AIM To investigate the prognostic role of fibrinogen-toalbumin ratio(FAR) on patients with gallbladder cancer(Gbc) in this study.METHODS One hundred and fifty-four Gbc patients were retro-spectively analyzed, who rece...AIM To investigate the prognostic role of fibrinogen-toalbumin ratio(FAR) on patients with gallbladder cancer(Gbc) in this study.METHODS One hundred and fifty-four Gbc patients were retro-spectively analyzed, who received potentially curative cholecystectomy in our institute from March 2005 to December 2017. Receiver operating characteristic curve(ROc curve) was used to determine the optimal cut-offs for these biomarkers. In addition, Kaplan-Meier survival analysis as well as multivariate analysis were applied for prognostic analyses.RESULTS ROc curve revealed that the optimal cut-off value for FAR was 0.08. FAR was significantly correlated with age(P = 0.045), jaundice(P < 0.001), differentiation(P = 0.002), resection margin status(P < 0.001), T stage(P < 0.001), TNM stage(P < 0.001), and c A199(P < 0.001) as well as albumin levels(P < 0.001). Multivariate analysis indicated that the resection margin status [hazard ratio(HR): 2.343, 95% confidence interval(c I): 1.532-3.581, P < 0.001], TNM stage(P = 0.035), albumin level(HR = 0.595, 95%c I: 0.385-0.921, P = 0.020) and FAR(HR: 2.813, 95%c I: 1.765-4.484, P < 0.001) were independent prognostic factors in Gbc patients.CONCLUSION An elevated preoperative FAR was significantly correlated with unfavorable overall survival in Gbc patients, while an elevated preoperative albumin level was a protective prognostic factor for patients with Gbc. The preoperative FAR could be used to predict the prognosis of Gbc patients, which was easily accessible, costeffective and noninvasive.展开更多
AIM To investigate the prognostic value of the combination of preoperative plasma fibrinogen and CA199 in patients with gallbladder carcinoma(GBC).METHODS The clinicopathological data of 154 GBC patients were retrospe...AIM To investigate the prognostic value of the combination of preoperative plasma fibrinogen and CA199 in patients with gallbladder carcinoma(GBC).METHODS The clinicopathological data of 154 GBC patients were retrospectively reviewed after surgery. A receiver operating characteristic(ROC) curve was plotted to verify the optimum cut-off values for plasma fibrinogen and CA199. Univariate and multivariate survival analyses were performed to identify the factors associated with GBC prognosis. based on the HRs calculated via multivariate survival analyses, patients with elevated plasma fibrinogen and CA199 levels were allocated a score of 2.1; those with an elevated plasma fibrinogen level only were allocated a score of 1, those with an elevated CA199 level only were allocated a score of 1.1, and those with neither of these abnormalities were allocated a score of 0.RESULTS ROC curve analysis showed that the optimum cut-off values for preoperative plasma fibrinogen and CA199 were 3.47 g/L and 25.45 U/mL, respectively. Multivariate analysis indicated that elevated preoperative plasma fibrinogen and CA199 levels were significantly correlated with worse overall survival(OS)(HR = 1.711, 95%CI: 1.114-2.627, P = 0.014, and HR = 1.842, 95%CI: 1.111-3.056, P = 0.018). When we combined these two parameters, the area under the ROC curve increased from 0.735(for preoperative plasma fibrinogen only) and 0.729(for preoperative CA199 only) to 0.765. When this combined variable was added to the multivariate analysis, the combination of plasma fibrinogen and CA199(P < 0.001), resection margin(P < 0.001) and TNM stage(P = 0.010) were independent prognostic factors for GBC.CONCLUSION The combination of plasma fibrinogen and CA199 may serve as a more efficient independent prognostic biomarker for postoperative GBC patients than either parameter alone.展开更多
AIM To integrate clinically significant variables related to prognosis after curative resection for gallbladder carcinoma(GBC) into a predictive nomogram.METHODS One hundred and forty-two GBC patients who underwent cu...AIM To integrate clinically significant variables related to prognosis after curative resection for gallbladder carcinoma(GBC) into a predictive nomogram.METHODS One hundred and forty-two GBC patients who underwent curative intent surgical resection at Peking Union Medical College Hospital(PUMCH) were included. This retrospective case study was conducted at PUMCH of the Chinese Academy of Medical Sciences and Peking Union Medical College(CAMS & PUMC) in China from January 1, 2003 to January 1, 2018. The continuous variable carbohydrate antigen 19-9(CA19-9) was converted into a categorical variable(cCA19-9) based on the normal reference range. Stages 0 to IIIA were merged into one category, while the remaining stages were grouped into another category. Pathological grade X(GX) was treated as a missing value. A multivariate Cox proportional hazards model was used to select variables to construct a nomogram. Discrimination and calibration of the nomogram were performed via the concordance index(C-index) and calibration plots. The performance of the nomogram was estimated using the calibration curve. Receiver operating characteristic(ROC) curve analysis and decision curve analysis(DCA) were performed to evaluate the predictive accuracy and net benefit of the nomogram, respectively.RESULTS Of these 142 GBC patients, 55(38.7%) were male, and the median and mean age were 64 and 63.9 years, respectively. Forty-eight(33.8%) patients in this cohort were censored in the survival analysis. The median survival time was 20 months. A series of methods, including the likelihood ratio test and Akaike information criterion(AIC) as well as stepwise, forward, and backward analyses, were used to select the model, and all yielded identical results. Jaundice [hazard ratio(HR) = 2.9; 95% confidence interval(CI): 1.60-5.27], cCA19-9(HR = 3.2; 95%CI: 1.91-5.39), stage(HR = 1.89; 95%CI: 1.16-3.09), and resection(R)(HR = 2.82; 95%CI: 1.54-5.16) were selected as significant predictors and combined into a survival time predictive nomogram(C-index = 0.803; 95%CI: 0.766-0.839). High prediction accuracy(adjusted C-index = 0.797) was further verified via bootstrap validation. The calibration plot demonstrated good performance of the nomogram. ROC curve analysis revealed a high sensitivity and specificity. A high net benefit was proven by DCA.CONCLUSION A nomogram has been constructed to predict the overall survival of GBC patients who underwent radical surgery from a clinical database of GBC at PUMCH.展开更多
AIM To clarify the previous discrepant conclusions, we performed a meta-analysis to evaluate the prognostic value of red cell distribution width(RDW) in esophageal cancer(EC). METHODS We searched the PubM ed, EMBASE, ...AIM To clarify the previous discrepant conclusions, we performed a meta-analysis to evaluate the prognostic value of red cell distribution width(RDW) in esophageal cancer(EC). METHODS We searched the PubM ed, EMBASE, Web of Science and Cochrane Library databases to identify clinical studies, followed by using STATA version 12.0 for statistical analysis. Studies that met the following criteria were considered eligible:(1) Studies including EC patients who underwent radical esophagectomy;(2) studies including patients with localized disease without distant metastasis;(3) studies including patients without preoperative neoadjuvant therapy;(4) studies including patients without previous antiinflammatory therapies and with available preoperative laboratory outcomes;(5) studies reporting association between the preoperative RDW and overall survival(OS)/disease-free survival(DFS)/cancer-specific survival(CSS); and(6) studies published in English.RESULTS A total of six articles, published between 2015 and 2017, fulfilled the selection criteria in the end. Statistical analysis showed that RDW was not associated with the prognosis of EC patients, irrespective of OS/CSS [hazard ratio(HR) = 1.27, 95% confidence interval(CI): 0.97-1.57, P = 0.000] or DFS(HR = 1.42, 95%CI: 0.96-1.88, P = 0.000). Subgroup analysis indicated that elevated RDW was significantly associated with worse OS/CSS of EC patients when RDW > 13%(HR = 1.45, 95%CI: 1.13-1.76, P = 0.000), when the patient number ≤ 400(HR = 1.45, 95%CI: 1.13-1.76, P = 0.000) and when the study type was retrospective(HR = 1.42, 95%CI : 1.16-1.69, P = 0.000).CONCLUSION Contrary to our general understanding, this meta-analysis revealed that RDW cannot serve as an indicator of poor prognosis in patients with EC. However, it may still be a useful predictor of unfavorable prognosis using an appropriate cut-off value.展开更多
