Gas flexible pipes are critical multi-layered equipment for offshore oil and gas development.Under high pressure conditions,small molecular components of natural gas dissolve into the polymer inner liner of the flexib...Gas flexible pipes are critical multi-layered equipment for offshore oil and gas development.Under high pressure conditions,small molecular components of natural gas dissolve into the polymer inner liner of the flexible pipes and further diffuse into the annular space,incurring annular pressure build-up and/or production of acidic environment,which poses serious challenges to the structure and integrity of the flexible pipes.Gas permeation in pipes is a complex phenomenon governed by various factors such as internal pressure and temperature,annular structure,external temperature.In a long-distance gas flexible pipe,moreover,gas permeation exhibits non-uniform features,and the gas permeated into the annular space flows along the metal gap.To assess the complex gas transport behavior in long-distance gas flexible pipes,a mathematical model is established in this paper considering the multiphase flow phenomena inside the flexible pipes,the diffusion of gas in the inner liner,and the gas seepage in the annular space under varying permeable properties of the annulus.In addition,the effect of a variable temperature is accounted.A numerical calculation method is accordingly constructed to solve the coupling mathematical equations.The annular permeability was shown to significantly influence the distribution of annular pressure.As permeability increases,the annular pressure tends to become more uniform,and the annular pressure at the wellhead rises more rapidly.After annular pressure relief followed by shut-in,the pressure increase follows a convex function.By simulating the pressure recovery pattern after pressure relief and comparing it with test results,we deduce that the annular permeability lies between 123 and 512 m D.The results help shed light upon assessing the annular pressure in long distance gas flexible pipes and thus ensure the security of gas transport in the emerging development of offshore resources.展开更多
Thousands of long-distance mobile mRNAs were identified from different grafting systems,based on high-throughput sequencing technology.Moreover,the long-distance delivery of RNAs was proved to involve multiple mechani...Thousands of long-distance mobile mRNAs were identified from different grafting systems,based on high-throughput sequencing technology.Moreover,the long-distance delivery of RNAs was proved to involve multiple mechanisms.Here,we analyzed the homology,motif,and tRNA-like structure(TLS)of long-distance mobile mRNAs identified by RNA-seq as well as the RNA-binding protein(RBP)in nine grafting combinations including Arabidopsis thaliana,Vitis vinifera,Cucumis sativus,Citrullus lanatus,Nicotiana benthamiana,Malus domestica,Pyrus spp.,Glycine max and Phaseolus vulgaris.Although several mRNAs were found to be shared in herbaceous,woody,and related species,the vast majority of long-distance mobile mRNAs were species-specific.Four non-specific movement-related motifs were identified,while the TLS was not necessary for mRNA long distance mobility.In addition,we found that RBPs were conserved among herbaceous and woody plants as well as related species.This paper reports a further in-depth analysis of the endogenous mechanisms by which the species-specific transportable m RNAs were selected by bioinformatics,in order to provide insights for future research on long-distance mobile mRNAs.展开更多
We report on the production of large sodium Bose^Einstein condensates in a hybrid of magnetic quadrupole and optical dipole trap. With an optimized spin-flip Zeeman slower, 2 ~ 1010 sodium atoms are captured in the ma...We report on the production of large sodium Bose^Einstein condensates in a hybrid of magnetic quadrupole and optical dipole trap. With an optimized spin-flip Zeeman slower, 2 ~ 1010 sodium atoms are captured in the magneto-optical trap (MOT). A long distance magnetic transfer setup moves the cold atom over 46cm from the MOT chamber to the UHV science chamber, which provides great optical access and long conservative trap lifetime. After evaporative cooling in the hybrid trap, we produce nearly pure condensates of 1 ~ 107 atoms with lifetime of 80 s in the optical dipole trap.展开更多
BACKGROUND There is a substantial population of long-stay patients who non-emergently transfer directly from the neonatal intensive care unit(NICU)to the pediatric intensive care unit(PICU)without an interim discharge...BACKGROUND There is a substantial population of long-stay patients who non-emergently transfer directly from the neonatal intensive care unit(NICU)to the pediatric intensive care unit(PICU)without an interim discharge home.These infants are often medically complex and have higher mortality relative to NICU or PICUonly admissions.Given an absence of data surrounding practice patterns for nonemergent NICU to PICU transfers,we hypothesized that we would encounter a broad spectrum of current practices and a high proportion of dissatisfaction with current processes.AIM To characterize non-emergent NICU to PICU transfer practices across the United States and query PICU providers’evaluations of their effectiveness.METHODS A cross-sectional survey was drafted,piloted,and sent to one physician representative from each of 115 PICUs across the United States based on membership in the PARK-PICU research consortium and membership in the Children’s Hospital Association.The survey was administered via internet(REDCap).Analysis was performed using STATA,primarily consisting of descriptive statistics,though logistic regressions were run examining the relationship between specific transfer steps,hospital characteristics,and effectiveness of transfer.RESULTS One PICU attending from each of 81 institutions in the United States completed the survey(overall 70%response rate).Over half(52%)indicated their hospital transfers patients without using set clinical criteria,and only 33%indicated that their hospital has a standardized protocol to facilitate non-emergent transfer.Fewer than half of respondents reported that their institution’s nonemergent NICU to PICU transfer practices were effective for clinicians(47%)or patient families(38%).Respondents evaluated their centers’transfers as less effective when they lacked any transfer criteria(P=0.027)or set transfer protocols(P=0.007).Respondents overwhelmingly agreed that having set clinical criteria and standardized protocols for non-emergent transfer were important to the patient-family experience and patient safety.CONCLUSION Most hospitals lacked any clinical criteria or protocols for non-emergent NICU to PICU transfers.More positive perceptions of transfer effectiveness were found among those with set criteria and/or transfer protocols.展开更多
