Objective： To compare moxibustion sensation and infrared thermography by the assessment of heat-sensitization on Guanyuan （CV4） in patients with primary dysmenorrhea, and to prove the possibility of adopting infrar...Objective： To compare moxibustion sensation and infrared thermography by the assessment of heat-sensitization on Guanyuan （CV4） in patients with primary dysmenorrhea, and to prove the possibility of adopting infrared thermography as an objective demonstration of acupoints heat-sensitization. Methods： Seventy-one patients with primary dysmenorrhea were enrolled to receive moxibustion and infrared to detect the heat-sensitization of Guanyuan （CV 4）. The results were then analyzed and compared. Results： The infrared radiation showed a lower temperature when the acupoint Guanyuan （CV4） was sensitized in patients with primary dysmenorrhea. Compared with moxibustion sensation, its sensitivity rate （real positive rate） was 76.6%, divergence rate （real negative rate） was 70.1%, and the accuracy rate was 74.6%. After giving moxibustion to Guanyuan （CV4）, the infrared radiation area was significantly expanded longitudinally and transversely. Compared with moxibustion test, the sensitivity rate （real positive rate） of infrared test was 78.7%, divergencerate （real negative rate） was 83.3%, and the accuracy rate was 80.3%. Conclusion： To a certain extent, the heat-sensitization of the acupoint Guanyuan （CV4） in patients with primary dysmenorrhea can be revealed by infrared thermography. The acupoint heat-sensitization phenomena （heat extension or transmission） after giving moxibustion to the heat-sensitized acupoints can also be demonstrated objectively by infrared thermography, besides experienced subjectively by the receivers.展开更多
Objective： To compare the difference of infrared radiation temperature on body surface of points between healthy people and patients with hyperplasia of mammary glands. Method： The thermaCATMT P30 infrared thermal i...Objective： To compare the difference of infrared radiation temperature on body surface of points between healthy people and patients with hyperplasia of mammary glands. Method： The thermaCATMT P30 infrared thermal imaging system was selected to measure the infrared radiation temperature on body surface of eight points in four meridians in 74 patients with hyperplasia of mammary glands and 63 healthy people. Results： The infrared radiation temperatures on body surface of right Youmen （KI 21） in cases with hyperplasia of mammary glands were significantly higher than the healthy people （P=-0.009）, and the infrared radiation temperatures on left Youmen （KI 21） and other points had no significant difference with healthy people （P〉0.05）. Conclusion： The infrared radiation temperatures on body surface of right Youmen （KI 21） have significant differences with healthy people. This might occur because of the pathogenesis of hyperplasia of mammary glands and of the specificity of the point Youmen （KI 21）.展开更多
Introduction The Large High Altitude Air Shower Observatory plans to build a hybrid extensive air shower array with an area of about 1 km^(2) at an altitude of 4,410 m a.s.l.in Sichuan province,China,to explore the or...Introduction The Large High Altitude Air Shower Observatory plans to build a hybrid extensive air shower array with an area of about 1 km^(2) at an altitude of 4,410 m a.s.l.in Sichuan province,China,to explore the origin of high-energy cosmic rays.KM2A LHAASO-KM2A will detect gamma ray sources with a sensitivity of about 1%Crab Unit at 100 TeV.It covers an area of 1 km^(2) with a total of 5195 scintillation detectors.Its angular resolution reaches about 0.3 degrees,and the energy resolution is better than 25%.With the help of 1171 muon detectors,cosmic nuclei background will be rejected to a level of 10-4 at 50 TeV.The design and performances of the scintillation detectors and muon detectors are described in detail.WCDA LHAASO-WCDA focuses on surveying the northern sky for steady and transient sources from 100 GeV to 20 TeV,with a very high background rejection power and a good angular resolution.The WCDA