AIM To clarify the prognostic significance of preoperative albumin-to-alkaline phosphatase ratio(AAPR) in cholangiocarcinoma(CCA) subjects receiving surgery.METHODS In this retrospective study, we included 303 CCA pat...AIM To clarify the prognostic significance of preoperative albumin-to-alkaline phosphatase ratio(AAPR) in cholangiocarcinoma(CCA) subjects receiving surgery.METHODS In this retrospective study, we included 303 CCA patients receiving surgery without preoperative therapy between 2002 and 2014. Clinicopathological characteristics(including AAPR) were analyzed to determine predictors of postoperative overall survival and recurrence-free survival(RFS). In addition,univariate and multivariate Cox proportional hazards models were conducted,followed by application of time-dependent receiver operating curves to identify the optimal cut-off.RESULTS Univariate and multivariate analyses revealed both decreased overall survival[hazard ratio(HR): 2.88, 95%CI: 1.19-5.78] and recurrence-free survival(HR: 2.31,95%CI: 1.40–3.29) in patients with AAPR < 0.41 compared to those with AAPR ≥0.41. The optimal cut-off of AAPR was 0.41. Of the 303 subjects, 253(83.5%) had an AAPR over 0.41. The overall 1-, 3- and 5-year survival rates were 70.2%, 38.0% and 16.5%, respectively in the low(< 0.41) AAPR group, which were significantly lower than those in the high(≥ 0.41) AAPR group(81.7%, 53.9%, and 33.4%,respectively)(P < 0.0001). Large tumor size, multiple tumors, and advanced clinical stage were also identified as significant predictors of poor prognosis.CONCLUSION Our outcomes showed that AAPR was a potential valuable prognostic indicator in CCA patients undergoing surgery, which should be further confirmed by prospective studies. Moreover, it is necessary to investigate the mechanisms concerning the correlation of low AAPR with poor post-operative survival in CCA patients.展开更多
Background: Metastatic colorectal cancer(mCRC) patients with progressive disease after all available standard therapies need new medication for further treatment. Famitinib is a small-molecule multikinase inhibitor, w...Background: Metastatic colorectal cancer(mCRC) patients with progressive disease after all available standard therapies need new medication for further treatment. Famitinib is a small-molecule multikinase inhibitor, with promising anticancer activities. This multicenter, randomized, double-blinded, placebo-controlled, phase II clinical trial was designed to evaluate the safety and efficacy of famitinib in mCRC.Methods: Famitinib or placebo was administered orally once daily. The primary endpoint was progression-free survival(PFS). Secondary endpoints included objective response rate(ORR), disease control rate(DCR), overall survival(OS), quality-of-life(QoL), and safety.Results: Between July 18,2012 and Jan 22,2014, a total of 167 patients were screened, and 154 patients were randomized in a 2:1 ratio to receive either famitinib(n = 99) or placebo(n = 55). The median PFS was 2.8 and 1.5 months in the famitinib and placebo groups(hazard ratio = 0.60,95% confidence interval = 0.41-0.86, P = 0.004). The DCR was 59.8% and 31.4%(P = 0.002) and the ORR was 2.2% and 0.0%(P = 0.540) in the famitinib and placebo groups,respectively. The most frequent grade 3-4 adverse events were hypertension(11.1%), hand-foot syndrome(10.1%),thrombocytopenia(10.1%) and neutropenia(9.1%). Serious adverse events occurred in 11(11.1%) patients in the famitinib group and 5(9.1%) in the placebo group(P = 0.788). The median OS of the famitinib and placebo groups was 7.4 and 7.2 months(P = 0.657).Conclusion: Famitinib prolonged PFS in refractory mCRC patients with acceptable tolerability.Trial registration This study was registered on ClinicalTrials.gov(NCT01762293) and was orally presented in the 2015 ASCO-Gastrointestinal展开更多
BACKGROUND Ubiquitin-specific protease 15(USP15)is an important member of the ubiquitinspecific protease family,the largest deubiquitinase subfamily,whose expression is dysregulated in many types of cancer.However,the...BACKGROUND Ubiquitin-specific protease 15(USP15)is an important member of the ubiquitinspecific protease family,the largest deubiquitinase subfamily,whose expression is dysregulated in many types of cancer.However,the biological function and the underlying mechanisms of USP15 in gastric cancer(GC)progression have not been elucidated.AIM To explore the biological role and underlying mechanisms of USP15 in GC progression.METHODS Bioinformatics databases and western blot analysis were utilized to determine the expression of USP15 in GC.Immunohistochemistry was performed to evaluate the correlation between USP15 expression and clinicopathological characteristics of patients with GC.A loss-and gain-of-function experiment was used to investigate the biological effects of USP15 on GC carcinogenesis.RNA sequencing,immunofluorescence,and western blotting were performed to explore the potential mechanism by which USP15 exerts its oncogenic functions.RESULTS USP15 was up-regulated in GC tissue and cell lines.The expression level of USP15 was positively correlated with clinical characteristics(tumor size,depth of invasion,lymph node involvement,tumor-node-metastasis stage,perineural invasion,and vascular invasion),and was related to poor prognosis.USP15 knockdown significantly inhibited cell proliferation,invasion and epithelialmesenchymal transition(EMT)of GC in vitro,while overexpression of USP15 promoted these processes.Knockdown of USP15 inhibited tumor growth in vivo.Mechanistically,RNA sequencing analysis showed that USP15 regulated the Wnt signaling pathway in GC.Western blotting confirmed that USP15 silencing led to significant down-regulation ofβ-catenin and Wnt/β-catenin downstream genes(c-myc and cyclin D1),while overexpression of USP15 yielded an opposite result and USP15 mutation had no change.Immunofluorescence indicated that USP15 promoted nuclear translocation ofβ-catenin,suggesting activation of the Wnt/β-catenin signaling pathway,which may be the critical mechanism promoting GC progression.Finally,rescue experiments showed that the effect of USP15 on gastric cancer progression was dependent on Wnt/β-catenin pathway.CONCLUSION USP15 promotes cell proliferation,invasion and EMT progression of GC via regulating the Wnt/β-catenin pathway,which suggests that USP15 is a novel potential therapeutic target for GC.展开更多