We propose a scheme for long-distance quantum state transfer between different atoms based on cavity-assisted interactions. In our scheme, a coherent optical pulse sequentially interacts with two distant atoms trapped...We propose a scheme for long-distance quantum state transfer between different atoms based on cavity-assisted interactions. In our scheme, a coherent optical pulse sequentially interacts with two distant atoms trapped in separated cavities. Through the measurement of the state of the first atom and the homodyne detection of the final output coherent light, the quantum state can be transferred into the second atom with a success probability of unity and a fidelity of unity. In addition, our scheme neither requires the high-Q cavity working in the strong coupling regime nor employs the single-photon quantum channel, which greatly relaxes the experimental requirements.展开更多
In radiology,magnetic resonance imaging(MRI)is an essential diagnostic tool that provides detailed images of a patient’s anatomical and physiological structures.MRI is particularly effective for detecting soft tissue...In radiology,magnetic resonance imaging(MRI)is an essential diagnostic tool that provides detailed images of a patient’s anatomical and physiological structures.MRI is particularly effective for detecting soft tissue anomalies.Traditionally,radiologists manually interpret these images,which can be labor-intensive and time-consuming due to the vast amount of data.To address this challenge,machine learning,and deep learning approaches can be utilized to improve the accuracy and efficiency of anomaly detection in MRI scans.This manuscript presents the use of the Deep AlexNet50 model for MRI classification with discriminative learning methods.There are three stages for learning;in the first stage,the whole dataset is used to learn the features.In the second stage,some layers of AlexNet50 are frozen with an augmented dataset,and in the third stage,AlexNet50 with an augmented dataset with the augmented dataset.This method used three publicly available MRI classification datasets:Harvard whole brain atlas(HWBA-dataset),the School of Biomedical Engineering of Southern Medical University(SMU-dataset),and The National Institute of Neuroscience and Hospitals brain MRI dataset(NINS-dataset)for analysis.Various hyperparameter optimizers like Adam,stochastic gradient descent(SGD),Root mean square propagation(RMS prop),Adamax,and AdamW have been used to compare the performance of the learning process.HWBA-dataset registers maximum classification performance.We evaluated the performance of the proposed classification model using several quantitative metrics,achieving an average accuracy of 98%.展开更多
Transfer RNA(tRNA)-derived fragments,a new type of tRNA-derived small RNA(tsRNA),can be cleaved from tRNA by enzymes to regulate target gene expression at the transcriptional and translational levels.tsRNAs are not on...Transfer RNA(tRNA)-derived fragments,a new type of tRNA-derived small RNA(tsRNA),can be cleaved from tRNA by enzymes to regulate target gene expression at the transcriptional and translational levels.tsRNAs are not only degradation fragments but also have biological functions,including those in immune inflammation,metabolic disorders,and cell death.tsRNA dysregulation is closely associated with multiple diseases,including various cancers and acute pancreatitis(AP).AP is a common gastrointestinal disease,and its incidence increases annually.AP development is associated with tsRNAs,which regulate cell injury and induce inflammation,especially pyroptosis and ferroptosis.Notably,serum tRF36 has the potential to serve as a non-invasive diagnostic biomarker and leads to pancreatic acinar cell ferroptosis causing inflammation to promote AP.We show the characteristics of tsRNAs and their diagnostic value and function in AP,and discuss the potential opportunities and challenges of using tsRNAs in clinical applications and research.展开更多
BACKGROUND Thumb replantation following complete traumatic avulsion requires complex techniques to restore function,especially in cases of avulsion at the level of the metacarpophalangeal joint(MCP I)and avulsion of t...BACKGROUND Thumb replantation following complete traumatic avulsion requires complex techniques to restore function,especially in cases of avulsion at the level of the metacarpophalangeal joint(MCP I)and avulsion of the flexor pollicis longus(FPL)at the musculotendinous junction.Possible treatments include direct tendon suture or tendon transfer,most commonly from the ring finger.To optimize function and avoid donor finger complications,we performed thumb replantation with flexion restoration using brachioradialis(BR)tendon transfer with palmaris longus(PL)tendon graft.CASE SUMMARY A 20-year-old left-handed male was admitted for a complete traumatic left thumb amputation following an accident while sliding from the top of a handrail.The patient presented with skin and bone avulsion at the MCP I,avulsion of the FPL tendon at the musculotendinous junction(zone 5),avulsion of the extensor pollicis longus tendon(zone T3),and avulsion of the thumb’s collateral arteries and nerves.The patient was treated with two stage thumb repair.The first intervention consisted of thumb replantation with MCP I arthrodesis,resection of avulsed FPL tendon and implantation of a silicone tendon prosthesis.The second intervention consisted of PL tendon graft and BR tendon transfer.Follow-up at 10 months showed good outcomes with active interphalangeal flexion of 70°,grip strength of 45 kg,key pinch strength of 15 kg and two-point discrimination threshold of 4 mm.CONCLUSION Flexion restoration after complete thumb amputation with FPL avulsion at the musculotendinous junction can be achieved using BR tendon transfer with PL tendon graft.展开更多
Based on Bingham rheological model,a three-dimensional numerical simulation model for long-distance pipeline transportation is established by computational fluid dynamics(CFD)to study the pipeline transportationproper...Based on Bingham rheological model,a three-dimensional numerical simulation model for long-distance pipeline transportation is established by computational fluid dynamics(CFD)to study the pipeline transportationproperties of high sliming paste from a copper mine in China.Based on the rheological properties test,the pressure and velocity of pipeline and elbow are simulated by CFD under different mass concentrations and different stowing capacities.The results show that the pipeline resistance of whole-tailings paste with high sliming while without pumping agent is much higher than that with high sliming and pumping agent at the same mass concentration,and the pipeline resistance of whole-tailings paste with high sliming while without pumping agent is much higher than that with low sliming while without pumping agent.It is very important to add pumping agent to whole-tailings paste with high sliming,and the resistance changes with mass concentration and stowing capacity at the same cement-to-sand ratio of1:5and tailings-to-waste ratio of6:1.However,the change is just limited,that is to say,the paste transportation system is of good stability.Furthermore,at the elbow,the maximum pressure and velocity transfer to the outside of the pipe from the inside.However,lubricating layer is formed at the pipe wall because of high content of fine particles in whole-tailings paste,which will protect the elbow from abrasion.CFD provides an intuitive and accurate basis for pipeline transportation study,and would have a wider application space in the study of paste rheological properties and resistance reduction methods.展开更多
