Measurement of the neutron-induced total cross sections of ^(nat)Pb from 0.3 eV to 20 MeV on the Back-n at CSNS

The neutron-induced total cross sections of natural lead have been measured in a wide energy range(0.3 eV-20 MeV)on the back-streaming white neutron beamline(Back-n)at the China Spallation Neutron Source.Neutron energy was determined by the neutron total cross-section spectrometer using the time-of-flight technique.A fast multi-cell fission chamber was used as the neutron detector,and a 10-mm-thick high-purity natural lead sample was employed for the neutron transmission measurements.The on-beam background was determined using Co,In,Ag,and Cd filters.The excitation function of ^(nat)Pb(n,tot)reaction below 20 MeV was calculated using the TALYS-1.96 nuclear-reaction modeling program.The present results were compared with previous results,the evaluated data available in the five major evaluated nuclear data libraries(i.e.,ENDF/B-VIII.0,JEFF-3.3,JENDL-5,CENDL-3.2,and BROND-3.1),and the theoretical calculation curve.Good agreement was found between the new results and those of previous experiments and with the theoretical curves in the corresponding region.This measurement obtained the neutron total cross section of natural lead with good accuracy over a wide energy range and added experimental data in the resonance energy range.This provides more reliable experimental data for nuclear engineering design and nuclear data evaluation of lead.

Commissioning of laser electron gamma beamline SLEGS at SSRF

The Shanghai Laser Electron Gamma Source(SLEGS)is a powerful gamma source that provides MeV gamma-ray beams for nuclear science and technology.It was developed as one of the 16 beamline stations in the Phase Ⅱ Project of the Shanghai Synchrotron Radiation Facility.The slant-scattering mode is for the first time systematically employed in laser Compton scattering at SLEGS to produce energy-tunable quasi-monoenergetic gamma-ray beams.The SLEGS officially completed its commissioning from July to December 2021.Gamma rays in the energy range of 0.25-21.7 MeV with a flux of 2.1×10^(4)-1.2×10^(7) photons/s and an energy spread of 2-15% were produced during the test.This paper reports the results from commissioning the SLEGS beamline.

Laparoscopic vs open abdominoperineal resection in the multimodality management of low rectal cancers

AIM: To evaluate the safety and feasibility of laparoscopic abdominoperineal resection compared with the open procedure in multimodality management of rectal cancer.METHODS: A total of 106 rectal cancer patients who underwent open abdominoperineal resection(OAPR) were matched with 106 patients who underwent laparoscopic abdominoperineal resection(LAPR) in a 1 to 1 fashion, between 2009 and 2013 at Fudan University Shanghai Cancer Center. Propensity score matching was carried out based on age, gender, pathological staging of the disease and administration of neoadjuvant chemoradiation. Data regarding preoperative staging, surgical technique, pathologicalresults, postoperative recovery and complications were reviewed and compared between the LAPR and OAPR groups. Perineal closure around the stoma and pelvic floor reconstruction were performed only in OAPR, not in LAPR. Therefore, abdominoperineal resection procedure-specific surgical complications including parastomal hernia and perineal wound complications were compared between the open and laparoscopic procedure. Regular surveillance of the two cohorts was carried out to gather prognostic data. Diseasefree survival was analyzed using Kaplan-Meier estimate and log-rank test. Subgroup analysis was performed in patients with locally advanced disease treated with preoperative chemoradiation followed by surgical resection. RESULTS: No significant difference was found between the LAPR group and the OAPR group in terms of clinicopathological features. The operation time(180.8 ± 47.8 min vs 172.1 ± 49.2 min, P = 0.190), operative blood loss(93.9 ± 60.0 m L vs 88.4 ± 55.2 m L, P = 0.494), total number of retrieved lymph nodes(12.9 ± 6.9 vs 12.9 ± 5.4, P = 0.974), surgical complications(12.3% vs 15.1%, P = 0.549) and pathological characteristics were comparable between the LAPR and OAPR group, respectively. Compared with OAPR patients, LAPR patients showed significantly shorter postoperative analgesia(2.4 ± 0.7 d vs 2.7 ± 0.6 d, P < 0.001), earlier first flatus(57.3 ± 7.9 h vs 63.5 ± 9.2 h, P < 0.001), shorter urinary drainage time(6.5 ± 3.4 d vs 7.8 ± 1.3 d, P < 0.001), and shorter postoperative admission(11.2 ± 4.7 d vs 12.6 ± 4.0 d, P = 0.014). With regard to APR-specific complications(perineal wound complications and parastomal hernia), there were no significant differences between the two groups. Similar results were found in the 26 pairs of patients administered neoadjuvant chemoradiation in subgroup analysis. During the follow-up period, no port site recurrences were observed. CONCLUSION: Laparoscopic abdominoperineal resection for multidisciplinary management of rectal cancer is safe, and is associated with earlier recovery and shorter admission time in combination with neoadjuvant chemoradiation.