BACKGROUND Positive peritoneal wash cytology with no peritoneal metastasis(CY1P0)is a special type of distant gastric cancer metastasis,which describes a patient with positive peritoneal lavage cytology,but no definit...BACKGROUND Positive peritoneal wash cytology with no peritoneal metastasis(CY1P0)is a special type of distant gastric cancer metastasis,which describes a patient with positive peritoneal lavage cytology,but no definitive peritoneal metastasis,and there are no widely accepted treatment guidelines.We enrolled 48 primary CY1P0 gastric cancer patients treated by radical gastrectomy in this study.Our study illustrated the efficacy of radical gastrectomy for CY1P0 gastric cancer patients,and suggested that the pathological N factor and vascular invasion were significant independent risk factors for overall survival(OS).AIM To assess the survival of CY1P0 gastric cancer patient post-radical gastrectomy,and to identify factors associated with long-term prognosis.METHODS Our study included 48 patients with primary CY1P0 gastric cancer who had radical gastrectomies at the Cancer Hospital,Chinese Academy of Medical Sciences,Beijing,China between 2013 and 2018.R0 resection was achieved in all 48 patients.Twelve patients received neoadjuvant chemotherapy.Thirty patients received adjuvant chemotherapy and four received adjuvant chemoradiotherapy.OS statistics were available for 48 patients.Follow-up continued through March 2020.Univariate and multivariate analyses were performed using a Cox proportional hazards model to identify prognostic factors.RESULTS Median OS was 22.0 mo(95%confidence interval:13.366-30.634 mo)post-surgery.Univariate analyses demonstrated that tumor site(P=0.021),pathological N factor(P=0.001),pathological T factor(P=0.028),vascular invasion(P=0.046),and the level of CA199 prior to initiating therapy(P=0.002)were significant risk factors for OS.Multivariate analyses demonstrated that pathological N factor(P=0.001)and vascular invasion(P=0.031)were significant independent risk factors for OS.CONCLUSION This study suggested that radical gastrectomy may be efficient for CY1P0 gastric cancer patient post-radical gastrectomy and the pathological N factor and vascular invasion are significant independent risk factors for OS.展开更多
BACKGROUND The association between body mass index(BMI)and clinical outcomes remains unclear among patients with resectable gastric cancer.AIM To investigate the relationship between BMI and long-term survival of gast...BACKGROUND The association between body mass index(BMI)and clinical outcomes remains unclear among patients with resectable gastric cancer.AIM To investigate the relationship between BMI and long-term survival of gastric cancer patients.METHODS This retrospective study included 2526 patients who underwent radical gastrectomy for gastric cancer between September 2013 and June 2018.The patients were divided into four groups:Group A(low BMI,<18.5 kg/m2),group B(normal BMI,18.5-24.9 kg/m2),group C(overweight,25-29.9 kg/m2),and group D(obese,≥30 kg/m2).Clinicopathological findings and survival outcomes were recorded and analyzed.RESULTS Preoperative weight loss was more common in the low-BMI group,while diabetes was more common in the obese group.Upper-third gastric cancer accounted for a large proportion of cases in the higher BMI groups.Major perioperative complications tended to increase with BMI.The 5-year overall survival rates were 66.4%for group A,75.0%for group B,77.1%for group C,and 78.6%for group D.The 5-year overall survival rate was significantly lower in group A than in group C(P=0.008)or group D(P=0.031).Relative to a normal BMI value,a BMI of<18.5 kg/m^(2)was associated with poor survival(hazard ratio:1.558,95%confidence interval:1.125-2.158,P=0.008).CONCLUSION Low BMI,but not high BMI,independently predicted poor survival in patients with resectable gastric cancer.展开更多
BACKGROUND For Siewert type Ⅱ/Ⅲ adenocarcinoma of gastroesophageal junction(AGE), the efficacy of adjuvant chemoradiotherapy(CRT) after D2/R0 resection remains uncertain.AIM To determine whether CRT was superior to ...BACKGROUND For Siewert type Ⅱ/Ⅲ adenocarcinoma of gastroesophageal junction(AGE), the efficacy of adjuvant chemoradiotherapy(CRT) after D2/R0 resection remains uncertain.AIM To determine whether CRT was superior to chemotherapy(CT) alone after D2/R0 resection for locally advanced Siewert type Ⅱ/Ⅲ AGE.METHODS We identified 316 locally advanced Siewert type Ⅱ/Ⅲ AGE patients who were treated with D2/R0 resection at National Cancer Center from 2011 to 2018.57 patients received adjuvant CRT and 259 patients received adjuvant CT.We followed patients for overall survival(OS), relapse-free survival, and recurrence pattern.RESULTS Five-year OS rates of the CRT group and the CT group for all patients were 66.7% and 41.9%(P = 0.010).Five-year OS rates of the CRT group and the CT group for Siewert type Ⅲ AGE patients were 65.7% and 43.9%(P = 0.006).Among the 195 patients whose recurrence information could be obtained, 18 cases(34.6%) and 61 cases(42.7%) were diagnosed as recurrence in the CRT group and CT group, respectively.The local and regional recurrence rates in the CRT group were lower than that in the CT group(22.2% vs 24.6%, 27.8% vs 39.3%).Multivariable cox regression analysis showed that vascular invasion, nerve invasion, and adjuvant CRT were important prognostic factors for Siewert type Ⅲ AGE.CONCLUSION For locally advanced Siewert type Ⅲ AGE, adjuvant CRT may prolong OS and reduce the regional recurrence rate.展开更多
BACKGROUND Laparoscopic total gastrectomy(LTG)has drawn increasing attention over the years.Although LTG has shown surgical benefits compared to open TG(OTG)in early stage gastric cancer(GC),little is known about the ...BACKGROUND Laparoscopic total gastrectomy(LTG)has drawn increasing attention over the years.Although LTG has shown surgical benefits compared to open TG(OTG)in early stage gastric cancer(GC),little is known about the surgical and oncological outcomes of LTG for advanced GC following neoadjuvant therapy(NAT).AIM To compare the long-and short-term outcomes of advanced GC patients who underwent LTG vs OTG following NAT.METHODS Advanced GC patients who underwent TG following NAT between April 2011 and May 2018 at the Cancer Hospital of the Chinese Academy of Medical Sciences were enrolled and stratified into two groups:LTG and OTG.Propensity score matching analysis was performed at a 1:1 ratio to overcome possible bias.RESULTS In total,185 patients were enrolled(LTG:78;OTG:109).Of these,138 were paired after propensity score matching.After adjustment for propensity score matching,baseline parameters were similar between the two groups.Compared to OTG,LTG was associated with a significantly shorter length of hospital stay(P=0.012).The rates of R0 resection,lymph node harvest,and postoperative morbidity did not significantly differ between the two groups.Overall survival(OS)outcomes were comparable between the two groups.Pathological T and N stages were found to be independent risk factors for OS.CONCLUSION LTG can be a feasible method for advanced GC patients following NAT,as it appears to be associated with better short-and comparable long-term outcomes compared to OTG.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
