BACKGROUND Gastrointestinal endoscopy technology has significantly improved the diagnostic accuracy and the successful treatment of gastrointestinal diseases.However,a series of ethical issues have emerged,such as exp...BACKGROUND Gastrointestinal endoscopy technology has significantly improved the diagnostic accuracy and the successful treatment of gastrointestinal diseases.However,a series of ethical issues have emerged,such as expanding treatment indications,which affect the fair distribution of medical resources.There is limited research on ethical issues in the field of digestive endoscopy.AIM To investigate the level of ethical awareness among gastrointestinal endoscopy practitioners and analyze the ethical issues involved in gastrointestinal endoscopy technology.METHODS A questionnaire survey was performed to collect relevant data(gender,age,degree of education,professional title,personnel category,the level of understanding medical ethical principles,ethics training and its learning pathways)from gastrointestinal endoscopy practitioners at the Second Hospital of Dalian Medical University and Dalian Friendship Hospital,including licensed physicians and nurses(including trainees and graduate students).RESULTS The majority of gastrointestinal endoscopy practitioners have received training on ethics,but there is still considerable room for improvement in their ethical awareness.Different learning pathways may affect the mastery of ethical principles, and understanding of ethical principles is more easily achieved through hospital ethics institutions.CONCLUSIONTo address the ethical issues in gastrointestinal endoscopy technology, it is necessary to enhance the humanisticeducation of gastrointestinal endoscopy practitioners, incorporate ethical standards into the technology assessmentprocess, and establish a patient-centered diagnostic and treatment model to improve the ethical awareness of practitionersand achieve a balance between technology and ethics.展开更多
BACKGROUND Small intestinal bacterial overgrowth(SIBO)is suspected and excluded frequently in functional gastrointestinal(GI)disorders.Children presenting with various esophago-gastro-duodenal(upper GI)symptoms are ra...BACKGROUND Small intestinal bacterial overgrowth(SIBO)is suspected and excluded frequently in functional gastrointestinal(GI)disorders.Children presenting with various esophago-gastro-duodenal(upper GI)symptoms are rarely subjected to investig-ations for SIBO.AIM To estimate the frequency of SIBO in children having functional upper GI sym-ptoms(as cases)and to compare the result of the SIBO status to that of the con-trols.METHODS Children aged 6 to 18 who presented with upper GI symptoms were selected for the study.All children were subjected to upper GI endoscopy before being advised of any proton pump inhibitors(PPIs).Children with normal endoscopy were assigned as cases,and children having any endoscopic lesion were design-ated as controls.Both groups were subjected to a glucose-hydrogen breath test by Bedfont Gastrolyser.RESULTS A total of 129 consecutive children who were naive to PPIs and had normal ba-seline investigations were included in the study.Among them,67 patients had endoscopic lesions and served as the control group,with six cases being excluded due to the presence of Helicobacter pylori in gastric biopsies.Sixty-two children with normal endoscopy results formed the case group.In the case group,35 children(59%)tested positive for hydrogen breath tests,compared to 13 children(21%)in the control group.The calculated odds ratio was 5.38(95%confidence interval:2.41-12.0),which was statistically significant.Further analysis of symptoms revealed that nausea,halitosis,foul-smelling eructation,and epigastric fullness were positive predictors of SIBO.CONCLUSION It is worthwhile to investigate and treat SIBO in all children presenting with upper GI symptoms that are not explained by endoscopy findings.展开更多
This study presents the results of a Monte Carlo simulation to compare the statistical power of Siegel-Tukey and Savage tests.The main purpose of the study is to evaluate the statistical power of both tests in scenari...This study presents the results of a Monte Carlo simulation to compare the statistical power of Siegel-Tukey and Savage tests.The main purpose of the study is to evaluate the statistical power of both tests in scenarios involving Normal,Platykurtic and Skewed distributions over different sample sizes and standard deviation values.In the study,standard deviation ratios were set as 2,3,4,1/2,1/3 and 1/4 and power comparisons were made between small and large sample sizes.For equal sample sizes,small sample sizes of 5,8,10,12,16 and 20 and large sample sizes of 25,50,75 and 100 were used.For different sample sizes,the combinations of(4,16),(8,16),(10,20),(16,4),(16,8)and(20,10)small sample sizes and(10,30),(30,10),(50,75),(50,100),(75,50),(75,100),(100,50)and(100,75)large sample sizes were examined in detail.According to the findings,the power analysis under variance heterogeneity conditions shows that the Siegel-Tukey test has a higher statistical power than the other nonparametric Savage test at small and large sample sizes.In particular,the Siegel-Tukey test was reported to offer higher precision and power under variance heterogeneity,regardless of having equal or different sample sizes.展开更多
Objective: Hereditary breast and ovarian cancer syndrome (HBOC) increases the risk of developing breast, ovarian, prostate, and pancreatic cancers. With the insurance coverage for BRCA genetic testing, the number of i...Objective: Hereditary breast and ovarian cancer syndrome (HBOC) increases the risk of developing breast, ovarian, prostate, and pancreatic cancers. With the insurance coverage for BRCA genetic testing, the number of individuals diagnosed with HBOC has increased. To use these test results effectively, cascade genetic testing (CGT) is recommended for at-risk relatives;however, it is not yet widely available. The purpose of this study was to investigate the willingness of the general population to share genetic test results and undergo CGT, as well as to analyze the factors influencing these decisions. Based on these findings, the study aimed to identify the types of support needed to support the sharing of genetic test results and promote the use of CGT. Methods: An online survey was conducted with 500 participants (50 men and women from each of the five generations, ranging from 20 to 69 years). Results: Among the HBOC blood relatives, 51.2% wanted to share the genetic results and 71.9% expressed a willingness to undergo CGT. “Matters to be shared with relatives” and “Helpful for my cancer prevention” were identified as key factors promoting the willingness to share the BRCA genetic test results and undergo CGT. The motivation for “Helpful for my cancer prevention” had a particularly strong influence on the decision to undergo CGT. Conclusion: In the general population, there is an emerging understanding that the genetic information impacts not only the individuals but also their entire families and can be valuable for cancer prevention. To promote the sharing of BRCA genetic test results and CGT uptake, the healthcare providers should offer support tailored to each family’s circumstances and establish cancer prevention measures recommended for HBOC.展开更多