For a water supply system with long-distance diversion pipelines, in addition to the water hammer problems that occur beyond pumps, the safety of the water diversion pipeline in front of pumps also deserves attention....For a water supply system with long-distance diversion pipelines, in addition to the water hammer problems that occur beyond pumps, the safety of the water diversion pipeline in front of pumps also deserves attention. In this study, a water hammer protection scheme combined with an overflow surge tank and a regulating valve was developed. A mathematical model of the overflow surge tank was developed, and an analytical formula for the height of the overflow surge tank was derived. Furthermore, a practical water supply project was used to evaluate the feasibility of the combined protection scheme and analyze the sensitivity of valve regulation rules. The results showed that the combined protection scheme effectively reduced the height of the surge tank, lessened the difficulties related to construction, and reduced the necessary financial investment for the project. The two-stage closing rule articulated as fast first and then slow could minimize the overflow volume of the surge tank when the power failure occurred, while the two-stage opening rule articulated as slow first and then fast could be more conducive to the safety of the water supply system when the pump started up.展开更多
The extensively built long-distance water transmission pipelines have become the main water sources for urban areas. To ensure the reliability and safety of the water supply, from the viewpoint of overall management, ...The extensively built long-distance water transmission pipelines have become the main water sources for urban areas. To ensure the reliability and safety of the water supply, from the viewpoint of overall management, it would be necessary to establish a system of information management for the pipeline. The monitoring, calculating and analyzing functions of the system serve to give controlling instructions and safe operating rules to the automatic equipment and technician, making sure the resistance coefficient distribution along the pipeline is reasonable; the hydraulic state transition is smooth when operating conditions change or water supply accidents occur, avoiding the damage of water hammer. This paper covered the composition structures of the information management system of long-distance water transmission pipelines and the functions of the subsystems, and finally elaborated on the approaches and steps of building a mathematics model for the analysis of dynamic hydraulic status.展开更多
Resonant and nonresonant intermolecular vibrational energy transfers in Gdm- SCN/KSCN=1/1, GdmSCN/KS^13CN=1/1 and GdmSCN/KS^13C^15N=1/1 mixed crystals in melts and in aqueous solutions are studied with the two dimensi...Resonant and nonresonant intermolecular vibrational energy transfers in Gdm- SCN/KSCN=1/1, GdmSCN/KS^13CN=1/1 and GdmSCN/KS^13C^15N=1/1 mixed crystals in melts and in aqueous solutions are studied with the two dimensional infrared spectroscopy. The energy transfers in the samples are slower with a larger energy donor/acceptor gap, independent of the Raman spectra. The energy gap dependences of the nonresonant energy transfers cannot be described by the phonon compensation mechanism. Instead, the experi- mental energy gap dependences can be quantitatively described by the dephasing mechanism. Temperature dependences of resonant and nonresonant energy transfer rates in the melts are also consistent with the prediction of the dephasing mechanism. The series of results suggest that the dephasing mechanism can be dominant not only in solutions, but also in melts (pure liquids without solvents), only if the molecular motions (translations and rotations) are much faster than the nonresonant energy transfer processes.展开更多
The limited physical size for autonomous underwater vehicles (AUV) or unmanned underwater vehicles (UUV) makes it difficult to acquire enough space gain for localizing long-distance targets. A new technique about ...The limited physical size for autonomous underwater vehicles (AUV) or unmanned underwater vehicles (UUV) makes it difficult to acquire enough space gain for localizing long-distance targets. A new technique about long-distance target apperception with passive synthetic aperture array for underwater vehicles is presented. First, a synthetic aperture-processing algorithm based on the FFT transform in the beam space (BSSAP) is introduced. Then, the study on the flank array passive long-distance apperception techniques in the frequency scope of 11-18 kHz is implemented from the view of improving array gains, detection probability and augmenting detected range under a certain sea environment. The results show that the BSSAP algorithm can extend the aperture effectively and improve detection probability. Because of the augment of the transmission loss, the detected range has the trend of decline with the increase of frequency under the same target source level. The synthesized array could improve the space gain by nearly 7 dB and SNR is increased by about 5 dB. The detected range is enhanced to nearly 2 km under the condition of 108-118 dB of the target source level for AUV system in measurement interval of nearly 1 s.展开更多
The influence of inner cell mass (ICM) and trophectoderm (TE) score on pregnancy out- comes in frozen-thawed blastocyst transfer cycles was analyzed. A retrospective analysis of 741 cycles of frozen-thawed blastos...The influence of inner cell mass (ICM) and trophectoderm (TE) score on pregnancy out- comes in frozen-thawed blastocyst transfer cycles was analyzed. A retrospective analysis of 741 cycles of frozen-thawed blastosysts transfer was performed. All cycles were divided into four groups based on the number and morphological score of blastocysts: S-ICM B/TE B group (n=91), the single blastocyst transfer oflCM B and TE B; D-ICM B/TE B group (n=579), double blastocysts transfer oflCM B/TE B; D-1CM B/TE C group (n=35), double blastocysts transfer of ICM B/TE C; and D-ICM C/TE B group (n=36), double blastocysts transfer ofTE B/ICM C. The pregnancy outcomes were compared among the four groups. As compared with D-ICM B/TE C group, the clinical pregnancy rate, implantation rate and multiple pregnancy rate were increased in D-ICM B/TE B group (74.96% vs. 57.14%, 57.43% vs. 37.14%, and .48.62% vs. 25%, respectively, P〈0.05 for all). Clinical pregnancy rate and implantation rate in D-ICM B/TE B group were also higher than in D-ICM C/TE B group (74.96% vs. 50%, and 57.43% vs. 33.33%, both P〈0.05). Multivariable Logistic regression analysis indicated that ICM score was a better predictive parameter for clinical pregnancy (OR=3.05, CI 1.70-5.46, P〈0.001), while the trophectoderm score was a better one for early abortion (OR=0.074, CI 0.03-0.19, P〈0.001). Clinical pregnancy rate and multiple pregnancy rate in S-ICM B/TE B group were significantly lower than those in D-ICM B/TE B group (46.15% vs. 74.96%, and 2.38% vs. 48.62%, both P〈0.05), but there was no si~,,niflcant difference in the implantation rate between the two groups. It was suggested that the higher score of ICM and TE may be indicative of the better pregnancy outcomes. The ICM score is a better predictor of clinical pregnancy than TE, while TE score is a better one in predicting early abortion. Sin- gle ICM B/TE B blastocyst transfer in frozen-thawed cycles can also get satisfactory pregnancy out- comes.展开更多