Six high-resolution TiO-band image sequences from the New Vacuum Solar Telescope (NVST) are used to investigate the properties of intergranular bright points (igBPs). We detect the igBPs using a Laplacian and morp...Six high-resolution TiO-band image sequences from the New Vacuum Solar Telescope (NVST) are used to investigate the properties of intergranular bright points (igBPs). We detect the igBPs using a Laplacian and morphological dilation algorithm (LMD) and automatically track them using a three- dimensional segmentation algorithm, and then investigate the morphologic, photometric and dynamic prop- erties of igBPs in terms of equivalent diameter, intensity contrast, lifetime, horizontal velocity, diffusion index, motion range and motion type. The statistical results confirm previous studies based on G-band or TiO-band igBPs from other telescopes. These results illustrate that TiO data from the NVST are stable and reliable, and are suitable for studying igBPs. In addition, our method is feasible for detecting and track- ing igBPs with TiO data from the NVST. With the aid of vector magnetograms obtained from the Solar Dynamics Observatory/Helioseismic and Magnetic Imager, the properties of igBPs are found to be strongly influenced by their embedded magnetic environments. The areal coverage, size and intensity contrast values of igBPs are generally larger in regions with higher magnetic flux. However, the dynamics of igBPs, includ- ing the horizontal velocity, diffusion index, ratio of motion range and index of motion type are generally larger in the regions with lower magnetic flux. This suggests that the absence of strong magnetic fields in the medium makes it possible for the igBPs to look smaller and weaker, diffuse faster, and move faster and further along a straighter path.展开更多
The Large Sky Area Multi-Object Fiber Spectroscopic Telescope(LAMOST)started a medianresolution spectroscopic(MRS,R~7500)survey since October 2018.The main scientific goals of MRS,including binary stars,pulsators and ...The Large Sky Area Multi-Object Fiber Spectroscopic Telescope(LAMOST)started a medianresolution spectroscopic(MRS,R~7500)survey since October 2018.The main scientific goals of MRS,including binary stars,pulsators and other variable stars,were launched with a time-domain spectroscopic survey.However,the systematic errors,including the bias induced from wavelength calibration and the systematic difference between different spectrographs,have to be carefully considered during radial velocity measurement.In this work,we provide a technique to correct the systematics in the wavelength calibration based on the relative radial velocity measurements from LAMOST MRS spectra.We show that,for the stars with multi-epoch spectra,the systematic bias which is induced from the exposures on different nights can be corrected well for LAMOST MRS in each spectrograph.In addition,the precision of radial velocity zero-point of multi-epoch time-domain observations reaches below 0.5 km s^(-1).As a by-product,we also give the constant star candidates^(**),which can be the secondary radial-velocity standard star candidates of LAMOST MRS time-domain surveys.展开更多
BACKGROUND At present,there is insufficient medical evidence to determine whether adjuvant chemotherapy is necessary for T2N0M0 gastric cancer.AIM To obtain a risk score to assess the need for adjuvant chemotherapy in...BACKGROUND At present,there is insufficient medical evidence to determine whether adjuvant chemotherapy is necessary for T2N0M0 gastric cancer.AIM To obtain a risk score to assess the need for adjuvant chemotherapy in patients with T2N0M0 gastric cancer.METHODS We identified 325 patients with pathological T2N0M0 stage primary gastric cancer at the National Cancer Center between 2011 and 2018.Univariate and multivariate Cox regression analyses were performed to predict factors affecting prognosis.Vascular invasion,tumor site,and body mass index were assessed,and a scoring system was established.We compared the survival outcomes and benefits of adjuvant chemotherapy between the different subgroups.RESULTS Five-year survival rates of the score 0,1,2,and 3 groups were 92%,95%,80%,and 50%,respectively(P<0.001).In the score 2-3 group,five-year survival rates for patients in the adjuvant chemotherapy group and postoperative observation group were 95%and 61%,respectively(P=0.021).CONCLUSION For patients with T2N0M0 stage gastric cancer and two or more risk factors,adjuvant chemotherapy after D2 gastrectomy may have a survival benefit.展开更多
BACKGROUND For advanced gastric cancer patients with pancreatic head invasion,some studies have suggested that extended multiorgan resections(EMR)improves survival.However,other reports have shown high rates of morbid...BACKGROUND For advanced gastric cancer patients with pancreatic head invasion,some studies have suggested that extended multiorgan resections(EMR)improves survival.However,other reports have shown high rates of morbidity and mortality after EMR.EMR for T4b gastric cancer remains controversial.AIM To evaluate the surgical approach for pT4b gastric cancer with pancreatic head invasion.METHODS A total of 144 consecutive patients with gastric cancer with pancreatic head invasion were surgically treated between 2006 and 2016 at the China National Cancer Center.Gastric cancer was confirmed in 76 patients by postoperative pathology and retrospectively analyzed.The patients were divided into the gastrectomy plus en bloc pancreaticoduodenectomy group(GP group)and gastrectomy alone group(GA group)by comparing the clinicopathological features,surgical outcomes,and prognostic factors of these patients.RESULTS There were 24 patients(16.8%)in the GP group who had significantly larger lesions(P<0.001),a higher incidence of advanced N stage(P=0.030),and less neoadjuvant chemotherapy(P<0.001)than the GA group had.Postoperative morbidity(33.3%vs 15.3%,P=0.128)and mortality(4.2%vs 4.8%,P=1.000)were not significantly different in the GP and GA groups.The overall 3-year survival rate of the patients in the GP group was significantly longer than that in the GA group(47.6%,median 30.3 mo vs 20.4%,median 22.8 mo,P=0.010).Multivariate analysis identified neoadjuvant chemotherapy[hazard ratio(HR)0.290,95%confidence interval(CI):0.103–0.821,P=0.020],linitis plastic(HR 2.614,95%CI:1.024–6.675,P=0.033),surgical margin(HR 0.274,95%CI:0.102–0.738,P=0.010),N stage(HR 3.489,95%CI:1.334–9.120,P=0.011),and postoperative chemoradiotherapy(HR 0.369,95%CI:0.163–0.836,P=0.017)as independent predictors of survival in patients with pT4b gastric cancer and pancreatic head invasion.CONCLUSION Curative resection of the invaded pancreas should be performed to improve survival in selected patients.Invasion of the pancreatic head is not a contraindication for surgery.展开更多
基金Supported by the National key Project research and Development Projects,No.S2016G9012International Science and Technology Cooperation Projects,No.2015DFA30650The Capital Special research Project for Clinical Application,No.Z151100004015170
文摘AIM To investigate the prognostic role of fibrinogen-toalbumin ratio(FAR) on patients with gallbladder cancer(Gbc) in this study.METHODS One hundred and fifty-four Gbc patients were retro-spectively analyzed, who received potentially curative cholecystectomy in our institute from March 2005 to December 2017. Receiver operating characteristic curve(ROc curve) was used to determine the optimal cut-offs for these biomarkers. In addition, Kaplan-Meier survival analysis as well as multivariate analysis were applied for prognostic analyses.RESULTS ROc curve revealed that the optimal cut-off value for FAR was 0.08. FAR was significantly correlated with age(P = 0.045), jaundice(P < 0.001), differentiation(P = 0.002), resection margin status(P < 0.001), T stage(P < 0.001), TNM stage(P < 0.001), and c A199(P < 0.001) as well as albumin levels(P < 0.001). Multivariate analysis indicated that the resection margin status [hazard ratio(HR): 2.343, 95% confidence interval(c I): 1.532-3.581, P < 0.001], TNM stage(P = 0.035), albumin level(HR = 0.595, 95%c I: 0.385-0.921, P = 0.020) and FAR(HR: 2.813, 95%c I: 1.765-4.484, P < 0.001) were independent prognostic factors in Gbc patients.CONCLUSION An elevated preoperative FAR was significantly correlated with unfavorable overall survival in Gbc patients, while an elevated preoperative albumin level was a protective prognostic factor for patients with Gbc. The preoperative FAR could be used to predict the prognosis of Gbc patients, which was easily accessible, costeffective and noninvasive.