consists of three water ponds with a total area of 78,000 m^(2),and the effective water depth is 4 m.Each water pond is divided into 5m×5m cells partitioned by black plastic curtains to prevent penetration of the light from neighboring cells.An 8-inch PMT sits at the bottom center of each cell,looking upward to collect Cherenkov light generated by shower secondary particles in water.WFCTA LHAASO-WFCTA is composed of 12 wide-field-of-view Cherenkov/fluorescence telescopes.Each telescope consists of a spherical light collector of about 4.7 m^(2) and focal plane camera of 32×32 pixels with a pixel size of 0.5 degree.LHAASO prototype arrays A prototype array about 1%of LHAASO has been constructed at Yangbajing Cosmic Ray Observatory and has been in operation for more than 2 years.Its performance fully meets the design requirements.Conclusion The LHAASO detectors are designed to fulfill the physical goals in gamma ray astronomy and cosmic ray physics.One-fourth of LHAASO will be constructed and put into operation to produce physical data by the end of 2018.The whole array will be finished in the beginning of 2021.展开更多
Objective To assess the association of socioeconomic status with the burden of cataract blindness in terms of year lived with disability(YLD) rates and to determine whether ultraviolet radiation(UVR) levels modify the...Objective To assess the association of socioeconomic status with the burden of cataract blindness in terms of year lived with disability(YLD) rates and to determine whether ultraviolet radiation(UVR) levels modify the effect of socioeconomic status on this health burden.Methods National and subnational age-standardized YLD rates associated with cataract-related blindness were derived from the Global Burden of Disease(GBD) study 2017. The human development index(HDI) from the Human Development Report was used as a measure of socioeconomic status.Estimated ground-level UVR exposure was obtained from the Ozone Monitoring Instrument(OMI)dataset of the National Aeronautics and Space Administration(NASA).Results Across 185 countries, socioeconomic status was inversely associated with the burden of cataract blindness. Countries with a very high HDI had an 84% lower age-standardized YLD rate [95%confidence interval(CI): 60%–93%, P < 0.001] than countries with a low HDI;for high-HDI countries, the proportion was 76%(95% CI: 53%–88%, P < 0.001), and for medium-HDI countries, the proportion was48%(95% CI: 15%–68%, P = 0.010;P for trend < 0.001). The interaction analysis showed that UVR exposure played an interactive role in the association between socioeconomic status and cataract blindness burden(P value for interaction = 0.047).Conclusion Long-term high-UVR exposure amplifies the association of poor socioeconomic status with the burden of cataract-related blindness. The findings emphasize the need for strengthening UVR exposure protection interventions in developing countries with high-UVR exposure.展开更多
OBJECTIVE:To explore the pathologic characteristics of hyperplasia of the mammary gland(HMG) by observing differences in infrared radiation temperature of points of HMG in patients with different syndromes compared wi...OBJECTIVE:To explore the pathologic characteristics of hyperplasia of the mammary gland(HMG) by observing differences in infrared radiation temperature of points of HMG in patients with different syndromes compared with healthy controls.METHODS:AFLIRSystems Therma CAM P30 infrared thermal camera was used to detect the infrared temperature of Shanzhong(CV 17),Qimen(LR 14),Zhongwan(CV 12),Qihai(CV 6),Guanyuan(CV 4),Taixi(KI 3),and Taichong(LR 3) in 113 patients with HMG.Of these patients,71 were placed in the Liver Qi stagnation group,34 were placed in the Dysfunction of conception and thoroughfare vessels group,and 8 were placed in the Phlegm and blood stasis in combination group.The infrared radiation temperature of each point in the patients was compared with that of healthy controls,and the differences in the infrared radiation temperatures of the points in the patients were analyzed.RESULTS:Overall,the bilateral corresponding point