Background： Allogeneic blood transfusion-induced immunomodulation （TRIM） and its adverse effect on the prognosis of patients treated surgically for cancer remain complex and controversial. However, the potential ri...Background： Allogeneic blood transfusion-induced immunomodulation （TRIM） and its adverse effect on the prognosis of patients treated surgically for cancer remain complex and controversial. However, the potential risk associated with allogeneic blood transfusion has heightened interest in the use of autologous blood transfusion. In the present study, the serum concentrations of neopterin, interferon-gamma （IFN-γ）, T lymphocyte subsets （CD3^＋, CD4^＋, CD8^＋, CD4^＋/CD8^＋） and a possible association between these variables were investigated. The purpose was to further evaluate the effect of autologous versus allogeneic blood transfusion on immunological status in patients undergoing surgery for gastric cancer. Methods： Sixty ASA Ⅰ～Ⅱ（American Society of Anesthesiologists） patients undergoing elective radical resection for stomach cancer were randomly allocated to receive either allogeneic blood transfusion （n=30） or autologous blood transfusion （n=30）. Serum concentrations of the neopterin, IFN-γ and T lymphocyte subsets in the recipients were measured before induction of anesthesia, after operation, and on the 5th postoperative day. Results： Both two groups, serum neopterin, IFN-γ, percentages of T-cell subsets （CD3^＋, CD4^＋）, and CD4^＋/CD8^＋ ratio had significantly decreased after operation, but decreased more significantly in group H （receiving allogeneic blood transfusion） than those in group A （receiving autologous whole blood transfusion） （P〈0.05）. On the 5th postoperative day,serum neopterin, IFN-γ, CD3^＋, CD4^＋ T-cells, and CD4^＋/CD8^＋ ratio returned to the baseline values in group A. In contrast, the above remain decreasing in group H, where there were no significant relations between serum neopterin and IFN-γ. Conclusion：Perioperative surgical trauma and stress have an immunosuppressive impact on gastric cancer patients. Allogeneic blood transfusion exacerbates the impaired immune response. Autologous blood transfusion migh展开更多
BACKGROUND Intrahepatic cholangiocarcinoma(ICC)is a heterogeneous hepatobiliary cancer with limited treatment options.A number of studies have illuminated the relationship between inflammation-based prognostic scores ...BACKGROUND Intrahepatic cholangiocarcinoma(ICC)is a heterogeneous hepatobiliary cancer with limited treatment options.A number of studies have illuminated the relationship between inflammation-based prognostic scores and outcomes in patients with ICC.However,the use of reliable and personalized prognostic algorithms in ICC after resection is pending.AIM To assess the prognostic value of the gamma-glutamyltransferase to lymphocyte ratio(GLR)in ICC patients following curative resection.METHODS ICC patients following curative resection(2009-2017)were divided into two cohorts:The derivation cohort and validation cohort.The derivation cohort was used to explore an optimal cut-off value,and the validation cohort was used to further evaluate the score.Overall survival(OS)and recurrence-free survival(RFS)were analyzed,and predictors of OS and RFS were determined.RESULTS A total of 527 ICC patients were included and randomly divided into the derivation cohort(264 patients)and the validation cohort(263 patients).The two patient cohorts had comparable baseline characteristics.The optimal cut-off value for the GLR was 33.7.Kaplan-Meier curves showed worse OS and RFS in the GLR>33.7 group compared with GLR≤33.7 group in both cohorts.After univariate and multivariate analysis,the results indicated that GLR was an independent prognostic factor of OS[derivation cohort:hazard ratio(HR)=1.620,95%confidence interval(CI):1.066-2.462,P=0.024;validation cohort:HR=1.466,95%CI:1.033-2.142,P=0.048]and RFS[derivation cohort:HR=1.471,95%CI:1.029-2.103,P=0.034;validation cohort:HR=1.480,95%CI:1.057-2.070,P=0.022].CONCLUSION The preoperative GLR is an independent prognostic factor for ICC patients following hepatectomy.A high preoperative GLR is associated with worse OS and RFS.展开更多
