·AIM:To determine the value of Schirmer Ⅰtest (SⅠt) without anesthesia and with topical anesthesia for diagnosing dry eye (DE). ·METHODS:Totally 220 eyes in 110 patients, male (44) and female (66), (39.56&...·AIM:To determine the value of Schirmer Ⅰtest (SⅠt) without anesthesia and with topical anesthesia for diagnosing dry eye (DE). ·METHODS:Totally 220 eyes in 110 patients, male (44) and female (66), (39.56±12.67) years old diagnosed with DE were examined. SⅠt without anesthesia was performed firstly, and 15 minutes later, it was applied again in the same person after topical anesthesia with 0.5% proparacaine hydrochloride eye drops. The wetting strips counted <10mm per 5 minutes were defined positive, while ≤5mm per 5 minutes were defined strong positive. ·RESULTS:The wetting length in SⅠt after topical anesthesia was significantly lower than that in SⅠt without anesthesia(P < 0.001). The positive rate and strong positive rate of SⅠt after topical anesthesia were significantly higher than that of SⅠt without anesthesia (P <0.001). The positive rate and strong positive rate of SⅠt without anesthesia and the strong positive rate of SⅠt after topical anesthesia in patients with aqueous-deficiency dry eye (ADDE) were significantly higher than those in total patients whereas those in patients with evaporative dry eye (EDE) were significantly lower than those in total patients (P <0.001). ·CONCLUSION:SⅠt after topical anesthesia with 0.5% proparacaine hydrochloride eye drops is more objective and reliable than that without anesthesia in reflecting the status of DE, and its diagnostic value in patients with ADDE was even higher, making itself a meaningful evidence for the diagnosis and treatment of DE.展开更多
In recent years,there is a scenario in urban tunnel constructions to build super-large-span tunnels for traffic diversion and route optimization purposes.However,the increased size makes tunnel support more difficult....In recent years,there is a scenario in urban tunnel constructions to build super-large-span tunnels for traffic diversion and route optimization purposes.However,the increased size makes tunnel support more difficult.Unfortunately,there are few studies on the failure and support mechanism of the surrounding rocks in the excavation of supported tunnel,while most model tests of super-large-span tunnels focus on the failure characteristics of surrounding rocks in tunnel excavation without supports.Based on excavation compensation method(ECM),model tests of a super-large-span tunnel excavation by different anchor cable support methods in the initial support stage were carried out.The results indicate that during excavation of super-large-span tunnel,the stress and displacement of the shallow surrounding rocks decrease,following a step-shape pattern,and the tunnel failure is mainly concentrated on the vault and spandrel areas.Compared with conventional anchor cable supports,the NPR(negative Poisson’s ratio)anchor cable support is more suitable for the initial support stage of the super-large-span tunnels.The tunnel support theory,model test materials,methods,and the results obtained in this study could provide references for study of similar super-large-span tunnels。展开更多
Huaihe River Basin(HRB) is located in China’s north-south climatic transition zone,which is very sensitive to global climate change.Based on the daily maximum temperature,minimum temperature,and precipitation data of...Huaihe River Basin(HRB) is located in China’s north-south climatic transition zone,which is very sensitive to global climate change.Based on the daily maximum temperature,minimum temperature,and precipitation data of 40 meteorological stations and nine monthly large-scale ocean-atmospheric circulation indices data during 1959–2019,we present an assessment of the spatial and temporal variations of extreme temperature and precipitation events in the HRB using nine extreme climate indices,and analyze the teleconnection relationship between extreme climate indices and large-scale ocean-atmospheric circulation indices.The results show that warm extreme indices show a significant(P < 0.05) increasing trend,while cold extreme indices(except for cold spell duration) and diurnal temperature range(DTR) show a significant decreasing trend.Furthermore,all extreme temperature indices show significant mutations