathways defective (GM2929) or failing to assemble the repair complex (GM5864) respectively. It may explain the both strains had a similar higher mutation rate than GM124 did. It indicated that DNA cytosine methylase might play an important role in mismatch repair of DNA damage induced by N+ implantation. The further related research were also discussed.展开更多
In order to study the mechanism of irradiation-induced damage ofbotanic samples caused by low energy heavy ions, transmission energy spectrum mea-surement was performed. Kidney bean slice samples 100μm in thickness w...In order to study the mechanism of irradiation-induced damage ofbotanic samples caused by low energy heavy ions, transmission energy spectrum mea-surement was performed. Kidney bean slice samples 100μm in thickness were irradi-ated by 50 kev N+ ions. The irradiation beam current density was about 30μA/cm2,and the irradiation ion doses were 1×1015, 1×1016, 3×1016 and 1×1017 ions@cm-2,respectively. A target set up that could greatly reduce the incident ion current densitywas designed to achieve the damage-free measurement. The 3.2 MeV H+ transmittedion energy spectrum measurement was carried out before and after the irradiation.From the transmission ion energy spectrum, it was found that the kidney bean sliceitself was structurally inhomogeneous compared with the PET films (C10HsO4). Ourresults indicated that the average mass thickness changed little when the N+ iondose was below 3×1016 ions.cm-2, but changed obviously whcn ion dose was beyond3×1016 ions.cm-2.展开更多
A new detection method has been applied to study the penetration depth of low-energy heavy ions in botanic samples. Highly oriented pyrolytic graphite (HOPG) pieces were placed behind the target samples with certain t...A new detection method has been applied to study the penetration depth of low-energy heavy ions in botanic samples. Highly oriented pyrolytic graphite (HOPG) pieces were placed behind the target samples with certain thickness to receive energetic penetrated ions during the irradiation. After irradiation, statistic number density of protrusion-like damage induced by energetic penetrated ions can be ob- tained through scanning tunneling microscope (STM) observation on the surfaces of HOPG. The results of test indicate that the detection limit can be as low as 1.0×109 protrusions/cm2. With the method, the penetration depth of at least 60μm can be detected in kidney bean slices irradiated by N+ ions with dose of 0.3-3×1017ions/cm2.展开更多
An identification of Phe dipeptide from L-phenylalanine monomers after keV nitro- gen and argon ion implantation, by using the HPLC （high performance liquid chromatography） and LC-MS（liquid chromatography mass spec...An identification of Phe dipeptide from L-phenylalanine monomers after keV nitro- gen and argon ion implantation, by using the HPLC （high performance liquid chromatography） and LC-MS（liquid chromatography mass spectrometer） methods is reported. The results showed a similar yield behavior for both ion species, namely： 1） the yield of dipeptides under alkalescent conditions was distinctly higher than that under acidic or neutral conditions; 2） for different ion species, the dose-yield curves tracked a similar trend which was called a counter-saddle curve. The dipeptide formation may implicate a recombination repair mechanism of damaged biomolecules that energetic ions have left in their wake. Accordingly a physicochemical self-repair mechanism by radiation itself for the ion-beam radiobiological effects is proposed.展开更多
通过离子注入联合紫外线辐射诱变选育高产酿酒酵母菌株,根据存活率及突变率确定离子注入的诱变条件为电荷18 ke V,剂量400×10^(14) cm^(-2),紫外线辐射60 s。在该条件下,诱变获得的菌株正突变率和致死率都最高,诱变效果最好。在该...通过离子注入联合紫外线辐射诱变选育高产酿酒酵母菌株,根据存活率及突变率确定离子注入的诱变条件为电荷18 ke V,剂量400×10^(14) cm^(-2),紫外线辐射60 s。在该条件下,诱变获得的菌株正突变率和致死率都最高,诱变效果最好。在该条件下进行研究后获得目标菌株SC-N9015,酒精产量从14.65%提升到15.53%。多次传代实验结果显示遗传性状稳定。研究表明,通过低能氮离子注入和紫外线联合诱变选育高产酒精酵母效果显著。展开更多
文摘Systematic experiments about the antitumor effects of low energy laser irradiation combined with the traditional antitumor medicine of cyclophosphamide were conducted using the experimental model of mouse S180 ascites sarcoma.The three groups of tumor bearing mice were irradiated upon the inner corners with the dosages of 11 00,14 67 and 22 00 J·cm -2 LELI respectively,and injected with CYT intraperitoneally to observe the changes of the survival time,the ascites growth speed,and the kinetic changes of immune functions.The survival times of the three groups of CYT/LELI combination were obviously longer than those of the tumor and CYT control groups.Correspondingly,the amounts of ascites,tumor cells densities and total tumor cells in CYT/LELI groups decreased significantly,while the death ratio of the tumor cells increased.Comparatively,the group of 22 00 J·cm -2 LELI combined with CYT showed the most ideal antitumor effects,and the life prolongation ratio was up to 53 20%.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10675009)
文摘Physical and chemical phenomena of low-energy ion irradiation on solid surfaces have been studied systematically for many years, due to the wide applications in surface modification, ion implantation and thin-film growth. Recently the bombardment of nano-scale materials with low-energy ions gained much attention. Comared to bulk materials, nano-scale materials show different physical and chemical properties. In this article, we employed molecular dynamics simulations to study the damage caused by low-energy ion irradiation on copper nanowires. By simulating the ion bombardment of 5 different incident energies, namely, 1 keV, 2 keV, 3 keV, 4 keV and 5 keV, we found that the sputtering yield of the incident ion is linearly proportional to the energies of incident ions. Low-energy impacts mainly induce surface damage to the nanowires, and only a few bulk defects were observed. Surface vacancies and adatoms accumulated to form defect clusters on the surface, and their distribution are related to the type of crystal plane, e.g. surface vacancies prefer to stay on （100） plane, while adatoms prefer （110） plane. These results reveal that the size effect will influence the interaction between low-energy ion and nanowire.
