The α phase Mo carbide has been widely investigated recently for its high activity in hydrogen production from water gas shift (WGS) reaction. However, high loading of noble metals as well as high economic and enviro...The α phase Mo carbide has been widely investigated recently for its high activity in hydrogen production from water gas shift (WGS) reaction. However, high loading of noble metals as well as high economic and environmental cost derived from high-temperature ammonification and carbonization process will lead to high cost of hydrogen production. Thus, the efficient controlling of phase transfer is promising. Herein, metals (Au, Pt, Rh, Cu) with a wide range of loadings were impregnated on flame spray pyrolysis (FSP) made MoO_(3) to produce Mo carbides by one-step carbonization. A breakthrough high metal-normalized hydrogen production rate of 213 mmol H2·gmetal^(-1)·s^(-1) was achieved on 0.025 wt% Rh/MoCx, which was much higher than Pt and Au based Mo carbides ever reported. The addition of trace Rh induced direct MoO_(3) transformation to high purity α-MoC_(1-x) in one-step carbonization instead of two-steps ammonification and carbonization process. In comparison to Rh, the addition of Pt, Au and Cu tend to transfer MoO_(3) into β-Mo2C at the same conditions. Besides, the one with 2 wt% Rh exhibited high stability in WGS reaction even at high temperature (300 ℃) due to its inhibition on carbides oxidation induced by H2O. We demonstrate that it is feasible to control phase transfer of Mo carbides even by trace amount of metals to simplify the production process of catalysts. The catalytic performance improved by Rh in aspects of both activity and stability provides a guide for producing more stable Mo carbides catalysts.展开更多
Malware detection has become mission sensitive as its threats spread from computer systems to Internet of things systems.Modern malware variants are generally equipped with sophisticated packers,which allow them bypas...Malware detection has become mission sensitive as its threats spread from computer systems to Internet of things systems.Modern malware variants are generally equipped with sophisticated packers,which allow them bypass modern machine learning based detection systems.To detect packed malware variants,unpacking techniques and dynamic malware analysis are the two choices.However,unpacking techniques cannot always be useful since there exist some packers such as private packers which are hard to unpack.Although dynamic malware analysis can obtain the running behaviours of executables,the unpacking behaviours of packers add noisy information to the real behaviours of executables,which has a bad affect on accuracy.To overcome these challenges,in this paper,we propose a new method which first extracts a series of system calls which is sensitive to malicious behaviours,then use principal component analysis to extract features of these sensitive system calls,and finally adopt multi-layers neural networks to classify the features of malware variants and legitimate ones.Theoretical analysis and real-life experimental results show that our packed malware variants detection technique is comparable with the the state-of-art methods in terms of accuracy.Our approach can achieve more than 95.6\%of detection accuracy and 0.048 s of classification time cost.展开更多
The incidence of pancreatic cancer has been rising worldwide,and its clinical diagnosis and treatment remain a great challenge.To present the update and improvements in the clinical diagnosis and treatment of pancreat...The incidence of pancreatic cancer has been rising worldwide,and its clinical diagnosis and treatment remain a great challenge.To present the update and improvements in the clinical diagnosis and treatment of pancreatic cancer in recent years,Chinese Pancreatic Association,the Chinese Society of Surgery,Chinese Medical Association revised the Guidelines for the Diagnosis and Treatment of Pancreatic Cancer in China(2014)after reviewing evidence-based and problem-oriented literature published during 2015-2021,mainly focusing on highlight issues regarding diagnosis and surgical treatment of pancreatic cancer,conversion strategies for locally advanced pancreatic cancer,treatment of pancreatic cancer with oligo metastasis,adjuvant and neoadjuvant therapy,standardized processing of surgical specimens and evaluation of surgical margin status,systemic treatment for unresectable pancreatic cancer,genetic testing,as well as postoperative follow up of patients with pancreatic cancer.Forty recommendation items were finally proposed based on the above issues,and the quality of evidence and strength of recommendations were graded using the Grades of Recommendation,Assessment,Development,and Evaluation system.This guideline aims to standardize the clinical diagnosis and therapy,especially surgical treatment of pancreatic cancer in China,and further improve the prognosis of patients with pancreatic cancer.展开更多
Dear Editor,The integrinαvβ3 receptor is a promising target for anticancer therapy.1,2 However,there are no effective marketed treatments targetingαvβ3.One possible limitation of Arginine-Glycine-Aspartic(RGD)-mim...Dear Editor,The integrinαvβ3 receptor is a promising target for anticancer therapy.1,2 However,there are no effective marketed treatments targetingαvβ3.One possible limitation of Arginine-Glycine-Aspartic(RGD)-mimeticαvβ3 antagonists has been shown to cause partial agonism,which could induce major conformational changes that trigger paradoxical cell adhesion and angiogenesis.展开更多
