Search

In order to provide tourists with better tourism services, a system method of personal information recommendation platform based on deep learning tourism is proposed. The system includes noise reduction autoencoder, feature extraction module, data preprocessing module, recommendation calculation module, expert evaluation module, recommendation result output module, customer feedback module, and storage module. The personal information recommendation platform system based on deep learning tourism of the present invention enables tourists to obtain tourism information conveniently and quickly through scientific information organization and presentation form and helps tourists to better arrange tourism plans and form tourism decisions. By effectively aggregating multiple neighborhoods of nodes, embedding high-order collaboration information into the node embedding vector, obtaining the potential preferences of users, solving the problems of user data sparse and cold start, and finally through experimental analysis, a research method is proposed. It is used to build the model of tourist attraction recommendation system. Experimental results show that the proposed method for cold-start user recommendation has the best performance in terms of accuracy, recall, and normalized loss cumulative gain, and it is 17.9% higher than BPR in recall rate Recall@5 and 11.8% higher in accuracy rate. It is proved that the system has a significant impact on the diversity and novelty of tourist attraction recommendation.

Organizing synthetic polymers, especially achiral polymers, into one-dimensional helical nanoarchitectures is challenging, which typically relies on pre-existing templates, such as properly folded DNA or polypeptide chains. Herein, we show that sonication-assisted self-assembly of achiral polymers linked by imine bond can self-organize into helical nanofibers, as proven from scanning electron microscopy and spectroscopy techniques. A systematic study of various imine-linked polymers reveals that the helical nanofibers are generated through the ∝-πstacking of adjacent polymers under the assistance of sonication rather than the influence by the topological structures of polymers and solvent context. The approach developed in this work may facilitate the access to previously inaccessible helical aggregates and promote the design of helical nanostructures from achiral building blocks in nanofabrication and nanoengineering. Ministry of Education (MOE) This research is supported by the National Natural Science Foundation of China (No. 22101208), the Fundamental Research Funds for the Central Universities, the Program for Professors of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning, and the Singapore Ministry of Education Academic Research Funds (Nos. RG3/21 and MOET2EP10120-0003).

Supplementary Data from Evaluation of a 1,4,7,10-Tetraazacyclododecane-1,4,7,10-Tetraacetic Acid–Conjugated Bombesin-Based Radioantagonist for the Labeling with Single-Photon Emission Computed Tomography, Positron Emission Tomography, and Therapeutic Radionuclides

The Sin3/HDAC complexes are highly conserved from yeast to humans and function by deacetylating histones, condensing chromatin, and modulating gene expression. Despite the continued analysis of HDAC inhibitors in clinical trials, our mechanistic understanding of the HDAC activity is hindered by the lack of a high-resolution structure of complexes from this family. Here we report the cryo-electron microscopy structure of Saccharomyces cerevisiae Rpd3S/Sin3B bound to a nucleosome, at atomic resolution. In the structure, two copies of Rco1 and two copies of Eaf3 are integrated through the scaffold subunit Sin3, which wraps the catalytic Rpd3/HDAC. Rco1 and Eaf3 recognize the H3 tails with a specific methylation pattern. N-terminal disordered region of Rco1 contacts the histones at the acidic patch. Furthermore, Rco1, Eaf3 and the Sin3 subunits also bind to extranucleosomal and nucleosomal DNA. These multivalent interactions not only facilitate detaching histone tails from nucleosomes but also optimally orient the complex to H3 tail, catalyzing deacetylation of H3K18 in our structure. The complex architecture and dimeric Rco1-Eaf3 heterodimer offer the ergonomics allowing one Rpd3S simultaneously engages two neighboring nucleosomes. Our study elucidates the central roles played by the non-catalytic subunits in a class I HDAC complex provides a structural framework for the understanding of HDAC regulation by histone modifications.