Propagation properties of spatially pseudo-partially coherent Gaussian Schell-model beams through the atmo- spheric turbulence over a long-distance uplink path are studied by numerical simulation. A linear coordinatio...Propagation properties of spatially pseudo-partially coherent Gaussian Schell-model beams through the atmo- spheric turbulence over a long-distance uplink path are studied by numerical simulation. A linear coordination trans- formation is introduced to overcome the window effect and the loss-of-resolution problem. The beam spreading, beam wandering, and intensity scintillation as functions of turbulence strength, source correlation length, and change fre- quency of random phase that models the partial coherence of the source are analyzed. It is found that the beam spreading and the intensity scintillation of the partially coherent beam are less affected by the turbulence than those of the coherent one, but it suffers from a more severe diffractive effect, and the change frequency of random phase has no evident influence on it. The beam wandering is insensitive to the variation of source correlation length, and decreases firstly then goes to a fixed value as the change frequency increases.展开更多
in order to verify the heat-tolerance effect, two trainings, 90 min marching with load (WBGT 24. 6~35.6℃) and 10 km running (WBGT 25.0~31.1℃) were performed in laboratory and field under hot climate.Ten to twelve ...in order to verify the heat-tolerance effect, two trainings, 90 min marching with load (WBGT 24. 6~35.6℃) and 10 km running (WBGT 25.0~31.1℃) were performed in laboratory and field under hot climate.Ten to twelve times (days) of training were carried out展开更多
In the big data environment, enterprises must constantly assimilate big dataknowledge and private knowledge by multiple knowledge transfers to maintain theircompetitive advantage. The optimal time of knowledge transfe...In the big data environment, enterprises must constantly assimilate big dataknowledge and private knowledge by multiple knowledge transfers to maintain theircompetitive advantage. The optimal time of knowledge transfer is one of the mostimportant aspects to improve knowledge transfer efficiency. Based on the analysis of thecomplex characteristics of knowledge transfer in the big data environment, multipleknowledge transfers can be divided into two categories. One is the simultaneous transferof various types of knowledge, and the other one is multiple knowledge transfers atdifferent time points. Taking into consideration the influential factors, such as theknowledge type, knowledge structure, knowledge absorptive capacity, knowledge updaterate, discount rate, market share, profit contributions of each type of knowledge, transfercosts, product life cycle and so on, time optimization models of multiple knowledgetransfers in the big data environment are presented by maximizing the total discountedexpected profits (DEPs) of an enterprise. Some simulation experiments have beenperformed to verify the validity of the models, and the models can help enterprisesdetermine the optimal time of multiple knowledge transfer in the big data environment.展开更多
Seed long-distance dispersal(LDD) events are typically rare, but are important in the population processes that determine large-scale forest changes and the persistence of species in fragmented landscapes. However, pr...Seed long-distance dispersal(LDD) events are typically rare, but are important in the population processes that determine large-scale forest changes and the persistence of species in fragmented landscapes. However, previous studies focused on species dispersed via animal-mediated LDD, and ignored those dispersed by wind. The aim of this study was to assess the effects of canopy openness, edge, seed source, and patch tree density on the LDD of seeds by wind in forest. We collected birch seeds, a typical wind-dispersed species, throughout a larch plantation. We then assessed the relationship between birch LDD and each factor that may influence LDD of seeds by wind including distance to edge, canopy openness size, distance to mature forest, and the tree density of the larch plantation. We used univariate linear regression analysis to assess the influence of those factors on birch LDD, and partial correlations to calculate the contribution of each factor to LDD. The results showed that both canopy openness and edge had significant influences on birch LDD. Specifically, a negative relationship was observed between distance to edge and birch LDD, whereas there was a positive correlation between canopy openness size and LDD. In contrast, the distance to the mature forest was not correlated with birch LDD. Our results suggest that patch tree density could potently affect the probability of LDD by wind vectors, which provides novel and revealing insights regarding the effect of fragmentation on wind dynamics. The data also provide compelling evidence for the previously undocumented effect of habitat fragmentation on wind-dispersed organisms. As such, these observations will facilitate reasonable conservation planning, which requires a detailed understanding of the mechanisms by which patch properties hamper the delivery of seeds of wind-dispersed plants to fragmented areas.展开更多
Objective:To know whether sperm DNA fragmentation(SDF)affects the clinical outcomes in the cumulative transfers of an intracytoplasmic sperm injection(ICSI)cycle along with blastocyst transfers in couples with normozo...Objective:To know whether sperm DNA fragmentation(SDF)affects the clinical outcomes in the cumulative transfers of an intracytoplasmic sperm injection(ICSI)cycle along with blastocyst transfers in couples with normozoospermic males.Methods:The study included 252 couples who underwent their first ICSI cycles along with blastocyst transfer and whose male partner semen samples were normozoospermic according to the World Health Organization 2010 criteria.All the couples were classified into two groups based on the SDF:the low SDF group(SDF≤30%,n=162)and the high SDF group(SDF>30%,n=90).Clinical as well as laboratory outcomes were correlated between the two groups.Sperm DNA fragmentation was assessed on the post-wash semen samples by acridine orange test.The main outcome measures were the live birth rate and miscarriage rate.Results:A significant decrease in the live birth rates was observed in the high SDF group compared to the low SDF group in fresh embryo transfer cycles(P<0.05).However,no significant difference was observed in the clinical outcomes either in the frozen embryo transfer cycles or in the overall cumulative transfer cycles(P>0.05).No significant difference was observed in the laboratory outcomes between the two SDF groups.A remarkable decrease in sperm motility was observed in the high SDF group compared to the low SDF group(P<0.05).Conclusions:Sperm DNA fragmentation does not affect the clinical outcomes in the cumulative transfers of an ICSI cycle along with blastocyst transfers in couples with normozoospermic males.展开更多