Liquid biopsy of cancers,detecting tumor-related information from liquid samples,has attracted wide attentions as an emerging technology.Our previously reported large-area PERFECT(Precise-Efficient-Robust-Flexible-Eas...Liquid biopsy of cancers,detecting tumor-related information from liquid samples,has attracted wide attentions as an emerging technology.Our previously reported large-area PERFECT(Precise-Efficient-Robust-Flexible-Easy-ControllableThin)filter has demonstrated competitive sensitivity in recovering rare tumor cells from clinical samples.However,it is time-consuming and easily biased to manually inspect rare target cells among numerous background cells distributed in a large area(Φ≥13 mm).This puts forward an urgent demand for rapid and bias-free inspection.Hereby,this paper implemented deep learning-based object detection for the inspection of rare tumor cells from large-field images of PERFECT filters with hematoxylin-eosin(HE)-stained cells recovered from bronchoalveolar lavage fluid(BALF).CenterNet,EfficientDet,and YOLOv5 were trained and validated with 240 and 60 image blocks containing tumor and/or background cells,respectively.YOLOv5 was selected as the basic network given the highest mAP@0.5 of 92.1%,compared to those of CenterNet and EfficientDet at 85.2%and 91.6%,respectively.Then,tricks including CIoU loss,image flip,mosaic,HSV augmentation and TTA were applied to enhance the performance of the YOLOv5 network,improving mAP@0.5 to 96.2%.This enhanced YOLOv5 network-based object detection,named as BALFilter Reader,was tested and cross-validated on 24 clinical cases.The overall diagnosis performance(~2 min)with sensitivity@66.7%±16.7%,specificity@100.0%±0.0%and accuracy@75.0%±12.5%was superior to that from two experienced pathologists(10–30 min)with sensitivity@61.1%,specificity@16.7%and accuracy@50.0%,with the histopathological result as the gold standard.The AUC of the BALFilter Reader is 0.84±0.08.Moreover,a customized Web was developed for a user-friendly interface and the promotion of wide applications.The current results revealed that the developed BALFilter Reader is a rapid,bias-free and easily accessible AI-enabled tool to promote the transplantation of the BALFilter technique.This work can easily expand to other cytopathological diagnoses and improve the application value of micro/nanotechnology-based liquid biopsy in the era of intelligent pathology.展开更多
基金This study was supported by DICP(Grant:DICP 1202012)the Natural Science Foundation of China(22078315)+1 种基金the LiaoNing Revitalization Talents Program(XLYC1907066)the Youth Innovation Promotion Association of Chinese Academy of Sciences(2018214).
文摘The α phase Mo carbide has been widely investigated recently for its high activity in hydrogen production from water gas shift (WGS) reaction. However, high loading of noble metals as well as high economic and environmental cost derived from high-temperature ammonification and carbonization process will lead to high cost of hydrogen production. Thus, the efficient controlling of phase transfer is promising. Herein, metals (Au, Pt, Rh, Cu) with a wide range of loadings were impregnated on flame spray pyrolysis (FSP) made MoO_(3) to produce Mo carbides by one-step carbonization. A breakthrough high metal-normalized hydrogen production rate of 213 mmol H2·gmetal^(-1)·s^(-1) was achieved on 0.025 wt% Rh/MoCx, which was much higher than Pt and Au based Mo carbides ever reported. The addition of trace Rh induced direct MoO_(3) transformation to high purity α-MoC_(1-x) in one-step carbonization instead of two-steps ammonification and carbonization process. In comparison to Rh, the addition of Pt, Au and Cu tend to transfer MoO_(3) into β-Mo2C at the same conditions. Besides, the one with 2 wt% Rh exhibited high stability in WGS reaction even at high temperature (300 ℃) due to its inhibition on carbides oxidation induced by H2O. We demonstrate that it is feasible to control phase transfer of Mo carbides even by trace amount of metals to simplify the production process of catalysts. The catalytic performance improved by Rh in aspects of both activity and stability provides a guide for producing more stable Mo carbides catalysts.
基金National Science foundation of China under Grant No.61772191,No.61472131.
文摘Malware detection has become mission sensitive as its threats spread from computer systems to Internet of things systems.Modern malware variants are generally equipped with sophisticated packers,which allow them bypass modern machine learning based detection systems.To detect packed malware variants,unpacking techniques and dynamic malware analysis are the two choices.However,unpacking techniques cannot always be useful since there exist some packers such as private packers which are hard to unpack.Although dynamic malware analysis can obtain the running behaviours of executables,the unpacking behaviours of packers add noisy information to the real behaviours of executables,which has a bad affect on accuracy.To overcome these challenges,in this paper,we propose a new method which first extracts a series of system calls which is sensitive to malicious behaviours,then use principal component analysis to extract features of these sensitive system calls,and finally adopt multi-layers neural networks to classify the features of malware variants and legitimate ones.Theoretical analysis and real-life experimental results show that our packed malware variants detection technique is comparable with the the state-of-art methods in terms of accuracy.Our approach can achieve more than 95.6\%of detection accuracy and 0.048 s of classification time cost.
