Quantitative effect of kerogen type on the hydrocarbon generation potential of Paleogene lacustrine source rocks,Liaohe Western Depression,China

Kerogen types exert a decisive effect on the onset and capacity of hydrocarbon generation of source rocks.Lacustrine source rocks in the Liaohe Western Depression are characterized by thick deposition,high total organic carbon(TOC)content,various kerogen types,and a wide range of thermal maturity.Consequently,their hydrocarbon generation potential and resource estimation can be misinterpreted.In this study,geochemical tests,numerical analysis,hydrocarbon generation kinetics,and basin modeling were integrated to investigate the differential effects of kerogen types on the hydrocarbon generation potential of lacustrine source rocks.Optimized hydrocarbon generation and expulsion(HGE)models of different kerogen types were established quantitatively upon abundant Rock-Eval/TOC/vitrinite reflectance(R_(o))datasets.Three sets of good-excellent source rocks deposited in the fourth(Es4),third(Es3),and first(Es1)members of Paleogene Shahejie Formation,are predominantly types I-II_(1),II_(1)-II_(2),and II-III,respectively.The activation energy of types I-II_(2)kerogen is concentrated(180-230 kcal/mol),whereas that of type III kerogen is widely distributed(150-280 kcal/mol).The original hydrocarbon generation potentials of types I,II_(1),II_(2),and III kerogens are 790,510,270,and 85 mg/g TOC,respectively.The Ro values of the hydrocarbon generation threshold for type I-III source rocks gradually increase from 0.42%to 0.74%,and Ro values of the hydrocarbon expulsion threshold increase from 0.49%to 0.87%.Types I and II_(1)source rocks are characterized by earlier hydrocarbon generation,more rapid hydrocarbon expulsion,and narrower hydrocarbon generation windows than types II_(2)and III source rocks.The kerogen types also affect the HGE history and resource potential.Three types(conventional,tight,and shale oil/gas)and three levels(realistic,expected,and prospective)of hydrocarbon resources of different members in the Liaohe Western Depression are evaluated.Findings suggest that the Es3 member has considerable conventional and unconventional hydrocarbon resources.This study can quantitatively characterize the hydrocarbon generation potential of source rocks with different kerogen types,and facilitate a quick and accurate assessment of hydrocarbon resources,providing strategies for future oil and gas exploration.

Non-contact wide-field viewing system-assisted scleral buckling surgery for retinal detachment in silicone oilfilled eyes

AIM:To evaluate scleral buckling(SB)surgery using a noncontact wide-field viewing system and 23-gauge intraocular illumination for the treatment of rhegmatogenous retinal detachment in silicone oil(SO)-filled eyes.METHODS:Totally 9 patients(9 eyes)with retinal detachment in SO-filled eyes were retrospectively analyzed.All patients underwent non-contact wide-field viewing system-assisted buckling surgery with 23-gauge intraocular illumination.SO was removed at an appropriate time based on recovery.The patients were followed up for at least 3mo after SO removal.Retinal reattachment,complications,visual acuity and intraocular pressure(IOP)before and after surgery were observed.RESULTS:Patients were followed up for a mean of 8.22mo(3-22mo)after SO removal.All patients had retinal reattachment.At the final follow-up,visual acuity showed improvement for 8 patients,and no change for 1 patient.The IOP was high in 3 patients before surgery,but it stabilized after treatment;it was not affected in the other patients.None of the patients had infections,hemorrhage,anterior ischemia,or any other complication.CONCLUSION:This new non-contact wide-field viewing system-assisted SB surgery with 23-gauge intraocular illumination is effective and safe for retinal detachment in SO-filled eyes.

Optimization of a magneto–optic trap using nanofibers

We experimentally demonstrate a reliable method based on a nanofiber to optimize the number of cold atoms in a magneto–optical trap(MOT) and to monitor the MOT in real time.The atomic fluorescence is collected by a nanofiber with subwavelength diameter of about 400 nm.The MOT parameters are experimentally adjusted in order to match the maximum number of cold atoms provided by the fluorescence collected by the nanofiber.The maximum number of cold atoms is obtained when the intensities of the cooling and re-pumping beams are about 23.5 mW/cm^2 and 7.1 mW/cm^2,respectively;the detuning of the cooling beam is-13.0 MHz, and the axial magnetic gradient is about 9.7 Gauss/cm.We observe a maximum photon counting rate of nearly(4.5 ± 0.1)× 10^5 counts/s.The nanofiber–atom system can provide a powerful and flexible tool for sensitive atom detection and for monitoring atom–matter coupling.It can be widely used from quantum optics to quantum precision measurement.