in both the controls and patients exhibited no significant difference in infrared radiation temperature.In all cases,the infrared radiation temperature of the points from proximal to distal tended to decrease.In a comparison of the patients and controls,the infrared radiation temperature of the trunk points Shanzhong(CV 17),Qimen(LR 14),Zhongwan(CV12),Qihai(CV6),and Guanyuan(CV 4) of the patients was higher than that of the controls,while the infrared radiation temperature of the lower extremity points Taixi(KI 3) and Taichong(LR 3) was lower than that of the controls.Of these points,Shanzhong(CV 17)(P=0.0368),Zhongwan(CV 12)(P=0.0028),Qihai(CV 6)(P=0.0085),and Guanyuan(CV4)(P=0.0018) showed significant differences.In a comparison of the corresponding point on the same side in the Liver Qi stagnation group and controls,the infrared radiation temperature of Shanzhong(CV17)(P=0.0089),right-side Qimen(LR 14)(P=0.0382),Zhongwan(CV 12)(P= 0.0000),Qihai(CV 6)(P=0.0011),and Guanyuan(CV 4)(P=0.0000) of the patients was significantly higher than that of the controls,while the differences in 展开更多
A sub-array of the Large High Altitude Air Shower Observatory(LHAASO),KM2A is mainly designed to observe a large fraction of the northern sky to hunt for γ-ray sources at energies above 10 TeV.Even though the detecto...A sub-array of the Large High Altitude Air Shower Observatory(LHAASO),KM2A is mainly designed to observe a large fraction of the northern sky to hunt for γ-ray sources at energies above 10 TeV.Even though the detector construction is still underway,half of the KM2A array has been operating stably since the end of 2019.In this paper,we present the KM2A data analysis pipeline and the first observation of the Crab Nebula,a standard candle in very high energy γ-ray astronomy.We detect γ-ray signals from the Crab Nebula in both energy ranges of 10-100 TeV and>100 TeV with high significance,by analyzing the KM2A data of 136 live days between December 2019 and May 2020.With the observations,we test the detector performance,including angular resolution,pointing accuracy and cosmic-ray background rejection power.The energy spectrum of the Crab Nebula in the energy range 10-250 TeV fits well with a single power-law function dN/dE=(1.13±0.05stat±0.08sys)×10^(-14).(E/20 TeV)-309±0.06stat±0.02syscm^(-2) s^(-1) TeV^(-1).It is consistent with previous measurements by other experiments.This opens a new window of γ-ray astronomy above 0.1 PeV through which new ultrahigh-energy γ-ray phenomena,such as cosmic PeVatrons,might be discovered.展开更多
Background Nitic oxide （NO） has been implicated in the pathogenesis of various inflammatory diseases, including sunburn and pigmentation induced by ultraviolet irradiation. Epigallocatechin-3-gallate （EGCG） is the...Background Nitic oxide （NO） has been implicated in the pathogenesis of various inflammatory diseases, including sunburn and pigmentation induced by ultraviolet irradiation. Epigallocatechin-3-gallate （EGCG） is the major effective component in green tea and can protect skin from ultraviolet-induced damage. The purpose of this study was to investigate the protective mechanisms of EGCG on inducible nitric oxide synthase （iNOS） expression and NO generation by ultraviolet B （UVB） irradiation in HaCaT cells. Methods HaCaT cells were irradiated with UVB 30 mJ/cm^2 and pretreated with EGCG at varying concentrations. The iNOS mRNA was detected by reverse transcriptase polymerase chain reaction （RT-PCR） and NO production was quantified by spectrophotometric method. The expression of NF-κB P65 was measured by immunofluorescence cytochemistry staining. Results The expression of iNOS mRNA and generation of NO in HaCaT cells were increased by UVB irradiation. EGCG down regulated the UVB-induced iNOS mRNA synthesis and NO generation in a dose dependent manner. The UVB-induced activation and translocation of NF-κB were also down regulated by EGCG treatment in HaCaT cells （P〈0.01）. Conclusions Green tea derived-EGCG can inhibit and down regulate the UVB-induced activation and translocation of NF-κB, expression of iNOS mRNA and generation of NO respectively, indicating EGCG may play a protective role from UVB-induced skin damage.展开更多
