The deformation of sea coast or sandy deposits caused by earthquakes can lead to catastrophic damages to various port structures. The volumetric deformation is mainly induced by densification of sand during the dissip...The deformation of sea coast or sandy deposits caused by earthquakes can lead to catastrophic damages to various port structures. The volumetric deformation is mainly induced by densification of sand during the dissipation of excess pore water pressure created by cyclic loading. Based on laboratory test, the reconsolidation volumetric characteristics of saturated sea sand are investigated. The experiments are conducted with a newly developed multi functional triaxial test equipment. Two types of dynamic loads are applied to the samples to clarify different kinds of affecting factors. It is found that the reconsolidation volumetric strain is correlated not only to the excess pore water pressure and the maximum shear strain during the dynamic loading, but also to the effective confining pressure. A new formula is put forward to calculate the volumetric strain during reconssolidation.展开更多
Acute respiratory tract infection</span><span style="font-family:""><span style="font-family:Verdana;"> (ARTI) in children is the most common infectious disease in childhood,...Acute respiratory tract infection</span><span style="font-family:""><span style="font-family:Verdana;"> (ARTI) in children is the most common infectious disease in childhood, and its pathogens include viruses, bacteria and fungi, mycoplasma, chlamydia and rickettsia. In recent years, with the continuous development of pathogen detection methods, the diagnosis and treatment of acute respiratory infections has received more and more clinical attention. The clinical diagnosis and treatment characteristics of acute respira</span><span style="font-family:Verdana;">tory infections in children and the research of clinical laboratory detection </span><span style="font-family:Verdana;">methods have also been continuously developed. The author collected refer</span><span style="font-family:Verdana;">ences to review the clinical features and new developments in laboratory</span><span style="font-family:Verdana;"> testing of acute respiratory tract infection in children.展开更多
900 abusers were tested for the presence of drug abuse and coronavirus disease.In the early stage,the throat and noise samples of these patients were examined by polymerase chain reaction(PCR).The mean age of the stud...900 abusers were tested for the presence of drug abuse and coronavirus disease.In the early stage,the throat and noise samples of these patients were examined by polymerase chain reaction(PCR).The mean age of the study group is 42±23.Hematological and serological examinations were performed on 131 patients.All data were analyzed by t-test and one-way analysis of variance(ANOVA).Therefore,P<0.05 is considered as the significance of the test results.The results showed that 131 patients in the study group had positive results of PCR tests and nearby they had Covid-19.Approximately 90%of patients with coronavirus disease showed positive serological tests and lymphopenic condition.All of urine or blood samples in the 131 patients were positive for the presence of abuse drugs.C-reactive protein(CRP)is one of important serologic test that detected on these patients.This study showed the importance of molecular genetics test such as PCR and also hematology and serology tests in distinguish of coronavirus diseases.展开更多
Acute respiratory infection in children (ARTI) is the most common childhood infectious disease, and its pathogens include bacteria, fungi, viruses, chlamydia, mycoplasma and rickettsia. In recent years, with the conti...Acute respiratory infection in children (ARTI) is the most common childhood infectious disease, and its pathogens include bacteria, fungi, viruses, chlamydia, mycoplasma and rickettsia. In recent years, with the continuous development of pathogen detection methods, the diagnosis and treatment of acute respiratory infections has received more and more attention from clinicians. The clinical diagnosis and treatment of acute respiratory infections in children and the research of laboratory detection methods have also been continuously developed. The manuscript presents a review of progress in the clinical diagnosis, treatment and laboratory testing of acute respiratory infections in children by collecting references.展开更多
Objective:Perform a literary review of the interference in the results of biochemical laboratory tests caused by antihypertensive drugs.Methods:This is a review of the scientific literature with descriptive research p...Objective:Perform a literary review of the interference in the results of biochemical laboratory tests caused by antihypertensive drugs.Methods:This is a review of the scientific literature with descriptive research performed according to the PRISMA model using the databases PUBMED,SCIELO,MEDLINE,LILACS,and searches of Brazilian Ministry of Health and Federal Pharmacy Council publications,reagent kits and package inserts approved by ANVISA.Literature and papers in Portuguese and English were selected,prioritizing the years 2010 to 2020.Results:The diuretic class of antihypertensive drugs causes decreases glucose tolerance,thus resulting in an increase in triglycerides.In long-term use,the drug captopril can increase serum levels of potassium,creatine kinase and decreases blood sodium.Methyldopa causes an increase in AST levels.Propranolol is associated with an increase in triglyceride levels and a decrease in HDL and glucose levels.The constant use of losartan results in an increase in HDL,a decrease in uric acid levels and a slight and transient increase in transaminases.In the Gold Analisa,Bioclin and Labtest reagent kits,most of the alterations occur due to the increase in levels of serum biomarkers according to the class of the antihypertensive drug.Conclusions:Biochemical alterations in serum can result in false-positive or false-negative reports,since it can be observed that most of the dosages caused increases due to the physiological effect of the drugs.The antihypertensive drugs that showed the highest incidence of interference were captopril,atenolol,losartan and propranolol.展开更多
A complex Laboratory Developed Test(LDT)is a clinical test developed within a single laboratory.It is typically configured from many fea-ture constraints from clinical repositories,which are part of the existing Lab-o...A complex Laboratory Developed Test(LDT)is a clinical test developed within a single laboratory.It is typically configured from many fea-ture constraints from clinical repositories,which are part of the existing Lab-oratory Information Management System(LIMS).Although these clinical repositories are automated,support for managing patient information with test results of an LDT is also integrated within the existing LIMS.Still,the support to configure LDTs design needs to be made available even in standard LIMS packages.The manual configuration of LDTs is a complex process and can generate configuration inconsistencies because many constraints between features can remain unsatisfied.It is a risky process and can lead patients to undergo unnecessary treatments.We proposed an optimized solution(opt-LDT)based on Genetic Algorithms to automate the configuration and resolve the inconsistencies in LDTs.Opt-LDT encodes LDT configuration as an optimization problem and generates a consistent configuration that satisfies the constraints of the features.We tested and validated opt-LDT for a local secondary care hospital in a real healthcare environment.Our results,averaged over ten runs,show that opt-LDT resolves 90%of inconsistencies while taking between 6 and 6.5 s for each configuration.Moreover,positive feedback based on a subjective questionnaire from clinicians regarding the performance,acceptability,and efficiency of opt-LDT motivates us to present our results for regulatory approval.展开更多
