Probing the α cluster of ^16O with the relativistic ^16O+^16O collisions has raised great interest in the heavy ion community. However, the effects of the α cluster on the soft hadron observables vary largely among different studies. In this paper, we explain the differences by the compactness of the α cluster in oxygen, using iEBE-VISHNU hydrodynamic simulations with different initial state α cluster configurations. We also find several observables, such as the intensive skewness of the [p_ T] correlator Γ_p_ T, the harmonic flows v_2{2}, v_2{4}, v_3{2}, and the v_n^2-δ[p_ T] correlations ρ(v_2^2, [p_ T]), ρ(v_3^2, [p_ T]) in ^16O+^16O collisions are sensitive to the compactness of the α cluster in the colliding nuclei, which can be used to constrain the configurations of ^16O in the future. Our study serves as an important step toward the quantitative exploration of the α cluster configuration in the light nuclei with relativistic heavy ion collisions.

The shape phase transition for certain isotope or isotone chains, associated with the quantum phase transition of finite nuclei, is an intriguing phenomenon in nuclear physics. A notable case is the Xe isotope chain, where the structure transits from a γ-soft rotor to a spherical vibrator, with the second-order shape phase transition occurring in the vicinity of ^{128-130}Xe. In this Letter, we focus on investigating the γ-soft deformation of ^{129}Xe associated with the second-order shape phase transition by constructing novel correlators for ultrarelativistic ^{129}Xe+^{129}Xe collisions. In particular, our iEBE-VISHNU model calculations show that the correlation between elliptic flow v_{2} and mean transverse momentum [p_{T}], denoted as ρ_{2}, as well as the [p_{T}] fluctuation Γ_{p_{T}}, which were previously used to claim the evidence of the rigid triaxial deformation of ^{129}Xe, can also be well explained by the γ-soft deformation of ^{129}Xe. We further propose two novel correlators ρ_{4,2} and ρ_{2,4}, which carry nontrivial higher-order correlations and show unique capabilities to distinguish between the γ-soft and the rigid triaxial deformation of ^{129}Xe in ^{129}Xe+^{129}Xe collisions at the LHC. The present study provides a novel way to explore the second-order shape phase transition of finite nuclei with ultrarelativistic heavy ion collisions.

The neutron skin thickness of the benchmark nucleus $^{208}$Pb is crucial for our understanding of the equation of state of nuclear matter. In this paper, we discuss the effect of the neutron skin on the flow ratio observables in the semi-isobaric collisions $^{208}$Pb+$^{208}$Pb and $^{197}$Au+$^{197}$Au using iEBE-VISHNU hydrodynamic simulations. Our results suggest that $^{208}$Pb and $^{197}$Au should have the same magnitude of neutron skin thickness to describe the anisotropic flow ratios between the semi-isobaric systems. Our method provides an unconventional way to determine the neutron skin with the existing relativistic heavy ion collision data.

By varying the intrinsic initial geometry, the p/d/$^3$He+Au collisions at the Relativistic Heavy Ion Collider (RHIC) provide a unique opportunity to understand the collective behavior and probe the possible sub-nucleon fluctuations in small systems. In this paper, we employ the hybrid model \vishnu~ with \trento~ initial conditions to study the collective flow and the fluid behavior in p/d/$^3$He+Au collisions. With fine-tuned parameters, \vishnu~ can describe the $v_2(p_T)$ and $v_3(p_T)$ data from the PHENIX and STAR collaborations. However, for some certain parameter sets with initial sub-nucleon fluctuation, the hydrodynamic simulations have already beyond their limits with the average Knudsen number $\langle K_n \rangle$ obviously larger than one. Our calculations demonstrate that, for a meaningful evaluation of the fluid behavior in the small systems, model simulations should also pay attention to the validity range of hydrodynamics.Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Article funded by SCOAP3 and published under licence by Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Science and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.

