Progenitor Leydig cells are derived from stem cells. The proliferation and differentiation of progenitor Leydig cells significantly contributes to Leydig cell number during puberty. However, the regulation of these pr...Progenitor Leydig cells are derived from stem cells. The proliferation and differentiation of progenitor Leydig cells significantly contributes to Leydig cell number during puberty. However, the regulation of these processes remains unclear. The objective of the present study was to determine whether luteinizing hormone (LH) or androgen contributes to the proliferation and differentiation of progenitor Leydig cells. Fourteen-day-old male Sprague-Dawley rats were treated for 7 days with NalGlu, which is a gonadotropin- releasing hormone antagonist, to reduce the secretion of LH in the pituitary and thus, androgen in the testis. Rats were co-administered with LH or 7a-methyl-nortestosterone (MENT), which is an androgen resistant to metabolism by 5a-reductase 1 in progenitor Leydig cells, and the subsequent effects of LH or androgen were measured. 3H-Thymidine was also intravenously injected into rats to study thymidine incorporation in progenitor Leydig cells. Progenitor Leydig cells were examined. NalGlu administration reduced progenitor Leydig cell proliferation by 83%. In addition, LH or MENT treatment restored Leydig cell proliferative capacity to 73% or 50% of control, respectively. The messenger RNA levels of proliferation-related genes were measured using real-time PCR. The expression levels of Igfl, Lifr, Pdgfra, Bcl2, Ccnd3and Pcnawere upregulated by MENT, and those of Pdgfra, Ccnd3and Pcnawere upregulated by LH. Both LH and MENT stimulated the differentiation of progenitor Leydig cells in vitro. We concluded that both LH and MENT were involved in regulating the development of progenitor Leydig cells.展开更多
AIM:To evaluate the prognostic value of high-mobility group box 1(HMGB1) expression in intrahepatic cholangiocarcinoma(IHCC) and the possible underlying mechanism.METHODS:Tissue microarray was constructed from 65 IHCC...AIM:To evaluate the prognostic value of high-mobility group box 1(HMGB1) expression in intrahepatic cholangiocarcinoma(IHCC) and the possible underlying mechanism.METHODS:Tissue microarray was constructed from 65 IHCC patients.Immunohistochemistry was performed to validate expression of HMGB1 and Vascular endothelial growth factor C(VEGF-C).Realtime PCR and Western blot analyses were used to study transcript and protein levels.The interaction between HMGB1 and VEGF-C was evaluated by si RNA,real-time PCR,and enzyme-linked immuno assays.The correlation between HMGB1 expression and other clinicopathologic parameters was analyzed byχ2 test,and the univariate as well as multivariate analyses were accomplished by Kaplan-Meier method and Coxregression model,respectively.RESULTS:Overall,overexpression of HMGB1 was found in 38/65(58.8%)IHCCs,whereas VEGF-C overexpression was present in 30/65(46.2%)cases.Overexpression of HMGB1 was significantly correlated with lymphatic microvessel density(P=0.031,r=0.268)and VEGF-C expression(P=0.041,r=0.254).With univariate analysis,both HMGB1(P=0.001)and VEGF-C(P=0.004)were identified to be significantly associated with overall survival rate.Multivariateanalysis indicated that HMGB1 could be served as an unfavorable independent prognostic factor in IHCCs(P=0.005).si RNA knockdown of HMGB1 inhibited transforming growth factor-β-induced epithelialmesenchymal transition(EMT)by elevating E-Cadherin expression and reducing expression of N-Cadherin,Vimentin and Snail in RBE cells.Further in vitro study revealed that HMGB1 silencing significantly decreased the level of VEGF-C,whereas the recombinant HMGB1increased the VEGF-C level in RBE cells(both P<0.05),which suggested that HMGB1 could promote lymphatic microvessel density,and subsequently lymphatic invasion,via promoting VEGF-C expression.CONCLUSION:Our results define an important role of HMGB1 in the progression of cholangiocarcinoma,and HMGB1 may serve as a prognostic marker for IHCC patients.展开更多
AIM: To investigate the correlation between nerve growth factor-tropomyosin-receptor-kinase (NGF-TrkA) signaling pathway and prognosis in intrahepatic cholangiocarcinoma (IHCC).