基金Supported by National key Project research and Development Projects,No.S2016G9012International Science and Technology Cooperation Projects,No.2015DFA30650The Capital Special research Project for Clinical Application,No.Z151100004015170
文摘AIM To investigate the prognostic value of the combination of preoperative plasma fibrinogen and CA199 in patients with gallbladder carcinoma(GBC).METHODS The clinicopathological data of 154 GBC patients were retrospectively reviewed after surgery. A receiver operating characteristic(ROC) curve was plotted to verify the optimum cut-off values for plasma fibrinogen and CA199. Univariate and multivariate survival analyses were performed to identify the factors associated with GBC prognosis. based on the HRs calculated via multivariate survival analyses, patients with elevated plasma fibrinogen and CA199 levels were allocated a score of 2.1; those with an elevated plasma fibrinogen level only were allocated a score of 1, those with an elevated CA199 level only were allocated a score of 1.1, and those with neither of these abnormalities were allocated a score of 0.RESULTS ROC curve analysis showed that the optimum cut-off values for preoperative plasma fibrinogen and CA199 were 3.47 g/L and 25.45 U/mL, respectively. Multivariate analysis indicated that elevated preoperative plasma fibrinogen and CA199 levels were significantly correlated with worse overall survival(OS)(HR = 1.711, 95%CI: 1.114-2.627, P = 0.014, and HR = 1.842, 95%CI: 1.111-3.056, P = 0.018). When we combined these two parameters, the area under the ROC curve increased from 0.735(for preoperative plasma fibrinogen only) and 0.729(for preoperative CA199 only) to 0.765. When this combined variable was added to the multivariate analysis, the combination of plasma fibrinogen and CA199(P < 0.001), resection margin(P < 0.001) and TNM stage(P = 0.010) were independent prognostic factors for GBC.CONCLUSION The combination of plasma fibrinogen and CA199 may serve as a more efficient independent prognostic biomarker for postoperative GBC patients than either parameter alone.
基金Chinese Academy of Medical Sciences Innovation Fund for Medical Science,No.2017-I2M-4-003International Science and Technology Cooperation Projects,No.2015DFA30650 and No.2016YFE0107100+3 种基金Capital Special Research Project for Health Development,No.2014-2-4012Beijing Natural Science Foundation,No.L172055National Ten-thousand Talent ProgramBeijing Science and Technology Cooperation Special Award Subsidy Project
文摘AIM To integrate clinically significant variables related to prognosis after curative resection for gallbladder carcinoma(GBC) into a predictive nomogram.METHODS One hundred and forty-two GBC patients who underwent curative intent surgical resection at Peking Union Medical College Hospital(PUMCH) were included. This retrospective case study was conducted at PUMCH of the Chinese Academy of Medical Sciences and Peking Union Medical College(CAMS & PUMC) in China from January 1, 2003 to January 1, 2018. The continuous variable carbohydrate antigen 19-9(CA19-9) was converted into a categorical variable(cCA19-9) based on the normal reference range. Stages 0 to IIIA were merged into one category, while the remaining stages were grouped into another category. Pathological grade X(GX) was treated as a missing value. A multivariate Cox proportional hazards model was used to select variables to construct a nomogram. Discrimination and calibration of the nomogram were performed via the concordance index(C-index) and calibration plots. The performance of the nomogram was estimated using the calibration curve. Receiver operating characteristic(ROC) curve analysis and decision curve analysis(DCA) were performed to evaluate the predictive accuracy and net benefit of the nomogram, respectively.RESULTS Of these 142 GBC patients, 55(38.7%) were male, and the median and mean age were 64 and 63.9 years, respectively. Forty-eight(33.8%) patients in this cohort were censored in the survival analysis. The median survival time was 20 months. A series of methods, including the likelihood ratio test and Akaike information criterion(AIC) as well as stepwise, forward, and backward analyses, were used to select the model, and all yielded identical results. Jaundice [hazard ratio(HR) = 2.9; 95% confidence interval(CI): 1.60-5.27], cCA19-9(HR = 3.2; 95%CI: 1.91-5.39), stage(HR = 1.89; 95%CI: 1.16-3.09), and resection(R)(HR = 2.82; 95%CI: 1.54-5.16) were selected as significant predictors and combined into a survival time predictive nomogram(C-index = 0.803; 95%CI: 0.766-0.839). High prediction accuracy(adjusted C-index = 0.797) was further verified via bootstrap validation. The calibration plot demonstrated good performance of the nomogram. ROC curve analysis revealed a high sensitivity and specificity. A high net benefit was proven by DCA.CONCLUSION A nomogram has been constructed to predict the overall survival of GBC patients who underwent radical surgery from a clinical database of GBC at PUMCH.