Relativistic heavy-ion collisions at RHIC and the LHC are aimed at studying the quark-gluon plasma and exploring QCD phase diagrams. Recently, it has been realized that these collisions also provide new opportunities to probe the structures of the colliding nuclei. By comparing theoretical calculations and experimental measurements, one can quantitatively constrain the structures of the ground state nuclei. In this paper, we review the progress in this new research area from both experimental and theoretical perspectives, including the study of the nuclear deformations, neutron skins, and alpha clusters for the colliding nuclei in 96Ru+96Ru, 96Zr+96Zr, 197Au+197Au, 238U+238U, 129Xe+129Xe, 208Pb+208Pb, and 16O+16O collisions at RHIC and the LHC.

4496Ru+4496Ru and 4096Zr+4096Zr collisions at sNN=200 GeV provide unique opportunities to study the geometry and fluctuations raised from the deformation of the colliding nuclei. Using iEBE-VISHNU hybrid model, we predict ac2{3} ratios between these two collision systems and demonstrate that the ratios of ac2{3}, as well as the ratios of the involving flow harmonics and event-plane correlations, are sensitive to quadrupole and octupole deformations, which could provide strong constrains on the shape differences between 96Ru and 96Zr. We also study the nonlinear response coefficients χ4,22, which show insensitivity to the deformation effect.

Objective: Recently, increasing number of lung cancer patients benefit from immune-checkpoint inhibitors (ICIs). However, the data of Chinese small cell lung cancer (SCLC) patients is limited. This study aims to analyze the response and survival data of ICIs treatment in SCLC and to explore the predictive biomarkers. Methods: Forty-seven SCLC patients who received ICIs treatment from Peking University Cancer Hospital from May 2017 to September 2019 was recruited. Clinical characteristics including sex, age, smoking status, ICIs strategy, PD-L1 expression and therapeutic efficacy were collected to explore the clinical predictive biomarkers for SCLC ICIs treatment. Results: Among the 47 patients, 18 (38.3%) cases were partial repose (PR), 11 (23.4%) were stable disease (SD), 18 (38.3%) were progressive disease (PD), and the objective response rate (ORR) was 38.3%, disease control rate (DCR) was 61.7%, the median progression-free survival (PFS) was 5.3 months. ICIs monotherapy accounts for 27.7%, the ORR was 15.4%, DCR was 53.8%, median PFS was 2.7 months. Combined therapy accounts for 72.3%, the ORR was 47.1%, DCR was 64.7%, median PFS was 5.4 months. Fourteen (29.8%) patients received ICIs as the first line treatment, their ORR was 85.7%, DCR was 100%, median PFS was 9.1 month. The ORR was not related to the age, sex, body mass index (BMI), smoking status and programmed death-ligand 1 (PD-L1) expression (P>0.05). The ORRs were higher in patients underwent PD-L1 monotherapy (P=0.001), combined therapy (P=0.002) and received ICIs as the first line treatment (P<0.001). Log-rank analysis indicated that the PFS of female patients were 12.0 months, significantly longer than 4.4 months of male patients in ICIs treatment (P=0.038). Patients who received PD-L1 monotherapy, combined treatment, or ICIs as the first line treatment had longer PFS than their counterparts, though no statistical significant was observed (P>0.05). Cox multivariate analysis showed that, the gender was not an independent predictor for PFS in ICIs treatment (HR=3.777, 95%CI=0.974~30.891, P=0.054). Conclusions: Immunotherapy is an effective treatment strategy for SCLC. Patients who receive combined ICIs treatment, first line ICIs treatment and PD-L1 treatment may get greater benefits. PD-L1 expression cannot predict the response and PFS in SCLC ICIs treatment.

Objective:To evaluate the safety and efficacy of hybrid operation in the revascularization in symptomatic extracranial vertebral artery long-segment occlusion.Methods:From June 2018 to January 2020, five patients with symptomatic extracranial vertebral artery occlusion underwent hybrid operation revascularization in Peking University Third Hospital. The neurological score of 5 patients before and after operation was observed, and the neurological function of them was evaluated.Results:5 patients were revascularized successfully. There were no complications and no new-onset stroke or bleeding. For case 1 and case 3, endarterectomy combined with Fogarty catheter embolectomy was performed. For case 2, case 4, and case 5, endarterectomy combined with distal vertebral artery angioplasty and stenting was performed. In case 4, vertebral artery was occluded in one month follow-up, but the patient had no symptoms and no intervention was given.Conclusion:Hybrid operation may be an alternative treatment for symptomatic long-segment occlusion of extracranial vertebral artery with poor drug treatment, but the choice of operation methods and stent still needs further study.