Purpose: Cancer-associated fibroblasts (CAFs) that overexpress fibroblast activation protein (FAP) are enriched in many epithelial carcinomas and in hematological neoplasms. Positron emission tomography/computed tomography (PET/CT) with radiolabeled FAP inhibitor (FAPI) is a new diagnostic tool for visualizing the tumor stroma. This prospective study aimed to profile FAPs in different subtypes of lymphomas and explore the potential utility of 68Ga-FAPI PET/CT in lymphomas. Methods: In this prospective study, we recruited 73 lymphoma patients who underwent 68Ga-FAPI PET/CT and recorded and measured semiquantitative parameters and ratios of their scan results. FAPI expression was assessed by immunochemistry in samples obtained from 22 of the lymphoma patients. Results: We evaluated 11 patients with Hodgkin lymphoma (HL) and 62 with non-Hodgkin lymphoma (NHL). Significantly elevated FAP uptake was observed in HL lesions, correlating with the intensity of FAP immunostaining (score, 3+). A positive association was found between the corresponding clinical classification of NHL and the 68Ga-FAPI uptake activity of the lesion. Aggressive NHL lesions, with moderate-to-strong FAP immunostaining (score, 2+ to 3+), exhibited intense to moderate 68Ga-FAPI uptake. Indolent NHL lesions showed weak FAP staining and mild to moderate 68Ga-FAPI uptake. No statistically significant correlation emerged between the sum of the product of the diameters and the corresponding maximum standardized uptake value (P = 0.424). The tumor-to-liver ratios were 6.26 ± 4.17 in indolent NHL and > 9 in other subtypes. Conclusion:68Ga-FAPI imaging can be used to detect FAP expression in lymphoma lesions and may be an alternate method for characterizing lymphoma profiles.

Breast cancer is a common type of cancer in females. Our previous studies indicated that leucine aminopeptidase 3 (LAP3) promotes migration and invasion of breast cancer cells. Vimentin is a mesenchymal marker, and its upregulation represents the promotion of epithelial–mesenchymal transition. In this study, we found that LAP3 and vimentin were highly expressed in breast cancer tissues, and the overexpression of LAP3 in breast cancer cells promoted the expression of vimentin. Western blot analysis indicated that the overexpression of LAP3 upregulated the phosphorylation of Erk1/2. MEK inhibitor PD98059 downregulated the expression of vimentin, matrix metalloproteinase-2/9 (MMP-2/9), and fascin through the inhibition of Erk1/2 activity. We hypothesized that LAP3 promoted tumor migration and invasion by upregulating vimentin. The knockdown of vimentin resulted in the inhibited migration and invasion of MDA-MB-231 and MDA-MB-468 cells. The expression of MMP-2/9 and fascin could also be downregulated. In conclusion, vimentin might play an important role in the promotion of breast cancer metastasis by LAP3.

Purpose Gallium-68 (68Ga)-labeled fibroblast-activation protein inhibitor (FAPI) is a novel tracer that binds fibroblast-activation protein (FAP), which is overexpressed in colorectal cancers with a prominent stroma including cancer-associated fibroblasts (CAFs). The present study aimed to compare the diagnostic performance of 68Ga-FAPI positron emission tomography (PET)/computed tomography (CT) with that of fluorine-18 (18F)-fluorodeoxyglucose (FDG) PET/CT in primary and metastatic colorectal cancer lesions. Methods This prospective study included the image analyses of 37 patients with colorectal cancer who were sequentially evaluated using PET/CT with 18F-FDG and 68Ga-FAPI. Tracer uptakes were compared using Wilcoxon’s signed-rank test. Results The cohort comprised 37 patients, including 18 treatment-naïve patients and 19 post-treatment patients. In primary colorectal cancer lesions, the average 68Ga-FAPI and 18F-FDG maximum standardized uptake values (SUVmax) were 12.5 ± 4.8 and 13.2 ± 5.7 (P = 0.38), respectively, in the treatment-naïve group and 6.0 ± 4.3 and 7.9 ± 7.2, respectively, in the neoadjuvant chemotherapy group (P = 0.09); the detection rate was 100% with both tracers (18/18). The SUVmax value of 68Ga-FAPI in signet-ring/mucinous carcinomas (12.3 ± 5.2) was higher than that of 18F-FDG (8.3 ± 4.0) (P = 0.03). In addition, the average 68Ga-FAPI uptake was lower than that of 18F-FDG in poorly differentiated carcinomas (12.7 ± 3.7 vs. 18.1 ± 4.1, P = 0.04). Compared with 18F-FDG PET/CT, clinical TNM staging based on 68Ga-FAPI PET/CT led to upstaging in 6 patients (16.2%) and downstaging in 3 patients (8.1%). In peritoneal and liver metastases, both the SUVmax and the target/background ratio were higher with 68Ga-FAPI compared to 18F-FDG (3.7 vs. 2.6, P = 0.02, and 6.5 vs. 0.89, P = 0.01, respectively). Conclusion As a novel PET/CT tracer, 68Ga-FAPI showed its advantage in the detection of lymph nodes, and distant metastases, which improved staging of CRC.