Tunable Optical Bandpass Filter via a Microtip-Touched Tapered Optical Fiber

We demonstrate a tunable bandpass optical filter based on a tapered optical fiber(TOF)touched by a hemispherical microfiber tip(MFT).Other than the interference and selective material absorption effects,the filter relies on the controllable and wavelength-dependent mode–mode interactions in TOF.Experimentally,a large range of tunability is realized by controlling the position of the MFT in contact with the TOF for various TOF radii,and two distinct bandpass filter mechanisms are demonstrated.The center wavelength of the bandpass filter can be tuned from 890 nm to 1000 nm,while the FWHM bandwidth can be tuned from 110 nm to 240 nm when the MFT touches the TOF in the radius range from 160 nm to 390 nm.The distinction ratio can reach 28±3 dB experimentally.The combined TOF-MFT is an in-line tunable bandpass optical filter that has great application potential in optical networks and spectroscopy,and the principle could also be generalized to other integrated photonic devices.

Advancing early warning and surveillance for zoonotic diseases under climate change:Interdisciplinary systematic perspectives

Zoonoses account for the majority of emerging infectious diseases and pose a serious threat to human and animal health.Under global warming and climate change,zoonoses are significantly affected by influencing hosts,vectors,and pathogen dynamics as well as their in-teractions.Traditional zoonoses surveillance relies on molecular or serological diagnostic methods to monitor pathogens from animal or patient samples,which may miss the early warning signs of pathogens spillover from the environment.Nowadays,new technologies such as remote sensing,environment-based screening,multi-omics,and big data science facilitate comprehensive active surveillance,offering great potential for early warning and prediction.Despite the recent technological advances,there is few reviews that explores the integration of cutting-edge technologies aimed at constructing a robust early warning system.Therefore,we discussed the opportunities,barriers,and limitations of interdisciplinary emerging technologies for exploring early warning and surveillance of zoonoses.This systematic review summarized a practical framework for early surveillance integrated with a modified SEIR model for zoonoses in the context of climate change.It also outlined challenges and future prospects in terms of data sharing,early detection of unknown zoonoses and the move towards global surveillance.

Reinvent Cloud Software Stacks for Resource Disagggiregation

Due to the unprecedented development of low-latency interconnect technology,building large-scale disaggre-gated architecture is drawing more and more attention from both industry and academia.Resource disaggregation is a new way to organize the hardware resources of datacenters,and has the potential to overcome the limitations,e.g.,low re-source utilization and low reliability,of conventional datacenters.However,the emerging disaggregated architecture brings severe performance and latency problems to the existing cloud systems.In this paper,we take memory disaggregation as an example to demonstrate the unique challenges that the disaggregated datacenter poses to the existing cloud software stacks,e.g.,programming interface,language runtime,and operating system,and further discuss the possible ways to rein-vent the cloud systems.

Promoting Vasa Vasorum Neovascularization of Vein Grafts Extenuates Hypoxia of the Wall and Its Subsequent Influence on Intimal Hyperplasia

Background： The autologous saphenous vein is the most common conduit for coronary artery bypass grafting, but the vein graft disease will occur. This study used Matrigel basement membrane matrix with many different growth factors to promote vasa vasorum neovascularization and extenuate the hypoxia to improve remodeling. Methods： This study observed the hypoxia and thickness of the vein grafts at different times. Normal veins and vein grafts with 15 min ofischemia one day postoperatively were harvested in the neck of rabbits. Paired vein grafts with 15 min ischemia bilaterally （control vs. Matrigel basement membrane matrix） were performed and harvested at 2, 6, and 12 weeks postoperatively. The rabbits were randomly divided into four postoperative groups （six rabbits in each group）： Group 1, one day postoperatively; Group 2, 2 weeks postoperatively; Group 3, 6 weeks postoperatively; and Group 4, 12 weeks postoperatively. The dimensions of vessel wall were captured, and the mean thicknesses of intima, media, and adventitia were measured. The hypoxia-inducible factor （HIF）- 1α and HIF-2ot labeling indices ofintima, media, and adventitia were also measured. Results： In Group 1, the labeling index of HIF-1α was high in the normal vein and decreased significantly in the vein grail one day postoperatively （intima： 80 4- 3% vs. 12 4- 1%, P = 0.01 ; media： 67 ±5% vs. 11 ± 1%, P = 0.01 ; adventitia： 40 ± 10% vs. 7 ±2%, P = 0.03）. The labeling index of HIF-2α had similar trend as HIF-1α （intima： 80 ± 10% vs. 10 ± 5%, P = 0.02; media： 60± 14% vs. 12 ± 2%, P = 0.01 ; adventitia： 45±20% vs. 10±4%, P = 0.03）. Compared with the control vein gratrol vein grafts with Matrigel basement membrane matrix had lower labeling indices of HIF-1α and HIF-2α in media and adventitia at Group 2 （HIF-1α： 34 ± 5% vs. 20 ±4%, P = 0.04 for media： 23 ± 3% vs. 11 ± 2%, P = 0.03 for adventitia; HIF-2α： 37 ± 6% vs. 21 ± 4%, P = 0.03 for media; 24 ±4% vs. 13 ± 2%, P = 0.04 for adventitia） and Group 3 （HIF-1α： 33 ± 4% vs. 7 ± 2%, P = 0.04 for media; 13 ± 3% vs. 3± 1%, P = 0.02 for adventitia; HIF-2α： 27 ± 4% vs. 12 ± 3%, P = 0.02 for media; 19 ± 2% vs. 6 ± 1%, P = 0.02 for adventitia）. There were no differences in mean thickness of intima, media, and adventitia between bilateral vein grafts at 2, 6, and 12 weeks postoperatively. Conclusions： This study indicated that promoting vasa vasorum neovascularization of vein grafts extenuated hypoxia, but did not influence the intimal hyperplasia of the wall,