According to the engineering investigation of long-distance oil and gas pipelines, the criterions and measures of route selection are drawn as follows: the flat landform is the first choice in route alignment. The fo...According to the engineering investigation of long-distance oil and gas pipelines, the criterions and measures of route selection are drawn as follows: the flat landform is the first choice in route alignment. The foot of mountain is the first choice when the route passes by the valley. The route should pass by but the shady and deposited slope and not in sunny and erosive slope as possible as it can. The pipeline should be vertical to contour climbing and descending the mountain except steep slope. Tunnel can be used in crossing foothill. Perpendicularly traversing the river is better than beveling; the worst choice is to put the pipeline along the river. Bypass is the best choice in karsts area. The order of route selection should be pre-choosing, investigation, optimization and adjustment.展开更多
基金supported by the Natural Science Research Project of Guangling College of Yangzhou University,China (ZKZD18004)General Program of Natural Science Research in Higher Education Institutions of Jiangsu Province,China (20KJD430006)。
文摘Gas flexible pipes are critical multi-layered equipment for offshore oil and gas development.Under high pressure conditions,small molecular components of natural gas dissolve into the polymer inner liner of the flexible pipes and further diffuse into the annular space,incurring annular pressure build-up and/or production of acidic environment,which poses serious challenges to the structure and integrity of the flexible pipes.Gas permeation in pipes is a complex phenomenon governed by various factors such as internal pressure and temperature,annular structure,external temperature.In a long-distance gas flexible pipe,moreover,gas permeation exhibits non-uniform features,and the gas permeated into the annular space flows along the metal gap.To assess the complex gas transport behavior in long-distance gas flexible pipes,a mathematical model is established in this paper considering the multiphase flow phenomena inside the flexible pipes,the diffusion of gas in the inner liner,and the gas seepage in the annular space under varying permeable properties of the annulus.In addition,the effect of a variable temperature is accounted.A numerical calculation method is accordingly constructed to solve the coupling mathematical equations.The annular permeability was shown to significantly influence the distribution of annular pressure.As permeability increases,the annular pressure tends to become more uniform,and the annular pressure at the wellhead rises more rapidly.After annular pressure relief followed by shut-in,the pressure increase follows a convex function.By simulating the pressure recovery pattern after pressure relief and comparing it with test results,we deduce that the annular permeability lies between 123 and 512 m D.The results help shed light upon assessing the annular pressure in long distance gas flexible pipes and thus ensure the security of gas transport in the emerging development of offshore resources.
基金supported by the 111 Project(Grant No.B17043)the 2115 Talent Development Program of China Agricultural University。
文摘Thousands of long-distance mobile mRNAs were identified from different grafting systems,based on high-throughput sequencing technology.Moreover,the long-distance delivery of RNAs was proved to involve multiple mechanisms.Here,we analyzed the homology,motif,and tRNA-like structure(TLS)of long-distance mobile mRNAs identified by RNA-seq as well as the RNA-binding protein(RBP)in nine grafting combinations including Arabidopsis thaliana,Vitis vinifera,Cucumis sativus,Citrullus lanatus,Nicotiana benthamiana,Malus domestica,Pyrus spp.,Glycine max and Phaseolus vulgaris.Although several mRNAs were found to be shared in herbaceous,woody,and related species,the vast majority of long-distance mobile mRNAs were species-specific.Four non-specific movement-related motifs were identified,while the TLS was not necessary for mRNA long distance mobility.In addition,we found that RBPs were conserved among herbaceous and woody plants as well as related species.This paper reports a further in-depth analysis of the endogenous mechanisms by which the species-specific transportable m RNAs were selected by bioinformatics,in order to provide insights for future research on long-distance mobile mRNAs.
基金Supported by the National Basic Research Program of China under Grant No 2013CB922002the National Natural Science Foundation of China under Grant No 11474347
文摘We report on the production of large sodium Bose^Einstein condensates in a hybrid of magnetic quadrupole and optical dipole trap. With an optimized spin-flip Zeeman slower, 2 ~ 1010 sodium atoms are captured in the magneto-optical trap (MOT). A long distance magnetic transfer setup moves the cold atom over 46cm from the MOT chamber to the UHV science chamber, which provides great optical access and long conservative trap lifetime. After evaporative cooling in the hybrid trap, we produce nearly pure condensates of 1 ~ 107 atoms with lifetime of 80 s in the optical dipole trap.
文摘BACKGROUND There is a substantial population of long-stay patients who non-emergently transfer directly from the neonatal intensive care unit(NICU)to the pediatric intensive care unit(PICU)without an interim discharge home.These infants are often medically complex and have higher mortality relative to NICU or PICUonly admissions.Given an absence of data surrounding practice patterns for nonemergent NICU to PICU transfers,we hypothesized that we would encounter a broad spectrum of current practices and a high proportion of dissatisfaction with current processes.AIM To characterize non-emergent NICU to PICU transfer practices across the United States and query PICU providers’evaluations of their effectiveness.METHODS A cross-sectional survey was drafted,piloted,and sent to one physician representative from each of 115 PICUs across the United States based on membership in the PARK-PICU research consortium and membership in the Children’s Hospital Association.The survey was administered via internet(REDCap).Analysis was performed using STATA,primarily consisting of descriptive statistics,though logistic regressions were run examining the relationship between specific transfer steps,hospital characteristics,and effectiveness of transfer.RESULTS One PICU attending from each of 81 institutions in the United States completed the survey(overall 70%response rate).Over half(52%)indicated their hospital transfers patients without using set clinical criteria,and only 33%indicated that their hospital has a standardized protocol to facilitate non-emergent transfer.Fewer than half of respondents reported that their institution’s nonemergent NICU to PICU transfer practices were effective for clinicians(47%)or patient families(38%).Respondents evaluated their centers’transfers as less effective when they lacked any transfer criteria(P=0.027)or set transfer protocols(P=0.007).Respondents overwhelmingly agreed that having set clinical criteria and standardized protocols for non-emergent transfer were important to the patient-family experience and patient safety.CONCLUSION Most hospitals lacked any clinical criteria or protocols for non-emergent NICU to PICU transfers.More positive perceptions of transfer effectiveness were found among those with set criteria and/or transfer protocols.