With the increasing construction of port facilities,cross-sea bridges,and offshore engineering projects,uplift piles embedded in marine sedimentary soft soil are becoming increasingly necessary.The load-displacement c...With the increasing construction of port facilities,cross-sea bridges,and offshore engineering projects,uplift piles embedded in marine sedimentary soft soil are becoming increasingly necessary.The load-displacement curve of uplift piles is crucial for evaluating their uplift bearing characteristics,which facilitates the risk evaluation,design,and construction of large infrastructural supports.In this study,a load-displacement curve model based on piezocone penetration test(CPTU)data is proposed via the load transfer method.Experimental tests are conducted to analyze the uplift bearing characteristics and establish a correlation between the proposed model and CPTU data.The results of the proposed load-displacement curve are compared with the results from numerical simulations and those calculated by previous methods.The results show that the proposed curves appropriately evaluated the uplift bearing characteristics and improved the accuracy in comparison with previous methods.展开更多
Tacrolimus(Tac)is a cornerstone immunosuppressant in the treatment regimens for organ transplant recipients.However,its extensive clinical use has brought attention to its associated drug safety concerns.Recent case r...Tacrolimus(Tac)is a cornerstone immunosuppressant in the treatment regimens for organ transplant recipients.However,its extensive clinical use has brought attention to its associated drug safety concerns.Recent case reports highlighting Tac-induced gastrointestinal ulcers have prompted further investigation.In the present study,we analyzed Tac-associated adverse events using data from the U.S.Food and Drug Administration Adverse Event Reporting System(FAERS)to identify potential adverse event signals.Adverse event reports were collected up to the third quarter(Q3)of 2023,revealing 339 cases of Tac-related gastrointestinal ulcers.A disproportionality analysis was conducted utilizing the Bayesian confidence propagation neural network of information component(IC)and reporting odds ratio(ROR)methods.All statistical analyses were performed using R version 3.6.1.The findings demonstrated a significant signal for gastrointestinal ulcers associated with Tac use,with a ROR1 of 1.87(95%CI:1.68-2.08)and an IC1 of 0.89(95%CI:0.73-1.05)when compared to all other drugs.When compared specifically to cyclosporine,Tac also showed a significant signal(ROR2=1.55,95%CI:1.28-1.86;IC2=0.24,95%CI:0.04-0.44).Further analysis identified age,male gender,and European descent as risk factors for mortality outcomes in patients with Tac-associated gastrointestinal ulcers.These findings highlighted the critical need for clinicians to strengthen the monitoring and early detection of gastrointestinal ulcers in patients undergoing Tac therapy.Enhanced vigilance in this regard is essential to optimize the management and care of transplant patients.展开更多
Polymer flooding is an important means of improving oil recovery and is widely used in Daqing,Xinjiang,and Shengli oilfields,China.Different from conventional injection media such as water and gas,viscoelastic polymer...Polymer flooding is an important means of improving oil recovery and is widely used in Daqing,Xinjiang,and Shengli oilfields,China.Different from conventional injection media such as water and gas,viscoelastic polymer solutions exhibit non-Newtonian and nonlinear flow behavior including shear thinning and shear thickening,polymer convection,diffusion,adsorption,retention,inaccessible pore volume,and reduced effective permeability.However,available well test model of polymer flooding wells generally simplifies these characteristics on pressure transient response,which may lead to inaccurate results.This work proposes a novel two-phase numerical well test model to better describe the polymer viscoelasticity and nonlinear flow behavior.Different influence factors that related to near-well blockage during polymer flooding process,including the degree of blockage(inner zone permeability),the extent of blockage(composite radius),and polymer flooding front radius are explored to investigate these impacts on bottom hole pressure responses.Results show that polymer viscoelasticity has a significant impact on the transitional flow segment of type curves,and the effects of near-well formation blockage and polymer concentration distribution on well test curves are very similar.Thus,to accurately interpret the degree of near-well blockage in injection wells,it is essential to first eliminate the influence of polymer viscoelasticity.Finally,a field case is comprehensively analyzed and discussed to illustrate the applicability of the proposed model.展开更多
Purpose-The indoor vibration compaction test(IVCT)was a key step in controlling the compaction quality for high-speed railway graded aggregate(HRGA),which currently had a research gap on the assessment indicators and ...Purpose-The indoor vibration compaction test(IVCT)was a key step in controlling the compaction quality for high-speed railway graded aggregate(HRGA),which currently had a research gap on the assessment indicators and compaction parameters.Design/methodology/approach-To address these issues,a novel multi-indicator IVCT method was proposed,including physical indicator dry density(ρd)and mechanical indicators dynamic stiffness(Krb)and bearing capacity coefficient(K20).Then,a series of IVCTs on HRGA under different compaction parameters were conducted with an improved vibration compactor,which could monitor the physical-mechanical indicators in real-time.Finally,the optimal vibration compaction parameters,including the moisture content(ω),the diameter-to-maximum particle size ratio(Rd),the thickness-to-maximum particle size ratio(Rh),the vibration frequency(f),the vibration mass(Mc)and the eccentric distance(re),were determined based on the evolution characteristics for the physical-mechanical indicators during compaction.Findings-All results indicated that theρd gradually increased and then stabilized,and the Krb initially increased and then decreased.Moreover,the inflection time of the Krb was present as the optimal compaction time(Tlp)during compaction.Additionally,optimal compaction was achieved whenωwas the water-holding content after mud pumping,Rd was 3.4,Rh was 3.5,f was the resonance frequency,and the ratio between the excitation force and the Mc was 1.8.Originality/value-The findings of this paper were significant for the quality control of HRGA compaction.展开更多
BACKGROUND Functional abdominal pain disorders(FAPDs)are common gut–brain interaction disorders with unclear pathophysiology.While impaired gastrointestinal motility is thought to play a key role,small intestinal dys...BACKGROUND Functional abdominal pain disorders(FAPDs)are common gut–brain interaction disorders with unclear pathophysiology.While impaired gastrointestinal motility is thought to play a key role,small intestinal dysmotility remains largely unexplored.Orocecal transit time(OCTT),an indirect indicator of small intestinal transit,offers an insight into its potential contribution to FAPD's pathophysiology.AIM To assess OCTT in children with FAPDs compared with healthy children using the lactulose breath hydrogen test.METHODS Thirty-four children(44.1%males,age 5–12 years,mean 7.2±2.4 years)with FAPDs attending North Colombo Teaching Hospital,Ragama,Sri Lanka,were included in the analysis.FAPDs were diagnosed using the Rome IV criteria.None had clinical or laboratory evidence of organic diseases.They were compared with 19 healthy controls(47.1%males,age 5-12 years,mean 7.8±2.7 years)from the same geographical area.OCTT was calculated after an 8-hour fast using a previously validated technique.Breath hydrogen levels were measured at baseline and 15-minute intervals for 180 minutes post-lactulose ingestion(10 g in 10%solution).At each time point,3 breath samples were collected and analyzed.OCTT was quantified as the time taken to achieve a sustained breath hydrogen increase>10 parts per million above baseline.Symptoms were recorded using the Rome IV questionnaire,and symptom severity was graded on a 0-4 Likert scale.RESULTS Patients with FAPDs had increased OCTT(median,90 minutes;interquartile range,75-120 minutes)compared to controls(median,75 minutes;interquartile range,60-75 minutes)(P=0.0045,Mann-Whitney U-test).Children with functional dyspepsia had the longest mean OCTT(110.8±26.7 minutes).There was no significant correlation between abdominal pain severity and OCTT(r=0.18,P=0.35,Spearman correlation coefficient).OCTT did not differ between those exposed to stressful events and those not exposed to such events(P>0.05).CONCLUSION Children with FAPDs have longer OCTT than healthy controls.However,the lack of a significant correlation between OCTT and symptom severity suggests that delayed small intestinal transit alone is not a substantial contributor to FAPD pathophysiology.展开更多