基金Supported by CAMS Innovation Fund for Medical Science(CIFMS),No.2017-12M-4-003International Science and technology Cooperation Projects,No.2015DFA30650 and No.2016yFE0107100+1 种基金Capital Special Research Project for Health Development,No.2014-2-4012Beijing Natural Science Foundation,No.L172055
文摘AIM To clarify the previous discrepant conclusions, we performed a meta-analysis to evaluate the prognostic value of red cell distribution width(RDW) in esophageal cancer(EC). METHODS We searched the PubM ed, EMBASE, Web of Science and Cochrane Library databases to identify clinical studies, followed by using STATA version 12.0 for statistical analysis. Studies that met the following criteria were considered eligible:(1) Studies including EC patients who underwent radical esophagectomy;(2) studies including patients with localized disease without distant metastasis;(3) studies including patients without preoperative neoadjuvant therapy;(4) studies including patients without previous antiinflammatory therapies and with available preoperative laboratory outcomes;(5) studies reporting association between the preoperative RDW and overall survival(OS)/disease-free survival(DFS)/cancer-specific survival(CSS); and(6) studies published in English.RESULTS A total of six articles, published between 2015 and 2017, fulfilled the selection criteria in the end. Statistical analysis showed that RDW was not associated with the prognosis of EC patients, irrespective of OS/CSS [hazard ratio(HR) = 1.27, 95% confidence interval(CI): 0.97-1.57, P = 0.000] or DFS(HR = 1.42, 95%CI: 0.96-1.88, P = 0.000). Subgroup analysis indicated that elevated RDW was significantly associated with worse OS/CSS of EC patients when RDW > 13%(HR = 1.45, 95%CI: 1.13-1.76, P = 0.000), when the patient number ≤ 400(HR = 1.45, 95%CI: 1.13-1.76, P = 0.000) and when the study type was retrospective(HR = 1.42, 95%CI : 1.16-1.69, P = 0.000).CONCLUSION Contrary to our general understanding, this meta-analysis revealed that RDW cannot serve as an indicator of poor prognosis in patients with EC. However, it may still be a useful predictor of unfavorable prognosis using an appropriate cut-off value.
基金National Key Project Research and Development Projects,No.S2016G9012International Science and Technology Cooperation Projects,No.2015DFA30650the Capital Special Research Project for Clinical Application,No.Z151100004015170
文摘AIM To clarify the prognostic significance of preoperative albumin-to-alkaline phosphatase ratio(AAPR) in cholangiocarcinoma(CCA) subjects receiving surgery.METHODS In this retrospective study, we included 303 CCA patients receiving surgery without preoperative therapy between 2002 and 2014. Clinicopathological characteristics(including AAPR) were analyzed to determine predictors of postoperative overall survival and recurrence-free survival(RFS). In addition,univariate and multivariate Cox proportional hazards models were conducted,followed by application of time-dependent receiver operating curves to identify the optimal cut-off.RESULTS Univariate and multivariate analyses revealed both decreased overall survival[hazard ratio(HR): 2.88, 95%CI: 1.19-5.78] and recurrence-free survival(HR: 2.31,95%CI: 1.40–3.29) in patients with AAPR < 0.41 compared to those with AAPR ≥0.41. The optimal cut-off of AAPR was 0.41. Of the 303 subjects, 253(83.5%) had an AAPR over 0.41. The overall 1-, 3- and 5-year survival rates were 70.2%, 38.0% and 16.5%, respectively in the low(< 0.41) AAPR group, which were significantly lower than those in the high(≥ 0.41) AAPR group(81.7%, 53.9%, and 33.4%,respectively)(P < 0.0001). Large tumor size, multiple tumors, and advanced clinical stage were also identified as significant predictors of poor prognosis.CONCLUSION Our outcomes showed that AAPR was a potential valuable prognostic indicator in CCA patients undergoing surgery, which should be further confirmed by prospective studies. Moreover, it is necessary to investigate the mechanisms concerning the correlation of low AAPR with poor post-operative survival in CCA patients.
文摘Background: Metastatic colorectal cancer(mCRC) patients with progressive disease after all available standard therapies need new medication for further treatment. Famitinib is a small-molecule multikinase inhibitor, with promising anticancer activities. This multicenter, randomized, double-blinded, placebo-controlled, phase II clinical trial was designed to evaluate the safety and efficacy of famitinib in mCRC.Methods: Famitinib or placebo was administered orally once daily. The primary endpoint was progression-free survival(PFS). Secondary endpoints included objective response rate(ORR), disease control rate(DCR), overall survival(OS), quality-of-life(QoL), and safety.Results: Between July 18,2012 and Jan 22,2014, a total of 167 patients were screened, and 154 patients were randomized in a 2:1 ratio to receive either famitinib(n = 99) or placebo(n = 55). The median PFS was 2.8 and 1.5 months in the famitinib and placebo groups(hazard ratio = 0.60,95% confidence interval = 0.41-0.86, P = 0.004). The DCR was 59.8% and 31.4%(P = 0.002) and the ORR was 2.2% and 0.0%(P = 0.540) in the famitinib and placebo groups,respectively. The most frequent grade 3-4 adverse events were hypertension(11.1%), hand-foot syndrome(10.1%),thrombocytopenia(10.1%) and neutropenia(9.1%). Serious adverse events occurred in 11(11.1%) patients in the famitinib group and 5(9.1%) in the placebo group(P = 0.788). The median OS of the famitinib and placebo groups was 7.4 and 7.2 months(P = 0.657).Conclusion: Famitinib prolonged PFS in refractory mCRC patients with acceptable tolerability.Trial registration This study was registered on ClinicalTrials.gov(NCT01762293) and was orally presented in the 2015 ASCO-Gastrointestinal
基金Supported by National Natural Science Foundation of China,No.81760432Science and Technology Department of Jiangxi Province,No.20202BBGL73036and Jiangxi Provincial Outstanding Young Talents Projects,No.20204BCJ23016.
文摘BACKGROUND Ubiquitin-specific protease 15(USP15)is an important member of the ubiquitinspecific protease family,the largest deubiquitinase subfamily,whose expression is dysregulated in many types of cancer.However,the biological function and the underlying mechanisms of USP15 in gastric cancer(GC)progression have not been elucidated.AIM To explore the biological role and underlying mechanisms of USP15 in GC progression.METHODS Bioinformatics databases and western blot analysis were utilized to determine the expression of USP15 in GC.Immunohistochemistry was performed to evaluate the correlation between USP15 expression and clinicopathological characteristics of patients with GC.A loss-and gain-of-function experiment was used to investigate the biological effects of USP15 on GC carcinogenesis.RNA sequencing,immunofluorescence,and western blotting were performed to explore the potential mechanism by which USP15 exerts its oncogenic functions.RESULTS USP15 was up-regulated in GC tissue and cell lines.The expression level of USP15 was positively correlated with clinical characteristics(tumor size,depth of invasion,lymph node involvement,tumor-node-metastasis stage,perineural invasion,and vascular invasion),and was related to poor prognosis.USP15 knockdown significantly inhibited cell proliferation,invasion and epithelialmesenchymal transition(EMT)of GC in vitro,while overexpression of USP15 promoted these processes.Knockdown of USP15 inhibited tumor growth in vivo.Mechanistically,RNA sequencing analysis showed that USP15 regulated the Wnt signaling pathway in GC.Western blotting confirmed that USP15 silencing led to significant down-regulation ofβ-catenin and Wnt/β-catenin downstream genes(c-myc and cyclin D1),while overexpression of USP15 yielded an opposite result and USP15 mutation had no change.Immunofluorescence indicated that USP15 promoted nuclear translocation ofβ-catenin,suggesting activation of the Wnt/β-catenin signaling pathway,which may be the critical mechanism promoting GC progression.Finally,rescue experiments showed that the effect of USP15 on gastric cancer progression was dependent on Wnt/β-catenin pathway.CONCLUSION USP15 promotes cell proliferation,invasion and EMT progression of GC via regulating the Wnt/β-catenin pathway,which suggests that USP15 is a novel potential therapeutic target for GC.