The ataxia-telangiectasia mutated (ATM) and ATM-Rad3-related (ATR) are apical kinases that orchestrate the multifaceted DNA damage response (DDR) to a variety of genotoxic insults and regulate genomic stability. Whether RNA virus also manipulates the host's DDR machine to facilitate replication is largely unknown. In this study, we revealed that single-stranded RNA virus replication specifically elicits host ATM- and ATR-mediated pathway activation and boosts their expression. The activated ATM and ATR are hijacked to the virus replication factory in the cytoplasm and facilitate viral gene expression and replication. Specific inhibitors targeting ATM and ATR strikingly block the viral proliferation and replication and inhibit expression of virus proteins. Our results reveal a novel, or otherwise noncanonical, conserved function of ATM/ATR outside DDR in promoting the replication of single-stranded RNA virus and provide an important mechanism of host-pathogen interactions.The online version contains supplementary material available at 10.1007/s42764-022-00064-3.

Purpose: Identification of microsatellite instability high (MSI-H) colorectal cancer (CRC) is crucial for screening patients most likely to benefit from immunotherapy. We aim to investigate whether the metabolic characteristics is related to MSI status and can be used to predict the MSI-H CRC. Methods: A retrospective analysis was conducted on 420 CRC patients who were identified via [18F]fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography(CT) prior to therapy. Maximum standardised uptake (SUVmax), mean standardised uptake (SUVmean), metabolic tumour volume (MTV) and total lesion glycolysis (TLG) of the primary tumour were calculated and compared between MSI-H and microsatellite stability (MSS). Predictive factors of MSI status were selected from metabolic parameters and clinicopathological profiles via a multivariate analysis.Results: Of 420 colorectal cancers, 44 exhibited a high incidence of MSI. Both MTV and TLG were significantly higher in MSI-H group compared with the MSS group (P=0.004 and P=0.010, respectively). Logistic regression analysis indicated that CRC with MSI-H were related to younger age (P=0.013), primary lesion located at right hemi-colon (PP=0.019). MTV more than 32.19 cm3 of colorectal cancer was linked to the presence of MSI (P=0.019). Conclusion: Tumor metabolic burden were higher in MSI-H CRC which may be useful for predicting the MSI status of CRC patient and thus aid in determination of immunotherapy for patients with CRC.

Identification of microsatellite instability high (MSI-H) colorectal cancer (CRC) is crucial for screening patients most likely to benefit from immunotherapy. We aim to investigate whether the metabolic characteristics is related to MSI status and can be used to predict the MSI-H CRC.A retrospective analysis was conducted on 420 CRC patients who were identified via [Of 420 colorectal cancers, 44 exhibited a high incidence of MSI. Both MTV and TLG were significantly higher in MSI-H group compared with the MSS group (P = 0.004 and P = 0.010, respectively). Logistic regression analysis indicated that CRC with MSI-H were related to younger age (P = 0.013), primary lesion located at right hemi-colon (P 0.001) and larger MTV on PET/CT imaging (P = 0.019). MTV more than 32.19 of colorectal cancer was linked to the presence of MSI (P = 0.019).Tumor metabolic burden were higher in MSI-H CRC which may be useful for predicting the MSI status of CRC patient and thus aid in determination of immunotherapy for patients with CRC.