BACKGROUND Familial adenomatous polyposis(FAP)is a disorder of autosomal dominant inheritance that is responsible for around 1%of colorectal cancer(CRC)cases.AIM To determine the mutation profile of FAP-specific to th...BACKGROUND Familial adenomatous polyposis(FAP)is a disorder of autosomal dominant inheritance that is responsible for around 1%of colorectal cancer(CRC)cases.AIM To determine the mutation profile of FAP-specific to the Hungarian population.METHODS This prospective single-center study enrolled patients with clinically suspected FAP or attenuated FAP(aFAP).Whole-exome next-generation sequencing was performed to detect variants of 50 FAP priority genes and 173 CRC predisposing genes or other CRC disease-associated genes.To identify larger deletions and insertions,a multiplex amplifiable probe hybridization technique was used.The identified genes were then classified according to the American College of Medical Genetics and Genomics guidelines.RESULTS A total of 26 index patients with clinically suspected FAP(n=21)and aFAP(n=5)were enrolled.APC gene alterations were confirmed in 92.31%of the cases(region 1B deletion,n=2;whole-gene deletion,n=4;frameshift mutation,n=2;nonsense mutation,n=5,and splice mutation,n=1),with the remaining two cases having CHEK2 and MSH3 gene alterations.According to pathogenicity,21 cases had pathogenic mutations,6 cases had likely pathogenic mutations,and 16 cases had variants of unknown significance(VUS).The most frequent of the latter were the POLE(n=5)and PIEZO1(n=4)gene variants.CONCLUSION Germline mutations in the APC gene were confirmed in more than 90%of Hungarian patients with clinically suspected FAP.Although the role of VUS genes is unclear,they are highly likely to play a role in the development of CRC.展开更多
It is challenging to diagnose isolated hyperbilirubinemia with rare and complex etiologies under the constraints of traditional testing conditions.Herein,we present a rare case of coexisting Gilbert syndrome(GS)and er...It is challenging to diagnose isolated hyperbilirubinemia with rare and complex etiologies under the constraints of traditional testing conditions.Herein,we present a rare case of coexisting Gilbert syndrome(GS)and erythropoietic protoporphyria(EPP),which has not been previously documented.CASE SUMMARY We present a rare case of coexisting GS and EPP in a 23-year-old Chinese male with a long history of jaundice and recently found splenomegaly.Serial nonspecific hemolysis screening tests yielded inconsistent results,and investigations for common hemolytic etiologies were negative.However,Levitt’s carbon monoxide breath test,which measures erythrocyte lifespan(the gold-standard marker of hemolysis),demonstrated significant hemolysis,revealing a markedly shortened erythrocyte lifespan of 11 days(normal average 120 days).Genetic testing subsequently confirmed EPP with a homozygous ferrochelatase gene mutation and GS with a heterozygous uridine diphosphate glucuronosyl trans-ferase 1A1 gene mutation.CONCLUSION The rapid,non-invasive Levitt’s carbon monoxide breath test resolved the diagnostic challenge posed by a rare and complex cause of hyperbilirubinemia.展开更多
Objective To assess whether quick cognitive screening test （QCST） could quickly identify mild cognitive impairment （MCI）. Methods QCST and a full set of standardized neuropsychological tests, including mini-mental...Objective To assess whether quick cognitive screening test （QCST） could quickly identify mild cognitive impairment （MCI）. Methods QCST and a full set of standardized neuropsychological tests, including mini-mental state examination （MMSE） and montreal cognitive assessment （MoCA） were performed. A total number of 121 cases of MCI [41 cases of amnestic MCI-single domain （aMCI-s）; 44 of amnestic MCI-multiple domain （aMCI-m）; 36 of nonamnestic MCI （naMCI）], 79 cases of mild Alzheimer’s disease （AD） and 186 healthy elderly volunteers were employed in the present study. All the participants （55-85 years old） had an educational level no less than 5 years. QCST subtests included word list recall, naming test, animal fluency test, similarity test, color trail-1min, clock drawing test, finger construction test, and digit span test. The total score of QCST was 90 points, 10 points for each index of subtests. Results The total scores of QCST in MCI, AD and the control groups were （58.13±8.18）, （44.53±10.54） and （72.92±6.85） points, respectively. According to the educational level, the cut off scores of participants with an educational level of 5-8 years, 9-12 years and more than 13 years were 63, 65 and 68 points, respectively. The sensitivity and specificity of QCST in detection of MCI were 87.6% （85.7% for aMCI-s, 90.1% for aMCI-m and 89.5% for naMCI） and 84.3%, respectively. The area under the curve was 0.923 （95% CI： 0.892-0.953）. Delayed memory, color trail-1min and similarity test could help distinguish between aMCI and naMCI. Conclusion QCST may have a good sensitivity and specificity for MCI detection, which warrants its further clinical application.展开更多
KeLa-2 gas reservoir is the largest uncompartimentalized gas field so far discovered in China, with a reserve of hundreds of billions of cubic meters of dry gas. It has such features as extremely long interval (550m)...KeLa-2 gas reservoir is the largest uncompartimentalized gas field so far discovered in China, with a reserve of hundreds of billions of cubic meters of dry gas. It has such features as extremely long interval (550m), high pressure (74.5MPa) and pressure coefficient (2.022). Gas reservoirs with a pressure coefficient of over 2.0 are not commonly found. The abnormal high-pressure reservoirs are quite different in characteristic and performance during the process of depletion exploitation. Therefore, it is necessary to know the property of pressure sensitivity for this abnormal high-pressure reservoir. The aim of this paper is to test the reservoir pressure sensitivity and to analyze its effect on the deliverability of gas. Through some experiments, the permeability change with the confining pressure of rock samples from KeLa-2 abnormal high-pressure gas reservoir is measured. A power function is used to match the measured data, and to derive an empirical equation to describe the change of permeability through the change of the reservoir pressure or effective overburden pressure. Considering the permeability change during the development of reservoirs, a conventional deliverability equation is modified, and the deliverability curve for KeLa-2 gas reservoir is predicted. The research indicates that the extent of the pressure sensitivity of rock samples from KeLa-2 is higher than that from the Daqing oilfield. KeLa-2 reservoir rock has the feature of an undercompaction state. The pressure sensitivity of a reservoir may decrease the well deliverability. It is concluded that for KeLa-2 reservoir the predicted absolute open flow (AOF), when the pressure sensitivity is taken into account, is approximately 70% of the AOF when permeability is constant and does not change with pressure.展开更多