The detection of dark matter has made great progresses in recent years. We give a brief review on the status and progress in dark matter detection, including the progresses in direct detection, collider detection at L...The detection of dark matter has made great progresses in recent years. We give a brief review on the status and progress in dark matter detection, including the progresses in direct detection, collider detection at LHC and focus on the indirect detection. The results from PAMELA, ATIC, Fermi-LAT and relevant studies on these results are introduced. Then we give the progress on indirect detection of gamma rays from Fermi-LAT and ground based Cerenkov telescopes. Finally the detection of neutrinos and constraints on the nature of dark matter are reviewed briefly.展开更多
Intrinsic radiation of materials is one of the major backgrounds for many rare-event search experiments.Thus,the production of pure materials in an underground laboratory is a promising approach for eliminating cosmog...Intrinsic radiation of materials is one of the major backgrounds for many rare-event search experiments.Thus,the production of pure materials in an underground laboratory is a promising approach for eliminating cosmogenic radionuclides.In this paper,we demonstrate a procedure to evaluate the yields of cosmogenic radionuclides in copper and germanium in the second phase of the China Jinping Underground Laboratory.Our results show that for copper and germanium materials,the largest cosmogenic background comes from 3 H and57,58,60Co,and 3 H and 68Ge,respectively,which all have yields on the order of 10-7 kg-1 day-1.The corresponding radioactivities after 90 days pf exposure underground are estimated to be lower than 10-6μBq kg-1.展开更多
Black rockfish Sebastes schlegelii juveniles （30-40 mm total length） were immersed in a range of calcein （CAL） solutions at concentrations ranging from 50 to 250 mg/L and alizarin red S （ARS） solutions at concen...Black rockfish Sebastes schlegelii juveniles （30-40 mm total length） were immersed in a range of calcein （CAL） solutions at concentrations ranging from 50 to 250 mg/L and alizarin red S （ARS） solutions at concentrations ranging from 100 to 500 mg/L in filtered seawater （salinity 30） for 24 h. Fluorescent marks were detected in otoliths （sagittae, asteriscus）, scales, fin rays （dorsal, pectoral, ventral, anal, and caudal fin rays）, and fin spines （dorsal, ventral, and anal fin spines） after a 60-d growth experiment. With the exception of 50-100 rng/L CAL, acceptable marks were produced in the otoliths and fin spines by all concentrations of CAL and ARS. In particular, marks were clearly visible under normal light in the sagittae, asteriscus, and fin spines offish immersed in 200 500 mg/L, 300-500 rag/L, and 200-500 mg/LARS, respectively. Scales and fin rays had acceptable marks at much higher concentrations （≥50 mg/L CAL, ≥300 mg/L ARS for scales and ≥50 mg/L CAL,≥200 mg/L ARS for fin rays）. The mark quality was highest （i.e., acceptable marks were observed in all sampled structures after immersion marking） in fish immersed in 150-250 mg/L CAL or 300-500 mg/LARS. In addition, there was no significant difference in survival and growth of marked fish compared with controls 60 d post-marking （P〉0.05）.展开更多
Two new solutions of the homogeneous diffusion equation in 1D are derived in the presence of losses and a trigonometric profile for a profile of density. A simulation for the ankle in the energy distribution of cosmic...Two new solutions of the homogeneous diffusion equation in 1D are derived in the presence of losses and a trigonometric profile for a profile of density. A simulation for the ankle in the energy distribution of cosmic rays (CRs) is provided in the framework of the fine tuning of the involved parameters. A theoretical image for the overall diffusion of CRs in galactic coordinates is provided.展开更多