during 1959-2019.Spatially,a stronger warming trend occurs in eastern HRB than western HRB,while maximum 5-d precipitation(Rx5day) and rainstorm days(R25) show an increasing trend in the southern,central,and northwestern regions of HRB.Arctic oscillation(AO),Atlantic multidecadal oscillation(AMO),and East Atlantic/Western Russia(EA/WR) have a stronger correlation with extreme climate indices compared to other circulation indices.AO and AMO(EA/WR) exhibit a significant(P < 0.05) negative(positive)correlation with frost days and diurnal temperature range.Extreme warm events are strongly correlated with the variability of AMO and EA/WR in most parts of HRB,while extreme cold events are closely related to the variability of AO and AMO in eastern HRB.In contrast,AMO,AO,and EA/WR show limited impacts on extreme precipitation events in most parts of HRB.展开更多
To make oral test accurately reflect the actual English spoken ability of candidates and play its role in guiding and promoting the improvement of English learners in the teaching, we must ensure that the design of sc...To make oral test accurately reflect the actual English spoken ability of candidates and play its role in guiding and promoting the improvement of English learners in the teaching, we must ensure that the design of scientific questions, the feasibility and validity of judgments to make an accurate and fair measurement of testers' language ability.展开更多
AIM: To determine the role of subjective assessment using Mc Monnies dry eye questionnaire in diagnosing dry eye disease and its association with clinical tests.METHODS: There were 500 patients screened for dry eye us...AIM: To determine the role of subjective assessment using Mc Monnies dry eye questionnaire in diagnosing dry eye disease and its association with clinical tests.METHODS: There were 500 patients screened for dry eye using Mc Monnies dry eye questionnaire between May to October 2013 at the outpatient Department of Ophthalmology of a medical college hospital. All 500 patients were subjected to clinical tests. Dry eye was defined as having one or more symptoms often or all the time. Positive signs were if one or both eyes revealed tear film breakup time(TBUT) of ≤10s, a Schirmer test score of ≤10 mm, a Rose Bengal staining score of ≥1, a Lissamine green staining score of ≥1 or existence of meibomian gland disease(≥grade 1). Statistical analysis was performed to describe the distribution of symptoms and signs, to assess the correlations between Mc Monnies score(MS) and variable clinical signs of dry eye, and to explore the association between dry eye symptoms and variable clinical signs. Analysis was performed using software package Epi info. A Probability(P) value using Chi-square test of 【0.005 was taken as significant.· RESULTS: Dry eye prevalence with symptoms(questionnaire), Schirmer test, TBUT, Rose Bengal staining and Lissamine green staining was 25.6%,15.20%, 20.80%, 23.60%, and 22.60% respectively. Among those with severe symptoms(MS】20), 75.86% had a low TBUT(【10s), 58.62% had a low Schirmer’s I test(≤10 mm),86.20% had Rose Bengal staining score of ≥1, 79.31%had Lissamine green staining score of ≥1. We found statistically significant associations between positive Schirmer test and arthritis(P 【0.002), dryness elsewhere(P 【0.001), contact lens use(P 【 0.002), systemic medication(P 【0.0001), sleeping with eyes partly open(P 【0.002), history of dry eyes treatment(P 【0.0001),environmental factors(P 【0.001), swimming(P 【0.001).· CONCLUSION: Subjective assessment plays an important role in diagnosing dry eye disease. There is strong correlation between MS and Schirmer test, TBUT,Rose Bengal staining and Lissamine green staining in normal as well as marginal and pathological dry eye.展开更多