[ Objective] The aim of this study was to evaluate the clinical effect of the inactivated vaccine in oil emulsion against Newcastle disease and Fowl cholera, and provide conditions for combined prevention and control ...[ Objective] The aim of this study was to evaluate the clinical effect of the inactivated vaccine in oil emulsion against Newcastle disease and Fowl cholera, and provide conditions for combined prevention and control of Newcastle disease and Fowl cholera. [ Method] The mixture of avian pasteurella multocida （type A） virulent strain 1502 and Newcastle disease virus attenuated strain La Sota was prepared into five batches of the inactivated vaccine in oil emulsion to use in the field test for assessing its safety and effects on immune protection of chicken, duck and goose. [ Result] The field safety test showed that there was no adverse reaction in the vaccinated chickens, ducks and geese. The field test of immune effect for chickens suggested that the titers of hemagglutination inhibition antibody for Nescastle disease virus （ ND-HI ） in 7 - 14 day- old chickens and 60 -90 day-old young chickens were 2 -3 log2 higher than the control group after being vaccinated for 3 weeks, which could last for more than 4 months. The protection rate against avian pasteurella multocida was over 75.0% and its immune effect could last for 6 months. The field test of immune effect for duck and goose indicated that the titers of ND-HI antibody were all higher than 4.2 log2 in vaccinated ducks and geese while lower than 2 log2 in the control group after being vaccinated for 3 weeks. The protection rate against avian pasteurella multocida in vaccinated ducks and geese was higher than 75.0% and 62.5% respectively. [ Conclusion] The binary vaccine is safe for poultry and has good immune effects.展开更多
The strong wind characteristics of the Runyang Suspension Bridge（ RSB） including the wind speed and direction, the turbulence intensity, the turbulence integral length and power spectrum are analyzed based on measur...The strong wind characteristics of the Runyang Suspension Bridge（ RSB） including the wind speed and direction, the turbulence intensity, the turbulence integral length and power spectrum are analyzed based on measurement data from the wind environment monitoring subsystem of the structural health monitoring system （SHMS）of the RSB and field tests during strong winds. The differences between the typhoon and the strong northern wind are especially studied. It is found that the mean wind speed of the strong northern wind is a little smaller and the mean wind direction is more stable than that of the typhoon. The turbulence intensity of both the typhoon and the strong northern wind is greater than the values suggested in Chinese code, and the turbulence integral length difference between the typhoon and a strong northern wind is not clear. As for the along-wind turbulence power spectrum, the spectrum of the strong northern wind can fit the Kaimal spectrum better than that of the typhoon. The obtained results can provide measurement data for founding a strong wind characteristic database and determining the strong wind characteristic parameter values of the RSB.展开更多
The importance of studying the behavior of the soil at the sea bottom under the action of wave force has arisen with the development of offshore engineering.In this paper,the behavior of the soft clay under the action...The importance of studying the behavior of the soil at the sea bottom under the action of wave force has arisen with the development of offshore engineering.In this paper,the behavior of the soft clay under the action of wave forces is studied by performing centrifugal tests.The soil profile and the wave characters were simulated in the centrifugal model cell according to the typical environmental conditions of the oil fields in the Bohai gulf.Test results show that the soft clay layer will be seriously softened near the upper surface under the maximum wave height and slightly affected in the deeper layer,and that no liquefaction was recorded in the silty sand sublayer during the test.It is proven that the centrifugal test is a valid technique for simulating the interaction between soil and wave.展开更多
The mechanical properties of the SiC fiber-reinforced Mg-Al metal matrix composite materials have been studied on internal microstructure by (scanning electron microscopy) SEM in-situ tensile test. The emergence and p...The mechanical properties of the SiC fiber-reinforced Mg-Al metal matrix composite materials have been studied on internal microstructure by (scanning electron microscopy) SEM in-situ tensile test. The emergence and propagation of the crack, and the fracture behavior in materials have been observed and studied. It is found that in the case of the tensile test, the crack emerged in SiC fiber initially. In the case of the strong cohesion of the fiber-metal interface, the crack propagated in the fiber, meanwhile the fibers in the neighborhood of the cracked fiber began to crack and the Mg-Al metal deformed plastically, and at last the material fractured. Otherwise the toughness of the materials grows in the case of the lower cohesion of the fiber-metal matrix interface.展开更多
Listening Comprehension test of CET-6 has a great adjustment in its item types and weighting of score since December,2015, however, there have been few researches concerning the validity of newly innovated CET-6 liste...Listening Comprehension test of CET-6 has a great adjustment in its item types and weighting of score since December,2015, however, there have been few researches concerning the validity of newly innovated CET-6 listening comprehension test.This paper tries to explore the construct validity and content validity of it. Based on the comparison between the test contents of lis-tening and the test requirements in CET syllabus,it is found that CET-6 listening shows good content relevance. Structural equa-tion modeling(SEM) was used to investigate the construct validity of CET-6 listening, which demonstrates that it mainly tests stu-dents' ability to understand details and inference, while ignoring socio-linguistic competence and psych-physiological compe-tence. Therefore, certain changes are desirable to increase the validity of the listening part of CET-6.展开更多
Speaking,as a productive skill,is a priority for many foreign-language learners.They often evaluate their success in language learning on the basis of how much they feel they have improved in their spoken language pro...Speaking,as a productive skill,is a priority for many foreign-language learners.They often evaluate their success in language learning on the basis of how much they feel they have improved in their spoken language proficiency.Consequently,testing of oral skills has hardly been neglected in college English examination.The communicative testing theory in 1970s greatly influenced language testing,especially the oral tests.This essay briefly explores the theory of communicative language testing and discusses the methods of TOEFL oral test and college English oral test and proposes ways to the latter one for further improve ment.展开更多