The spectra of cloud-to-ground lightning return strokes channels are obtained by a slit-less high-speed spectrograph. Based on the positive correlation between discharge current and the intensity of ionic lines in the spectra, variation characteristics of return stroke current along the discharge channel are investigated. The result shows that there are three types of the variation trend for discharge current with the increase of height along the channel, they are exponential attenuation, linear attenuation and basically unchanged, respectively. The attenuation factor is roughly positive correlated with the discharge intensity. During strong discharge process the current tends to decay exponentially. In addition, during return stroke process, the current attenuation gradually flattens with time.

The aim of this study was to evaluate PET/FDG metabolic parameters in locally advanced GEJC and correlate it with molecular pathological profiles. We retrospectively analyzed data from 66 patients with a histopathological diagnosis of GEJC who had undergone 18F-FDG PET/CT before surgical resection. Maximum standardized uptake (SUVmax), mean standardized uptake (SUVmean), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of the primary tumor were measured and calculated using the region of interest (ROI) technique. The relationship between metabolic parameters and the Lauren’s classification, histologic differentiation, Ki-67 staining and positivity for human epidermal growth factor receptor 2 (HER2), c-Met, and epidermal growth factor receptor (EGFR) were investigated through immunohistochemical (IHC) analyses. Of the total 66 patients, significant differences were observed between intestinal and non-intestinal (mixed and diffuse) adenocarcinomas in SUVmax (8.23 ± 2.83 vs. 6.29 ± 2.41, P = 0.008), SUVmean (4.85 ± 1.47 vs. 3.93 ± 1.22, P = 0.017), MTV (24.96 cm3 vs. 8.90 cm3; P = 0.004), and TLG (97.38 cm3 vs. 37.09 cm3, P = 0.005) values. SUVmax, MTV, and TLG of moderately differentiated adenocarcinomas were significantly higher than those of the poorly differentiated ones. SUVmax was significantly higher in tissues with a higher Ki-67 index or in the c-MET-negative group (P = 0.045, P = 0.036). No significant correlation was found between metabolic parameters and the expression of HER2 or EGFR in GEJC. 18F-FDG PET/CT may be useful for predicting the molecular pathological profiles of GEJC and for determining appropriate therapeutic strategy.

Prostate-specific membrane antigen (PSMA)-targeted radioligands have played an important role in the diagnosis of prostate cancer. In this study, we developed an Al18F-labeled radiotracer and evaluated its potential for prostate cancer imaging. Methods: Al18F-PSMA-BCH (BCH is Beijing Cancer Hospital) was efficiently prepared manually. The binding affinity to PSMA was evaluated in vitro using the 22Rv1 (PSMA-positive) cell line. Small-animal PET imaging, biodistribution studies of Al18F-PSMA-BCH in mice bearing 22Rv1 and PC-3 (PSMA-negative) xenografted tumors, and a comparison with 68Ga-PSMA-617 in mice bearing LNCaP tumors were performed. PET/CT imaging was performed on 11 newly diagnosed prostate cancer patients at 1 and 2 h after injection. Biodistribution and preliminary efficacy were evaluated, and radiation dosimetry was estimated using OLINDA/EXM 2.0 software. Results: Al18F-PSMA-BCH was prepared within 30 min and was found to bind to PSMA with a dissociation constant of 2.90 ± 0.83 nM. Small-animal PET imaging of Al18F-PSMA-BCH could clearly differentiate 22Rv1 tumors from PC-3 tumors, as confirmed by ex vivo biodistribution data (7.87% ± 2.37% and 0.54% ± 0.22% injected dose/g at 1 h in 22Rv1 and PC-3 tumors, respectively). The uptake of Al18F-PSMA-BCH in 22Rv1 tumors could be substantially blocked by excess ZJ-43, a PSMA inhibitor. High-level accumulation of Al18F-PSMA-BCH was observed in PSMA-expressing organs, with increased uptake at later time points. Thirty-seven tumor lesions were detected in 11 patients, and the SUVmax in 27 lesions increased between 1 and 2 h after injection (10.60 vs. 14.11). The SUVmax in primary lesions in patients with high-risk prostate cancer was higher than that in patients with intermediate-risk prostate cancer. The kidneys received the highest estimated dose, 0.135 mGy/MBq, and the effective dose was 0.016 mGy/MBq. Conclusion: Al18F-PSMA-BCH was conveniently prepared with a reasonable yield within 30 min and showed a promising imaging capability for prostate cancer with reasonable radiation exposure. Al18F-PSMA-BCH can be used for prostate cancer imaging as a novel 18F PET radiotracer.