Measurements ofthe 197Au(n, γ) crosssectionupto100keV at the CSNSBack-nfacility

The neutron capture cross section of 197 Au was measured using the time-of-flight(TOF)technique at the Back-n facility of the China Spallation Neutron Source(CSNS)in the 1 eV to 100 keV range.Prompt c-rays originating from neutron-induced capture events were detected by four C_(6)D_(6) liquid scintillator detectors.Pulse height weighting technology(PHWT)was used to analyze the data.The results are in good agreement with ENDF/B-VIII.0,CENDL-3.1,and other evaluated libraries in the resonance region,and in agreement with both n TOF and GELINA experimental data in the 5–100 keV range.Finally,the resonance peaks in the energy range from 1eV to 1 keV were fitted by the SAMMY R-matrix code.

Measurements of the ^(107)Ag neutron capture cross sections with pulse height weighting technique at the CSNS Back-n facility

Silver indium cadmium(Ag–In–Cd) control rod is widely used in pressurized water reactor nuclear power plants,and it is continuously consumed in a high neutron flux environment. The mass ratio of ^(107)Ag in the Ag–In–Cd control rod is 41.44%. To accurately calculate the consumption value of the control rod, a reliable neutron reaction cross section of the ^(107)Ag is required. Meanwhile,^(107)Ag is also an important weak r nucleus. Thus, the cross sections for neutron induced interactions with ^(107)Ag are very important both in nuclear energy and nuclear astrophysics. The(n, γ) cross section of ^(107)Ag has been measured in the energy range of 1–60 eV using a back streaming white neutron beam line at China spallation neutron source. The resonance parameters are extracted by an R-matrix code. All the cross section of ^(107)Ag and resonance parameters are given in this paper as datasets. The datasets are openly available at http://www.doi.org/10.11922/sciencedb.j00113.00010.

New experimental measurement of^(nat)Se(n,γ)cross section between 1 eV to 1 keV at the CSNS Back-n facility

The^(74)Se is one of 35 p-nuclei,and^(82)Se is a r-process only nucleus,and their(n,γ)cross sections are vital input parameters for nuclear astrophysics reaction network calculations.The neutron capture cross section in the resonance range of isotopes and even natural selenium samples has not been measured.Promptγ-rays originating from neutron-induced capture events were detected by four C_(6)D_(6) liquid scintillator detectors at the Back-n facility of China Spallation Neutron Source(CSNS).The pulse height weighting technique(PHWT)was used to analyze the data in the 1 e V to 100 ke V region.The deduced neutron capture cross section was compared with ENDF/B-VIII.0,JEFF-3.2,and JENDL-4.0,and some differences were found.Resonance parameters were extracted by the R-matrix code SAMMY in the 1 e V-1 ke V region.All the cross sections ofnatSe and resonance parameters are given in the datasets.The datasets are openly available at http://www.doi.org/10.11922/sciencedb.j00113.00019.

Simulation and test of the SLEGS TOF spectrometer at SSRF

The Shanghai laser electron gamma source(SLEGS)is a powerful tool for exploring photonuclear physics,such as giant dipole resonance(GDR)and pygmy dipole resonance,which are the main mechanisms of collective nuclear motion.The goal of the SLEGS neutron time-of-flight(TOF)spectrometer is to measure GDR and specific nuclear structures in the energy region above the neutron threshold.The SLEGS TOF spectrometer was designed to hold 20 sets of EJ301 and LaBr3 detectors.Geant4 was used to simulate the efficiency of each detector and the entire spectrometer,which provides a reference for the selection of detectors and layout of the SLEGS TOF spectrometer.Under the events of 208Pb,implementations of coincidence and time-of-flight technology for complex experiments are available;thus,and neutron decay events can be separated.The performance of SLEGS TOF spectrometer was systematically evaluated using offline experiments,in which the time resolution reached approximately 0.9 ns.