CET-6 is a nationwide and standardized test to evaluate college students' English levels. Now more than 10 million college students take part in the exam every year. On August 14, 2013, the CET-4 and CET-6 examina...CET-6 is a nationwide and standardized test to evaluate college students' English levels. Now more than 10 million college students take part in the exam every year. On August 14, 2013, the CET-4 and CET-6 examination committee reformed the structure of the CET-6 papers. After that the sentence translation was changed into paragraph translation,the scores of translation section also increased to 15 points which is more difficult and more important than before. There is no doubt that CET-6will exert a great impact on the teaching and learning of College English in China. This thesis focuses on the washback effect of CET-6 translation test towards college English teaching and learning.First of all, this paper introduces the CET-6 translation test requirements, and the score requirements of translation part. The author also illustrates some significant language testing research of both domestic and foreign scholars, and explains the concept of reliability and validity. Secondly, through the survey method of interviews and questionnaire the author study the characteristics of teaching in college classroom, the effect of translation teaching, and how do students to study translation. The author makes a further research on the interaction between the translation test and the teaching and learning based on the relevant theories. At last, the author finds that the negative washback effect of the CET-6 translation test is greater than the positive one. The author reflects on the current translation teaching and learning in China, and hopes to minimize the negative effects of CET-6 translation test.展开更多
文摘BACKGROUND Gastrointestinal endoscopy technology has significantly improved the diagnostic accuracy and the successful treatment of gastrointestinal diseases.However,a series of ethical issues have emerged,such as expanding treatment indications,which affect the fair distribution of medical resources.There is limited research on ethical issues in the field of digestive endoscopy.AIM To investigate the level of ethical awareness among gastrointestinal endoscopy practitioners and analyze the ethical issues involved in gastrointestinal endoscopy technology.METHODS A questionnaire survey was performed to collect relevant data(gender,age,degree of education,professional title,personnel category,the level of understanding medical ethical principles,ethics training and its learning pathways)from gastrointestinal endoscopy practitioners at the Second Hospital of Dalian Medical University and Dalian Friendship Hospital,including licensed physicians and nurses(including trainees and graduate students).RESULTS The majority of gastrointestinal endoscopy practitioners have received training on ethics,but there is still considerable room for improvement in their ethical awareness.Different learning pathways may affect the mastery of ethical principles, and understanding of ethical principles is more easily achieved through hospital ethics institutions.CONCLUSIONTo address the ethical issues in gastrointestinal endoscopy technology, it is necessary to enhance the humanisticeducation of gastrointestinal endoscopy practitioners, incorporate ethical standards into the technology assessmentprocess, and establish a patient-centered diagnostic and treatment model to improve the ethical awareness of practitionersand achieve a balance between technology and ethics.
文摘BACKGROUND Small intestinal bacterial overgrowth(SIBO)is suspected and excluded frequently in functional gastrointestinal(GI)disorders.Children presenting with various esophago-gastro-duodenal(upper GI)symptoms are rarely subjected to investig-ations for SIBO.AIM To estimate the frequency of SIBO in children having functional upper GI sym-ptoms(as cases)and to compare the result of the SIBO status to that of the con-trols.METHODS Children aged 6 to 18 who presented with upper GI symptoms were selected for the study.All children were subjected to upper GI endoscopy before being advised of any proton pump inhibitors(PPIs).Children with normal endoscopy were assigned as cases,and children having any endoscopic lesion were design-ated as controls.Both groups were subjected to a glucose-hydrogen breath test by Bedfont Gastrolyser.RESULTS A total of 129 consecutive children who were naive to PPIs and had normal ba-seline investigations were included in the study.Among them,67 patients had endoscopic lesions and served as the control group,with six cases being excluded due to the presence of Helicobacter pylori in gastric biopsies.Sixty-two children with normal endoscopy results formed the case group.In the case group,35 children(59%)tested positive for hydrogen breath tests,compared to 13 children(21%)in the control group.The calculated odds ratio was 5.38(95%confidence interval:2.41-12.0),which was statistically significant.Further analysis of symptoms revealed that nausea,halitosis,foul-smelling eructation,and epigastric fullness were positive predictors of SIBO.CONCLUSION It is worthwhile to investigate and treat SIBO in all children presenting with upper GI symptoms that are not explained by endoscopy findings.
文摘This study presents the results of a Monte Carlo simulation to compare the statistical power of Siegel-Tukey and Savage tests.The main purpose of the study is to evaluate the statistical power of both tests in scenarios involving Normal,Platykurtic and Skewed distributions over different sample sizes and standard deviation values.In the study,standard deviation ratios were set as 2,3,4,1/2,1/3 and 1/4 and power comparisons were made between small and large sample sizes.For equal sample sizes,small sample sizes of 5,8,10,12,16 and 20 and large sample sizes of 25,50,75 and 100 were used.For different sample sizes,the combinations of(4,16),(8,16),(10,20),(16,4),(16,8)and(20,10)small sample sizes and(10,30),(30,10),(50,75),(50,100),(75,50),(75,100),(100,50)and(100,75)large sample sizes were examined in detail.According to the findings,the power analysis under variance heterogeneity conditions shows that the Siegel-Tukey test has a higher statistical power than the other nonparametric Savage test at small and large sample sizes.In particular,the Siegel-Tukey test was reported to offer higher precision and power under variance heterogeneity,regardless of having equal or different sample sizes.
文摘Objective: Hereditary breast and ovarian cancer syndrome (HBOC) increases the risk of developing breast, ovarian, prostate, and pancreatic cancers. With the insurance coverage for BRCA genetic testing, the number of individuals diagnosed with HBOC has increased. To use these test results effectively, cascade genetic testing (CGT) is recommended for at-risk relatives;however, it is not yet widely available. The purpose of this study was to investigate the willingness of the general population to share genetic test results and undergo CGT, as well as to analyze the factors influencing these decisions. Based on these findings, the study aimed to identify the types of support needed to support the sharing of genetic test results and promote the use of CGT. Methods: An online survey was conducted with 500 participants (50 men and women from each of the five generations, ranging from 20 to 69 years). Results: Among the HBOC blood relatives, 51.2% wanted to share the genetic results and 71.9% expressed a willingness to undergo CGT. “Matters to be shared with relatives” and “Helpful for my cancer prevention” were identified as key factors promoting the willingness to share the BRCA genetic test results and undergo CGT. The motivation for “Helpful for my cancer prevention” had a particularly strong influence on the decision to undergo CGT. Conclusion: In the general population, there is an emerging understanding that the genetic information impacts not only the individuals but also their entire families and can be valuable for cancer prevention. To promote the sharing of BRCA genetic test results and CGT uptake, the healthcare providers should offer support tailored to each family’s circumstances and establish cancer prevention measures recommended for HBOC.
基金supported by the China Postdoctoral Science Foundation(Grant No.2024M760734)National Science Fund for Distinguished Young Scholars(Grant No.42225206)the National Natural Science Foundation of China(Grant Nos.41877231 and 42072299).
