In the development of coalbed methane(CBM)reservoirs using multistage fractured horizontal wells,there often exist areas that are either repeatedly stimulated or completely unstimulated between fracturing stages,leadi...In the development of coalbed methane(CBM)reservoirs using multistage fractured horizontal wells,there often exist areas that are either repeatedly stimulated or completely unstimulated between fracturing stages,leading to suboptimal reservoir performance.Currently,there is no well-established method for accurately evaluating the effectiveness of such stimulation.This study introduces,for the first time,the concept of the Fracture Network Bridging Coefficient(FNBC)as a novel metric to assess stimulation performance.By quantitatively coupling the proportions of unstimulated and overstimulated volumes,the FNBC effectively characterizes the connectivity and efficiency of the fracture network.A background grid calibration method is developed to quantify the stage-controlled volume,effectively stimulated volume,unstimulated volume,and repeatedly stimulated volume among different stages of horizontal wells.Furthermore,an optimization model is constructed by taking the FNBC as the objective function and the fracturing injection rate and fluid volume as optimization variables.The Simultaneous Perturbation Stochastic Approximation(SPSA)algorithm is employed to iteratively perturb and optimize these variables,progressively improving the FNBC until the optimal displacement rate and fluid volume corresponding to the maximum FNBC are obtained.Field application in a typical CBM multistage fractured horizontal well in China demonstrates that the FNBC increased from 0.358 to 0.539(a 50.6% improvement),with the injection rate rising from 16 m^(3)/min to 24 m^(3)/min and the average fluid volume per stage increasing from 2490 m^(3) to 3192 m^(3),significantly enhancing the stimulation effectiveness.This research provides theoretical support for designing high-efficiency stimulation strategies in unconventional reservoirs under dynamic limits.展开更多
Azvudine and nirmatrelvir/ritonavir(Paxlovid)are recommended for COVID-19 treatment in China,but their safety and efficacy in the elderly population are not fully known.In this multicenter,retrospective,cohort study,w...Azvudine and nirmatrelvir/ritonavir(Paxlovid)are recommended for COVID-19 treatment in China,but their safety and efficacy in the elderly population are not fully known.In this multicenter,retrospective,cohort study,we identified 5131 elderly hospitalized COVID-19 patients from 32,864 COVID-19 patients admitted to nine hospitals in Henan Province,China,from December 5,2022,to January 31,2023.The primary outcome was all-cause death,and the secondary outcome was composite disease progression.Propensity score matching(PSM)was performed to control for confounding factors,including demographics,vaccination status,comorbidities,and laboratory tests.After 2:1 PSM,1786 elderly patients receiving azvudine and 893 elderly patients receiving Paxlovid were included.Kaplan-Meier and Cox regression analyses revealed that compared with Paxlovid group,azvudine could significantly reduce the risk of all-cause death(log-rank P=0.002;HR:0.71,95%CI:0.573-0.883,P=0.002),but there was no difference in composite disease progression(log-rank P=0.52;HR:1.05,95%CI:0.877-1.260,P=0.588).Four sensitivity analyses verified the robustness of above results.Subgroup analysis suggested that a greater benefit of azvudine over Paxlovid was observed in elderly patients with primary malignant tumors(P for interaction=0.005,HR:0.32,95%CI:0.18−0.57)compared to patients without primary malignant tumors.Safety analysis revealed that azvudine treatment had a lower incidence of adverse events and higher lymphocyte levels than Paxlovid treatment.In conclusion,azvudine treatment is not inferior to Paxlovid treatment in terms of all-cause death,composite disease progression and adverse events in elderly hospitalized COVID-19 patients.展开更多