In northeastern Sicily(Italy),sandstone rock masses widely crop out as cover deposits over crystalline terrains belonging to the orogenic belt.Despite being part of the same geological formation,these sandstones are c...In northeastern Sicily(Italy),sandstone rock masses widely crop out as cover deposits over crystalline terrains belonging to the orogenic belt.Despite being part of the same geological formation,these sandstones are characterized by highly different features in terms of texture and physico-mechanical properties.This poses a scientific question on the possibility of tracing these rocks to a single statistical model,which could be representative of their main engineering geological properties.Therefore,it is worth investigating on the possible reasons of such differences,that should be searched either in the current geographical sandstone distribution or in the rock texture.For this study,sandstone samples were collected from different sites and were analyzed at both the hand and thin section scales.Three sandstone types were recognized,characterized by a different texture.Then,the laboratory characterization allowed estimating their main physico-mechanical and ultrasonic properties,such as porosity,density,mechanical strength,deformability,and ultrasonic velocities.The rock mechanical strength proved linked to the rock compactness and to the presence of lithic fragments,while pores and a pseudo-matrix between grains represent weakening features.Rock data were also statistically analyzed by grouping the specimens according to a geographical criterion,with respect to their sampling area,but no link was found between location and rock properties.Finally,with the aim of achieving mathematical laws that could be used to predict some rock properties from others,useful for practical purposes when dealing with such a high property variability,single and multiple regression analyses were carried out.Results show that the Uniaxial Compressive Strength,porosity,and P-wave velocity are the best predictors for a quick,indirect estimation of the main physico-mechanical parameters.The methodological approach developed for this research can be taken as reference to study other worldwide cases,involving rocks characterized by a wide range of physico-mechanical properties and covering large regional territories.展开更多
The Norwegian Public Roads Administration(NPRA) is planning for an upgrade of the E39 highway route at the westcoast of Norway. Fixed links shall replace ferries at seven fjord crossings. Wide spans and large depths a...The Norwegian Public Roads Administration(NPRA) is planning for an upgrade of the E39 highway route at the westcoast of Norway. Fixed links shall replace ferries at seven fjord crossings. Wide spans and large depths at the crossings combined with challenging subsea topography and environmental loads call for an extension of existing practice. A variety of bridge concepts are evaluated in the feasibility study. The structures will experience significant loads from deadweight, traffic and environment. Anchoring of these forces is thus one of the challenges met in the project. Large-size subsea rock anchors are considered a viable alternative. These can be used for anchoring of floating structures but also with the purpose of increasing capacity of fixed structures. This paper presents first a thorough study of factors affecting rock anchor bond capacity. Laboratory testing of rock anchors subjected to cyclic loading is thereafter presented. Finally, the paper presents a model predicting the capacity of a rock anchor segment, in terms of a ribbed bar, subjected to a cyclic load history. The research assumes a failure mode occurring in the interface between the rock anchor and the surrounding grout. The constitutive behavior of the bonding interface is investigated for anchors subjected to cyclic one-way tensile loads. The model utilizes the static bond capacity curve as a basis, defining the ultimate bond sbuand the slip s1 at τ. A limited number of input parameters are required to apply the model. The model defines the bond-slip behavior with the belonging rock anchor capacity depending on the cyclic load level(τcy/τ), the cyclic load ratio(R= τcy/τcy), and the number of load cycles(N). The constitutive model is intended to model short anchor lengths representing an incremental length of a complete rock anchor.展开更多
Rock avalanches are generally difficult to prevent and control due to their high velocities and the extensive destruction they cause.However,barrier structures constructed along the path of a rock avalanche can partia...Rock avalanches are generally difficult to prevent and control due to their high velocities and the extensive destruction they cause.However,barrier structures constructed along the path of a rock avalanche can partially mitigate the magnitudes and consequences of such catastrophic events.We selected a rock avalanche in Nayong County,Guizhou Province,China as a case to study the effect of the location and height of a retaining wall on the dynamic characteristics of rock avalanche by using both actual terrain-based laboratory-model tests and coupled PFC3D-FLAC3D numerical simulations.Our findings demonstrate that a retaining wall can largely block a rock avalanche and its protective efficacy is significantly influenced by the integrity of the retaining wall.Coupled numerical simulation can serve as a powerful tool for analyzing the interaction between a rock avalanche and a retaining wall,facilitating precise observations of its deformation and destruction.The impact-curve characteristics of the retaining wall depend upon whether or not the rock avalanche-induced destruction is taken into account.The location of the retaining wall exerts a greater influence on the outcome compared to the height and materials of the retaining wall,while implementing a stepped retaining-wall pattern in accordance with the terrain demonstrates optimal efficacy in controlling rock avalanche.展开更多
Recently a research team at Ohio University,USA,conducted a unique full-scale feld load test to simulate the aeration pipe installations at a copper extraction mine operated in Chile.The overliner material taken from ...Recently a research team at Ohio University,USA,conducted a unique full-scale feld load test to simulate the aeration pipe installations at a copper extraction mine operated in Chile.The overliner material taken from the mine was used in recreating the in situ conditions.Electric heaters were utilized to raise the temperature inside each pipe to simulate the essential element of the copper extraction process.The maximum vertical deflection reached by the test pipes was close to 20%,when the simulated heap pile height was 80 m.The plastic pipes and the overliner material were also tested in the laboratory.Based on the results,the maximum heap pile fll depth was recommended for the aeration system.The results indicated that the vertical deflection was the primary performance index for the aeration pipes installed in heap piles at mines.Lastly,the pipe made of polypropylene resin was super.展开更多