文摘With the increasing construction of port facilities,cross-sea bridges,and offshore engineering projects,uplift piles embedded in marine sedimentary soft soil are becoming increasingly necessary.The load-displacement curve of uplift piles is crucial for evaluating their uplift bearing characteristics,which facilitates the risk evaluation,design,and construction of large infrastructural supports.In this study,a load-displacement curve model based on piezocone penetration test(CPTU)data is proposed via the load transfer method.Experimental tests are conducted to analyze the uplift bearing characteristics and establish a correlation between the proposed model and CPTU data.The results of the proposed load-displacement curve are compared with the results from numerical simulations and those calculated by previous methods.The results show that the proposed curves appropriately evaluated the uplift bearing characteristics and improved the accuracy in comparison with previous methods.
文摘Tacrolimus(Tac)is a cornerstone immunosuppressant in the treatment regimens for organ transplant recipients.However,its extensive clinical use has brought attention to its associated drug safety concerns.Recent case reports highlighting Tac-induced gastrointestinal ulcers have prompted further investigation.In the present study,we analyzed Tac-associated adverse events using data from the U.S.Food and Drug Administration Adverse Event Reporting System(FAERS)to identify potential adverse event signals.Adverse event reports were collected up to the third quarter(Q3)of 2023,revealing 339 cases of Tac-related gastrointestinal ulcers.A disproportionality analysis was conducted utilizing the Bayesian confidence propagation neural network of information component(IC)and reporting odds ratio(ROR)methods.All statistical analyses were performed using R version 3.6.1.The findings demonstrated a significant signal for gastrointestinal ulcers associated with Tac use,with a ROR1 of 1.87(95%CI:1.68-2.08)and an IC1 of 0.89(95%CI:0.73-1.05)when compared to all other drugs.When compared specifically to cyclosporine,Tac also showed a significant signal(ROR2=1.55,95%CI:1.28-1.86;IC2=0.24,95%CI:0.04-0.44).Further analysis identified age,male gender,and European descent as risk factors for mortality outcomes in patients with Tac-associated gastrointestinal ulcers.These findings highlighted the critical need for clinicians to strengthen the monitoring and early detection of gastrointestinal ulcers in patients undergoing Tac therapy.Enhanced vigilance in this regard is essential to optimize the management and care of transplant patients.
基金supported by the National Natural Science Foundation of China(52104049)the Young Elite Scientist Sponsorship Program by Beijing Association for Science and Technology(BYESS2023262)。
文摘Polymer flooding is an important means of improving oil recovery and is widely used in Daqing,Xinjiang,and Shengli oilfields,China.Different from conventional injection media such as water and gas,viscoelastic polymer solutions exhibit non-Newtonian and nonlinear flow behavior including shear thinning and shear thickening,polymer convection,diffusion,adsorption,retention,inaccessible pore volume,and reduced effective permeability.However,available well test model of polymer flooding wells generally simplifies these characteristics on pressure transient response,which may lead to inaccurate results.This work proposes a novel two-phase numerical well test model to better describe the polymer viscoelasticity and nonlinear flow behavior.Different influence factors that related to near-well blockage during polymer flooding process,including the degree of blockage(inner zone permeability),the extent of blockage(composite radius),and polymer flooding front radius are explored to investigate these impacts on bottom hole pressure responses.Results show that polymer viscoelasticity has a significant impact on the transitional flow segment of type curves,and the effects of near-well formation blockage and polymer concentration distribution on well test curves are very similar.Thus,to accurately interpret the degree of near-well blockage in injection wells,it is essential to first eliminate the influence of polymer viscoelasticity.Finally,a field case is comprehensively analyzed and discussed to illustrate the applicability of the proposed model.
基金funded by the National Key R&D Program“Transportation Infrastructure”project(No.2022YFB2603400)the Technology Research and Development Plan Program of China State Railway Group Co.,Ltd.(No.Q2024T001)the National project pre research project of Suzhou City University(No.2023SGY019).
文摘Purpose-The indoor vibration compaction test(IVCT)was a key step in controlling the compaction quality for high-speed railway graded aggregate(HRGA),which currently had a research gap on the assessment indicators and compaction parameters.Design/methodology/approach-To address these issues,a novel multi-indicator IVCT method was proposed,including physical indicator dry density(ρd)and mechanical indicators dynamic stiffness(Krb)and bearing capacity coefficient(K20).Then,a series of IVCTs on HRGA under different compaction parameters were conducted with an improved vibration compactor,which could monitor the physical-mechanical indicators in real-time.Finally,the optimal vibration compaction parameters,including the moisture content(ω),the diameter-to-maximum particle size ratio(Rd),the thickness-to-maximum particle size ratio(Rh),the vibration frequency(f),the vibration mass(Mc)and the eccentric distance(re),were determined based on the evolution characteristics for the physical-mechanical indicators during compaction.Findings-All results indicated that theρd gradually increased and then stabilized,and the Krb initially increased and then decreased.Moreover,the inflection time of the Krb was present as the optimal compaction time(Tlp)during compaction.Additionally,optimal compaction was achieved whenωwas the water-holding content after mud pumping,Rd was 3.4,Rh was 3.5,f was the resonance frequency,and the ratio between the excitation force and the Mc was 1.8.Originality/value-The findings of this paper were significant for the quality control of HRGA compaction.
基金Supported by The University of Kelaniya,No.RP/03/04/13/01/01.
文摘BACKGROUND Functional abdominal pain disorders(FAPDs)are common gut–brain interaction disorders with unclear pathophysiology.While impaired gastrointestinal motility is thought to play a key role,small intestinal dysmotility remains largely unexplored.Orocecal transit time(OCTT),an indirect indicator of small intestinal transit,offers an insight into its potential contribution to FAPD's pathophysiology.AIM To assess OCTT in children with FAPDs compared with healthy children using the lactulose breath hydrogen test.METHODS Thirty-four children(44.1%males,age 5–12 years,mean 7.2±2.4 years)with FAPDs attending North Colombo Teaching Hospital,Ragama,Sri Lanka,were included in the analysis.FAPDs were diagnosed using the Rome IV criteria.None had clinical or laboratory evidence of organic diseases.They were compared with 19 healthy controls(47.1%males,age 5-12 years,mean 7.8±2.7 years)from the same geographical area.OCTT was calculated after an 8-hour fast using a previously validated technique.Breath hydrogen levels were measured at baseline and 15-minute intervals for 180 minutes post-lactulose ingestion(10 g in 10%solution).At each time point,3 breath samples were collected and analyzed.OCTT was quantified as the time taken to achieve a sustained breath hydrogen increase>10 parts per million above baseline.Symptoms were recorded using the Rome IV questionnaire,and symptom severity was graded on a 0-4 Likert scale.RESULTS Patients with FAPDs had increased OCTT(median,90 minutes;interquartile range,75-120 minutes)compared to controls(median,75 minutes;interquartile range,60-75 minutes)(P=0.0045,Mann-Whitney U-test).Children with functional dyspepsia had the longest mean OCTT(110.8±26.7 minutes).There was no significant correlation between abdominal pain severity and OCTT(r=0.18,P=0.35,Spearman correlation coefficient).OCTT did not differ between those exposed to stressful events and those not exposed to such events(P>0.05).CONCLUSION Children with FAPDs have longer OCTT than healthy controls.However,the lack of a significant correlation between OCTT and symptom severity suggests that delayed small intestinal transit alone is not a substantial contributor to FAPD pathophysiology.