基金supported by the National Natural Science Foundation of China(Grant No.60978009)the National Basic Research Program of China(Grant Nos.2009CB929604 and 2007CB925204)
文摘We propose a scheme for long-distance quantum state transfer between different atoms based on cavity-assisted interactions. In our scheme, a coherent optical pulse sequentially interacts with two distant atoms trapped in separated cavities. Through the measurement of the state of the first atom and the homodyne detection of the final output coherent light, the quantum state can be transferred into the second atom with a success probability of unity and a fidelity of unity. In addition, our scheme neither requires the high-Q cavity working in the strong coupling regime nor employs the single-photon quantum channel, which greatly relaxes the experimental requirements.
文摘In radiology,magnetic resonance imaging(MRI)is an essential diagnostic tool that provides detailed images of a patient’s anatomical and physiological structures.MRI is particularly effective for detecting soft tissue anomalies.Traditionally,radiologists manually interpret these images,which can be labor-intensive and time-consuming due to the vast amount of data.To address this challenge,machine learning,and deep learning approaches can be utilized to improve the accuracy and efficiency of anomaly detection in MRI scans.This manuscript presents the use of the Deep AlexNet50 model for MRI classification with discriminative learning methods.There are three stages for learning;in the first stage,the whole dataset is used to learn the features.In the second stage,some layers of AlexNet50 are frozen with an augmented dataset,and in the third stage,AlexNet50 with an augmented dataset with the augmented dataset.This method used three publicly available MRI classification datasets:Harvard whole brain atlas(HWBA-dataset),the School of Biomedical Engineering of Southern Medical University(SMU-dataset),and The National Institute of Neuroscience and Hospitals brain MRI dataset(NINS-dataset)for analysis.Various hyperparameter optimizers like Adam,stochastic gradient descent(SGD),Root mean square propagation(RMS prop),Adamax,and AdamW have been used to compare the performance of the learning process.HWBA-dataset registers maximum classification performance.We evaluated the performance of the proposed classification model using several quantitative metrics,achieving an average accuracy of 98%.
基金Supported by the Central South University Innovation-Driven Research Programme,No.2023CXQD075。
文摘Transfer RNA(tRNA)-derived fragments,a new type of tRNA-derived small RNA(tsRNA),can be cleaved from tRNA by enzymes to regulate target gene expression at the transcriptional and translational levels.tsRNAs are not only degradation fragments but also have biological functions,including those in immune inflammation,metabolic disorders,and cell death.tsRNA dysregulation is closely associated with multiple diseases,including various cancers and acute pancreatitis(AP).AP is a common gastrointestinal disease,and its incidence increases annually.AP development is associated with tsRNAs,which regulate cell injury and induce inflammation,especially pyroptosis and ferroptosis.Notably,serum tRF36 has the potential to serve as a non-invasive diagnostic biomarker and leads to pancreatic acinar cell ferroptosis causing inflammation to promote AP.We show the characteristics of tsRNAs and their diagnostic value and function in AP,and discuss the potential opportunities and challenges of using tsRNAs in clinical applications and research.
文摘BACKGROUND Thumb replantation following complete traumatic avulsion requires complex techniques to restore function,especially in cases of avulsion at the level of the metacarpophalangeal joint(MCP I)and avulsion of the flexor pollicis longus(FPL)at the musculotendinous junction.Possible treatments include direct tendon suture or tendon transfer,most commonly from the ring finger.To optimize function and avoid donor finger complications,we performed thumb replantation with flexion restoration using brachioradialis(BR)tendon transfer with palmaris longus(PL)tendon graft.CASE SUMMARY A 20-year-old left-handed male was admitted for a complete traumatic left thumb amputation following an accident while sliding from the top of a handrail.The patient presented with skin and bone avulsion at the MCP I,avulsion of the FPL tendon at the musculotendinous junction(zone 5),avulsion of the extensor pollicis longus tendon(zone T3),and avulsion of the thumb’s collateral arteries and nerves.The patient was treated with two stage thumb repair.The first intervention consisted of thumb replantation with MCP I arthrodesis,resection of avulsed FPL tendon and implantation of a silicone tendon prosthesis.The second intervention consisted of PL tendon graft and BR tendon transfer.Follow-up at 10 months showed good outcomes with active interphalangeal flexion of 70°,grip strength of 45 kg,key pinch strength of 15 kg and two-point discrimination threshold of 4 mm.CONCLUSION Flexion restoration after complete thumb amputation with FPL avulsion at the musculotendinous junction can be achieved using BR tendon transfer with PL tendon graft.
基金Project(2016YFC0600709)supported by the National Key R&D Program of ChinaProject(51574013)supported by the National Natural Science Foundation of ChinaProject(FRF-TP-17-024A1)supported by the Fundamental Research Funds for the Central Universities,China
文摘Based on Bingham rheological model,a three-dimensional numerical simulation model for long-distance pipeline transportation is established by computational fluid dynamics(CFD)to study the pipeline transportationproperties of high sliming paste from a copper mine in China.Based on the rheological properties test,the pressure and velocity of pipeline and elbow are simulated by CFD under different mass concentrations and different stowing capacities.The results show that the pipeline resistance of whole-tailings paste with high sliming while without pumping agent is much higher than that with high sliming and pumping agent at the same mass concentration,and the pipeline resistance of whole-tailings paste with high sliming while without pumping agent is much higher than that with low sliming while without pumping agent.It is very important to add pumping agent to whole-tailings paste with high sliming,and the resistance changes with mass concentration and stowing capacity at the same cement-to-sand ratio of1:5and tailings-to-waste ratio of6:1.However,the change is just limited,that is to say,the paste transportation system is of good stability.Furthermore,at the elbow,the maximum pressure and velocity transfer to the outside of the pipe from the inside.However,lubricating layer is formed at the pipe wall because of high content of fine particles in whole-tailings paste,which will protect the elbow from abrasion.CFD provides an intuitive and accurate basis for pipeline transportation study,and would have a wider application space in the study of paste rheological properties and resistance reduction methods.