When the pore pressure in a porous rock changes, stress arching will occur within the rock and the surrounding region. Stress arching ratio is defined as the total stress changes in the porous rock to the pore pressur...When the pore pressure in a porous rock changes, stress arching will occur within the rock and the surrounding region. Stress arching ratio is defined as the total stress changes in the porous rock to the pore pressure change in the region. The region may have the same or different elastic moduli with the surrounding rock, which is usually referred to as inclusion or inhomogeneity. Stress arching is responsible for many geomechanical problems encountered during production or injection; in addition, it is a crucial parameter in stress estimation during field development. This paper aims to present laboratory measurements of vertical stress arching ratio in a material surrounding the inclusion(inhomogeneity).To the authors’ knowledge, few laboratory experiments have been reported on direct measurement of stress arching. The inclusion is a cylindrical sandstone(44 mm in diameter and 50 mm in height)embedded in a larger cylindrical sandstone(150 mm in diameter and 154 mm in height), both of which are made synthetically. These two parts are separated and sealed by a internal polyurethane sleeve.Vertical stress changes are recorded by a mini hydraulic sensor embedded in surrounding rock. Laboratory results are compared to those obtained by numerical models. These models are checked with analytical formulations. The results of numerical models show a good agreement with laboratory data.The numerical results also indicate that the sensor response is affected by elastic properties of the internal sleeve. According to the sensitivity analysis performed, in the absence of the internal sleeve,properties of the inclusion have significant effects on the surrounding stress arching induced.展开更多
Objective:To summarize the follow-up results of laboratory examination,echocardiographic and chest CT of patients with COVID-19 at the time of 2 years after discharge in Chengdu.Methods:A total of 29 COVID-19 survivor...Objective:To summarize the follow-up results of laboratory examination,echocardiographic and chest CT of patients with COVID-19 at the time of 2 years after discharge in Chengdu.Methods:A total of 29 COVID-19 survivors who have participated in the 1-year follow-up and 2-year follow-up at Public Health Clinical Center of Chengdu were included in our study.Their blood laboratory tests,echocardiography and chest CT results were analyzed in order to evaluate the long-term recovery of COVID-19 survivors.Results:The most common abnormal laboratory test results at the 2-year follow-up were increased serum fibronectin(21 cases,72.4%)and decreased NK cell counts(19 cases,65.5%).Compared with laboratory test results at the 1-year follow-up,platelet count,hydroxybutyrate dehydrogenase and creatine kinase isoenzyme were decreased(all P<0.05),while serum fibrinogen,triglyceride,insulin and non-specific immunoglobulin A were increased(all P<0.05).Serum specific total SARS-CoV-2 antibody amount in COVID-19 survivors at half a year after COVID-19 vaccine was significantly higher than that before vaccination.More than half of patients(55.2%)had normal echocardiography results at the 2-year follow-up,the main abnormal results of them were valve regurgitation(7 cases,24.1%)and reduced left ventricular diastolic function(9 cases,31.0%).Compared with 1-year follow-up,7 patients had fewer abnormal cardiac ultrasound results.28 cases underwent chest CT at the 2-year follow-up,the mainly abnormal results were ground glass shadow(17.9%),pulmonary nodules(diameter<6mm)(32.1%)and scattered cable shadow(39.3%).71.4%(20/28)of them had no significant change between the two chest CT results.Conclusion:The mainly abnormal blood laboratory indicators in COVID-19 survivors at 2-year follow-up after discharge were increased serum fibronectin and decreased NK cell counts.Although echocardiography and chest CT results were no significant change between 1-year follow-up and 2-year follow-up among COVID-19 survivors,there were still some patients whose abnormal results were decreasing.Serum specific total SARS-CoV-2 antibody amount in COVID-19 survivors at half a year after COVID-19 vaccine was still significantly higher than that before vaccination,but the amount of specific antibody had a downward trend with time.展开更多
It is essential to assess the evolution of soil fabric as it has an important role in the mechanical responses of soils during complex loading conditions.This contribution carries out the physical experiments using th...It is essential to assess the evolution of soil fabric as it has an important role in the mechanical responses of soils during complex loading conditions.This contribution carries out the physical experiments using three granular materials in the laboratory.The variations of compression and shear wave velocities(Vp and Vs)are investigated during load-unload cycles under dry and drained conditions.Supplementary discrete element method(DEM)simulations are performed to understand the evolution of soil fabric during the equivalent load-unload cycles using spherical particles.Vp and Vs are not always reversible even though the stress state regains its isotropic condition after unload,indicating that Vp and Vs are governed by not only the stress state but also the fabric change.The variations of Vp/Vs are density-and stress-dependent;a higher level of stress ratio(s01/s03)threshold is observed for denser packings to trigger a significant change in wave velocity ratio(Vp/Vs)for experimental results using spherical glass beads and simulation data using spherical particles.Considering the particle shape,a higher s01/s03 threshold is found for more angular particles than rounded particles.The DEM result reveals that Vp/Vs of spherical particles can be correlated linearly with the evolution of fabric ratio(Fver/Fhor)during loadunload in a pre-peak range under dry and drained conditions.展开更多
The objective of this study was to evaluate and recommend an asphalt mixture design with emerging additive technologies that would provide superior performance against asphalt concrete(AC)stripping and cracking.To ach...The objective of this study was to evaluate and recommend an asphalt mixture design with emerging additive technologies that would provide superior performance against asphalt concrete(AC)stripping and cracking.To achieve this objective,a laboratory test program was developed to evaluate the use of nanomaterials(nanoclay and graphene nanoplatelet),an emerging anti-stripping agent(adhere),and warm-mix asphalt technologies(ZycoTherm,Sasobit,and EvoTherm).Two mix types were evaluated,which were a stone-matrix asphalt(SMA)and a dense-graded binder mix.In addition,the modified Lottman test(AASHTO T 283)and the indirect tensile asphalt cracking test(IDEAL-CT)test were used as performance indicators of moisture damage resistance and cracking susceptibility.Results were analyzed statistically to identify and quantify the effects of the design variables and selected additives on the performance,moisture damage resistance,and durability of asphalt mixes.Based on the cracking test results,a superior cracking resistance performance was observed with ZycoTherm,irrespective of the mix type.Adhere had the lowest average cracking indices for both mix types,which suggest that it would not perform as well as the other additives in terms of cracking resistance.Overall,SMA mixes displayed greater cracking resistance than the dense-graded mixtures,which may have been the result of the reclaimed asphalt pavement(RAP)material used in the dense-graded mix and its lower asphalt binder content.In terms of moisture resistance,both nanomaterials(graphene nanoplatelet and nanoclay)did not perform well as they did not meet the minimum required tensile strength ratio(TSR)criterion(>0.80).In addition,nanomaterials showed the lowest TSR values in both mix types suggesting that their effectiveness against moisture-induced damage may not be as good as warm-mix additives.On the other hand,warm-mix additives were expected to show enhanced performance in terms of moisture resistance as compared to the other additives evaluated in this study.展开更多