Standard chemotherapy with cetuximab for treatment of colorectal cancer

AIM: To review and assess the evidence related to cetuximab treatment in metastatic colorectal cancer(mCRC) with regard to KRAS status.METHODS: PubMed, EMBASE, Cochrane database and American Society of Clinical Oncology meeting abstracts were searched for randomized controlled trials(RCTs) reporting the effect of KRAS status on efficacy of chemotherapy regimen with or without cetuximab in mCRC. Baseline information such as sex and age was summarized from the included studies.Hazard ratios of progression-free survival(PFS) and overall survival(OS) as well as objective response based on KRAS status were extracted for analysis.RESULTS: A total of 8 RCTs with 6780 patients were included. The combined analysis showed that cetuximab failed to improve the OS and PFS in patients with mCRC.However, in subgroup analysis, the pooled data showed that addition of cetuximab to irinotecan containing chemotherapy regimen was sufficient to improve OS and PFS in wild-type KRAS mCRC patients, but not in patients with mutant-type KRAS. The addition of cetuximab increased the incidence of adverse events such as diarrhea, rash, skin toxicity/rash, and nausea and vomiting. There was no significant publication bias existing in the included studies.CONCLUSION: The clinical benefit of cetuximab was only confirmed in patients with wild-type KRAS. KRAS status could be considered a biomarker of efficacy of cetuximab.

Core value of laparoscopic colorectal surgery

Since laparoscopy was first used in cholecystectomy in 1987, it has developed quickly and has been used in most fields of traditional surgery. People have now accepted its advantages like small incision, quick recovery, light pain, beauty and short hospital stays. In early times, there are still controversies about the application of laparoscopy in malignant tumor treatments, especially about the problems of oncology efficacy, incision implantation and operation security. However, these concerns have been fully eliminated by evidences on the basis of evidence-basis medicine. In recent years, new minimally invasive technologies are appearing continually, but they still have challenges and may increase the difficulties of radical dissection and the risks of potential complications, so they are confined to benign or early malignant tumors. The core value of the laparoscopic technique is to ensure the high quality of tumor's radical resection and less complications. On the basis of this, it is allowed to pursue more minimally invasive techniques. Since the development of laparoscopic colorectal surgery is rapid and unceasing, we have reasons to believe that laparoscopic surgery will become gold standard for colorectal surgery in the near future.

Short-term outcomes of laparoscopic total mesorectal excision compared to open surgery

AIM:To investigate the short-term outcome of laparoscopic total mesorectal excision(TME) in patients with mid and low rectal cancers.METHODS:A consecutive series of 138 patients with middle and low rectal cancer were randomly assigned to either the laparoscopic TME(LTME) group or the open TME(OTME) group between September 2008 and July 2011 at the Department of Colorectal Cancer of Shanghai Cancer Center,Fudan University and pathological data,as well as surgical technique were reviewed retrospectively.Short-term clinical and oncological outcome were compared in these two groups.Patients were followed in the outpatient clinic 2 wk after the surgery and then every 3 mo in the first year if no adjuvant chemoradiation was indicated.Statistical analysis was performed using SPSS 13.0 software.RESULTS:Sixty-seven patients were treated with LTME and 71 patients were treated with OTME(sex ratio 1.3:1vs 1.29:1,age 58.4 ± 13.6 years vs 59.6 ± 9.4 years,respectively).The resection was considered curative in all cases.The sphincter-preserving rate was 65.7%(44/67) vs 60.6%(43/71),P = 0.046;mean blood loss was 86.9 ± 37.6 mL vs 119.1 ± 32.7 mL,P = 0.018;postoperative analgesia was 2.1 ± 0.6 d vs 3.9 ± 1.8 d,P = 0.008;duration of urinary drainage was 4.7 ± 1.8 d vs 6.9 ± 3.4 d,P = 0.016,respectively.The conversion rate was 2.99%.The complication rate,circumferential margin involvement,distal margins and lymph node yield were similar for both procedures.No port site recurrence,anastomotic recurrence or mortality was observed during a median follow-up period of 21 mo(range:9-56 mo).CONCLUSION:Laparoscopic TME is safe and feasible,with an oncological adequacy comparable to the open approach.Further studies with more patients and longer follow-up are needed to confirm the present results.