基金Supported by the Research Grants of the National Research,Development and Innovation Office,No.K125377,No.K134863 and No.K143549New National Excellence Program of the Ministry of Human Capacities,No.UNKP-20-5-SZTE-161,No.UNKP-22-3-SZTE-233,No.UNKP-23-5-SZTE-719,No.UNKP-22-4-SZTE-296 and No.UNKP-22-3-SZTE-278+1 种基金Janos Bolyai Research Grant,No.BO/00723/22the Géza Hetényi Research Grant by Albert Szent-Györgyi Medical School,University of Szeged.
文摘BACKGROUND Familial adenomatous polyposis(FAP)is a disorder of autosomal dominant inheritance that is responsible for around 1%of colorectal cancer(CRC)cases.AIM To determine the mutation profile of FAP-specific to the Hungarian population.METHODS This prospective single-center study enrolled patients with clinically suspected FAP or attenuated FAP(aFAP).Whole-exome next-generation sequencing was performed to detect variants of 50 FAP priority genes and 173 CRC predisposing genes or other CRC disease-associated genes.To identify larger deletions and insertions,a multiplex amplifiable probe hybridization technique was used.The identified genes were then classified according to the American College of Medical Genetics and Genomics guidelines.RESULTS A total of 26 index patients with clinically suspected FAP(n=21)and aFAP(n=5)were enrolled.APC gene alterations were confirmed in 92.31%of the cases(region 1B deletion,n=2;whole-gene deletion,n=4;frameshift mutation,n=2;nonsense mutation,n=5,and splice mutation,n=1),with the remaining two cases having CHEK2 and MSH3 gene alterations.According to pathogenicity,21 cases had pathogenic mutations,6 cases had likely pathogenic mutations,and 16 cases had variants of unknown significance(VUS).The most frequent of the latter were the POLE(n=5)and PIEZO1(n=4)gene variants.CONCLUSION Germline mutations in the APC gene were confirmed in more than 90%of Hungarian patients with clinically suspected FAP.Although the role of VUS genes is unclear,they are highly likely to play a role in the development of CRC.
文摘It is challenging to diagnose isolated hyperbilirubinemia with rare and complex etiologies under the constraints of traditional testing conditions.Herein,we present a rare case of coexisting Gilbert syndrome(GS)and erythropoietic protoporphyria(EPP),which has not been previously documented.CASE SUMMARY We present a rare case of coexisting GS and EPP in a 23-year-old Chinese male with a long history of jaundice and recently found splenomegaly.Serial nonspecific hemolysis screening tests yielded inconsistent results,and investigations for common hemolytic etiologies were negative.However,Levitt’s carbon monoxide breath test,which measures erythrocyte lifespan(the gold-standard marker of hemolysis),demonstrated significant hemolysis,revealing a markedly shortened erythrocyte lifespan of 11 days(normal average 120 days).Genetic testing subsequently confirmed EPP with a homozygous ferrochelatase gene mutation and GS with a heterozygous uridine diphosphate glucuronosyl trans-ferase 1A1 gene mutation.CONCLUSION The rapid,non-invasive Levitt’s carbon monoxide breath test resolved the diagnostic challenge posed by a rare and complex cause of hyperbilirubinemia.
基金supported by the National Natural Science Foundation of China (No. 30570601)
文摘Objective To assess whether quick cognitive screening test （QCST） could quickly identify mild cognitive impairment （MCI）. Methods QCST and a full set of standardized neuropsychological tests, including mini-mental state examination （MMSE） and montreal cognitive assessment （MoCA） were performed. A total number of 121 cases of MCI [41 cases of amnestic MCI-single domain （aMCI-s）; 44 of amnestic MCI-multiple domain （aMCI-m）; 36 of nonamnestic MCI （naMCI）], 79 cases of mild Alzheimer’s disease （AD） and 186 healthy elderly volunteers were employed in the present study. All the participants （55-85 years old） had an educational level no less than 5 years. QCST subtests included word list recall, naming test, animal fluency test, similarity test, color trail-1min, clock drawing test, finger construction test, and digit span test. The total score of QCST was 90 points, 10 points for each index of subtests. Results The total scores of QCST in MCI, AD and the control groups were （58.13±8.18）, （44.53±10.54） and （72.92±6.85） points, respectively. According to the educational level, the cut off scores of participants with an educational level of 5-8 years, 9-12 years and more than 13 years were 63, 65 and 68 points, respectively. The sensitivity and specificity of QCST in detection of MCI were 87.6% （85.7% for aMCI-s, 90.1% for aMCI-m and 89.5% for naMCI） and 84.3%, respectively. The area under the curve was 0.923 （95% CI： 0.892-0.953）. Delayed memory, color trail-1min and similarity test could help distinguish between aMCI and naMCI. Conclusion QCST may have a good sensitivity and specificity for MCI detection, which warrants its further clinical application.
文摘KeLa-2 gas reservoir is the largest uncompartimentalized gas field so far discovered in China, with a reserve of hundreds of billions of cubic meters of dry gas. It has such features as extremely long interval (550m), high pressure (74.5MPa) and pressure coefficient (2.022). Gas reservoirs with a pressure coefficient of over 2.0 are not commonly found. The abnormal high-pressure reservoirs are quite different in characteristic and performance during the process of depletion exploitation. Therefore, it is necessary to know the property of pressure sensitivity for this abnormal high-pressure reservoir. The aim of this paper is to test the reservoir pressure sensitivity and to analyze its effect on the deliverability of gas. Through some experiments, the permeability change with the confining pressure of rock samples from KeLa-2 abnormal high-pressure gas reservoir is measured. A power function is used to match the measured data, and to derive an empirical equation to describe the change of permeability through the change of the reservoir pressure or effective overburden pressure. Considering the permeability change during the development of reservoirs, a conventional deliverability equation is modified, and the deliverability curve for KeLa-2 gas reservoir is predicted. The research indicates that the extent of the pressure sensitivity of rock samples from KeLa-2 is higher than that from the Daqing oilfield. KeLa-2 reservoir rock has the feature of an undercompaction state. The pressure sensitivity of a reservoir may decrease the well deliverability. It is concluded that for KeLa-2 reservoir the predicted absolute open flow (AOF), when the pressure sensitivity is taken into account, is approximately 70% of the AOF when permeability is constant and does not change with pressure.