Microstructure,Mechanical Properties,and Corrosion Behavior of Mg-Al-Ca Alloy Prepared by Friction Stir Processing

Friction stir processing(FSP)was used to modify the microstructure and improve the mechanical properties and corrosion resistance of an Mg-Al-Ca alloy.The results demonstrated that,after FSP,the grain size of the Mg-Al-Ca alloy was decreased from 13.3 to 6.7μm.Meanwhile,the Al_(8)Mn_(5) phase was broken and dispersed,and its amount was increased.The yield strength and ultimate tensile strength of the Mg-Al-Ca alloy were increased by 17.0%and 10.1%,respectively,due to the combination of fine grain,second phase,and orientation strengthening,while the elongation was slightly decreased.The immersion and electrochemical corrosion rates in 3.5 wt%NaCl solution decreased by 18.4%and 37.5%,respectively,which contributed to grain refinement.However,the stress corrosion cracking(SCC)resistance of the modified Mg-Al-Ca alloy decreased significantly,which was mainly due to the filiform corrosion induced by the Al_(8)Mn_(5) phase.SCC was mainly controlled by anodic dissolution,while the cathodic hydrogen evolution accelerated the SCC process.

Development and validation of a deep learning model to screen hypokalemia from electrocardiogram in emergency patients

Background:A deep learning model(DLM)that enables non-invasive hypokalemia screening from an electrocardiogram(ECG)may improve the detection of this life-threatening condition.This study aimed to develop and evaluate the performance of a DLM for the detection of hypokalemia from the ECGs of emergency patients.Methods:We used a total of 9908 ECG data from emergency patients who were admitted at the Second Affiliated Hospital of Nanchang University,Jiangxi,China,from September 2017 to October 2020.The DLM was trained using 12 ECG leads(lead Ⅰ,Ⅱ,Ⅲ,aVR,aVL,aVF,and V1–6)to detect patients with serum potassium concentrations<3.5 mmol/L and was validated using retrospective data from the Jiangling branch of the Second Affiliated Hospital of Nanchang University.The blood draw was completed within 10 min before and after the ECG examination,and there was no new or ongoing infusion during this period.Results:We used 6904 ECGs and 1726 ECGs as development and internal validation data sets,respectively.In addition,1278 ECGs from the Jiangling branch of the Second Affiliated Hospital of Nanchang University were used as external validation data sets.Using 12 ECG leads(leads Ⅰ,Ⅱ,Ⅲ,aVR,aVL,aVF,and V1–6),the area under the receiver operating characteristic curve(AUC)of the DLM was 0.80(95%confidence interval[CI]:0.77–0.82)for the internal validation data set.Using an optimal operating point yielded a sensitivity of 71.4%and a specificity of 77.1%.Using the same 12 ECG leads,the external validation data set resulted in an AUC for the DLM of 0.77(95%CI:0.75–0.79).Using an optimal operating point yielded a sensitivity of 70.0%and a specificity of 69.1%.Conclusions:In this study,using 12 ECG leads,a DLM detected hypokalemia in emergency patients with an AUC of 0.77 to 0.80.Artificial intelligence could be used to analyze an ECG to quickly screen for hypokalemia.