BACKGROUND Gallbladder carcinoma(GBC)carries a poor prognosis and requires a prediction method.Gamma-glutamyl transferase–to–platelet ratio(GPR)is a recently reported cancer prognostic factor.Although the mechanism ...BACKGROUND Gallbladder carcinoma(GBC)carries a poor prognosis and requires a prediction method.Gamma-glutamyl transferase–to–platelet ratio(GPR)is a recently reported cancer prognostic factor.Although the mechanism for the relationship between GPR and poor cancer prognosis remains unclear,studies have demonstrated the clinical effect of both gamma-glutamyl transferase and platelet count on GBC and related gallbladder diseases.AIM To assess the prognostic value of GPR and to design a prognostic nomogram for GBC.METHODS The analysis involved 130 GBC patients who underwent surgery at Peking Union Medical College Hospital from December 2003 to April 2017.The patients were stratified into a high-or low-GPR group.The predictive ability of GPR was evaluated by Kaplan–Meier analysis and a Cox regression model.We developed a nomogram based on GPR,which we verified using calibration curves.The nomogram and other prognosis prediction models were compared using timedependent receiver operating characteristic curves and the concordance index.RESULTS Patients in the high-GPR group had a higher risk of jaundice,were older,and had higher carbohydrate antigen 19-9 levels and worse postoperative outcomes.Univariate analysis revealed that GPR,age,body mass index,tumor–node–metastasis(TNM)stage,jaundice,cancer cell differentiation degree,and carcinoembryonic antigen and carbohydrate antigen 19-9 levels were related to overall survival(OS).Multivariate analysis confirmed that GPR,body mass index,age,and TNM stage were independent predictors of poor OS.Calibration curves were highly consistent with actual observations.Comparisons of timedependent receiver operating characteristic curves and the concordance index showed advantages for the nomogram over TNM staging.CONCLUSION GPR is an independent predictor of GBC prognosis,and nomogram-integrated GPR is a promising predictive model for OS in GBC.展开更多
Background: Indoleamine 2,3-dioxygenase 1 (IDO1) and tryptophan (Trp)catabolism have been demonstrated to play an important role in tumor immunosuppression. This study examined the expression and catalytic activity of...Background: Indoleamine 2,3-dioxygenase 1 (IDO1) and tryptophan (Trp)catabolism have been demonstrated to play an important role in tumor immunosuppression. This study examined the expression and catalytic activity of IDO1 in penilesquamous cell carcinoma (PSCC) and explored their clinical significance.Methods: IDO1 expression level, serum concentrations of Trp and kynurenine (Kyn)were examined in 114 PSCC patients by immunohistonchemistry and solid-phaseextraction-liquid chromatography-tandem mass spectrometry. The survival was analyzed using Kaplan-Meier method and the log-rank test. Hazard ratio of death was analyzed via univariate and multivariate Cox regression. Immune cell types were definedby principal component analysis. The correlativity was assessed by Pearson’s correlation analysis.Results: The expression level of IDO1 in PSCC cells was positively correlatedwith serum Kyn concentration and Kyn/Trp radio (KTR;both P < 0.001) but negatively correlated with serum Trp concentration (P = 0.001). Additionally, IDO1 upregulation in cancer cells and the increase of serum KTR were significantly associated with advanced N stage (both P < 0.001) and high pathologic grade (P = 0.008and 0.032, respectively). High expression level of IDO1 in cancer cells and serumKTR were associated with short disease-specific survival (both P < 0.001). However, besides N stage (hazard radio [HR], 6.926;95% confidence interval [CI],2.458-19.068;P < 0.001) and pathologic grade (HR, 2.194;95% CI, 1.021-4.529;P = 0.038), only serum KTR (HR, 2.780;95% CI, 1.066-7.215;P = 0.036) was anindependent predictor for PSCC prognosis. IDO1 expression was positively correlated with the expression of interferon-𝛾 (IFN𝛾, P < 0.001) and immunosuppressivemarkers (programmed cell death protein 1, cytotoxic T-lymphocyte-associated protein 4 and programmed death-ligand 1 and 2;all P < 0.05), and the infiltration ofimmune cells (including cytotoxic T lymphocytes, regulatory T lymphocytes, tumorassociated macrophages, and myeloid-derived suppressor展开更多