AIM:To introduce an air insufflation procedure and to investigate the effectiveness of air insufflation in preventing pancreatic fistula(PF).of 185 patients underwent pancreaticoduodenectomy(PD)at our institution,and ...AIM:To introduce an air insufflation procedure and to investigate the effectiveness of air insufflation in preventing pancreatic fistula(PF).of 185 patients underwent pancreaticoduodenectomy(PD)at our institution,and 74 patients were not involved in this study for various reasons.The clinical outcomes of 111 patients were retrospectively analyzed.The air insufflation test was performed in 46 patients to investigate the efficacy of the pancreaticojejunal anastomosis during surgery,and 65 patients who did not receive the air insufflation test served as controls.Preoperative assessments and intraoperative outcomes were compared between the 2 groups.Univariate and multivariate analyses were performed to identify the risk factors for PF.RESULTS:The two patient groups had similar baseline demographics,preoperative assessments,operative factors,pancreatic factors and pathological results.The overall mortality,morbidity,and PF rates were1.8%,48.6%,and 26.1%,respectively.No significant differences were observed in either morbidity or mortality between the two groups.The rate of clinical PF(grade B and grade C PF)was significantly lower in the air insufflation test group,compared with the nonair insufflation test group(6.5%vs 23.1%,P=0.02).Univariate analysis identified the following parameters as risk factors related to clinical PF:estimated blood loss;pancreatic duct diameter≤3 mm;invagination anastomosis technique;and not undergoing air insufflation test.By further analyzing these variables with multivariate logistic regression,estimated blood loss,pancreatic duct diameter≤3 mm and not undergoing air insufflation test were demonstrated to be independent risk factors.CONCLUSION:Performing an air insufflation test could significantly reduce the occurrence of clinical PF after PD.Not performing an air insufflation test was an independent risk factor for clinical PF.展开更多
A large ground-based optical/infrared telescope is being planned for a world-class astronomical site in China.The cloud-free night percentage is the primary meteorological consideration for evaluating candidate sites....A large ground-based optical/infrared telescope is being planned for a world-class astronomical site in China.The cloud-free night percentage is the primary meteorological consideration for evaluating candidate sites.The data from GMS and NOAA satellites and the MODIS instrument were utilized in this research,covering the period from 1996 to 2015.Our data analysis benefits from overlapping results from different independent teams as well as a uniform analysis of selected sites using GMS+NOAA data.Although significant ground-based monitoring is needed to validate these findings,we identify three different geographical regions with a high percentage of cloud-free conditions(~83%on average),which is slightly lower than at Mauna Kea and Cerro Armazones(~85%on average)and were chosen for the large international projects TMT and ELT respectively.Our study finds evidence that cloud distributions and the seasonal changes affected by the prevailing westerly winds and summer monsoons reduce the cloud cover in areas influenced by the westerlies.This is consistent with the expectations from climate change models and is suggestive that most of the identified sites will have reduced cloud cover in the future.展开更多
Based on previous site testing and satellite cloud data,Ali,Daocheng and Muztagh-ata have been selected as candidate sites for the Large Optical/Infrared Telescope(LOT) in China.We present the data collection,processi...Based on previous site testing and satellite cloud data,Ali,Daocheng and Muztagh-ata have been selected as candidate sites for the Large Optical/Infrared Telescope(LOT) in China.We present the data collection,processing,management and quality analysis for our site testing based on using similar hardware.We analyze meteorological data,seeing,background light,cloud and precipitable water vapor data from 2017 March 10 to 2019 March 10.We also investigated the relative usefulness of our all-sky camera data in comparison to that from the meteorological TERRA satellite data based on a night-by-night comparison of the correlation and consistency between them.We find a 6% discrepancy arising from a wide range of factors.展开更多