SARS-CoV-2 variants still pose threats to human public health.However,there has been little research regarding alterations in the tongue-coating microbiome in patients infected with the Omicron variant(PIOVs).Herein,w...SARS-CoV-2 variants still pose threats to human public health.However,there has been little research regarding alterations in the tongue-coating microbiome in patients infected with the Omicron variant(PIOVs).Herein,we collected 963 tongue-coating samples prospectively,including 349 samples from PIOVs,242 samples from recovered PIOVs,300 samples from healthy controls(HCs)and 72 samples from patients infected with the original strain(PIOSs).We randomly selected tongue-coating samples from PIOVs and HCs as the discovery cohort and validation cohort.Tongue-coating microbiota was analyzed using Miseq sequencing.Our results showed that the tongue-coating microbial diversity of PIOVs was increased.We found that in PIOVs,the abundance was increased in 20 genera,including Prevonella and Atopobium,while the abundance was decreased in 23 genera,including Neisseria and Haemoph-ilus.The classifier based on six optimal microbial markers had high diagnostic efficiency in the discovery cohort(area under the curve of 97.73%)and the validation cohort(area under the curve of 93.06%)between the PIOV and HC groups.Importantly,compared with PIOSs,PIOVs showed an increase in Fusobacterium.Recovery of patients was associated with the restoration of the tongue-coating microbiota.In conclusion,this study is the first to characterize the tongue-coating microbiota in PIOVs and to construct noninvasive diagnostic models,providing new strategies for the prevention and control of coronavirus variants.展开更多
Pumping combiner is a kernel component of high power fiber laser （HPFL）. We demonstrate two types of tapered fiber bundle （TFB） end-pumping combiner able to combining multi-kilowatts of pumping laser. After the ex...Pumping combiner is a kernel component of high power fiber laser （HPFL）. We demonstrate two types of tapered fiber bundle （TFB） end-pumping combiner able to combining multi-kilowatts of pumping laser. After the experimental test of coupling performance, the 3xl coupler is proved to have a power handling capacity of 2.11 kW with a coupling efficiency of 95.1%, and the 7× 1 coupler is capable of handling pumping power of 4.72 kW with a coupling efficiency of 99.4%. These two coupler have obtained the ability to be used in laser diodes （LDs） direct beam combining and the pumping coupling of multikilowatts level fiber lasers.展开更多
基金the financial support from National Natural Science Foundation of China(No.52474029)Strategic and Applied Scientific Research Project of PetroChina Company Limited(2023ZZ18,2023ZZ18YJ04).
文摘In the development of coalbed methane(CBM)reservoirs using multistage fractured horizontal wells,there often exist areas that are either repeatedly stimulated or completely unstimulated between fracturing stages,leading to suboptimal reservoir performance.Currently,there is no well-established method for accurately evaluating the effectiveness of such stimulation.This study introduces,for the first time,the concept of the Fracture Network Bridging Coefficient(FNBC)as a novel metric to assess stimulation performance.By quantitatively coupling the proportions of unstimulated and overstimulated volumes,the FNBC effectively characterizes the connectivity and efficiency of the fracture network.A background grid calibration method is developed to quantify the stage-controlled volume,effectively stimulated volume,unstimulated volume,and repeatedly stimulated volume among different stages of horizontal wells.Furthermore,an optimization model is constructed by taking the FNBC as the objective function and the fracturing injection rate and fluid volume as optimization variables.The Simultaneous Perturbation Stochastic Approximation(SPSA)algorithm is employed to iteratively perturb and optimize these variables,progressively improving the FNBC until the optimal displacement rate and fluid volume corresponding to the maximum FNBC are obtained.Field application in a typical CBM multistage fractured horizontal well in China demonstrates that the FNBC increased from 0.358 to 0.539(a 50.6% improvement),with the injection rate rising from 16 m^(3)/min to 24 m^(3)/min and the average fluid volume per stage increasing from 2490 m^(3) to 3192 m^(3),significantly enhancing the stimulation effectiveness.This research provides theoretical support for designing high-efficiency stimulation strategies in unconventional reservoirs under dynamic limits.
基金supported by the National Natural Science Foundation of China(82151525)National Key Research and Development Program of China(2022YFC2303100 and 2023YFC3043514)+1 种基金Young and Middle-aged Academic Leaders of Henan Provincial Health Commission(HNSWJW-2022013,China)the Scientific Research and Innovation Team of The First Affiliated Hospital of Zhengzhou University(QNCXTD2023002,China).