In this work, the performance of free-space optical(FSO) communication system based on maximal ratio combining using binary phase shift keying subcarrier intensity modulation over Gamma-Gamma fading channels has been ...In this work, the performance of free-space optical(FSO) communication system based on maximal ratio combining using binary phase shift keying subcarrier intensity modulation over Gamma-Gamma fading channels has been studied systematically. Under identically or non-identically distributed branches, the analytical expressions for the bit error rate function of signal-to-noise are derived by expressing the modified Bessel function of second kind with Meijer G-function for dualand triple-branch systems, respectively. In terms of H-fox function, the new expressions have more general forms and are more efficient for computation. It is found that the dual-and triple-branch systems significantly outperform the direct link system under weak, moderate and strong turbulence conditions. Monte Carlo simulation is also provided to confirm the accuracy of the proposed model.展开更多
We take an adaptive leaky integrate-and-fire neuron model to explore the effect of non-Poisson neurotransmitter on stochastic resonance and its signal-to-noise ratio(SNR)gain.Event triggered algorithm is adopted to sp...We take an adaptive leaky integrate-and-fire neuron model to explore the effect of non-Poisson neurotransmitter on stochastic resonance and its signal-to-noise ratio(SNR)gain.Event triggered algorithm is adopted to speed up the simulating process.It is revealed that both the output SNR and the SNR gain can be monotonically improved when increasing the shape parameter for Gamma distribution.Particularly,for large signal coupling strength,the 1:1 stochastic phase locking induced by Gamma noise is responsible for the frequency matching stochastic resonance,and the output signal-to-noise ratio can surpass the input signal-to-noise ratio,which is significantly different with Poisson case,while for extremely weak signal coupling strength,the SNR gain peak,which is far larger than unity,is due to noise induced resonance.The observations are meaningful in understanding the neural processing mechanisms from a more realistic viewpoint of synaptic modeling.展开更多
Purpose The discovery of gravitational waves and gamma-ray bursts heralds the era of multi-messenger astronomy.With the adoption of two small satellites to achieve the all-sky monitoring of gamma-ray bursts,the gravit...Purpose The discovery of gravitational waves and gamma-ray bursts heralds the era of multi-messenger astronomy.With the adoption of two small satellites to achieve the all-sky monitoring of gamma-ray bursts,the gravitational wave highenergy electromagnetic counterpart all-sky monitor(GECAM)possesses a quasi-real-time early warning ability and plays an important role in positioning the sources of gravitational waves and in subsequent observations.Each satellite of GECAM was fitted with 253-inch-diameter gamma-ray detectors(GRD),covering an energy range of 8–2 MeV.GRDs have adopted silicon photomultiplier tubes(SiPM)in lieu of photomultiplier tubes(PMT)to adapt to the dimensional limitations of micro-satellites.Methods A unique 3-inch circular SiPM array was designed.In this design,646×6 mm chips were arranged evenly in a circular manner with the seams filled with reflecting films,thus achieving satisfactory uniformity of light collection.The integrated pre-amplifier circuit on the back of the SiPM array adopted two-level grouping and summing;further,it achieved a satisfactory signal-to-noise ratio.Two high-gain and low-gain channels were adopted to achieve a large dynamic range,and two independent power supply units were used,where each unit can be closed separately,thus improving reliability.Results Performance studies show that this SiPM array meets the requirements of GECAM.Conclusion A 3-inch SiPM array have been developed that uses grouped summation,reflective films,a circular arrangement,two groups of independent power supplies,high-and low-gain signals,differential signal output technologies,etc.This solution can be used not only for GECAM,but also as a general solution for SiPM-based scintillation detectors.展开更多