Primary yields of protons measured using CR-39 in laser-induceddeuteron–deuteron fusion reactions

Investigating deuteron–deuteron(DD)fusion reactions in a plasma environment similar to the early stages of the Big Bang is an important topic in nuclear astrophysics.In this study,we experimentally investigated such reactions,using eight laser beams with the third harmonic impacting on a deuterated polyethylene target at the ShenGuang-II Upgrade laser facility.This work focused on the application of range-filter(RF)spectrometers,assembled from a 70 lm aluminum filter and two CR-39 nuclear track detectors,to measure the yields of primary DD-protons.Based on the track diameter calibration results of 3 MeV protons used to diagnose the tracks on the RF spectrometers,an approximate primary DD-proton yield of(8.5±1.7)×10^6 was obtained,consistent with the yields from similar laser facilities worldwide.This indicates that the RF spectrometer is an effective way to measure primary DD-protons.However,due to the low yields of D^3He-protons and its small track diameter,CR-39 detectors were unable to distinguish it from the background spots.Using other accurate detectors may help to measure these rare events.

Laparoscopic segmental colectomy for colonic lymphangiomas: A definitive, minimally invasive surgical option

Colonic lymphangioma is an unusual benign malformation.We herein describe two cases.A 36-year-old woman was admitted with one year of intermittent abdominal pain;colonoscopy,abdominopelvic computed tomography and endoscopic ultrasonography(EUS)revealed enlarged cystic masses at the ascending colon.In another 40-year-old man,colonoscopy and EUS revealed an asymptomatic lobulated cystic mass with four small sessile polyps at the sigmoid colon.Both patients underwent laparoscopic segmental colectomy.Both masses were histologically confirmed as cystic lymphangiomas,and the patients were discharged without complications.The management of colonic lymphangioma depends on the individual situation;close surveillance or endoscopic therapy may be appropriate for asymptomatic lesions smaller than 2.5 cm in diameter.Surgical intervention can be considered for larger lesions or in patients who develop complication risks.Laparoscopic segmental colon resection may be recommended to excise relatively large submucosal lesions because it is a definitive,minimally invasive intervention with a fast postoperative recovery.

Functional Liver Imaging Score Derived from Gadoxetic Acid-enhanced MRI Predicts Cachexia and Prognosis in Hepatocellular Carcinoma Patients

Objective Cachexia occurs in approximately half of hepatocellular carcinoma(HCC)patients as the disease progresses and is correlated with a poor prognosis.Therefore,early identification of HCC patients at risk of developing cachexia and their prognosis is crucial.This study investigated the functional liver imaging score(FLIS)derived from gadoxetic acid-enhanced magnetic resonance imaging(MRI)to identify cachexia in HCC patients and their prognosis.Methods Pretreatment clinical and MRI data from 339 HCC patients who underwent gadoxetic acid-enhanced MRI scans were retrospectively collected.Patient weights were recorded for 6 months following the MRI scan to diagnose cachexia.The FLIS was calculated as the sum of the enhancement quality score,the excretion quality score,and the portal vein sign quality score.A Cox proportional hazards model was used to determine the significant factors affecting overall survival(OS).Multivariable logistic regression was then conducted to identify variables predicting cachexia in HCC patients,which were subsequently used to predict OS.Results Cox regression analysis revealed a significant association between cachexia and worse OS.Both FLIS(0–4 vs.5–6 points)(OR,9.20;95%CI:4.68–18.10;P<0.001)andα-fetoprotein>100 ng/mL(OR,4.08;95%CI:2.13–7.83;P<0.001)emerged as significant predictors of cachexia in patients with HCC.Furthermore,FLIS(0–4 vs.5–6 points)(HR,1.73;95%CI:1.19–2.51;P=0.004)was significantly associated with OS.Patients in the FLIS 0–4 points group had shorter OS than those in the FLIS 5–6 points group[20 months(95%CI,14.7–25.3)vs.43 months(95%CI,27.7–58.3);P=0.001].Conclusion Cachexia was associated with worse OS.The functional liver imaging score emerged as a significant predictor of cachexia in HCC patients and their prognosis.

Chinese guideline for the application of rectal cancer staging recognition systems based on artificial intelligence platforms (2021 edition)

Development and Application of Artificial Intelligence Recognition Systems in Rectal Cancer Staging Whether for surgical treatment or for neoadjuvant chemoradiotherapy,imaging evaluation has become an important basis to perform the treatment plans.[1]The reading of imaging results requires a large number of experienced radiologists to complete,but shortages and uneven distributions of personnel cause delays and biases in imaging results.Therefore,independent research and development of automatic recognition systems of rectal cancer staging based on artificial intelligence(AI)platforms aim to partially replace practitioners’work and achieve rapid and accurate identification of rectal cancer staging.