基金supported by the National Natural Science Foundation of China(Grants No.52179062 and 51879087).
文摘For a water supply system with long-distance diversion pipelines, in addition to the water hammer problems that occur beyond pumps, the safety of the water diversion pipeline in front of pumps also deserves attention. In this study, a water hammer protection scheme combined with an overflow surge tank and a regulating valve was developed. A mathematical model of the overflow surge tank was developed, and an analytical formula for the height of the overflow surge tank was derived. Furthermore, a practical water supply project was used to evaluate the feasibility of the combined protection scheme and analyze the sensitivity of valve regulation rules. The results showed that the combined protection scheme effectively reduced the height of the surge tank, lessened the difficulties related to construction, and reduced the necessary financial investment for the project. The two-stage closing rule articulated as fast first and then slow could minimize the overflow volume of the surge tank when the power failure occurred, while the two-stage opening rule articulated as slow first and then fast could be more conducive to the safety of the water supply system when the pump started up.
基金Hi-Tech Research and Development Program of China (863 Program)(2002AA601140)
文摘The extensively built long-distance water transmission pipelines have become the main water sources for urban areas. To ensure the reliability and safety of the water supply, from the viewpoint of overall management, it would be necessary to establish a system of information management for the pipeline. The monitoring, calculating and analyzing functions of the system serve to give controlling instructions and safe operating rules to the automatic equipment and technician, making sure the resistance coefficient distribution along the pipeline is reasonable; the hydraulic state transition is smooth when operating conditions change or water supply accidents occur, avoiding the damage of water hammer. This paper covered the composition structures of the information management system of long-distance water transmission pipelines and the functions of the subsystems, and finally elaborated on the approaches and steps of building a mathematics model for the analysis of dynamic hydraulic status.
文摘Resonant and nonresonant intermolecular vibrational energy transfers in Gdm- SCN/KSCN=1/1, GdmSCN/KS^13CN=1/1 and GdmSCN/KS^13C^15N=1/1 mixed crystals in melts and in aqueous solutions are studied with the two dimensional infrared spectroscopy. The energy transfers in the samples are slower with a larger energy donor/acceptor gap, independent of the Raman spectra. The energy gap dependences of the nonresonant energy transfers cannot be described by the phonon compensation mechanism. Instead, the experi- mental energy gap dependences can be quantitatively described by the dephasing mechanism. Temperature dependences of resonant and nonresonant energy transfer rates in the melts are also consistent with the prediction of the dephasing mechanism. The series of results suggest that the dephasing mechanism can be dominant not only in solutions, but also in melts (pure liquids without solvents), only if the molecular motions (translations and rotations) are much faster than the nonresonant energy transfer processes.
文摘The limited physical size for autonomous underwater vehicles (AUV) or unmanned underwater vehicles (UUV) makes it difficult to acquire enough space gain for localizing long-distance targets. A new technique about long-distance target apperception with passive synthetic aperture array for underwater vehicles is presented. First, a synthetic aperture-processing algorithm based on the FFT transform in the beam space (BSSAP) is introduced. Then, the study on the flank array passive long-distance apperception techniques in the frequency scope of 11-18 kHz is implemented from the view of improving array gains, detection probability and augmenting detected range under a certain sea environment. The results show that the BSSAP algorithm can extend the aperture effectively and improve detection probability. Because of the augment of the transmission loss, the detected range has the trend of decline with the increase of frequency under the same target source level. The synthesized array could improve the space gain by nearly 7 dB and SNR is increased by about 5 dB. The detected range is enhanced to nearly 2 km under the condition of 108-118 dB of the target source level for AUV system in measurement interval of nearly 1 s.
文摘The influence of inner cell mass (ICM) and trophectoderm (TE) score on pregnancy out- comes in frozen-thawed blastocyst transfer cycles was analyzed. A retrospective analysis of 741 cycles of frozen-thawed blastosysts transfer was performed. All cycles were divided into four groups based on the number and morphological score of blastocysts: S-ICM B/TE B group (n=91), the single blastocyst transfer oflCM B and TE B; D-ICM B/TE B group (n=579), double blastocysts transfer oflCM B/TE B; D-1CM B/TE C group (n=35), double blastocysts transfer of ICM B/TE C; and D-ICM C/TE B group (n=36), double blastocysts transfer ofTE B/ICM C. The pregnancy outcomes were compared among the four groups. As compared with D-ICM B/TE C group, the clinical pregnancy rate, implantation rate and multiple pregnancy rate were increased in D-ICM B/TE B group (74.96% vs. 57.14%, 57.43% vs. 37.14%, and .48.62% vs. 25%, respectively, P〈0.05 for all). Clinical pregnancy rate and implantation rate in D-ICM B/TE B group were also higher than in D-ICM C/TE B group (74.96% vs. 50%, and 57.43% vs. 33.33%, both P〈0.05). Multivariable Logistic regression analysis indicated that ICM score was a better predictive parameter for clinical pregnancy (OR=3.05, CI 1.70-5.46, P〈0.001), while the trophectoderm score was a better one for early abortion (OR=0.074, CI 0.03-0.19, P〈0.001). Clinical pregnancy rate and multiple pregnancy rate in S-ICM B/TE B group were significantly lower than those in D-ICM B/TE B group (46.15% vs. 74.96%, and 2.38% vs. 48.62%, both P〈0.05), but there was no si~,,niflcant difference in the implantation rate between the two groups. It was suggested that the higher score of ICM and TE may be indicative of the better pregnancy outcomes. The ICM score is a better predictor of clinical pregnancy than TE, while TE score is a better one in predicting early abortion. Sin- gle ICM B/TE B blastocyst transfer in frozen-thawed cycles can also get satisfactory pregnancy out- comes.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 61107066 and 40805006)
文摘Propagation properties of spatially pseudo-partially coherent Gaussian Schell-model beams through the atmo- spheric turbulence over a long-distance uplink path are studied by numerical simulation. A linear coordination trans- formation is introduced to overcome the window effect and the loss-of-resolution problem. The beam spreading, beam wandering, and intensity scintillation as functions of turbulence strength, source correlation length, and change fre- quency of random phase that models the partial coherence of the source are analyzed. It is found that the beam spreading and the intensity scintillation of the partially coherent beam are less affected by the turbulence than those of the coherent one, but it suffers from a more severe diffractive effect, and the change frequency of random phase has no evident influence on it. The beam wandering is insensitive to the variation of source correlation length, and decreases firstly then goes to a fixed value as the change frequency increases.