Objectives Even though postoperative chemotherapy can eliminate residual tumor cells in patients with colorectal cancer (CRC), severe adversity, weakened immunity and drug resistance are still problems. Adjuvant cytokine‐induced killer (CIK) cell therapy is an alternative to CRC patients after surgery. The present study investigated the efficacy of adjuvant CIK cell therapy combined with chemotherapy in postoperative CRC patients. Methods This retrospective analysis included 137 postoperative CRC patients, including 71 who received adjuvant chemotherapy alone (control group) and 66 who received adjuvant immunotherapy based on CIK cells combined with chemotherapy (CIT group). Results Long‐term follow‐up study indicated that overall survival (OS) and progression‐free survival (PFS) were significantly longer in the CIT group than in the control group. Subgroup analyses showed that CIT treatment significantly improved OS and PFS of CRC patients classified as stage II and N0 stage and in patients with primary tumors in the rectum. Increasing the number of CIK infusions resulted in better prognosis. CRC patients aged, This study found that adjuvant treatment with cytokine‐induced killer (CIK) cells combined with chemotherapy was effective in treating postoperative patients with colorectal cancer (CRC), and the patients aged

Cancer-associated fibroblasts that overexpress fibroblast activation protein (FAP) are enriched in many epithelial carcinomas and in hematologic neoplasms. PET/CT with radiolabeled FAP inhibitor (FAPI) is a new diagnostic tool for visualizing the tumor stroma. This prospective study aimed to profile FAPs in different subtypes of lymphomas and explore the potential utility of (68)Ga-FAPI PET/CT in lymphomas. Methods: In this prospective study, we recruited 73 lymphoma patients who underwent (68)Ga-FAPI PET/CT and recorded and measured semiquantitative parameters and ratios of their scan results. FAPI expression was assessed by immunochemistry in samples obtained from 22 of the lymphoma patients. Results: We evaluated 11 patients with Hodgkin lymphoma and 62 with non-Hodgkin lymphoma (NHL). Significantly elevated FAP uptake was observed in Hodgkin lymphoma lesions, correlating with the intensity of FAP immunostaining (score, 3+). A positive association was found between the corresponding clinical classification of NHL and the (68)Ga-FAPI uptake activity of the lesion. Aggressive NHL lesions, with moderate to strong FAP immunostaining (score, 2+ to 3+), exhibited intense to moderate (68)Ga-FAPI uptake. Indolent NHL lesions showed weak FAP staining and mild to moderate (68)Ga-FAPI uptake. No statistically significant correlation emerged between the sum of the product of the diameters and the corresponding SUV(max) (P = 0.424). The tumor-to-liver ratios were 6.26 ± 4.17 in indolent NHL and more than 9 in other subtypes. Conclusion: (68)Ga-FAPI imaging can be used to detect FAP expression in lymphoma lesions and may be an alternate method for characterizing lymphoma profiles.