This paper presents the results of laboratory test on the feasibility of soil conditioning for earth pressurebalance (EPB) excavation in a tar sand, which is a natural material never studied in this respect. Thelabo...This paper presents the results of laboratory test on the feasibility of soil conditioning for earth pressurebalance (EPB) excavation in a tar sand, which is a natural material never studied in this respect. Thelaboratory test performed is based on a procedure and methods used in previous studies with differenttypes of soils, but for this special complex material, additional tests are also conducted to verify particularproperties of the tar sands, such as the tilt test and vane shear test usually used in cohesive materials, anda direct shear test. The laboratory test proves that the test procedure is applicable also to this type of soiland the conditioned material can be considered suitable for EPB excavations, although it is necessary touse a certain percentage of fine elements (filler) to create a material suitable to be mixed with foam. Thetest results show that the conditioned material fulfils the required standard for an EPB application.展开更多
This study aims to examine the influence of pre-existing discontinuities on the strengths of four natural rocks of different origins.A series of unconfined compression tests was performed on specimens of two types of ...This study aims to examine the influence of pre-existing discontinuities on the strengths of four natural rocks of different origins.A series of unconfined compression tests was performed on specimens of two types of sandstones,argillite and basalt that contain open and filled cracks.It was found that the presence of cracks tends to decrease the overall strength for all studied rocks;however,the magnitude of strength reduction is related to the property of rock.The larger strength decrease was observed for the relatively harder argillite and basalt,compared to the softer sandstone.It was also found that the infill material could increase the strength of rock specimens,while the obtained strength depended on the characteristics of the fill material.展开更多
Nylon cord rubber has the advantages of small residual deformation and is easy to lift and lower the tubing string in low-permeability oil and gas reservoirs.However,it is associated with low-pressure resistance and p...Nylon cord rubber has the advantages of small residual deformation and is easy to lift and lower the tubing string in low-permeability oil and gas reservoirs.However,it is associated with low-pressure resistance and poor sealing performance.To enhance the performance of nylon cord rubber,a three-dimensional numerical model of the nylon cord rubber was established and its accuracy experimentally determined.The Plackett-Burman test,the Steepest climbing test and the Response surface method were used to acquire the polynomial response surface model connecting structural parameters with bearing and sealing pressure.Using genetic algorithms,optimal structural parameters of nylon cord rubber were determined depending on field operation.The reliability of the optimized results was verified by laboratory tests.It was shown that after optimization,the bearing capacity of the expandable packer increased by 25%while the sealing performance increased by 66%.In addition,the bearing pressure was 70 MPa while the sealing pressure was 50 MPa.These measurements effectively met the on-site requirements of high-pressure and fine fracturing in low-permeability oil and gas reservoirs.展开更多
The current researches of wheel vibration and sound radiation mainly focus on the low noise damped wheel. Compared with the traditional research, the relationship between the sound and wheel/rail contact is difficulty...The current researches of wheel vibration and sound radiation mainly focus on the low noise damped wheel. Compared with the traditional research, the relationship between the sound and wheel/rail contact is difficulty and worth studying. However, there are few studies on the effect of wheel load on wheel vibration and sound radiation. In this paper, laboratory test carried out in a semi-anechoic room investigates the effect of wheel load on wheel natural frequencies, damping ratios, wheel vibration and its sound radiation, The laboratory test results show that the vibration of the wheel and total sound radiation decrease significantly with the increase of the wheel load from 0 t to 1 t. The sound energy level of the wheel decreases by 3.7 dB. When the wheel load exceeds 1 t. the attenuation trend of the vibration and sound radiation of the wheel becomes slow. And the increase of the wheel load causes the growth of the wheel natural frequencies and the mode damping ratios. Based on the finite element method (FEM) and boundary element method (BEM), a rolling noise prediction model is developed to calculate the influence of wheel load on the wheel vibration and sound radiation. In the calculation, the used wheel/rail excitation is the measured wheel/rail roughness. The calculated results show that the sound power level of the wheel decreases by about 0.4 dB when the wheel load increases by 0.5 t. The sound radiation of the wheel decreases slowly with wheel load increase, and this conclusion is verified by the field test. This research systematically studies the cffcct of wheel load on wheel vibration and sound radiation, gives the relationship between the sound and wheel/rail contact and analyzes the reasons, therefore, it provides a reference for further research.展开更多
Objective: Hepatocellular carcinoma(HCC) development among hepatitis B surface antigen(HBs Ag) carriers shows gender disparity, influenced by underlying liver diseases that display variations in laboratory tests. We a...Objective: Hepatocellular carcinoma(HCC) development among hepatitis B surface antigen(HBs Ag) carriers shows gender disparity, influenced by underlying liver diseases that display variations in laboratory tests. We aimed to construct a risk-stratified HCC prediction model for HBs Ag-positive male adults.Methods: HBs Ag-positive males of 35-69 years old(N=6,153) were included from a multi-center populationbased liver cancer screening study. Randomly, three centers were set as training, the other three centers as validation. Within 2 years since initiation, we administrated at least two rounds of HCC screening using Bultrasonography and α-fetoprotein(AFP). We used logistic regression models to determine potential risk factors,built and examined the operating characteristics of a point-based algorithm for HCC risk prediction.Results: With 2 years of follow-up, 302 HCC cases were diagnosed. A male-ABCD algorithm was constructed including participant's age, blood levels of GGT(γ-glutamyl-transpeptidase), counts of platelets, white cells,concentration of DCP(des-γ-carboxy-prothrombin) and AFP, with scores ranging from 0 to 18.3. The area under receiver operating characteristic was 0.91(0.90-0.93), larger than existing models. At 1.5 points of risk score,26.10% of the participants in training cohort and 14.94% in validation cohort were recognized at low risk, with sensitivity of identifying HCC remained 100%. At 2.5 points, 46.51% of the participants in training cohort and 33.68% in validation cohort were recognized at low risk with 99.06% and 97.78% of sensitivity, respectively. At 4.5 points, only 20.86% of participants in training cohort and 23.73% in validation cohort were recognized at high risk,with positive prediction value of 22.85% and 12.35%, respectively.Conclusions: Male-ABCD algorithm identified individual's risk for HCC occurrence within short term for their HCC precision surveillance.展开更多
文摘The deformation of sea coast or sandy deposits caused by earthquakes can lead to catastrophic damages to various port structures. The volumetric deformation is mainly induced by densification of sand during the dissipation of excess pore water pressure created by cyclic loading. Based on laboratory test, the reconsolidation volumetric characteristics of saturated sea sand are investigated. The experiments are conducted with a newly developed multi functional triaxial test equipment. Two types of dynamic loads are applied to the samples to clarify different kinds of affecting factors. It is found that the reconsolidation volumetric strain is correlated not only to the excess pore water pressure and the maximum shear strain during the dynamic loading, but also to the effective confining pressure. A new formula is put forward to calculate the volumetric strain during reconssolidation.