Foaming issues are encountered at the stages in crude oil production, transportation, processing, especially in chemical flooding enhanced oil recovery(EOR) oilfields. These accumulated foams would cause a lot of trou...Foaming issues are encountered at the stages in crude oil production, transportation, processing, especially in chemical flooding enhanced oil recovery(EOR) oilfields. These accumulated foams would cause a lot of trouble for downstream operation. The destruction of foams under ultrasonic has been increasingly paying attention in the background of green oilfield development. This study focuses on the decay kinetic characteristics of alkaline-surfactant-polymer-strengthened foams under the ultrasonic standing wave.The performance of the diverse foams was characterized. A decay kinetic model incorporating the energy correlation was developed and validated. The factors that affect the decay kinetic characteristics were discussed. The results indicated that the collapse rate and the collapse volume fraction decreased when the foam size decreased, the gas-liquid ratio decreased and the surface tension increased. Ultrasonic standing wave parameters have a significant impact on the decay behavior of the foam. Both the ultrasonic frequency and ultrasonic amplitude were increased by 50%, the collapse volume fraction of foams increased by about 1.25 times in the identical irradiation time. The relative deviation between the measured results and the model prediction was less than 10%. The potential collapse mechanism was also explained using the principle of energy correlation of foam surface. This study is not only beneficial to provide a robust and rigorous way to defoam of produced liquid in the alkaline/surfactant/polymer(ASP)flooding EOR process but also meaningful to well understand the decay process of oil-based foams.展开更多
We present optical frequency combs with a spectral emission of 48 cm-1and an output power of 420 m W based on a single-core quantum cascade laser at λ ~ 8.7μm. A flat top spectrum sustains up to 130 comb modes deliv...We present optical frequency combs with a spectral emission of 48 cm-1and an output power of 420 m W based on a single-core quantum cascade laser at λ ~ 8.7μm. A flat top spectrum sustains up to 130 comb modes delivering ~ 3.2 m W of optical power per mode, making it a valuable tool for dual comb spectroscopy. The homogeneous gain medium, relying on a slightly diagonal bound-to-continuum structure, promises to provide a broad and stable gain for comb operating. Remarkably, the dispersion of this device is measured within 300 fs2/mm to ensure stable comb operation over 90% of the total current range. The comb is observed with a narrow beatnote linewidth around 2 k Hz and has weak dependence on the applied current for stable comb operation.展开更多
基金We are grateful to Ms Chantal Sottas for technical assistance. This work was in part supported by the National Nature Science Foundation of China (nos. 30871434 and 31171425 to RS Ge, no. 30900846 to CQ Wang and no. 81200430 to YF Zhang).
文摘Progenitor Leydig cells are derived from stem cells. The proliferation and differentiation of progenitor Leydig cells significantly contributes to Leydig cell number during puberty. However, the regulation of these processes remains unclear. The objective of the present study was to determine whether luteinizing hormone (LH) or androgen contributes to the proliferation and differentiation of progenitor Leydig cells. Fourteen-day-old male Sprague-Dawley rats were treated for 7 days with NalGlu, which is a gonadotropin- releasing hormone antagonist, to reduce the secretion of LH in the pituitary and thus, androgen in the testis. Rats were co-administered with LH or 7a-methyl-nortestosterone (MENT), which is an androgen resistant to metabolism by 5a-reductase 1 in progenitor Leydig cells, and the subsequent effects of LH or androgen were measured. 3H-Thymidine was also intravenously injected into rats to study thymidine incorporation in progenitor Leydig cells. Progenitor Leydig cells were examined. NalGlu administration reduced progenitor Leydig cell proliferation by 83%. In addition, LH or MENT treatment restored Leydig cell proliferative capacity to 73% or 50% of control, respectively. The messenger RNA levels of proliferation-related genes were measured using real-time PCR. The expression levels of Igfl, Lifr, Pdgfra, Bcl2, Ccnd3and Pcnawere upregulated by MENT, and those of Pdgfra, Ccnd3and Pcnawere upregulated by LH. Both LH and MENT stimulated the differentiation of progenitor Leydig cells in vitro. We concluded that both LH and MENT were involved in regulating the development of progenitor Leydig cells.