We show that recently multi-messenger astronomy has provided compelling evidence that the bulk of high energy cosmic rays (CRs) are produced by highly relativistic narrow jets of plasmoids launched in core collapse of...We show that recently multi-messenger astronomy has provided compelling evidence that the bulk of high energy cosmic rays (CRs) are produced by highly relativistic narrow jets of plasmoids launched in core collapse of stripped-envelope massive stars to neutron stars and stellar mass black holes. Such events produce also a visible GRB if the jet happens to point in our direction. This has been long advocated by the cannon ball (CB) model of high energy CRs and GRBs, but the evidence has been provided only recently by what were widely believed to be unrelated discoveries. They include the very recent discovery of a knee around TeV in the energy spectrum of high energy CR electrons, the peak photon energy in the “brightest of all time” GRB221009A, and the failure of IceCube to detect high energy neutrinos from GRBs, including GRB221009A. They were all predicted by the cannonball (CB) model of high energy CRs and GRBs long before they were discovered in observations, despite a negligible probability to occur by chance.展开更多
文摘Objective： To compare moxibustion sensation and infrared thermography by the assessment of heat-sensitization on Guanyuan （CV4） in patients with primary dysmenorrhea, and to prove the possibility of adopting infrared thermography as an objective demonstration of acupoints heat-sensitization. Methods： Seventy-one patients with primary dysmenorrhea were enrolled to receive moxibustion and infrared to detect the heat-sensitization of Guanyuan （CV 4）. The results were then analyzed and compared. Results： The infrared radiation showed a lower temperature when the acupoint Guanyuan （CV4） was sensitized in patients with primary dysmenorrhea. Compared with moxibustion sensation, its sensitivity rate （real positive rate） was 76.6%, divergence rate （real negative rate） was 70.1%, and the accuracy rate was 74.6%. After giving moxibustion to Guanyuan （CV4）, the infrared radiation area was significantly expanded longitudinally and transversely. Compared with moxibustion test, the sensitivity rate （real positive rate） of infrared test was 78.7%, divergencerate （real negative rate） was 83.3%, and the accuracy rate was 80.3%. Conclusion： To a certain extent, the heat-sensitization of the acupoint Guanyuan （CV4） in patients with primary dysmenorrhea can be revealed by infrared thermography. The acupoint heat-sensitization phenomena （heat extension or transmission） after giving moxibustion to the heat-sensitized acupoints can also be demonstrated objectively by infrared thermography, besides experienced subjectively by the receivers.
基金State 973 plan (2005CB523306)National Natural Science Foundation (30572306)+1 种基金Shanghai Municipal Education Commission Project (07CZ034)State Administration of Traditional Chinese Medicine and Shanghai Leading Academic Discipline Project (T0304,T0302)
文摘Objective： To compare the difference of infrared radiation temperature on body surface of points between healthy people and patients with hyperplasia of mammary glands. Method： The thermaCATMT P30 infrared thermal imaging system was selected to measure the infrared radiation temperature on body surface of eight points in four meridians in 74 patients with hyperplasia of mammary glands and 63 healthy people. Results： The infrared radiation temperatures on body surface of right Youmen （KI 21） in cases with hyperplasia of mammary glands were significantly higher than the healthy people （P=-0.009）, and the infrared radiation temperatures on left Youmen （KI 21） and other points had no significant difference with healthy people （P〉0.05）. Conclusion： The infrared radiation temperatures on body surface of right Youmen （KI 21） have significant differences with healthy people. This might occur because of the pathogenesis of hyperplasia of mammary glands and of the specificity of the point Youmen （KI 21）.
基金This work is supported in China by NSFC(Nos.11205165,11375210,11375224,11405181,11475190 and 11635011)the Chinese Academy of Sciences,Institute of High Energy Physics,the Key Laboratory of Particle Astrophysics,CAS.