文摘Azvudine and nirmatrelvir/ritonavir(Paxlovid)are recommended for COVID-19 treatment in China,but their safety and efficacy in the elderly population are not fully known.In this multicenter,retrospective,cohort study,we identified 5131 elderly hospitalized COVID-19 patients from 32,864 COVID-19 patients admitted to nine hospitals in Henan Province,China,from December 5,2022,to January 31,2023.The primary outcome was all-cause death,and the secondary outcome was composite disease progression.Propensity score matching(PSM)was performed to control for confounding factors,including demographics,vaccination status,comorbidities,and laboratory tests.After 2:1 PSM,1786 elderly patients receiving azvudine and 893 elderly patients receiving Paxlovid were included.Kaplan-Meier and Cox regression analyses revealed that compared with Paxlovid group,azvudine could significantly reduce the risk of all-cause death(log-rank P=0.002;HR:0.71,95%CI:0.573-0.883,P=0.002),but there was no difference in composite disease progression(log-rank P=0.52;HR:1.05,95%CI:0.877-1.260,P=0.588).Four sensitivity analyses verified the robustness of above results.Subgroup analysis suggested that a greater benefit of azvudine over Paxlovid was observed in elderly patients with primary malignant tumors(P for interaction=0.005,HR:0.32,95%CI:0.18−0.57)compared to patients without primary malignant tumors.Safety analysis revealed that azvudine treatment had a lower incidence of adverse events and higher lymphocyte levels than Paxlovid treatment.In conclusion,azvudine treatment is not inferior to Paxlovid treatment in terms of all-cause death,composite disease progression and adverse events in elderly hospitalized COVID-19 patients.
基金supported by grants from the National Key Research and Development Program of China(2022YFC2303100)the Henan Province Epidemic Prevention and Control Emergency Scientific Research Project(221111311700 and 221111311600)+1 种基金the Independent and Innovation Project for Graduate Students of Zhengzhou University(20230444)Funding for Scientific Research and Innovation Team of The First Affiliated Hospital of Zhengzhou University(QNCXTD2023002).
文摘SARS-CoV-2 variants still pose threats to human public health.However,there has been little research regarding alterations in the tongue-coating microbiome in patients infected with the Omicron variant(PIOVs).Herein,we collected 963 tongue-coating samples prospectively,including 349 samples from PIOVs,242 samples from recovered PIOVs,300 samples from healthy controls(HCs)and 72 samples from patients infected with the original strain(PIOSs).We randomly selected tongue-coating samples from PIOVs and HCs as the discovery cohort and validation cohort.Tongue-coating microbiota was analyzed using Miseq sequencing.Our results showed that the tongue-coating microbial diversity of PIOVs was increased.We found that in PIOVs,the abundance was increased in 20 genera,including Prevonella and Atopobium,while the abundance was decreased in 23 genera,including Neisseria and Haemoph-ilus.The classifier based on six optimal microbial markers had high diagnostic efficiency in the discovery cohort(area under the curve of 97.73%)and the validation cohort(area under the curve of 93.06%)between the PIOV and HC groups.Importantly,compared with PIOSs,PIOVs showed an increase in Fusobacterium.Recovery of patients was associated with the restoration of the tongue-coating microbiota.In conclusion,this study is the first to characterize the tongue-coating microbiota in PIOVs and to construct noninvasive diagnostic models,providing new strategies for the prevention and control of coronavirus variants.
基金This work was supported in part by the National Natural Science Foundation of China （Grant No. 61307057）.
文摘Pumping combiner is a kernel component of high power fiber laser （HPFL）. We demonstrate two types of tapered fiber bundle （TFB） end-pumping combiner able to combining multi-kilowatts of pumping laser. After the experimental test of coupling performance, the 3xl coupler is proved to have a power handling capacity of 2.11 kW with a coupling efficiency of 95.1%, and the 7× 1 coupler is capable of handling pumping power of 4.72 kW with a coupling efficiency of 99.4%. These two coupler have obtained the ability to be used in laser diodes （LDs） direct beam combining and the pumping coupling of multikilowatts level fiber lasers.