基金Supported by National Natural Science Foundation of China No.81072110 and No.81171951grants from Independent Innovation Foundation of Shandong University,No.2010TB012Scientific Research Foundation for Returned Scholars,Ministry of Education of China
文摘AIM:To evaluate the prognostic value of high-mobility group box 1(HMGB1) expression in intrahepatic cholangiocarcinoma(IHCC) and the possible underlying mechanism.METHODS:Tissue microarray was constructed from 65 IHCC patients.Immunohistochemistry was performed to validate expression of HMGB1 and Vascular endothelial growth factor C(VEGF-C).Realtime PCR and Western blot analyses were used to study transcript and protein levels.The interaction between HMGB1 and VEGF-C was evaluated by si RNA,real-time PCR,and enzyme-linked immuno assays.The correlation between HMGB1 expression and other clinicopathologic parameters was analyzed byχ2 test,and the univariate as well as multivariate analyses were accomplished by Kaplan-Meier method and Coxregression model,respectively.RESULTS:Overall,overexpression of HMGB1 was found in 38/65(58.8%)IHCCs,whereas VEGF-C overexpression was present in 30/65(46.2%)cases.Overexpression of HMGB1 was significantly correlated with lymphatic microvessel density(P=0.031,r=0.268)and VEGF-C expression(P=0.041,r=0.254).With univariate analysis,both HMGB1(P=0.001)and VEGF-C(P=0.004)were identified to be significantly associated with overall survival rate.Multivariateanalysis indicated that HMGB1 could be served as an unfavorable independent prognostic factor in IHCCs(P=0.005).si RNA knockdown of HMGB1 inhibited transforming growth factor-β-induced epithelialmesenchymal transition(EMT)by elevating E-Cadherin expression and reducing expression of N-Cadherin,Vimentin and Snail in RBE cells.Further in vitro study revealed that HMGB1 silencing significantly decreased the level of VEGF-C,whereas the recombinant HMGB1increased the VEGF-C level in RBE cells(both P<0.05),which suggested that HMGB1 could promote lymphatic microvessel density,and subsequently lymphatic invasion,via promoting VEGF-C expression.CONCLUSION:Our results define an important role of HMGB1 in the progression of cholangiocarcinoma,and HMGB1 may serve as a prognostic marker for IHCC patients.
基金Supported by National Natural Science Foundation of China,No.81172044
文摘AIM: To investigate the correlation between nerve growth factor-tropomyosin-receptor-kinase (NGF-TrkA) signaling pathway and prognosis in intrahepatic cholangiocarcinoma (IHCC).
文摘AIM:To introduce an air insufflation procedure and to investigate the effectiveness of air insufflation in preventing pancreatic fistula(PF).of 185 patients underwent pancreaticoduodenectomy(PD)at our institution,and 74 patients were not involved in this study for various reasons.The clinical outcomes of 111 patients were retrospectively analyzed.The air insufflation test was performed in 46 patients to investigate the efficacy of the pancreaticojejunal anastomosis during surgery,and 65 patients who did not receive the air insufflation test served as controls.Preoperative assessments and intraoperative outcomes were compared between the 2 groups.Univariate and multivariate analyses were performed to identify the risk factors for PF.RESULTS:The two patient groups had similar baseline demographics,preoperative assessments,operative factors,pancreatic factors and pathological results.The overall mortality,morbidity,and PF rates were1.8%,48.6%,and 26.1%,respectively.No significant differences were observed in either morbidity or mortality between the two groups.The rate of clinical PF(grade B and grade C PF)was significantly lower in the air insufflation test group,compared with the nonair insufflation test group(6.5%vs 23.1%,P=0.02).Univariate analysis identified the following parameters as risk factors related to clinical PF:estimated blood loss;pancreatic duct diameter≤3 mm;invagination anastomosis technique;and not undergoing air insufflation test.By further analyzing these variables with multivariate logistic regression,estimated blood loss,pancreatic duct diameter≤3 mm and not undergoing air insufflation test were demonstrated to be independent risk factors.CONCLUSION:Performing an air insufflation test could significantly reduce the occurrence of clinical PF after PD.Not performing an air insufflation test was an independent risk factor for clinical PF.
基金partly supported by the Operation,Maintenance and Upgrading Fund for Astronomical Telescopes and Facility Instruments,budgeted from the Ministry of Finance of China(MOF)and administered by the Chinese Academy of Sciences(CAS)supported by the National Natural Science Foundation of China(Grant Nos.11573054,11703065,11603044 and 11873081)+1 种基金support from a CAS PIFIUK STFC grant ST/R006598/1。
文摘A large ground-based optical/infrared telescope is being planned for a world-class astronomical site in China.The cloud-free night percentage is the primary meteorological consideration for evaluating candidate sites.The data from GMS and NOAA satellites and the MODIS instrument were utilized in this research,covering the period from 1996 to 2015.Our data analysis benefits from overlapping results from different independent teams as well as a uniform analysis of selected sites using GMS+NOAA data.Although significant ground-based monitoring is needed to validate these findings,we identify three different geographical regions with a high percentage of cloud-free conditions(~83%on average),which is slightly lower than at Mauna Kea and Cerro Armazones(~85%on average)and were chosen for the large international projects TMT and ELT respectively.Our study finds evidence that cloud distributions and the seasonal changes affected by the prevailing westerly winds and summer monsoons reduce the cloud cover in areas influenced by the westerlies.This is consistent with the expectations from climate change models and is suggestive that most of the identified sites will have reduced cloud cover in the future.