During the COVID-19 epidemic, our national guidelines have suggested that surgical patients should wear a mask to decrease the potential transmission of COVID-19 in the operating room, as long as the condition allows. However, so far, there is no study to discuss the influence of wearing a mask on the ventilation and blood oxygenation status in patients of spontaneous breathing with supplementary oxygen through an anesthetic facemask. This is a before-after study in the same patient, and 10 healthy volunteers were recruited, by testing the arterial blood gas parameters at key time points before and after oxygen inhalation to evaluate the effects of two different supplementary oxygen methods (‘disposable medical mask + anesthetic facemask’ and ‘anesthetic facemask only’) on the oxygenation of subjects. Our data demonstrated whether wearing a disposable medical mask or not could effectively increase the oxygen supply of the subjects compared with the basic value before oxygen inhalation; however, compared with the group without mask, the arterial oxygen partial (PaO(2)) reduced significantly at each time points when subjects wearing a disposable medical mask. There was no significant difference in other parameters, and our data showed that age growth and smoking had no significant effects on the difference of PaO(2) between the groups with and without masks. This study demonstrates effective oxygen supplementation through anesthetic facemask in subjects with spontaneous breathing who is wearing a disposable medical mask, whose pulse oxygen saturation and arterial oxygen saturation can reach 100% rapidly, and this provides a theoretical basis for the management of patients with disseminated respiratory diseases to wear masks in the operating room; however, the rate and amount of PaO(2) increase are both decreased as compared to those who is not wearing a disposable medical mask during supplementary oxygenation. Whether this difference will affect the clinical outcome needs further study.

Objective The present study investigated the prognosis value of preoperative fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in patients with local advanced gastric cancer (LAGC). Methods In total, 144 patients [median age 63 (range: 48−80) years old] with LAGC underwent18F-FDG PET/CT prior to any treatment. The maximum standardized uptake values (SUVmax), mean standardized uptake values (SUVmean), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) of the primary lesion were measured on PET/CT and correlated with clinicopathological features and survival. Results Significant differences in SUVmean, SUVmax, MTV and TLG were found according to Lauren’s classification, histologic grade and T category (P

Accumulating evidence suggests that p53 plays a suppressive role in cancer metastasis, yet the underlying mechanism remains largely unclear. Regulation of actin dynamics is essential for the control of cell migration, which is an important step in metastasis. The Arp2/3 complex is a major nucleation factor to initiate branched actin polymerization that drives cell migration. However, it is unknown whether p53 could suppress metastasis through modulating Arp2/3 function. Here, we report that WDR63 is transcriptionally upregulated by p53. We show with migration assays and mouse xenograft models that WDR63 negatively regulates cell migration, invasion, and metastasis downstream of p53. Mechanistically, WDR63 interacts with the Arp2/3 complex and inhibits Arp2/3‐mediated actin polymerization. Furthermore, WDR63 overexpression is sufficient to dampen the increase in cell migration, invasion, and metastasis induced by p53 depletion. Together, these findings suggest that WDR63 is an important player in the regulation of Arp2/3 function and also implicate WDR63 as a critical mediator of p53 in suppressing metastasis.

The presence and functions of nuclear actin have been controversial due to the lack of molecular mechanisms. Nuclear actin and actin-related proteins (Arps) are subunits of several chromatin remodelers, including the evolutionarily conserved INO80 chromatin-remodeling complex. Here, we present an improved cryo-EM structure of the yeast INO80 complex and the first 3D reconstruction of the INO80 actin/Arp module. The modular and subunit architecture is defined using a combination of subunit deletion analysis and published crosslinking-mass spectrometry. The functional interactions of the INO80 actin/Arp module with a nucleosome is 3D EM reconstructed in two different binding states. Nucleosomes initially bind to the Arp8 subunit and the substantial conformational changes maximize nucleosome contacts of the actin/Arp module, which could promote the bound nucleosome to be engaged onto the INO80 ATPase domain. Our findings suggest that the conserved nuclear actin/Arp module acts a conformational switch of the INO80 for nucleosome binding.