AIM To investigate the value of the gamma-glutamyltraspeptidase(GGT)-to-platelet(PLT) ratio(GPR) in the diagnosis of hepatic fibrosis in patients with chronic hepatitis B(CHB). METHODS We included 390 untreated CHB pa...AIM To investigate the value of the gamma-glutamyltraspeptidase(GGT)-to-platelet(PLT) ratio(GPR) in the diagnosis of hepatic fibrosis in patients with chronic hepatitis B(CHB). METHODS We included 390 untreated CHB patients in this study. The GPR, aspartate aminotransferase(AST)-to-PLT ratio index(APRI), and fibrosis-4(FIB-4) of all patients were analysed to determine if these parameter were correlated with age, gender, medical history, liver function [total bilirubin(TBil), alanine aminotransferase(ALT), and AST], GGT, PLT count, or hepatic fibrosis stage. The GPR, APRI, and FIB-4, as well as the combination of the GPR and APRI or the GPR and FIB-4 were assessed in different cirrhosis stages using receiver operating characteristic(ROC) curve analysis to evaluate their value in diagnosing hepatic fibrosis in CHB patients. RESULTS The GPR, APRI, and FIB-4 were not correlated withCHB patients' age, gender, or disease duration(P > 0.05), but all of these parameters were positively correlated with serum ALT, AST, GGT, and PLT count(P < 0.01). Additionally, the GPR, APRI, and FIB-4 were positively correlated with hepatic fibrosis(P < 0.01); the areas under the ROC curve for the GPR in F1, F2, F3, and F4 stages were 0.723, 0.741, 0.826, and 0.833, respectively, which were significantly higher than the respective values for the FIB-4 and APRI(F1: 0.581, 0.612; F2: 0.706, 0.711; F3: 0.73, 0.751; and F4: 0.799, 0.778). The respective diagnostic cut-off points for each stage were 0.402, 0.448, 0.548, and 0.833, respectively. The diagnostic sensitivity and specificity were, respectively, 88.8% and 87.5% in F1, 72.7% and 89.7% in F2, 81.3% and 98.6% in F3, and 80% and 97.4% in F4 when the GPR and APRI were connected in parallel; 86.6% and 90.2%, 78.4% and 96%, 78.6% and 97.4%, and 73.2% and 97.9%, respectively, when the GPR and APRI were connected in series; 80.2% and 89%, 65% and 89%, 70.3% and 98.5%, and 78.8% and 96.8%, respectively, when the GPR and FIB-4 were connected in parallel; and 83.6% and 87.9%, 76.8% and 96.6%, 展开更多
基金Project supported by the Health Department of Zhejiang Province(No. 2004A040)the Education Department of Zhejiang Province (No. G20030486), China
文摘Background： Allogeneic blood transfusion-induced immunomodulation （TRIM） and its adverse effect on the prognosis of patients treated surgically for cancer remain complex and controversial. However, the potential risk associated with allogeneic blood transfusion has heightened interest in the use of autologous blood transfusion. In the present study, the serum concentrations of neopterin, interferon-gamma （IFN-γ）, T lymphocyte subsets （CD3^＋, CD4^＋, CD8^＋, CD4^＋/CD8^＋） and a possible association between these variables were investigated. The purpose was to further evaluate the effect of autologous versus allogeneic blood transfusion on immunological status in patients undergoing surgery for gastric cancer. Methods： Sixty ASA Ⅰ～Ⅱ（American Society of Anesthesiologists） patients undergoing elective radical resection for stomach cancer were randomly allocated to receive either allogeneic blood transfusion （n=30） or autologous blood transfusion （n=30）. Serum concentrations of the neopterin, IFN-γ and T lymphocyte subsets in the recipients were measured before induction of anesthesia, after operation, and on the 5th postoperative day. Results： Both two groups, serum neopterin, IFN-γ, percentages of T-cell subsets （CD3^＋, CD4^＋）, and CD4^＋/CD8^＋ ratio had significantly decreased after operation, but decreased more significantly in group H （receiving allogeneic blood transfusion） than those in group A （receiving autologous whole blood transfusion） （P〈0.05）. On the 5th postoperative day,serum neopterin, IFN-γ, CD3^＋, CD4^＋ T-cells, and CD4^＋/CD8^＋ ratio returned to the baseline values in group A. In contrast, the above remain decreasing in group H, where there were no significant relations between serum neopterin and IFN-γ. Conclusion：Perioperative surgical trauma and stress have an immunosuppressive impact on gastric cancer patients. Allogeneic blood transfusion exacerbates the impaired immune response. Autologous blood transfusion migh