文摘Introduction The Large High Altitude Air Shower Observatory plans to build a hybrid extensive air shower array with an area of about 1 km^(2) at an altitude of 4,410 m a.s.l.in Sichuan province,China,to explore the origin of high-energy cosmic rays.KM2A LHAASO-KM2A will detect gamma ray sources with a sensitivity of about 1%Crab Unit at 100 TeV.It covers an area of 1 km^(2) with a total of 5195 scintillation detectors.Its angular resolution reaches about 0.3 degrees,and the energy resolution is better than 25%.With the help of 1171 muon detectors,cosmic nuclei background will be rejected to a level of 10-4 at 50 TeV.The design and performances of the scintillation detectors and muon detectors are described in detail.WCDA LHAASO-WCDA focuses on surveying the northern sky for steady and transient sources from 100 GeV to 20 TeV,with a very high background rejection power and a good angular resolution.The WCDA consists of three water ponds with a total area of 78,000 m^(2),and the effective water depth is 4 m.Each water pond is divided into 5m×5m cells partitioned by black plastic curtains to prevent penetration of the light from neighboring cells.An 8-inch PMT sits at the bottom center of each cell,looking upward to collect Cherenkov light generated by shower secondary particles in water.WFCTA LHAASO-WFCTA is composed of 12 wide-field-of-view Cherenkov/fluorescence telescopes.Each telescope consists of a spherical light collector of about 4.7 m^(2) and focal plane camera of 32×32 pixels with a pixel size of 0.5 degree.LHAASO prototype arrays A prototype array about 1%of LHAASO has been constructed at Yangbajing Cosmic Ray Observatory and has been in operation for more than 2 years.Its performance fully meets the design requirements.Conclusion The LHAASO detectors are designed to fulfill the physical goals in gamma ray astronomy and cosmic ray physics.One-fourth of LHAASO will be constructed and put into operation to produce physical data by the end of 2018.The whole array will be finished in the beginning of 2021.
基金supported by a grant from the National Natural Science Foundation of China No. 81673133 and No.81273034。
文摘Objective To assess the association of socioeconomic status with the burden of cataract blindness in terms of year lived with disability(YLD) rates and to determine whether ultraviolet radiation(UVR) levels modify the effect of socioeconomic status on this health burden.Methods National and subnational age-standardized YLD rates associated with cataract-related blindness were derived from the Global Burden of Disease(GBD) study 2017. The human development index(HDI) from the Human Development Report was used as a measure of socioeconomic status.Estimated ground-level UVR exposure was obtained from the Ozone Monitoring Instrument(OMI)dataset of the National Aeronautics and Space Administration(NASA).Results Across 185 countries, socioeconomic status was inversely associated with the burden of cataract blindness. Countries with a very high HDI had an 84% lower age-standardized YLD rate [95%confidence interval(CI): 60%–93%, P < 0.001] than countries with a low HDI;for high-HDI countries, the proportion was 76%(95% CI: 53%–88%, P < 0.001), and for medium-HDI countries, the proportion was48%(95% CI: 15%–68%, P = 0.010;P for trend < 0.001). The interaction analysis showed that UVR exposure played an interactive role in the association between socioeconomic status and cataract blindness burden(P value for interaction = 0.047).Conclusion Long-term high-UVR exposure amplifies the association of poor socioeconomic status with the burden of cataract-related blindness. The findings emphasize the need for strengthening UVR exposure protection interventions in developing countries with high-UVR exposure.
基金Supported by the National Basic Research Program of China(2009CB522901)the Key Program of the State Administration of Traditional Chinese Medicine of the People's Republic of Chinathe Shanghai Municipal Science Foundation(11DZ1973300,11ZR1436700)