文摘Acute respiratory tract infection</span><span style="font-family:""><span style="font-family:Verdana;"> (ARTI) in children is the most common infectious disease in childhood, and its pathogens include viruses, bacteria and fungi, mycoplasma, chlamydia and rickettsia. In recent years, with the continuous development of pathogen detection methods, the diagnosis and treatment of acute respiratory infections has received more and more clinical attention. The clinical diagnosis and treatment characteristics of acute respira</span><span style="font-family:Verdana;">tory infections in children and the research of clinical laboratory detection </span><span style="font-family:Verdana;">methods have also been continuously developed. The author collected refer</span><span style="font-family:Verdana;">ences to review the clinical features and new developments in laboratory</span><span style="font-family:Verdana;"> testing of acute respiratory tract infection in children.
文摘900 abusers were tested for the presence of drug abuse and coronavirus disease.In the early stage,the throat and noise samples of these patients were examined by polymerase chain reaction(PCR).The mean age of the study group is 42±23.Hematological and serological examinations were performed on 131 patients.All data were analyzed by t-test and one-way analysis of variance(ANOVA).Therefore,P<0.05 is considered as the significance of the test results.The results showed that 131 patients in the study group had positive results of PCR tests and nearby they had Covid-19.Approximately 90%of patients with coronavirus disease showed positive serological tests and lymphopenic condition.All of urine or blood samples in the 131 patients were positive for the presence of abuse drugs.C-reactive protein(CRP)is one of important serologic test that detected on these patients.This study showed the importance of molecular genetics test such as PCR and also hematology and serology tests in distinguish of coronavirus diseases.
文摘Acute respiratory infection in children (ARTI) is the most common childhood infectious disease, and its pathogens include bacteria, fungi, viruses, chlamydia, mycoplasma and rickettsia. In recent years, with the continuous development of pathogen detection methods, the diagnosis and treatment of acute respiratory infections has received more and more attention from clinicians. The clinical diagnosis and treatment of acute respiratory infections in children and the research of laboratory detection methods have also been continuously developed. The manuscript presents a review of progress in the clinical diagnosis, treatment and laboratory testing of acute respiratory infections in children by collecting references.
文摘Objective:Perform a literary review of the interference in the results of biochemical laboratory tests caused by antihypertensive drugs.Methods:This is a review of the scientific literature with descriptive research performed according to the PRISMA model using the databases PUBMED,SCIELO,MEDLINE,LILACS,and searches of Brazilian Ministry of Health and Federal Pharmacy Council publications,reagent kits and package inserts approved by ANVISA.Literature and papers in Portuguese and English were selected,prioritizing the years 2010 to 2020.Results:The diuretic class of antihypertensive drugs causes decreases glucose tolerance,thus resulting in an increase in triglycerides.In long-term use,the drug captopril can increase serum levels of potassium,creatine kinase and decreases blood sodium.Methyldopa causes an increase in AST levels.Propranolol is associated with an increase in triglyceride levels and a decrease in HDL and glucose levels.The constant use of losartan results in an increase in HDL,a decrease in uric acid levels and a slight and transient increase in transaminases.In the Gold Analisa,Bioclin and Labtest reagent kits,most of the alterations occur due to the increase in levels of serum biomarkers according to the class of the antihypertensive drug.Conclusions:Biochemical alterations in serum can result in false-positive or false-negative reports,since it can be observed that most of the dosages caused increases due to the physiological effect of the drugs.The antihypertensive drugs that showed the highest incidence of interference were captopril,atenolol,losartan and propranolol.
文摘A complex Laboratory Developed Test(LDT)is a clinical test developed within a single laboratory.It is typically configured from many fea-ture constraints from clinical repositories,which are part of the existing Lab-oratory Information Management System(LIMS).Although these clinical repositories are automated,support for managing patient information with test results of an LDT is also integrated within the existing LIMS.Still,the support to configure LDTs design needs to be made available even in standard LIMS packages.The manual configuration of LDTs is a complex process and can generate configuration inconsistencies because many constraints between features can remain unsatisfied.It is a risky process and can lead patients to undergo unnecessary treatments.We proposed an optimized solution(opt-LDT)based on Genetic Algorithms to automate the configuration and resolve the inconsistencies in LDTs.Opt-LDT encodes LDT configuration as an optimization problem and generates a consistent configuration that satisfies the constraints of the features.We tested and validated opt-LDT for a local secondary care hospital in a real healthcare environment.Our results,averaged over ten runs,show that opt-LDT resolves 90%of inconsistencies while taking between 6 and 6.5 s for each configuration.Moreover,positive feedback based on a subjective questionnaire from clinicians regarding the performance,acceptability,and efficiency of opt-LDT motivates us to present our results for regulatory approval.