基金the National Key Technologies RD Program,No.2018YFC1106803the Natural Science Foundation of China,No.81972747,No.81872004,No.81770615 and No.81672882the Science and Technology Support Program of Sichuan Province,No.2019YFQ0001 and No.2017SZ0003。
文摘BACKGROUND Intrahepatic cholangiocarcinoma(ICC)is a heterogeneous hepatobiliary cancer with limited treatment options.A number of studies have illuminated the relationship between inflammation-based prognostic scores and outcomes in patients with ICC.However,the use of reliable and personalized prognostic algorithms in ICC after resection is pending.AIM To assess the prognostic value of the gamma-glutamyltransferase to lymphocyte ratio(GLR)in ICC patients following curative resection.METHODS ICC patients following curative resection(2009-2017)were divided into two cohorts:The derivation cohort and validation cohort.The derivation cohort was used to explore an optimal cut-off value,and the validation cohort was used to further evaluate the score.Overall survival(OS)and recurrence-free survival(RFS)were analyzed,and predictors of OS and RFS were determined.RESULTS A total of 527 ICC patients were included and randomly divided into the derivation cohort(264 patients)and the validation cohort(263 patients).The two patient cohorts had comparable baseline characteristics.The optimal cut-off value for the GLR was 33.7.Kaplan-Meier curves showed worse OS and RFS in the GLR>33.7 group compared with GLR≤33.7 group in both cohorts.After univariate and multivariate analysis,the results indicated that GLR was an independent prognostic factor of OS[derivation cohort:hazard ratio(HR)=1.620,95%confidence interval(CI):1.066-2.462,P=0.024;validation cohort:HR=1.466,95%CI:1.033-2.142,P=0.048]and RFS[derivation cohort:HR=1.471,95%CI:1.029-2.103,P=0.034;validation cohort:HR=1.480,95%CI:1.057-2.070,P=0.022].CONCLUSION The preoperative GLR is an independent prognostic factor for ICC patients following hepatectomy.A high preoperative GLR is associated with worse OS and RFS.
基金Supported by CAMS Innovation Fund for Medical Sciences,No.2016-I2M-1-001Tsinghua University-Peking Union Medical College Hospital Cooperation Project,No.PTQH201904552。
文摘BACKGROUND Gallbladder carcinoma(GBC)carries a poor prognosis and requires a prediction method.Gamma-glutamyl transferase–to–platelet ratio(GPR)is a recently reported cancer prognostic factor.Although the mechanism for the relationship between GPR and poor cancer prognosis remains unclear,studies have demonstrated the clinical effect of both gamma-glutamyl transferase and platelet count on GBC and related gallbladder diseases.AIM To assess the prognostic value of GPR and to design a prognostic nomogram for GBC.METHODS The analysis involved 130 GBC patients who underwent surgery at Peking Union Medical College Hospital from December 2003 to April 2017.The patients were stratified into a high-or low-GPR group.The predictive ability of GPR was evaluated by Kaplan–Meier analysis and a Cox regression model.We developed a nomogram based on GPR,which we verified using calibration curves.The nomogram and other prognosis prediction models were compared using timedependent receiver operating characteristic curves and the concordance index.RESULTS Patients in the high-GPR group had a higher risk of jaundice,were older,and had higher carbohydrate antigen 19-9 levels and worse postoperative outcomes.Univariate analysis revealed that GPR,age,body mass index,tumor–node–metastasis(TNM)stage,jaundice,cancer cell differentiation degree,and carcinoembryonic antigen and carbohydrate antigen 19-9 levels were related to overall survival(OS).Multivariate analysis confirmed that GPR,body mass index,age,and TNM stage were independent predictors of poor OS.Calibration curves were highly consistent with actual observations.Comparisons of timedependent receiver operating characteristic curves and the concordance index showed advantages for the nomogram over TNM staging.CONCLUSION GPR is an independent predictor of GBC prognosis,and nomogram-integrated GPR is a promising predictive model for OS in GBC.