The Sm3+-activated K2Gd(PO4)(WO4) phosphors were prepared by a high temperature solid state reaction in air atmosphere and their photoluminescence properties were investigated in detail. These phosphors manifest the intense absorption under the 404 nm and give rise to bright red luminescence at the main emission peaks of 568, 604, 649 and 708 nm, corresponding to the 4G5/2→6HJ/2 (J = 5, 7, 9, 11) transitions of Sm3+ ions, respectively. The type of energy transfer between Sm3+ ions were affirmed as among nearest-neighbor ions and the critical distance Rc of concentration quenching was calculated to be 27.23 A. Furthermore, K2Gd0.98(PO4)(WO4):0.02Sm3+ was provided with superb color coordinate (0.5806, 0.4164) also high color purity. Temperature related photoluminescence spectra and decay curves indicated that the K2Gd0.98(PO4)(WO4):0.02Sm3+ possessed good thermal stability and quantum efficiency was determined to be 91.2%. These remarkable features revealed that the K2Gd(PO4)(WO4):Sm3+ phosphors are high-performance phosphors for applications of white light-emitting diodes.

The characteristics of lightning corona sheath are of common concern in the lightning physics and lightning protection research. Using the spectra of two natural cloud-to-ground lightning including multiple return strokes recorded by a slit-less spectrograph, we investigated the electrical conductivity distribution along the radial direction of the channel. The results indicated that a high conductivity channel of above 104 S/m existed within an average radius of around 1.8 cm and corresponded to the temperature of around 20,000 K. This finding reflects the characteristics of the current-carrying channel. The electrical conductivity decayed steeply to about 500 S/m with increasing radius and then decayed slowly. Based on these results, it was estimated that the corona sheath radii of the return stroke channel were around 3.34–19.10 cm. The corona sheath radius was positively correlated with the leader charge quantity and the apparent diameter of the corresponding leader channel. A wide corona-channel radius corresponds to an intense discharge.

The spectra of two negative cloud-to-ground lightning discharge processes with multi-return strokes are obtained by a slit-less high-speed spectrograph, which the temporal resolution is 110 μs. Combined with the synchronous electrical observation data and theoretical calculation, the physical characteristics during return strokes process are analysed. A positive correlation between discharge current and intensity of ionic lines in the spectra is verified, and based on this feature, the current evolution characteristics during four return strokes are investigated. The results show that the time from peak current to the half-peak value estimated by multi point-fitting is about 101 μs–139 μs. The Joule heat in per unit length of four return strokes channel is in the order of 10 5 J/m–10 6 J/m. The radius of arc discharge channel is positively related to the discharge current, and the more intense the current is, the greater the radius of channel is. Furthermore, the evolution for radius of arc core channel in the process of return stroke is consistent with the change trend of discharge current after the peak value. Compared with the decay of the current, the temperature decreases more slowly.

The high time-resolved spectra of two natural positive cloud-to-ground (CG) lightning of which one of them contains multiple return strokes have been taken by a high-speed slit-less spectrograph. On combining with the synchronous electric field change waveform, the temperature, electrical conductivity of the return stroke channel, radius of the core current channel and the peak value of current are calculated. The correlation between the peak current and the time interval of five M components which overlapped with the continuous current following the subsequent return stroke R1 of multiple return strokes positive CG lightning were analysed. The results show that the average temperatures of the return stroke channels for two positive CG lightning are about 28,900–29,800 K, the radius of the core current channel is about 0.36–1.01 cm, the estimated peak currents of the return strokes are about 18.6–38.0 kA, which are all larger than the typical values of common negative CG lightning. The peak currents of the M components are positively correlated with the time intervals between them.

Objective High-dose chemotherapy (HDC) followed by autologous hematopoietic stem cell transplantation (auto-HSCT) plays an important role in improving outcomes of diffuse large B cell lymphoma (DLBCL) patients. 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) has been widely accepted in response assessment and prediction of prognosis in DLBCL. Here, we report the value of 18F-FDG PET/CT pre- and post-HSCT in predicting outcomes of patients with DLBCL. Methods DLBCL patients who had PET/CT scan before and after HSCT were included. PET results were interpreted based upon Deauville criteria. The prognostic value of 18F-FDG PET/CT in auto-HSCT was evaluated. Results Eighty-four patients were enrolled. In univariate analysis, pre- and post-HSCT PET findings were correlated with 3-year progression-free survival (PFS) [hazard ratio (HR)=4.391, P=0.001; HR=7.607, P