文摘In northeastern Sicily(Italy),sandstone rock masses widely crop out as cover deposits over crystalline terrains belonging to the orogenic belt.Despite being part of the same geological formation,these sandstones are characterized by highly different features in terms of texture and physico-mechanical properties.This poses a scientific question on the possibility of tracing these rocks to a single statistical model,which could be representative of their main engineering geological properties.Therefore,it is worth investigating on the possible reasons of such differences,that should be searched either in the current geographical sandstone distribution or in the rock texture.For this study,sandstone samples were collected from different sites and were analyzed at both the hand and thin section scales.Three sandstone types were recognized,characterized by a different texture.Then,the laboratory characterization allowed estimating their main physico-mechanical and ultrasonic properties,such as porosity,density,mechanical strength,deformability,and ultrasonic velocities.The rock mechanical strength proved linked to the rock compactness and to the presence of lithic fragments,while pores and a pseudo-matrix between grains represent weakening features.Rock data were also statistically analyzed by grouping the specimens according to a geographical criterion,with respect to their sampling area,but no link was found between location and rock properties.Finally,with the aim of achieving mathematical laws that could be used to predict some rock properties from others,useful for practical purposes when dealing with such a high property variability,single and multiple regression analyses were carried out.Results show that the Uniaxial Compressive Strength,porosity,and P-wave velocity are the best predictors for a quick,indirect estimation of the main physico-mechanical parameters.The methodological approach developed for this research can be taken as reference to study other worldwide cases,involving rocks characterized by a wide range of physico-mechanical properties and covering large regional territories.
基金sponsored by the Norwegian Public Roads Administration(NPRA)
文摘The Norwegian Public Roads Administration(NPRA) is planning for an upgrade of the E39 highway route at the westcoast of Norway. Fixed links shall replace ferries at seven fjord crossings. Wide spans and large depths at the crossings combined with challenging subsea topography and environmental loads call for an extension of existing practice. A variety of bridge concepts are evaluated in the feasibility study. The structures will experience significant loads from deadweight, traffic and environment. Anchoring of these forces is thus one of the challenges met in the project. Large-size subsea rock anchors are considered a viable alternative. These can be used for anchoring of floating structures but also with the purpose of increasing capacity of fixed structures. This paper presents first a thorough study of factors affecting rock anchor bond capacity. Laboratory testing of rock anchors subjected to cyclic loading is thereafter presented. Finally, the paper presents a model predicting the capacity of a rock anchor segment, in terms of a ribbed bar, subjected to a cyclic load history. The research assumes a failure mode occurring in the interface between the rock anchor and the surrounding grout. The constitutive behavior of the bonding interface is investigated for anchors subjected to cyclic one-way tensile loads. The model utilizes the static bond capacity curve as a basis, defining the ultimate bond sbuand the slip s1 at τ. A limited number of input parameters are required to apply the model. The model defines the bond-slip behavior with the belonging rock anchor capacity depending on the cyclic load level(τcy/τ), the cyclic load ratio(R= τcy/τcy), and the number of load cycles(N). The constitutive model is intended to model short anchor lengths representing an incremental length of a complete rock anchor.
基金Hunan Provincial key Laboratory of key Technology on Hydropower Development Open Research Fund (PKLHD202203)
文摘Rock avalanches are generally difficult to prevent and control due to their high velocities and the extensive destruction they cause.However,barrier structures constructed along the path of a rock avalanche can partially mitigate the magnitudes and consequences of such catastrophic events.We selected a rock avalanche in Nayong County,Guizhou Province,China as a case to study the effect of the location and height of a retaining wall on the dynamic characteristics of rock avalanche by using both actual terrain-based laboratory-model tests and coupled PFC3D-FLAC3D numerical simulations.Our findings demonstrate that a retaining wall can largely block a rock avalanche and its protective efficacy is significantly influenced by the integrity of the retaining wall.Coupled numerical simulation can serve as a powerful tool for analyzing the interaction between a rock avalanche and a retaining wall,facilitating precise observations of its deformation and destruction.The impact-curve characteristics of the retaining wall depend upon whether or not the rock avalanche-induced destruction is taken into account.The location of the retaining wall exerts a greater influence on the outcome compared to the height and materials of the retaining wall,while implementing a stepped retaining-wall pattern in accordance with the terrain demonstrates optimal efficacy in controlling rock avalanche.
文摘Recently a research team at Ohio University,USA,conducted a unique full-scale feld load test to simulate the aeration pipe installations at a copper extraction mine operated in Chile.The overliner material taken from the mine was used in recreating the in situ conditions.Electric heaters were utilized to raise the temperature inside each pipe to simulate the essential element of the copper extraction process.The maximum vertical deflection reached by the test pipes was close to 20%,when the simulated heap pile height was 80 m.The plastic pipes and the overliner material were also tested in the laboratory.Based on the results,the maximum heap pile fll depth was recommended for the aeration system.The results indicated that the vertical deflection was the primary performance index for the aeration pipes installed in heap piles at mines.Lastly,the pipe made of polypropylene resin was super.
文摘When the pore pressure in a porous rock changes, stress arching will occur within the rock and the surrounding region. Stress arching ratio is defined as the total stress changes in the porous rock to the pore pressure change in the region. The region may have the same or different elastic moduli with the surrounding rock, which is usually referred to as inclusion or inhomogeneity. Stress arching is responsible for many geomechanical problems encountered during production or injection; in addition, it is a crucial parameter in stress estimation during field development. This paper aims to present laboratory measurements of vertical stress arching ratio in a material surrounding the inclusion(inhomogeneity).To the authors’ knowledge, few laboratory experiments have been reported on direct measurement of stress arching. The inclusion is a cylindrical sandstone(44 mm in diameter and 50 mm in height)embedded in a larger cylindrical sandstone(150 mm in diameter and 154 mm in height), both of which are made synthetically. These two parts are separated and sealed by a internal polyurethane sleeve.Vertical stress changes are recorded by a mini hydraulic sensor embedded in surrounding rock. Laboratory results are compared to those obtained by numerical models. These models are checked with analytical formulations. The results of numerical models show a good agreement with laboratory data.The numerical results also indicate that the sensor response is affected by elastic properties of the internal sleeve. According to the sensitivity analysis performed, in the absence of the internal sleeve,properties of the inclusion have significant effects on the surrounding stress arching induced.