Investigation of well-motivated parameter space in the theories of Beyond the Standard Model (BSM) plays an important role in new physics discoveries. However, a large-scale exploration of models with multi-parameter or equivalent solutions with a finite separation, such as supersymmetric models, is typically a time-consuming and challenging task. In this paper, we propose a self-exploration method, named Machine Learning Scan (MLS), to achieve an efficient test of models. As a proof-of-concept, we apply MLS to investigate the subspace of MSSM and CMSSM and find that such a method can reduce the computational cost and may be helpful for accelerating the exploration of supersymmetry.

In the minimal supersymmetric standard model (MSSM) the lightest superparticle (LSP) can be a TeV neutralino (mainly dominated by higgsino or wino) which serves as a dark matter candidate with correct thermal relic density. In this work we confront the 1–3 TeV neutralino dark matter with the latest direct and indirect detections from PandaX and AMS-02/DAMPE. Considering various scenarios with decoupled sfermions, with A -mediated annihilation, with squark or stop coannihilation, we find that the parameter space is stringently constrained by the direct detection limits. In the allowed parameter space, the TeV neutralino dark matter annihilation contribution to the anti-proton flux is found to agree with the AMS-02 data while its contribution to eletron/positron flux is too small to cause any visible excess.

Objective To investigate the clinical results of combined stents(naked self-expanding stent and covered stent) placement for the construction of transjugular intrahepatic portosystemic shunt(TIPS)for the treatment of portal hypertention complications. Methods A total of 61 patients who suffered from upper digestive tract hemorrhage or intractable ascites due to portal hypertension post liver cirrhosis underwent TIPS from April 2011 to May 2017.The shunt was constructed with stepwise placement of a naked self-expending stent and a covered stent for the purpose of precisely covering the parenchymal segment of the shunt. Portosystemic gradient(PSG)before and after TIPS was measured.The rates of hemostasis, major complications(re-bleeding or hepatic encephalopathy)and patient's survival were observed. Results The 61 patients were followed up for 5 -73 months (median,26 months),including 34 cases for more than 24 months,18 cases for more than 36 months,and 7 cases for more than 60 months.There were 9 fatal cases,including 3 cases of multiple organs dysfunction,2 cases of late-staged cancer,1 case of hepatic encephalopathy,1 case of pulmonary infection,and 2 cases of re-bleeding.The remaining 52 patients were followed up for(26.8 ± 20.2)months.The re-bleeding rate, cumulative patency rate of the shunts, cumulative incidence of encephalopathy, and patients' survival were 6.56%, 83.58%,19.60%, and 82.88%, respectively.Among this 52 long-term survivors, the mean Child-Pugh scores before TIPS and at the end of the follow-up were(7.47 ±1.60)points and(7.04 ±1.12)points,without significant difference (t=1.961,P=0.055). Conclusions Combined naked self-expending stent and covered stent is relatively safe and feasible.It has satisfying results for the treatment of portal hypertention complications.