基金National Natural Science Foundation of China,Grant/Award Number:81772755
文摘Background: Indoleamine 2,3-dioxygenase 1 (IDO1) and tryptophan (Trp)catabolism have been demonstrated to play an important role in tumor immunosuppression. This study examined the expression and catalytic activity of IDO1 in penilesquamous cell carcinoma (PSCC) and explored their clinical significance.Methods: IDO1 expression level, serum concentrations of Trp and kynurenine (Kyn)were examined in 114 PSCC patients by immunohistonchemistry and solid-phaseextraction-liquid chromatography-tandem mass spectrometry. The survival was analyzed using Kaplan-Meier method and the log-rank test. Hazard ratio of death was analyzed via univariate and multivariate Cox regression. Immune cell types were definedby principal component analysis. The correlativity was assessed by Pearson’s correlation analysis.Results: The expression level of IDO1 in PSCC cells was positively correlatedwith serum Kyn concentration and Kyn/Trp radio (KTR;both P < 0.001) but negatively correlated with serum Trp concentration (P = 0.001). Additionally, IDO1 upregulation in cancer cells and the increase of serum KTR were significantly associated with advanced N stage (both P < 0.001) and high pathologic grade (P = 0.008and 0.032, respectively). High expression level of IDO1 in cancer cells and serumKTR were associated with short disease-specific survival (both P < 0.001). However, besides N stage (hazard radio [HR], 6.926;95% confidence interval [CI],2.458-19.068;P < 0.001) and pathologic grade (HR, 2.194;95% CI, 1.021-4.529;P = 0.038), only serum KTR (HR, 2.780;95% CI, 1.066-7.215;P = 0.036) was anindependent predictor for PSCC prognosis. IDO1 expression was positively correlated with the expression of interferon-𝛾 (IFN𝛾, P < 0.001) and immunosuppressivemarkers (programmed cell death protein 1, cytotoxic T-lymphocyte-associated protein 4 and programmed death-ligand 1 and 2;all P < 0.05), and the infiltration ofimmune cells (including cytotoxic T lymphocytes, regulatory T lymphocytes, tumorassociated macrophages, and myeloid-derived suppressor
基金supported by the National Natural Science Foundation of China (Grant No. 61671347)the Fundamental ResearchFunds for the Central Universities (Grant No. 20106151859 & 20106161859)supported by 111 Project of China (B08038)
文摘In this work, the performance of free-space optical(FSO) communication system based on maximal ratio combining using binary phase shift keying subcarrier intensity modulation over Gamma-Gamma fading channels has been studied systematically. Under identically or non-identically distributed branches, the analytical expressions for the bit error rate function of signal-to-noise are derived by expressing the modified Bessel function of second kind with Meijer G-function for dualand triple-branch systems, respectively. In terms of H-fox function, the new expressions have more general forms and are more efficient for computation. It is found that the dual-and triple-branch systems significantly outperform the direct link system under weak, moderate and strong turbulence conditions. Monte Carlo simulation is also provided to confirm the accuracy of the proposed model.
基金the Non Poisson Modeling of Neuron Synaptic Input and Critical Dynamics for Cortical Networks(Grant No.11772241).
文摘We take an adaptive leaky integrate-and-fire neuron model to explore the effect of non-Poisson neurotransmitter on stochastic resonance and its signal-to-noise ratio(SNR)gain.Event triggered algorithm is adopted to speed up the simulating process.It is revealed that both the output SNR and the SNR gain can be monotonically improved when increasing the shape parameter for Gamma distribution.Particularly,for large signal coupling strength,the 1:1 stochastic phase locking induced by Gamma noise is responsible for the frequency matching stochastic resonance,and the output signal-to-noise ratio can surpass the input signal-to-noise ratio,which is significantly different with Poisson case,while for extremely weak signal coupling strength,the SNR gain peak,which is far larger than unity,is due to noise induced resonance.The observations are meaningful in understanding the neural processing mechanisms from a more realistic viewpoint of synaptic modeling.
基金This research was supported by the Key Research Program of Frontier Sciences,Chinese Academy of Sciences(QYZDBSSW-SLH012)the National Natural Science Foundation of China(11775251,11775252)the strategic leading science and technology program of Chinese Academy of Sciences(XDA 15360100,XDA 15360102).