文摘OBJECTIVE:To explore the pathologic characteristics of hyperplasia of the mammary gland(HMG) by observing differences in infrared radiation temperature of points of HMG in patients with different syndromes compared with healthy controls.METHODS:AFLIRSystems Therma CAM P30 infrared thermal camera was used to detect the infrared temperature of Shanzhong(CV 17),Qimen(LR 14),Zhongwan(CV 12),Qihai(CV 6),Guanyuan(CV 4),Taixi(KI 3),and Taichong(LR 3) in 113 patients with HMG.Of these patients,71 were placed in the Liver Qi stagnation group,34 were placed in the Dysfunction of conception and thoroughfare vessels group,and 8 were placed in the Phlegm and blood stasis in combination group.The infrared radiation temperature of each point in the patients was compared with that of healthy controls,and the differences in the infrared radiation temperatures of the points in the patients were analyzed.RESULTS:Overall,the bilateral corresponding point in both the controls and patients exhibited no significant difference in infrared radiation temperature.In all cases,the infrared radiation temperature of the points from proximal to distal tended to decrease.In a comparison of the patients and controls,the infrared radiation temperature of the trunk points Shanzhong(CV 17),Qimen(LR 14),Zhongwan(CV12),Qihai(CV6),and Guanyuan(CV 4) of the patients was higher than that of the controls,while the infrared radiation temperature of the lower extremity points Taixi(KI 3) and Taichong(LR 3) was lower than that of the controls.Of these points,Shanzhong(CV 17)(P=0.0368),Zhongwan(CV 12)(P=0.0028),Qihai(CV 6)(P=0.0085),and Guanyuan(CV4)(P=0.0018) showed significant differences.In a comparison of the corresponding point on the same side in the Liver Qi stagnation group and controls,the infrared radiation temperature of Shanzhong(CV17)(P=0.0089),right-side Qimen(LR 14)(P=0.0382),Zhongwan(CV 12)(P= 0.0000),Qihai(CV 6)(P=0.0011),and Guanyuan(CV 4)(P=0.0000) of the patients was significantly higher than that of the controls,while the differences in
基金Supported in China by National Key R&D program of China under the grants(2018YF A0404201.2018YFA0404202.2018YF A0404203)by NSFC(12022502,190527,135011,11761141001.U1931112,11775131,U1931201,11905043,U1931108)by NSFSPC(ZR2019MA014),and in Thailand by RTA6280002 from Thailand Science Research and Innovation。
文摘A sub-array of the Large High Altitude Air Shower Observatory(LHAASO),KM2A is mainly designed to observe a large fraction of the northern sky to hunt for γ-ray sources at energies above 10 TeV.Even though the detector construction is still underway,half of the KM2A array has been operating stably since the end of 2019.In this paper,we present the KM2A data analysis pipeline and the first observation of the Crab Nebula,a standard candle in very high energy γ-ray astronomy.We detect γ-ray signals from the Crab Nebula in both energy ranges of 10-100 TeV and>100 TeV with high significance,by analyzing the KM2A data of 136 live days between December 2019 and May 2020.With the observations,we test the detector performance,including angular resolution,pointing accuracy and cosmic-ray background rejection power.The energy spectrum of the Crab Nebula in the energy range 10-250 TeV fits well with a single power-law function dN/dE=(1.13±0.05stat±0.08sys)×10^(-14).(E/20 TeV)-309±0.06stat±0.02syscm^(-2) s^(-1) TeV^(-1).It is consistent with previous measurements by other experiments.This opens a new window of γ-ray astronomy above 0.1 PeV through which new ultrahigh-energy γ-ray phenomena,such as cosmic PeVatrons,might be discovered.
基金This study was supported by a grant from the National Natural Science Foundation of China (No. 30271195).
文摘Background Nitic oxide （NO） has been implicated in the pathogenesis of various inflammatory diseases, including sunburn and pigmentation induced by ultraviolet irradiation. Epigallocatechin-3-gallate （EGCG） is the major effective component in green tea and can protect skin from ultraviolet-induced damage. The purpose of this study was to investigate the protective mechanisms of EGCG on inducible nitric oxide synthase （iNOS） expression and NO generation by ultraviolet B （UVB） irradiation in HaCaT cells. Methods HaCaT cells were irradiated with UVB 30 mJ/cm^2 and pretreated with EGCG at varying concentrations. The iNOS mRNA was detected by reverse transcriptase polymerase chain reaction （RT-PCR） and NO production was quantified by spectrophotometric method. The expression of NF-κB P65 was measured by immunofluorescence cytochemistry staining. Results The expression of iNOS mRNA and generation of NO in HaCaT cells were increased by UVB irradiation. EGCG down regulated the UVB-induced iNOS mRNA synthesis and NO generation in a dose dependent manner. The UVB-induced activation and translocation of NF-κB were also down regulated by EGCG treatment in HaCaT cells （P〈0.01）. Conclusions Green tea derived-EGCG can inhibit and down regulate the UVB-induced activation and translocation of NF-κB, expression of iNOS mRNA and generation of NO respectively, indicating EGCG may play a protective role from UVB-induced skin damage.
基金Acknowledgements We thank Zhaohuan Yu for help in the manuscript preparation. This work was supported by the National Natural Science Foundation of China under the grant Nos. 11075169, 11135009, 11105155, 11105157, and 11175251.