OBJECTIVE:To investigate the long-term outcome of organ preservation with local excision or "watch and wait" strategy for mid-low rectal cancer patients evaluated as clinical complete remission (cCR) or near-cCR following neoadjuvant chemoradiotherapy (NCRT).METHODS:Clinical data of 62 mid-low rectal cancer patients evaluated as cCR/near-cCR after NCRT undergoing organ preservation surgery with local excision or receiving "watch and wait" strategy at Department of Gastrointestinal Surgery, Peking University Cancer Hospital and Institute from March 2011 to August 2017 were retrospectively analyzed. According to the approximate 1:2 pairing, 123 patients who underwent radical resection with complete pathological remission(ypCR) after neoadjuvant chemotherapy during the same period were selected for prognosis comparison. The primary endpoint of the study was 3-year non-regrowth disease-free survival (NR-DFS) and tumor specific survival (CSS). Survival analysis was performed using the Kaplan-Meier curve (Log-rank method). The secondary endpoint of the study was 3-year organ preservation and sphincter preservation.RESULTS:The retrospective study included 38 male and 24 female patients. The median age was 60 (31-79) years and the median distance from tumor to anal verge was 4(1-8) cm. The ratio of cCR and near-cCR was 79.0%(49/62) and 21.0%(13/62) respectively. Local regrowth rate was 24.2%(15/62). Of 15 with tumor regrowth, 9 patients received salvage radical rectal resection and no local recurrence was found during follow-up; 4 patients received salvage local excision among whom one patient had a local recurrence occurred patient; 2 patients refused further surgery. The overall metastasis rate was 8.1%(5/62), including resectable metastasis(4.8%,3/62) and unresectable metastasis (3.2%,2/62). The valid 3-year organ preservation rate and sphincter preservation rate were 85.5%(53/62) and 95.2%(59/62) respectively. The median follow-up was 36.2(8.6-89.0) months. The 3-year NR-DFS of patients with cCR and near-cCR was 88.6% and 83.1% respectively, which was not significantly different to that of patients with ypCR (94.7%, P=0.217). The 3-year CSS of patients with cCR and near-cCR was both 100%, which was not significantly different to that of patients with ypCR(93.4%, P=0.186).CONCLUSIONS:Mid-low rectal cancer patients with cCR or near-cCR after NCRT undergoing organ preservation with local excision or receiving "watch and wait" strategy have good long-term prognosis with low rates of local tumor regrowth and distant metastasis, which is similar to those with ypCR after radical surgery. This treatment mode may be used as an option for organ preservation in mid-low rectal cancer patients with good tumor remission after NCRT.

Objective To study the clinical significance of neglecting superficial femoral artery reconstruction for chronic lower extremity arteriosclerosis obliterans . Methods One hundred and fifty-five patients (220 limbs) treated for sever stenosis or occlusion of superficial femoral artery resulted by arteriosclerosis obliterans in ten years were reviewed .Among them there were 107 limbs treated by endovascular reconstruction of superficial femoral artery ( reconstruction group ) and the other 113 limbs were only treated with the accompanied iliac and/or profunda femoral artery lesion without superficial femoral artery treatment ( non-reconstruction group) . Results Compared with the non-reconstruction group , the reconstruction group had a better short-term total effective rate [70.1%(75/107) vs.46.0%(52/113), Z=-2.356, P=0.018].There were no significant differences between the two groups on long-term total effective rate [53.3%(57/107) vs.57.5%(65/113), Z=-0.633, P=0.527] and limb salvage rate [94.4%(101/107) vs.96.5%(109/113), χ2 =0.170, P=0.680].The reconstruction group had a higher re-operation rate [30.8%(33/107) vs.8.8%(10/113),χ2 =16.903, P=0.000] and a higher cost [(34 658.7 ±8322.7) yuan vs.(17 036.6 ±1603.0) yuan, t=22.082, P=0.000] as compared with the non-reconstruction group.There was no significant difference between the two groups on the morbidity of complications and death [0 vs.0.9%(1/113), Fisher’s exact test, P=1.000;1.9%(2/107) vs.1.8%(2/113), Fisher’s exact test,P=1.000]. Conclusion Dealing with accompanied iliac and profunda artery lesion and neglecting superficial femoral artery reconstruction is a safe , effective and inexpensive therapy for lower extremity arteriosclerosis obliterans , and should be the preferred alternative for some patients .

Investigation of well-motivated parameter space in the theories of Beyond the Standard Model (BSM) plays an important role in new physics discoveries. However, a large-scale exploration of models with multi-parameter or equivalent solutions with a finite separation, such as supersymmetric models, is typically a time-consuming and challenging task. In this paper, we propose a self-exploration method, named Machine Learning Scan (MLS), to achieve an efficient test of models. As a proof-of-concept, we apply MLS to investigate the subspace of MSSM and CMSSM and find that such a method can reduce the computational cost and may be helpful for accelerating the exploration of supersymmetry.