文摘Purpose The discovery of gravitational waves and gamma-ray bursts heralds the era of multi-messenger astronomy.With the adoption of two small satellites to achieve the all-sky monitoring of gamma-ray bursts,the gravitational wave highenergy electromagnetic counterpart all-sky monitor(GECAM)possesses a quasi-real-time early warning ability and plays an important role in positioning the sources of gravitational waves and in subsequent observations.Each satellite of GECAM was fitted with 253-inch-diameter gamma-ray detectors(GRD),covering an energy range of 8–2 MeV.GRDs have adopted silicon photomultiplier tubes(SiPM)in lieu of photomultiplier tubes(PMT)to adapt to the dimensional limitations of micro-satellites.Methods A unique 3-inch circular SiPM array was designed.In this design,646×6 mm chips were arranged evenly in a circular manner with the seams filled with reflecting films,thus achieving satisfactory uniformity of light collection.The integrated pre-amplifier circuit on the back of the SiPM array adopted two-level grouping and summing;further,it achieved a satisfactory signal-to-noise ratio.Two high-gain and low-gain channels were adopted to achieve a large dynamic range,and two independent power supply units were used,where each unit can be closed separately,thus improving reliability.Results Performance studies show that this SiPM array meets the requirements of GECAM.Conclusion A 3-inch SiPM array have been developed that uses grouped summation,reflective films,a circular arrangement,two groups of independent power supplies,high-and low-gain signals,differential signal output technologies,etc.This solution can be used not only for GECAM,but also as a general solution for SiPM-based scintillation detectors.
基金Supported by National Natural Science Foundation of China,No.81460301 and No.81760363Key Project of Natural Science Foundation of Ningxia,No.NZ15134
文摘AIM To investigate the value of the gamma-glutamyltraspeptidase(GGT)-to-platelet(PLT) ratio(GPR) in the diagnosis of hepatic fibrosis in patients with chronic hepatitis B(CHB). METHODS We included 390 untreated CHB patients in this study. The GPR, aspartate aminotransferase(AST)-to-PLT ratio index(APRI), and fibrosis-4(FIB-4) of all patients were analysed to determine if these parameter were correlated with age, gender, medical history, liver function [total bilirubin(TBil), alanine aminotransferase(ALT), and AST], GGT, PLT count, or hepatic fibrosis stage. The GPR, APRI, and FIB-4, as well as the combination of the GPR and APRI or the GPR and FIB-4 were assessed in different cirrhosis stages using receiver operating characteristic(ROC) curve analysis to evaluate their value in diagnosing hepatic fibrosis in CHB patients. RESULTS The GPR, APRI, and FIB-4 were not correlated withCHB patients' age, gender, or disease duration(P > 0.05), but all of these parameters were positively correlated with serum ALT, AST, GGT, and PLT count(P < 0.01). Additionally, the GPR, APRI, and FIB-4 were positively correlated with hepatic fibrosis(P < 0.01); the areas under the ROC curve for the GPR in F1, F2, F3, and F4 stages were 0.723, 0.741, 0.826, and 0.833, respectively, which were significantly higher than the respective values for the FIB-4 and APRI(F1: 0.581, 0.612; F2: 0.706, 0.711; F3: 0.73, 0.751; and F4: 0.799, 0.778). The respective diagnostic cut-off points for each stage were 0.402, 0.448, 0.548, and 0.833, respectively. The diagnostic sensitivity and specificity were, respectively, 88.8% and 87.5% in F1, 72.7% and 89.7% in F2, 81.3% and 98.6% in F3, and 80% and 97.4% in F4 when the GPR and APRI were connected in parallel; 86.6% and 90.2%, 78.4% and 96%, 78.6% and 97.4%, and 73.2% and 97.9%, respectively, when the GPR and APRI were connected in series; 80.2% and 89%, 65% and 89%, 70.3% and 98.5%, and 78.8% and 96.8%, respectively, when the GPR and FIB-4 were connected in parallel; and 83.6% and 87.9%, 76.8% and 96.6%,