基金Supported by National Natural Science Foundation of China,No.81772642。
文摘BACKGROUND Positive peritoneal wash cytology with no peritoneal metastasis(CY1P0)is a special type of distant gastric cancer metastasis,which describes a patient with positive peritoneal lavage cytology,but no definitive peritoneal metastasis,and there are no widely accepted treatment guidelines.We enrolled 48 primary CY1P0 gastric cancer patients treated by radical gastrectomy in this study.Our study illustrated the efficacy of radical gastrectomy for CY1P0 gastric cancer patients,and suggested that the pathological N factor and vascular invasion were significant independent risk factors for overall survival(OS).AIM To assess the survival of CY1P0 gastric cancer patient post-radical gastrectomy,and to identify factors associated with long-term prognosis.METHODS Our study included 48 patients with primary CY1P0 gastric cancer who had radical gastrectomies at the Cancer Hospital,Chinese Academy of Medical Sciences,Beijing,China between 2013 and 2018.R0 resection was achieved in all 48 patients.Twelve patients received neoadjuvant chemotherapy.Thirty patients received adjuvant chemotherapy and four received adjuvant chemoradiotherapy.OS statistics were available for 48 patients.Follow-up continued through March 2020.Univariate and multivariate analyses were performed using a Cox proportional hazards model to identify prognostic factors.RESULTS Median OS was 22.0 mo(95%confidence interval:13.366-30.634 mo)post-surgery.Univariate analyses demonstrated that tumor site(P=0.021),pathological N factor(P=0.001),pathological T factor(P=0.028),vascular invasion(P=0.046),and the level of CA199 prior to initiating therapy(P=0.002)were significant risk factors for OS.Multivariate analyses demonstrated that pathological N factor(P=0.001)and vascular invasion(P=0.031)were significant independent risk factors for OS.CONCLUSION This study suggested that radical gastrectomy may be efficient for CY1P0 gastric cancer patient post-radical gastrectomy and the pathological N factor and vascular invasion are significant independent risk factors for OS.
基金Supported by Capital’s Funds for Health Improvement and Research,No.CFH:2018-2-4022。
文摘BACKGROUND The association between body mass index(BMI)and clinical outcomes remains unclear among patients with resectable gastric cancer.AIM To investigate the relationship between BMI and long-term survival of gastric cancer patients.METHODS This retrospective study included 2526 patients who underwent radical gastrectomy for gastric cancer between September 2013 and June 2018.The patients were divided into four groups:Group A(low BMI,<18.5 kg/m2),group B(normal BMI,18.5-24.9 kg/m2),group C(overweight,25-29.9 kg/m2),and group D(obese,≥30 kg/m2).Clinicopathological findings and survival outcomes were recorded and analyzed.RESULTS Preoperative weight loss was more common in the low-BMI group,while diabetes was more common in the obese group.Upper-third gastric cancer accounted for a large proportion of cases in the higher BMI groups.Major perioperative complications tended to increase with BMI.The 5-year overall survival rates were 66.4%for group A,75.0%for group B,77.1%for group C,and 78.6%for group D.The 5-year overall survival rate was significantly lower in group A than in group C(P=0.008)or group D(P=0.031).Relative to a normal BMI value,a BMI of<18.5 kg/m^(2)was associated with poor survival(hazard ratio:1.558,95%confidence interval:1.125-2.158,P=0.008).CONCLUSION Low BMI,but not high BMI,independently predicted poor survival in patients with resectable gastric cancer.
基金Supported by National Natural Science Foundation of China,No.82072734.
文摘BACKGROUND For Siewert type Ⅱ/Ⅲ adenocarcinoma of gastroesophageal junction(AGE), the efficacy of adjuvant chemoradiotherapy(CRT) after D2/R0 resection remains uncertain.AIM To determine whether CRT was superior to chemotherapy(CT) alone after D2/R0 resection for locally advanced Siewert type Ⅱ/Ⅲ AGE.METHODS We identified 316 locally advanced Siewert type Ⅱ/Ⅲ AGE patients who were treated with D2/R0 resection at National Cancer Center from 2011 to 2018.57 patients received adjuvant CRT and 259 patients received adjuvant CT.We followed patients for overall survival(OS), relapse-free survival, and recurrence pattern.RESULTS Five-year OS rates of the CRT group and the CT group for all patients were 66.7% and 41.9%(P = 0.010).Five-year OS rates of the CRT group and the CT group for Siewert type Ⅲ AGE patients were 65.7% and 43.9%(P = 0.006).Among the 195 patients whose recurrence information could be obtained, 18 cases(34.6%) and 61 cases(42.7%) were diagnosed as recurrence in the CRT group and CT group, respectively.The local and regional recurrence rates in the CRT group were lower than that in the CT group(22.2% vs 24.6%, 27.8% vs 39.3%).Multivariable cox regression analysis showed that vascular invasion, nerve invasion, and adjuvant CRT were important prognostic factors for Siewert type Ⅲ AGE.CONCLUSION For locally advanced Siewert type Ⅲ AGE, adjuvant CRT may prolong OS and reduce the regional recurrence rate.
基金National Natural Science Foundation of China,No.81772642.
文摘BACKGROUND Laparoscopic total gastrectomy(LTG)has drawn increasing attention over the years.Although LTG has shown surgical benefits compared to open TG(OTG)in early stage gastric cancer(GC),little is known about the surgical and oncological outcomes of LTG for advanced GC following neoadjuvant therapy(NAT).AIM To compare the long-and short-term outcomes of advanced GC patients who underwent LTG vs OTG following NAT.METHODS Advanced GC patients who underwent TG following NAT between April 2011 and May 2018 at the Cancer Hospital of the Chinese Academy of Medical Sciences were enrolled and stratified into two groups:LTG and OTG.Propensity score matching analysis was performed at a 1:1 ratio to overcome possible bias.RESULTS In total,185 patients were enrolled(LTG:78;OTG:109).Of these,138 were paired after propensity score matching.After adjustment for propensity score matching,baseline parameters were similar between the two groups.Compared to OTG,LTG was associated with a significantly shorter length of hospital stay(P=0.012).The rates of R0 resection,lymph node harvest,and postoperative morbidity did not significantly differ between the two groups.Overall survival(OS)outcomes were comparable between the two groups.Pathological T and N stages were found to be independent risk factors for OS.CONCLUSION LTG can be a feasible method for advanced GC patients following NAT,as it appears to be associated with better short-and comparable long-term outcomes compared to OTG.