基金Chengdu Municipal High-level Clinical Key Specialty Construction Project-Infectious Diseases Special ProjectChengdu Municipal Health Commission Project(No.2021250):Chengdu Municipal Science and Technology Bureau Project(No.2021-YF05-00536-SN)。
文摘Objective:To summarize the follow-up results of laboratory examination,echocardiographic and chest CT of patients with COVID-19 at the time of 2 years after discharge in Chengdu.Methods:A total of 29 COVID-19 survivors who have participated in the 1-year follow-up and 2-year follow-up at Public Health Clinical Center of Chengdu were included in our study.Their blood laboratory tests,echocardiography and chest CT results were analyzed in order to evaluate the long-term recovery of COVID-19 survivors.Results:The most common abnormal laboratory test results at the 2-year follow-up were increased serum fibronectin(21 cases,72.4%)and decreased NK cell counts(19 cases,65.5%).Compared with laboratory test results at the 1-year follow-up,platelet count,hydroxybutyrate dehydrogenase and creatine kinase isoenzyme were decreased(all P<0.05),while serum fibrinogen,triglyceride,insulin and non-specific immunoglobulin A were increased(all P<0.05).Serum specific total SARS-CoV-2 antibody amount in COVID-19 survivors at half a year after COVID-19 vaccine was significantly higher than that before vaccination.More than half of patients(55.2%)had normal echocardiography results at the 2-year follow-up,the main abnormal results of them were valve regurgitation(7 cases,24.1%)and reduced left ventricular diastolic function(9 cases,31.0%).Compared with 1-year follow-up,7 patients had fewer abnormal cardiac ultrasound results.28 cases underwent chest CT at the 2-year follow-up,the mainly abnormal results were ground glass shadow(17.9%),pulmonary nodules(diameter<6mm)(32.1%)and scattered cable shadow(39.3%).71.4%(20/28)of them had no significant change between the two chest CT results.Conclusion:The mainly abnormal blood laboratory indicators in COVID-19 survivors at 2-year follow-up after discharge were increased serum fibronectin and decreased NK cell counts.Although echocardiography and chest CT results were no significant change between 1-year follow-up and 2-year follow-up among COVID-19 survivors,there were still some patients whose abnormal results were decreasing.Serum specific total SARS-CoV-2 antibody amount in COVID-19 survivors at half a year after COVID-19 vaccine was still significantly higher than that before vaccination,but the amount of specific antibody had a downward trend with time.
文摘It is essential to assess the evolution of soil fabric as it has an important role in the mechanical responses of soils during complex loading conditions.This contribution carries out the physical experiments using three granular materials in the laboratory.The variations of compression and shear wave velocities(Vp and Vs)are investigated during load-unload cycles under dry and drained conditions.Supplementary discrete element method(DEM)simulations are performed to understand the evolution of soil fabric during the equivalent load-unload cycles using spherical particles.Vp and Vs are not always reversible even though the stress state regains its isotropic condition after unload,indicating that Vp and Vs are governed by not only the stress state but also the fabric change.The variations of Vp/Vs are density-and stress-dependent;a higher level of stress ratio(s01/s03)threshold is observed for denser packings to trigger a significant change in wave velocity ratio(Vp/Vs)for experimental results using spherical glass beads and simulation data using spherical particles.Considering the particle shape,a higher s01/s03 threshold is found for more angular particles than rounded particles.The DEM result reveals that Vp/Vs of spherical particles can be correlated linearly with the evolution of fabric ratio(Fver/Fhor)during loadunload in a pre-peak range under dry and drained conditions.
基金support of the Transportation Consortium of SouthCentral States(Tran-SET)is greatly appreciated(Tran-SET project 21BLSU03).
文摘The objective of this study was to evaluate and recommend an asphalt mixture design with emerging additive technologies that would provide superior performance against asphalt concrete(AC)stripping and cracking.To achieve this objective,a laboratory test program was developed to evaluate the use of nanomaterials(nanoclay and graphene nanoplatelet),an emerging anti-stripping agent(adhere),and warm-mix asphalt technologies(ZycoTherm,Sasobit,and EvoTherm).Two mix types were evaluated,which were a stone-matrix asphalt(SMA)and a dense-graded binder mix.In addition,the modified Lottman test(AASHTO T 283)and the indirect tensile asphalt cracking test(IDEAL-CT)test were used as performance indicators of moisture damage resistance and cracking susceptibility.Results were analyzed statistically to identify and quantify the effects of the design variables and selected additives on the performance,moisture damage resistance,and durability of asphalt mixes.Based on the cracking test results,a superior cracking resistance performance was observed with ZycoTherm,irrespective of the mix type.Adhere had the lowest average cracking indices for both mix types,which suggest that it would not perform as well as the other additives in terms of cracking resistance.Overall,SMA mixes displayed greater cracking resistance than the dense-graded mixtures,which may have been the result of the reclaimed asphalt pavement(RAP)material used in the dense-graded mix and its lower asphalt binder content.In terms of moisture resistance,both nanomaterials(graphene nanoplatelet and nanoclay)did not perform well as they did not meet the minimum required tensile strength ratio(TSR)criterion(>0.80).In addition,nanomaterials showed the lowest TSR values in both mix types suggesting that their effectiveness against moisture-induced damage may not be as good as warm-mix additives.On the other hand,warm-mix additives were expected to show enhanced performance in terms of moisture resistance as compared to the other additives evaluated in this study.
文摘This paper presents the results of laboratory test on the feasibility of soil conditioning for earth pressurebalance (EPB) excavation in a tar sand, which is a natural material never studied in this respect. Thelaboratory test performed is based on a procedure and methods used in previous studies with differenttypes of soils, but for this special complex material, additional tests are also conducted to verify particularproperties of the tar sands, such as the tilt test and vane shear test usually used in cohesive materials, anda direct shear test. The laboratory test proves that the test procedure is applicable also to this type of soiland the conditioned material can be considered suitable for EPB excavations, although it is necessary touse a certain percentage of fine elements (filler) to create a material suitable to be mixed with foam. Thetest results show that the conditioned material fulfils the required standard for an EPB application.