文摘The detection of dark matter has made great progresses in recent years. We give a brief review on the status and progress in dark matter detection, including the progresses in direct detection, collider detection at LHC and focus on the indirect detection. The results from PAMELA, ATIC, Fermi-LAT and relevant studies on these results are introduced. Then we give the progress on indirect detection of gamma rays from Fermi-LAT and ground based Cerenkov telescopes. Finally the detection of neutrinos and constraints on the nature of dark matter are reviewed briefly.
基金supported by the National Natural Science Foundation of China(No.U1865205).
文摘Intrinsic radiation of materials is one of the major backgrounds for many rare-event search experiments.Thus,the production of pure materials in an underground laboratory is a promising approach for eliminating cosmogenic radionuclides.In this paper,we demonstrate a procedure to evaluate the yields of cosmogenic radionuclides in copper and germanium in the second phase of the China Jinping Underground Laboratory.Our results show that for copper and germanium materials,the largest cosmogenic background comes from 3 H and57,58,60Co,and 3 H and 68Ge,respectively,which all have yields on the order of 10-7 kg-1 day-1.The corresponding radioactivities after 90 days pf exposure underground are estimated to be lower than 10-6μBq kg-1.
基金Supported by the Special Fund for Agro-scientific Research in the Public Interest(No.201003068)the National Natural Science Foundation of China(Nos.31172447,41176117)
文摘Black rockfish Sebastes schlegelii juveniles （30-40 mm total length） were immersed in a range of calcein （CAL） solutions at concentrations ranging from 50 to 250 mg/L and alizarin red S （ARS） solutions at concentrations ranging from 100 to 500 mg/L in filtered seawater （salinity 30） for 24 h. Fluorescent marks were detected in otoliths （sagittae, asteriscus）, scales, fin rays （dorsal, pectoral, ventral, anal, and caudal fin rays）, and fin spines （dorsal, ventral, and anal fin spines） after a 60-d growth experiment. With the exception of 50-100 rng/L CAL, acceptable marks were produced in the otoliths and fin spines by all concentrations of CAL and ARS. In particular, marks were clearly visible under normal light in the sagittae, asteriscus, and fin spines offish immersed in 200 500 mg/L, 300-500 rag/L, and 200-500 mg/LARS, respectively. Scales and fin rays had acceptable marks at much higher concentrations （≥50 mg/L CAL, ≥300 mg/L ARS for scales and ≥50 mg/L CAL,≥200 mg/L ARS for fin rays）. The mark quality was highest （i.e., acceptable marks were observed in all sampled structures after immersion marking） in fish immersed in 150-250 mg/L CAL or 300-500 mg/LARS. In addition, there was no significant difference in survival and growth of marked fish compared with controls 60 d post-marking （P〉0.05）.
文摘Two new solutions of the homogeneous diffusion equation in 1D are derived in the presence of losses and a trigonometric profile for a profile of density. A simulation for the ankle in the energy distribution of cosmic rays (CRs) is provided in the framework of the fine tuning of the involved parameters. A theoretical image for the overall diffusion of CRs in galactic coordinates is provided.
文摘We show that recently multi-messenger astronomy has provided compelling evidence that the bulk of high energy cosmic rays (CRs) are produced by highly relativistic narrow jets of plasmoids launched in core collapse of stripped-envelope massive stars to neutron stars and stellar mass black holes. Such events produce also a visible GRB if the jet happens to point in our direction. This has been long advocated by the cannon ball (CB) model of high energy CRs and GRBs, but the evidence has been provided only recently by what were widely believed to be unrelated discoveries. They include the very recent discovery of a knee around TeV in the energy spectrum of high energy CR electrons, the peak photon energy in the “brightest of all time” GRB221009A, and the failure of IceCube to detect high energy neutrinos from GRBs, including GRB221009A. They were all predicted by the cannonball (CB) model of high energy CRs and GRBs long before they were discovered in observations, despite a negligible probability to occur by chance.