文摘<strong>Objective: </strong>Utilizing VISIA skin tester to quantitatively evaluate the effect of low energy far-infrared irradiation on healthy people’s facial skin. <strong>Methods:</strong> 60 volunteers were selected in hospital from September 2019 to June 2020, and the total score of face, skin spots, texture, wrinkles and pores were observed before and after low energy far-infrared irradiation treatment with VISIA skin tester. <strong>Results:</strong> After 2 weeks of low energy far-infrared irradiation treatment, the total skin score of volunteers increased significantly (P < 0.01). In the itemized statistics, the moisture value, stain value and wrinkle value increased significantly (P < 0.05). <strong>Conclusion:</strong> Low energy far-infrared irradiation can significantly improve the facial skin quality of healthy people.
基金The project supported by the National Nature Science Foundation of China (No. 19890300)
文摘Ever since the low energy N+ ion beam has been accepted that the mutation effects of ionizing radiation are attributed mainly to direct or indirect damage to DNA. Evidences based on naked DNA irradiation in support of a mutation spectrum appears to be consistent, but direct proof of such results in vivo are limited. Using mutS, dam and/or dcm defective Eschericha coli imitator strains, an preliminary experimental system on induction of in vivo mutation spectra of low energy N+ ion beam has been established in this study. It was observed that the mutation rates of rifampicin resistance induced by N+ implantation were quite high, ranging from 9.2 x 10~8 to 4.9× 10~5 at the dosage of 5.2×1014 ions/cm2. Strains all had more than 90-fold higher mutation rate than its spontaneous mutation rate determined by this method. It reveals that base substitutions involve in induction of mutation of low energy nitrogen ion beam implantation. The mutation rates of mutator strains were nearly 500-fold (GM2929), 400-fold (GM5864) and 6-fold larger than that of AB1157. The GM2929 and GM5864 both lose the ability of repair DNA mismatch damage by virtue of both dam and dcm pathways defective (GM2929) or failing to assemble the repair complex (GM5864) respectively. It may explain the both strains had a similar higher mutation rate than GM124 did. It indicated that DNA cytosine methylase might play an important role in mismatch repair of DNA damage induced by N+ implantation. The further related research were also discussed.
基金Supported by the National Natural Science Foundation of China (No.19675004 and No.19890300)
文摘In order to study the mechanism of irradiation-induced damage ofbotanic samples caused by low energy heavy ions, transmission energy spectrum mea-surement was performed. Kidney bean slice samples 100μm in thickness were irradi-ated by 50 kev N+ ions. The irradiation beam current density was about 30μA/cm2,and the irradiation ion doses were 1×1015, 1×1016, 3×1016 and 1×1017 ions@cm-2,respectively. A target set up that could greatly reduce the incident ion current densitywas designed to achieve the damage-free measurement. The 3.2 MeV H+ transmittedion energy spectrum measurement was carried out before and after the irradiation.From the transmission ion energy spectrum, it was found that the kidney bean sliceitself was structurally inhomogeneous compared with the PET films (C10HsO4). Ourresults indicated that the average mass thickness changed little when the N+ iondose was below 3×1016 ions.cm-2, but changed obviously whcn ion dose was beyond3×1016 ions.cm-2.
基金Supported by the National Natural Science Foundation of China under Grant No.19675004 and (No.19890300)
文摘A new detection method has been applied to study the penetration depth of low-energy heavy ions in botanic samples. Highly oriented pyrolytic graphite (HOPG) pieces were placed behind the target samples with certain thickness to receive energetic penetrated ions during the irradiation. After irradiation, statistic number density of protrusion-like damage induced by energetic penetrated ions can be ob- tained through scanning tunneling microscope (STM) observation on the surfaces of HOPG. The results of test indicate that the detection limit can be as low as 1.0×109 protrusions/cm2. With the method, the penetration depth of at least 60μm can be detected in kidney bean slices irradiated by N+ ions with dose of 0.3-3×1017ions/cm2.
基金the Innovative Project of Chinese Academy of Science:Single Ion Beam Micro-irradiation Technology of Molecular and Cytology Effect Research(KSCX2-SW-324)
文摘An identification of Phe dipeptide from L-phenylalanine monomers after keV nitro- gen and argon ion implantation, by using the HPLC （high performance liquid chromatography） and LC-MS（liquid chromatography mass spectrometer） methods is reported. The results showed a similar yield behavior for both ion species, namely： 1） the yield of dipeptides under alkalescent conditions was distinctly higher than that under acidic or neutral conditions; 2） for different ion species, the dose-yield curves tracked a similar trend which was called a counter-saddle curve. The dipeptide formation may implicate a recombination repair mechanism of damaged biomolecules that energetic ions have left in their wake. Accordingly a physicochemical self-repair mechanism by radiation itself for the ion-beam radiobiological effects is proposed.
文摘通过离子注入联合紫外线辐射诱变选育高产酿酒酵母菌株,根据存活率及突变率确定离子注入的诱变条件为电荷18 ke V,剂量400×10^(14) cm^(-2),紫外线辐射60 s。在该条件下,诱变获得的菌株正突变率和致死率都最高,诱变效果最好。在该条件下进行研究后获得目标菌株SC-N9015,酒精产量从14.65%提升到15.53%。多次传代实验结果显示遗传性状稳定。研究表明,通过低能氮离子注入和紫外线联合诱变选育高产酒精酵母效果显著。