基金The authors would like to acknowledge Mr.Beau McDonald for his invaluable help with laboratory testing.
文摘This study aims to examine the influence of pre-existing discontinuities on the strengths of four natural rocks of different origins.A series of unconfined compression tests was performed on specimens of two types of sandstones,argillite and basalt that contain open and filled cracks.It was found that the presence of cracks tends to decrease the overall strength for all studied rocks;however,the magnitude of strength reduction is related to the property of rock.The larger strength decrease was observed for the relatively harder argillite and basalt,compared to the softer sandstone.It was also found that the infill material could increase the strength of rock specimens,while the obtained strength depended on the characteristics of the fill material.
基金National Science and Technology major projects(2016ZX05042-004)Graduate Innovation Project(YCX2019059)for the financial support。
文摘Nylon cord rubber has the advantages of small residual deformation and is easy to lift and lower the tubing string in low-permeability oil and gas reservoirs.However,it is associated with low-pressure resistance and poor sealing performance.To enhance the performance of nylon cord rubber,a three-dimensional numerical model of the nylon cord rubber was established and its accuracy experimentally determined.The Plackett-Burman test,the Steepest climbing test and the Response surface method were used to acquire the polynomial response surface model connecting structural parameters with bearing and sealing pressure.Using genetic algorithms,optimal structural parameters of nylon cord rubber were determined depending on field operation.The reliability of the optimized results was verified by laboratory tests.It was shown that after optimization,the bearing capacity of the expandable packer increased by 25%while the sealing performance increased by 66%.In addition,the bearing pressure was 70 MPa while the sealing pressure was 50 MPa.These measurements effectively met the on-site requirements of high-pressure and fine fracturing in low-permeability oil and gas reservoirs.
基金Supported by National Science and Technology Support Program of China(Grant No.2009BAG12A01-B06)National Hi-tech Research and Development Program of China(863 Program,Grant No.2011AA11A103-2-2)+3 种基金Funds for Innovation Research Team of Ministry of Education of China(Grant Nos.IRT1178,SWJTU12ZT01)Fundamental Research Funds for the Central Universities and the Science of China(Grant No.SWJTU12ZT01)2015 Doctoral Innovation Funds of Southwest Jiaotong University of ChinaProject of State Key Laboratory of Traction Power of China(Grant No.2011TPL_T05)
文摘The current researches of wheel vibration and sound radiation mainly focus on the low noise damped wheel. Compared with the traditional research, the relationship between the sound and wheel/rail contact is difficulty and worth studying. However, there are few studies on the effect of wheel load on wheel vibration and sound radiation. In this paper, laboratory test carried out in a semi-anechoic room investigates the effect of wheel load on wheel natural frequencies, damping ratios, wheel vibration and its sound radiation, The laboratory test results show that the vibration of the wheel and total sound radiation decrease significantly with the increase of the wheel load from 0 t to 1 t. The sound energy level of the wheel decreases by 3.7 dB. When the wheel load exceeds 1 t. the attenuation trend of the vibration and sound radiation of the wheel becomes slow. And the increase of the wheel load causes the growth of the wheel natural frequencies and the mode damping ratios. Based on the finite element method (FEM) and boundary element method (BEM), a rolling noise prediction model is developed to calculate the influence of wheel load on the wheel vibration and sound radiation. In the calculation, the used wheel/rail excitation is the measured wheel/rail roughness. The calculated results show that the sound power level of the wheel decreases by about 0.4 dB when the wheel load increases by 0.5 t. The sound radiation of the wheel decreases slowly with wheel load increase, and this conclusion is verified by the field test. This research systematically studies the cffcct of wheel load on wheel vibration and sound radiation, gives the relationship between the sound and wheel/rail contact and analyzes the reasons, therefore, it provides a reference for further research.
基金supported by State Key Projects Specialized on Infectious Diseases (No. 2017ZX10201201-006)Key research projects for precision medicine (No. 2017YFC0908103)+1 种基金Innovation Fund for Medical Sciences of Chinese Academy of Medical Sciences (CIFMS, No. 2019-I2M-2-004, 2016-I2M-1-007, 2019-I2M-1-003)National Natural Science Foundation Fund (No. 81972628, No. 81974492)。
文摘Objective: Hepatocellular carcinoma(HCC) development among hepatitis B surface antigen(HBs Ag) carriers shows gender disparity, influenced by underlying liver diseases that display variations in laboratory tests. We aimed to construct a risk-stratified HCC prediction model for HBs Ag-positive male adults.Methods: HBs Ag-positive males of 35-69 years old(N=6,153) were included from a multi-center populationbased liver cancer screening study. Randomly, three centers were set as training, the other three centers as validation. Within 2 years since initiation, we administrated at least two rounds of HCC screening using Bultrasonography and α-fetoprotein(AFP). We used logistic regression models to determine potential risk factors,built and examined the operating characteristics of a point-based algorithm for HCC risk prediction.Results: With 2 years of follow-up, 302 HCC cases were diagnosed. A male-ABCD algorithm was constructed including participant's age, blood levels of GGT(γ-glutamyl-transpeptidase), counts of platelets, white cells,concentration of DCP(des-γ-carboxy-prothrombin) and AFP, with scores ranging from 0 to 18.3. The area under receiver operating characteristic was 0.91(0.90-0.93), larger than existing models. At 1.5 points of risk score,26.10% of the participants in training cohort and 14.94% in validation cohort were recognized at low risk, with sensitivity of identifying HCC remained 100%. At 2.5 points, 46.51% of the participants in training cohort and 33.68% in validation cohort were recognized at low risk with 99.06% and 97.78% of sensitivity, respectively. At 4.5 points, only 20.86% of participants in training cohort and 23.73% in validation cohort were recognized at high risk,with positive prediction value of 22.85% and 12.35%, respectively.Conclusions: Male-ABCD algorithm identified individual's risk for HCC occurrence within short term for their HCC precision surveillance.