基金partly supported by the Operation,Maintenance and Upgrading Fund for Astronomical Telescopes and Facility Instruments,budgeted from the Ministry of Finance of China (MOF) and administered by the Chinese Academy of Sciences (CAS)supported by the National NaturalScience Foundation of China (Grant Nos.11573054,11703065,11603044 and 11873081)HRAJ acknowledges support from a CAS PIFI and UK STFC grant ST/R006598/1。
文摘Based on previous site testing and satellite cloud data,Ali,Daocheng and Muztagh-ata have been selected as candidate sites for the Large Optical/Infrared Telescope(LOT) in China.We present the data collection,processing,management and quality analysis for our site testing based on using similar hardware.We analyze meteorological data,seeing,background light,cloud and precipitable water vapor data from 2017 March 10 to 2019 March 10.We also investigated the relative usefulness of our all-sky camera data in comparison to that from the meteorological TERRA satellite data based on a night-by-night comparison of the correlation and consistency between them.We find a 6% discrepancy arising from a wide range of factors.
基金financially supported by the National Natural Science Foundation of China (Grant No.52174060)the PetroChina Innovation Foundation (Grant No.2019D-5007-0501)The Postdoctoral Scientific Foundation of Heilongjiang Province in China (Grant No. LBH-Q20012)。
文摘Foaming issues are encountered at the stages in crude oil production, transportation, processing, especially in chemical flooding enhanced oil recovery(EOR) oilfields. These accumulated foams would cause a lot of trouble for downstream operation. The destruction of foams under ultrasonic has been increasingly paying attention in the background of green oilfield development. This study focuses on the decay kinetic characteristics of alkaline-surfactant-polymer-strengthened foams under the ultrasonic standing wave.The performance of the diverse foams was characterized. A decay kinetic model incorporating the energy correlation was developed and validated. The factors that affect the decay kinetic characteristics were discussed. The results indicated that the collapse rate and the collapse volume fraction decreased when the foam size decreased, the gas-liquid ratio decreased and the surface tension increased. Ultrasonic standing wave parameters have a significant impact on the decay behavior of the foam. Both the ultrasonic frequency and ultrasonic amplitude were increased by 50%, the collapse volume fraction of foams increased by about 1.25 times in the identical irradiation time. The relative deviation between the measured results and the model prediction was less than 10%. The potential collapse mechanism was also explained using the principle of energy correlation of foam surface. This study is not only beneficial to provide a robust and rigorous way to defoam of produced liquid in the alkaline/surfactant/polymer(ASP)flooding EOR process but also meaningful to well understand the decay process of oil-based foams.
基金supported by the National Natural Science Foundation of China(Grant Nos.61734006,61835011,61991430,and 62174158)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Grant No.2021107)the Key Program of the Chinese Academy of Sciences(Grant Nos.XDB43000000,YJKYYQ20190002,and QYZDJ-SSW-JSC027)。
文摘We present optical frequency combs with a spectral emission of 48 cm-1and an output power of 420 m W based on a single-core quantum cascade laser at λ ~ 8.7μm. A flat top spectrum sustains up to 130 comb modes delivering ~ 3.2 m W of optical power per mode, making it a valuable tool for dual comb spectroscopy. The homogeneous gain medium, relying on a slightly diagonal bound-to-continuum structure, promises to provide a broad and stable gain for comb operating. Remarkably, the dispersion of this device is measured within 300 fs2/mm to ensure stable comb operation over 90% of the total current range. The comb is observed with a narrow beatnote linewidth around 2 k Hz and has weak dependence on the applied current for stable comb operation.
基金Project supported by the National Natural Science Foundation of China(No.61475139)the National Basic Research Program(973 Program)of China(No.2013CB329501)+1 种基金the National High Technology Research and Development Program(863 Program)of China(No.2013AA063901)the Fundamental Research Funds for the Central Universities,China(No.2017FZA3005)