3610 Background: It has been reported that non-operative treatment (wait and see) is feasible for the selected rectal cancer cases with a complete clinical response (cCR) following neoadjuvant therapy (NT). The aim of this study is to determine whether "wait and see" policy is efficient for the cCR patients in China. Methods: We designed a prospective cohort study in China (ChiCTR-TRC-12002488). From Jul 2012 to August 2016, totally 45 patients with locally advanced rectal cancer who were cCR following NT were enrolled in the study; within whom, 32 patients were assigned to wait and see group, and the remaining 13 patients were assigned to surgery group (intent-to-treat grouping). Results: The median follow-up time was 24 months (range: 3-51). Of the patients who were followed up more than 12 months (n=37), 8 patients developed tumor progression (7 in wait and see group and 1 in surgery group, respectively). In the wait and see group, the local regrowth took an account of 23.1% (6/26), while the distant metastasis rate was 3.8% (1/26). In the surgery group, there were 23.1% (3/13) of patients who has residual cancer confirmed by postoperative pathological assessment. All the patients with tumor regrowth underwent radical surgery and no body died of cancer. Conclusions: Wait and see policy has an acceptable safety and efficiency, it may become an alternative treatment for the patients who were cCR following NT. Clinical trial information: ChiCTR-TRC-12002488. [Table: see text]

OBJECTIVE:To investigate the safety and efficacy of organ preservation surgery or "watch and wait" strategy for rectal cancer patients who are evaluated as clinical complete response(cCR) or near-cCR following neoadjuvant chemoradiotherapy (nCRT).METHOD:From March 2011 to June 2016, 35 patients with mid-low rectal cancers who were diagnosed as cCR or near-cCR following nCRT underwent organ preservation surgery with local excision or surveillance following "watch and wait" strategy in the Peking University Cancer Hospital. All the patients received re-evaluation and re-staging 6-12 weeks after the completion of nCRT, according to Habr-Gama and MSKCC criteria for the diagnosis of cCR or near-cCR. The near-cCR patients who received local excision and were pathologically diagnosed as T0Nx were also regarded as cCR. The end-points of this study included organ-preservation rate (OPR), sphincter-preservation rate (SPR), non-re-growth disease-free survival (NR-DFS), stoma-free survival, cancer-specific survival (CSS) and overall survival(OS). Kaplan-Meier curve was used to estimate the survival data at 3 years.RESULTS:A total of 35 cases were analyzed including 24 males (68.6%) and 11 females (31.4%). The median age was 60 (range 37-79) years and the median distance from tumor to anal edge was 4(2-8) cm. Thirty-three patients received 50.6 Gy/22f IMRT with capecitabine and two patients received 50 Gy/25f RT with capecitabine. The cCR and near-cCR rates were 74.3%(26/35) and 25.7%(9/35) respectively. Excision biopsy was performed in 4 near-cCR cases to confirm the diagnosis of cCR. The non-re-growth DFS rate was 14.3%(5/35) and the median time of tumor re-growth was 6.7 (4.7-37.4) months. In five patients with tumor re-growth, four were salvaged by radical rectal resections and one received local excision. The distant metastasis rate was 5.7%(2/35), one patient presented resectable liver metastasis and received radical resection, another patient presented multiple bone metastases and was still alive. The median follow-up time was 43.7(6.1-71.4) months. At three years, the organ-preservation rate was 88.6%(31/35), the sphincter-preservation rate was 97.1% (34/35). No local recurrence was observed in five patients who received salvage surgery. The non-re-growth DFS was 94.0%. Three patients died of non-rectal cancer related events. The cancer-specific survival was 100%, the overall survival was 92.7% and the stoma-free survival rate was 90.0%.CONCLUSIONS:Organ preservation surgery or "watch and wait" strategy for cCR or near-cCR patients is feasible and achieves good outcomes. This strategy can be an alternative to standard care, improve patient's quality of life and facilitate tailored treatment for mid-low rectal cancer following nCRT, however, it should be cautiously applied in near-cCR patients before local excision biopsy.