文摘in order to verify the heat-tolerance effect, two trainings, 90 min marching with load (WBGT 24. 6~35.6℃) and 10 km running (WBGT 25.0~31.1℃) were performed in laboratory and field under hot climate.Ten to twelve times (days) of training were carried out
基金supported by the National Natural Science Foundation ofChina (Grant No. 71704016,71331008, 71402010)the Natural Science Foundation of HunanProvince (Grant No. 2017JJ2267)+1 种基金the Educational Economy and Financial Research Base ofHunan Province (Grant No. 13JCJA2)the Project of China Scholarship Council forOverseas Studies (201508430121, 201208430233).
文摘In the big data environment, enterprises must constantly assimilate big dataknowledge and private knowledge by multiple knowledge transfers to maintain theircompetitive advantage. The optimal time of knowledge transfer is one of the mostimportant aspects to improve knowledge transfer efficiency. Based on the analysis of thecomplex characteristics of knowledge transfer in the big data environment, multipleknowledge transfers can be divided into two categories. One is the simultaneous transferof various types of knowledge, and the other one is multiple knowledge transfers atdifferent time points. Taking into consideration the influential factors, such as theknowledge type, knowledge structure, knowledge absorptive capacity, knowledge updaterate, discount rate, market share, profit contributions of each type of knowledge, transfercosts, product life cycle and so on, time optimization models of multiple knowledgetransfers in the big data environment are presented by maximizing the total discountedexpected profits (DEPs) of an enterprise. Some simulation experiments have beenperformed to verify the validity of the models, and the models can help enterprisesdetermine the optimal time of multiple knowledge transfer in the big data environment.
基金National Natural Science Foundation of China(No.31300526)National Key Technologies R&D Program of China(No.2012BAD22B04)Chinese Forest Ecosystem Research Network&GENE Award Funds on Ecological Paper
文摘Seed long-distance dispersal(LDD) events are typically rare, but are important in the population processes that determine large-scale forest changes and the persistence of species in fragmented landscapes. However, previous studies focused on species dispersed via animal-mediated LDD, and ignored those dispersed by wind. The aim of this study was to assess the effects of canopy openness, edge, seed source, and patch tree density on the LDD of seeds by wind in forest. We collected birch seeds, a typical wind-dispersed species, throughout a larch plantation. We then assessed the relationship between birch LDD and each factor that may influence LDD of seeds by wind including distance to edge, canopy openness size, distance to mature forest, and the tree density of the larch plantation. We used univariate linear regression analysis to assess the influence of those factors on birch LDD, and partial correlations to calculate the contribution of each factor to LDD. The results showed that both canopy openness and edge had significant influences on birch LDD. Specifically, a negative relationship was observed between distance to edge and birch LDD, whereas there was a positive correlation between canopy openness size and LDD. In contrast, the distance to the mature forest was not correlated with birch LDD. Our results suggest that patch tree density could potently affect the probability of LDD by wind vectors, which provides novel and revealing insights regarding the effect of fragmentation on wind dynamics. The data also provide compelling evidence for the previously undocumented effect of habitat fragmentation on wind-dispersed organisms. As such, these observations will facilitate reasonable conservation planning, which requires a detailed understanding of the mechanisms by which patch properties hamper the delivery of seeds of wind-dispersed plants to fragmented areas.
文摘Objective:To know whether sperm DNA fragmentation(SDF)affects the clinical outcomes in the cumulative transfers of an intracytoplasmic sperm injection(ICSI)cycle along with blastocyst transfers in couples with normozoospermic males.Methods:The study included 252 couples who underwent their first ICSI cycles along with blastocyst transfer and whose male partner semen samples were normozoospermic according to the World Health Organization 2010 criteria.All the couples were classified into two groups based on the SDF:the low SDF group(SDF≤30%,n=162)and the high SDF group(SDF>30%,n=90).Clinical as well as laboratory outcomes were correlated between the two groups.Sperm DNA fragmentation was assessed on the post-wash semen samples by acridine orange test.The main outcome measures were the live birth rate and miscarriage rate.Results:A significant decrease in the live birth rates was observed in the high SDF group compared to the low SDF group in fresh embryo transfer cycles(P<0.05).However,no significant difference was observed in the clinical outcomes either in the frozen embryo transfer cycles or in the overall cumulative transfer cycles(P>0.05).No significant difference was observed in the laboratory outcomes between the two SDF groups.A remarkable decrease in sperm motility was observed in the high SDF group compared to the low SDF group(P<0.05).Conclusions:Sperm DNA fragmentation does not affect the clinical outcomes in the cumulative transfers of an ICSI cycle along with blastocyst transfers in couples with normozoospermic males.
文摘According to the engineering investigation of long-distance oil and gas pipelines, the criterions and measures of route selection are drawn as follows: the flat landform is the first choice in route alignment. The foot of mountain is the first choice when the route passes by the valley. The route should pass by but the shady and deposited slope and not in sunny and erosive slope as possible as it can. The pipeline should be vertical to contour climbing and descending the mountain except steep slope. Tunnel can be used in crossing foothill. Perpendicularly traversing the river is better than beveling; the worst choice is to put the pipeline along the river. Bypass is the best choice in karsts area. The order of route selection should be pre-choosing, investigation, optimization and adjustment.