文摘The incidence of pancreatic cancer has been rising worldwide,and its clinical diagnosis and treatment remain a great challenge.To present the update and improvements in the clinical diagnosis and treatment of pancreatic cancer in recent years,Chinese Pancreatic Association,the Chinese Society of Surgery,Chinese Medical Association revised the Guidelines for the Diagnosis and Treatment of Pancreatic Cancer in China(2014)after reviewing evidence-based and problem-oriented literature published during 2015-2021,mainly focusing on highlight issues regarding diagnosis and surgical treatment of pancreatic cancer,conversion strategies for locally advanced pancreatic cancer,treatment of pancreatic cancer with oligo metastasis,adjuvant and neoadjuvant therapy,standardized processing of surgical specimens and evaluation of surgical margin status,systemic treatment for unresectable pancreatic cancer,genetic testing,as well as postoperative follow up of patients with pancreatic cancer.Forty recommendation items were finally proposed based on the above issues,and the quality of evidence and strength of recommendations were graded using the Grades of Recommendation,Assessment,Development,and Evaluation system.This guideline aims to standardize the clinical diagnosis and therapy,especially surgical treatment of pancreatic cancer in China,and further improve the prognosis of patients with pancreatic cancer.
基金This research was funded by National High Level Hospital Clinical Research Funding(Scientific and Technological Achievements Transformation Incubation Guidance Fund Project of Peking University First Hospital)(No.2022CX11,No.2022RT01)National Key R&D Program of China(No.2020YFC2008304)National Natural Science Foundation of China(No.81973320 and No.81903714).Thanks to Dr.Qian Wang in the State Key Laboratory of Natural and Biomimetic Drugs,Peking University for the experimental assistance of SPR.Thanks to K2 Oncology Co.Ltd.for experimental assistance with patient-derived organoids.
文摘Dear Editor,The integrinαvβ3 receptor is a promising target for anticancer therapy.1,2 However,there are no effective marketed treatments targetingαvβ3.One possible limitation of Arginine-Glycine-Aspartic(RGD)-mimeticαvβ3 antagonists has been shown to cause partial agonism,which could induce major conformational changes that trigger paradoxical cell adhesion and angiogenesis.
基金supported by the National Key R&D Program of China(Grant No.2020YFC2005405)the National Natural Science Foundation of China(Grant No.61904004 and Grant No.82027805)+2 种基金the Seeding Grant for Medicine and Information on Sciences awarded by Peking University(Grant No.BMU2018MI003)Dr.Yaoping Liu thanks the Postdoctoral Science Foundation of China(Grant Nos.2018M631261 and 2019T20018)supported by the 111 Project(B18001).
文摘Liquid biopsy of cancers,detecting tumor-related information from liquid samples,has attracted wide attentions as an emerging technology.Our previously reported large-area PERFECT(Precise-Efficient-Robust-Flexible-Easy-ControllableThin)filter has demonstrated competitive sensitivity in recovering rare tumor cells from clinical samples.However,it is time-consuming and easily biased to manually inspect rare target cells among numerous background cells distributed in a large area(Φ≥13 mm).This puts forward an urgent demand for rapid and bias-free inspection.Hereby,this paper implemented deep learning-based object detection for the inspection of rare tumor cells from large-field images of PERFECT filters with hematoxylin-eosin(HE)-stained cells recovered from bronchoalveolar lavage fluid(BALF).CenterNet,EfficientDet,and YOLOv5 were trained and validated with 240 and 60 image blocks containing tumor and/or background cells,respectively.YOLOv5 was selected as the basic network given the highest mAP@0.5 of 92.1%,compared to those of CenterNet and EfficientDet at 85.2%and 91.6%,respectively.Then,tricks including CIoU loss,image flip,mosaic,HSV augmentation and TTA were applied to enhance the performance of the YOLOv5 network,improving mAP@0.5 to 96.2%.This enhanced YOLOv5 network-based object detection,named as BALFilter Reader,was tested and cross-validated on 24 clinical cases.The overall diagnosis performance(~2 min)with sensitivity@66.7%±16.7%,specificity@100.0%±0.0%and accuracy@75.0%±12.5%was superior to that from two experienced pathologists(10–30 min)with sensitivity@61.1%,specificity@16.7%and accuracy@50.0%,with the histopathological result as the gold standard.The AUC of the BALFilter Reader is 0.84±0.08.Moreover,a customized Web was developed for a user-friendly interface and the promotion of wide applications.The current results revealed that the developed BALFilter Reader is a rapid,bias-free and easily accessible AI-enabled tool to promote the transplantation of the BALFilter technique.This work can easily expand to other cytopathological diagnoses and improve the application value of micro/nanotechnology-based liquid biopsy in the era of intelligent pathology.