BACKGROUND:In patients with colorectal cancer, a defunctioning ileostomy is commonly constructed to reduce anastomotic complications. However, many patients do not undergo a subsequent procedure to have their temporary stoma closed. OBJECTIVE:This study investigated the incidence of nonclosure of ileostomies and identified factors associated with nonclosure. DESIGN:This study is a retrospective analysis of prospectively collected data. SETTING:This study was conducted at a tertiary referral cancer hospital. PATIENTS:A total of 296 patients who received anterior resection with a defunctioning ileostomy with protective intention from 2006 to 2013 were included. MAIN OUTCOME MEASURES:The primary outcomes measured were the incidence of nonclosure of ileostomy and associated risk factors. RESULTS:Patients were followed for a median time of 29 months (range, 21-100 months). At the end of the study, 51 (17.2%) patients were left with a permanent ileostomy. The median time interval from the creation of a defunctioning ileostomy to closure was 192 days (range, 14-865 days). Multivariate analyses using a logistic regression model showed that metastatic diseases (OR, 0.179, p < 0.001), Charlson Comorbidity Index score >1 (OR, 0.268; p < 0.01), and complications from the index surgery (OR, 0.391; p = 0.013) were significant independent risk factors for failing to close a defunctioning ileostomy. LIMITATIONS:Although our study has a large patient cohort, it is limited by its retrospective nature. It is difficult to fully evaluate stoma complications after hospital discharge, and the prevalence may be underestimated. CONCLUSION:One in 6 temporary ileostomies constructed during an elective anterior resection for rectal cancer was not closed. Patients should be told before the index surgery that there is a risk of nonclosure and possible complications associated with permanent ileostomy.

Objective To explore the safety and efficacy of interventional therapy for high-risk pulmonary embolism. Methods We retrospectively analyzed 94 cases of high-risk pulmonary embolism who received interventional therapy ( thrombectomy, rapid thrombolysis plus anticoagulation, or mechanical embolus removal) from December 2002 to September 2012.Vital signs, heart functions, and clinical outcomes were observed and compared. Results Among the 94 cases, the success rate of operation was 98.9%(1 patient died during the interventional procedure).Six patients died after operation.In the remaining 88 cases, loss of follow-up occurred in 16 cases and 72 cases were followed for an average of 23.5 months (13-130 months), the rate of follow-up being 81.8%(72/88) .The cardiac functions were classified as class Ⅰ in 68 cases, class Ⅱ in 3 cases, and class Ⅳ in 1 case. According to our criteria, there were 68 cases of complete remission (94.4%, 68/72), 3 cases of partial improvement (4.2%, 3/72), and 1 case of inefficacy (1.4%, 1/72). Conclusion Interventional treatment for high-risk pulmonary embolism is an effective procedure, which can quickly and efficiently improve the prognosis and the life quality.

OBJECTIVE:To compare the perioperative safety and efficacy between hand-assisted laparoscopic surgery(HALS) and conventional open sigmoidectomy.METHODS:A total of 291 patients with sigmoid colon cancer who underwent surgery in our hospital from January 2010 to June 2013 were seperated into (HALS) group (n=200) and conventional open surgery (COS) group (n=91) with a non-randomized method. The perioperative safety and efficacy of two groups and perioperative outcomes were compared.RESULTS:These two groups were comparable in operative time, lymph node harvest, and postoperative complications. However, HALS group had less intraoperative bleeding [(57.9±28.3) ml vs. (82.5±47.6) ml, P=0.000], shorter time to flatus [(3.0±1.4) d vs. (3.3±0.9) d, P=0.000], and shorter hospital stay [(7.3±4.2) d vs. (8.9±4.4) d, P=0.004]. There werer no significant differences in overall survival time and disease-free survival time between the two groups during 6 months to 3 years follow-up.CONCLUSIONS:HALS results in similar outcomes of conventional open surgery for sigmoidectomy with the advantage of minimal invasiveness.