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the support received from the National Natural Science Foundation of China (Nos. 11573012, 11303011, 11263004, 11163004 and U1231205)the Open Research Program of the Key Laboratory of Solar Activity of the Chinese Academy of Sciences (Nos. KLSA201414 and KLSA201505)
文摘Six high-resolution TiO-band image sequences from the New Vacuum Solar Telescope (NVST) are used to investigate the properties of intergranular bright points (igBPs). We detect the igBPs using a Laplacian and morphological dilation algorithm (LMD) and automatically track them using a three- dimensional segmentation algorithm, and then investigate the morphologic, photometric and dynamic prop- erties of igBPs in terms of equivalent diameter, intensity contrast, lifetime, horizontal velocity, diffusion index, motion range and motion type. The statistical results confirm previous studies based on G-band or TiO-band igBPs from other telescopes. These results illustrate that TiO data from the NVST are stable and reliable, and are suitable for studying igBPs. In addition, our method is feasible for detecting and track- ing igBPs with TiO data from the NVST. With the aid of vector magnetograms obtained from the Solar Dynamics Observatory/Helioseismic and Magnetic Imager, the properties of igBPs are found to be strongly influenced by their embedded magnetic environments. The areal coverage, size and intensity contrast values of igBPs are generally larger in regions with higher magnetic flux. However, the dynamics of igBPs, includ- ing the horizontal velocity, diffusion index, ratio of motion range and index of motion type are generally larger in the regions with lower magnetic flux. This suggests that the absence of strong magnetic fields in the medium makes it possible for the igBPs to look smaller and weaker, diffuse faster, and move faster and further along a straighter path.
基金supported by National Key R&D Program of China(No.2019YFA0405500)the National Natural Science Foundation of China(NSFC,Grant No.11835057)+1 种基金the State Natural Sciences Foundation Monumental Projects(Nos.12090040.Z.W.H,12090041.H.W.)The Guoshoujing Telescope(the Large Sky Area Multi-Object Fiber Spectroscopic Telescope,LAMOST)is a National Major Scientific Project built by the Chinese Academy of Sciencesprovided by the National Development and Reform Commission。
文摘The Large Sky Area Multi-Object Fiber Spectroscopic Telescope(LAMOST)started a medianresolution spectroscopic(MRS,R~7500)survey since October 2018.The main scientific goals of MRS,including binary stars,pulsators and other variable stars,were launched with a time-domain spectroscopic survey.However,the systematic errors,including the bias induced from wavelength calibration and the systematic difference between different spectrographs,have to be carefully considered during radial velocity measurement.In this work,we provide a technique to correct the systematics in the wavelength calibration based on the relative radial velocity measurements from LAMOST MRS spectra.We show that,for the stars with multi-epoch spectra,the systematic bias which is induced from the exposures on different nights can be corrected well for LAMOST MRS in each spectrograph.In addition,the precision of radial velocity zero-point of multi-epoch time-domain observations reaches below 0.5 km s^(-1).As a by-product,we also give the constant star candidates^(**),which can be the secondary radial-velocity standard star candidates of LAMOST MRS time-domain surveys.
基金the National Natural Science Foundation of China,No.82072734.
文摘BACKGROUND At present,there is insufficient medical evidence to determine whether adjuvant chemotherapy is necessary for T2N0M0 gastric cancer.AIM To obtain a risk score to assess the need for adjuvant chemotherapy in patients with T2N0M0 gastric cancer.METHODS We identified 325 patients with pathological T2N0M0 stage primary gastric cancer at the National Cancer Center between 2011 and 2018.Univariate and multivariate Cox regression analyses were performed to predict factors affecting prognosis.Vascular invasion,tumor site,and body mass index were assessed,and a scoring system was established.We compared the survival outcomes and benefits of adjuvant chemotherapy between the different subgroups.RESULTS Five-year survival rates of the score 0,1,2,and 3 groups were 92%,95%,80%,and 50%,respectively(P<0.001).In the score 2-3 group,five-year survival rates for patients in the adjuvant chemotherapy group and postoperative observation group were 95%and 61%,respectively(P=0.021).CONCLUSION For patients with T2N0M0 stage gastric cancer and two or more risk factors,adjuvant chemotherapy after D2 gastrectomy may have a survival benefit.
基金the Institutional Review Board of National Clinical Research Center for Cancer/Cancer Hospital(No.14-067/857).
文摘BACKGROUND For advanced gastric cancer patients with pancreatic head invasion,some studies have suggested that extended multiorgan resections(EMR)improves survival.However,other reports have shown high rates of morbidity and mortality after EMR.EMR for T4b gastric cancer remains controversial.AIM To evaluate the surgical approach for pT4b gastric cancer with pancreatic head invasion.METHODS A total of 144 consecutive patients with gastric cancer with pancreatic head invasion were surgically treated between 2006 and 2016 at the China National Cancer Center.Gastric cancer was confirmed in 76 patients by postoperative pathology and retrospectively analyzed.The patients were divided into the gastrectomy plus en bloc pancreaticoduodenectomy group(GP group)and gastrectomy alone group(GA group)by comparing the clinicopathological features,surgical outcomes,and prognostic factors of these patients.RESULTS There were 24 patients(16.8%)in the GP group who had significantly larger lesions(P<0.001),a higher incidence of advanced N stage(P=0.030),and less neoadjuvant chemotherapy(P<0.001)than the GA group had.Postoperative morbidity(33.3%vs 15.3%,P=0.128)and mortality(4.2%vs 4.8%,P=1.000)were not significantly different in the GP and GA groups.The overall 3-year survival rate of the patients in the GP group was significantly longer than that in the GA group(47.6%,median 30.3 mo vs 20.4%,median 22.8 mo,P=0.010).Multivariate analysis identified neoadjuvant chemotherapy[hazard ratio(HR)0.290,95%confidence interval(CI):0.103–0.821,P=0.020],linitis plastic(HR 2.614,95%CI:1.024–6.675,P=0.033),surgical margin(HR 0.274,95%CI:0.102–0.738,P=0.010),N stage(HR 3.489,95%CI:1.334–9.120,P=0.011),and postoperative chemoradiotherapy(HR 0.369,95%CI:0.163–0.836,P=0.017)as independent predictors of survival in patients with pT4b gastric cancer and pancreatic head invasion.CONCLUSION Curative resection of the invaded pancreas should be performed to improve survival in selected patients.Invasion of the pancreatic head is not a contraindication for surgery.