文摘[ Objective] The aim of this study was to evaluate the clinical effect of the inactivated vaccine in oil emulsion against Newcastle disease and Fowl cholera, and provide conditions for combined prevention and control of Newcastle disease and Fowl cholera. [ Method] The mixture of avian pasteurella multocida （type A） virulent strain 1502 and Newcastle disease virus attenuated strain La Sota was prepared into five batches of the inactivated vaccine in oil emulsion to use in the field test for assessing its safety and effects on immune protection of chicken, duck and goose. [ Result] The field safety test showed that there was no adverse reaction in the vaccinated chickens, ducks and geese. The field test of immune effect for chickens suggested that the titers of hemagglutination inhibition antibody for Nescastle disease virus （ ND-HI ） in 7 - 14 day- old chickens and 60 -90 day-old young chickens were 2 -3 log2 higher than the control group after being vaccinated for 3 weeks, which could last for more than 4 months. The protection rate against avian pasteurella multocida was over 75.0% and its immune effect could last for 6 months. The field test of immune effect for duck and goose indicated that the titers of ND-HI antibody were all higher than 4.2 log2 in vaccinated ducks and geese while lower than 2 log2 in the control group after being vaccinated for 3 weeks. The protection rate against avian pasteurella multocida in vaccinated ducks and geese was higher than 75.0% and 62.5% respectively. [ Conclusion] The binary vaccine is safe for poultry and has good immune effects.
基金The National High Technology Research and Development Program of China (863Program) (No.2006AA04Z416)the Key Project of the National Natural Science Foundation of China(No.50538020)+2 种基金the National Science Fund for Distinguished Young Scholars(No.50725828)the National Natural Science Foundation of China for Young Scholars(No.50608017)the Ph.D. Programs Foundation of Ministry of Education of China (No.200802861012)
文摘The strong wind characteristics of the Runyang Suspension Bridge（ RSB） including the wind speed and direction, the turbulence intensity, the turbulence integral length and power spectrum are analyzed based on measurement data from the wind environment monitoring subsystem of the structural health monitoring system （SHMS）of the RSB and field tests during strong winds. The differences between the typhoon and the strong northern wind are especially studied. It is found that the mean wind speed of the strong northern wind is a little smaller and the mean wind direction is more stable than that of the typhoon. The turbulence intensity of both the typhoon and the strong northern wind is greater than the values suggested in Chinese code, and the turbulence integral length difference between the typhoon and a strong northern wind is not clear. As for the along-wind turbulence power spectrum, the spectrum of the strong northern wind can fit the Kaimal spectrum better than that of the typhoon. The obtained results can provide measurement data for founding a strong wind characteristic database and determining the strong wind characteristic parameter values of the RSB.
文摘The importance of studying the behavior of the soil at the sea bottom under the action of wave force has arisen with the development of offshore engineering.In this paper,the behavior of the soft clay under the action of wave forces is studied by performing centrifugal tests.The soil profile and the wave characters were simulated in the centrifugal model cell according to the typical environmental conditions of the oil fields in the Bohai gulf.Test results show that the soft clay layer will be seriously softened near the upper surface under the maximum wave height and slightly affected in the deeper layer,and that no liquefaction was recorded in the silty sand sublayer during the test.It is proven that the centrifugal test is a valid technique for simulating the interaction between soil and wave.
文摘The mechanical properties of the SiC fiber-reinforced Mg-Al metal matrix composite materials have been studied on internal microstructure by (scanning electron microscopy) SEM in-situ tensile test. The emergence and propagation of the crack, and the fracture behavior in materials have been observed and studied. It is found that in the case of the tensile test, the crack emerged in SiC fiber initially. In the case of the strong cohesion of the fiber-metal interface, the crack propagated in the fiber, meanwhile the fibers in the neighborhood of the cracked fiber began to crack and the Mg-Al metal deformed plastically, and at last the material fractured. Otherwise the toughness of the materials grows in the case of the lower cohesion of the fiber-metal matrix interface.
文摘Listening Comprehension test of CET-6 has a great adjustment in its item types and weighting of score since December,2015, however, there have been few researches concerning the validity of newly innovated CET-6 listening comprehension test.This paper tries to explore the construct validity and content validity of it. Based on the comparison between the test contents of lis-tening and the test requirements in CET syllabus,it is found that CET-6 listening shows good content relevance. Structural equa-tion modeling(SEM) was used to investigate the construct validity of CET-6 listening, which demonstrates that it mainly tests stu-dents' ability to understand details and inference, while ignoring socio-linguistic competence and psych-physiological compe-tence. Therefore, certain changes are desirable to increase the validity of the listening part of CET-6.
文摘Speaking,as a productive skill,is a priority for many foreign-language learners.They often evaluate their success in language learning on the basis of how much they feel they have improved in their spoken language proficiency.Consequently,testing of oral skills has hardly been neglected in college English examination.The communicative testing theory in 1970s greatly influenced language testing,especially the oral tests.This essay briefly explores the theory of communicative language testing and discusses the methods of TOEFL oral test and college English oral test and proposes ways to the latter one for further improve ment.
文摘CET-6 is a nationwide and standardized test to evaluate college students' English levels. Now more than 10 million college students take part in the exam every year. On August 14, 2013, the CET-4 and CET-6 examination committee reformed the structure of the CET-6 papers. After that the sentence translation was changed into paragraph translation,the scores of translation section also increased to 15 points which is more difficult and more important than before. There is no doubt that CET-6will exert a great impact on the teaching and learning of College English in China. This thesis focuses on the washback effect of CET-6 translation test towards college English teaching and learning.First of all, this paper introduces the CET-6 translation test requirements, and the score requirements of translation part. The author also illustrates some significant language testing research of both domestic and foreign scholars, and explains the concept of reliability and validity. Secondly, through the survey method of interviews and questionnaire the author study the characteristics of teaching in college classroom, the effect of translation teaching, and how do students to study translation. The author makes a further research on the interaction between the translation test and the teaching and learning based on the relevant theories. At last, the author finds that the negative washback effect of the CET-6 translation test is greater than the positive one. The author reflects on the current translation teaching and learning in China, and hopes to minimize the negative effects of CET-6 translation test.