AIM To assess the diagnostic accuracy of a new fecal test for detecting Helicobacter pylori(H. pylori), using ^(13)Curea breath test as the reference standard, and explore bacterial antibiotic resistance. METHODS We c...AIM To assess the diagnostic accuracy of a new fecal test for detecting Helicobacter pylori(H. pylori), using ^(13)Curea breath test as the reference standard, and explore bacterial antibiotic resistance. METHODS We conducted a prospective two-center diagnostic test accuracy study. We enrolled consecutive people≥ 18 years without previous diagnosis of H. pylori infection, referred for dyspepsia between February and October 2017. At enrollment, all participants underwent 13 C-urea breath test. Participants aged over 50 years were scheduled to undergo upper endoscopy with histology. Participants collected stool samples 1-3 d after enrollment for a new fecal investigation(THD fecal test). The detection of bacterial 23 S rRNA subunit gene indicated H. pylori infection. We also used the index diagnostic test to examine mutations conferring resistance to clarithromycin and levofloxacin. Independent investigators analyzed index test and reference test standard results blinded to the other test findings. We estimated sensitivity, specificity, positive(PPV) and negative(NPV) predictive value, diagnostic accuracy, positive and negative likelihood ratio(LR), together with 95% confidence intervals(CI).RESULTS We enrolled 294 consecutive participants(age: Median 37.0 years, IQR: 29.0-46.0 years; men: 39.8%). Ninetyfive(32.3%) participants had a positive ^(13)C-urea breath test. Twenty-three(7.8%) participants underwent upper endoscopy with histology, with a full concordance between ^(13)C-urea breath test and histology in detecting H. pylori infection. Four(1.4%) out of the 294 participants withdrew from the study after the enrollment visit and did not undergo THD fecal testing. In the 290 participants who completed the study, the THD fecal test sensitivity was 90.2%(CI: 84.2%-96.3%), specificity 98.5%(CI:96.8%-100%), PPV 96.5%(CI: 92.6%-100%), NPV 95.6%(CI: 92.8%-98.4%), accuracy 95.9%(CI: 93.6%-98.2%), positive LR 59.5(CI: 19.3-183.4), negative LR 0.10(CI: 0.05-0.18). Out of 83 infected participants identified with the THD fecal test, 34(41.0%) had bacterial genotypic changes consistent with antibiotic-resistant H. pylori infection. Of these, 27(32.5%) had bacterial strains resistant to clarithromycin, 3(3.6%) to levofloxacin, and 4(4.8%) to both antibiotics. CONCLUSION The THD fecal test has high performance for the non-invasive diagnosis of H. pylori infection while additionally enabling the assessment of bacterial antibiotic resistances.展开更多
Mechanical properties of structural materials are particularly important for design, performance realization and reliability analysis of microelectromechanical systems (MEMS). Furthermore, accurate database of mecha...Mechanical properties of structural materials are particularly important for design, performance realization and reliability analysis of microelectromechanical systems (MEMS). Furthermore, accurate database of mechanical properties at the micro scale can provide indispensable reference for establishing MEMS standard. Electroplated nickel film is one of the most favored structural materials used in MEMS, thus its mechanical properties has been studied for many years. However, the measured values show large scatter in Yotmg's modulus of nickel film. Young's modulus and yield stress of electroplated nickel film are measured by using a micro-tensile testing instrument. The tensile load applied on the specimen is measured by a load cell with accuracy 0.25 mN directly, without additional friction. Through measuring the axial stiffness coefficient of the tensile instnunent in situ, the tensile strain of the specimen is obtained by using two-serial spring model. The electroplated nickel films were fabricated from sulfarnate baths, and the gauge section is 500μm long and 10μm wide nominally, and thickness range between 25 μm and 50μm. The obtained Young's modulus from tensile testing is 83+6 GPa for nickel specimens electroplated at current density of 20 mA/cm2 and it increases to 124+5 GPa as current density is decreased to 10 mA/cm2. The phenomena are interpreted in terms of porosity of microstructure. The higher current density produced rnicrostucture with low density and high volume fraction of pores, and the microstructure of high porosity corresponds to a lower modulus. The measured values of Young's modulus are consistent with those of calculated from the exponential empirical formula between Young's modulus and porosity. The micro-tensile testing instrument can also be used for mechanical measurement of other MEMS films.展开更多
文摘·AIM:To determine the value of Schirmer Ⅰtest (SⅠt) without anesthesia and with topical anesthesia for diagnosing dry eye (DE). ·METHODS:Totally 220 eyes in 110 patients, male (44) and female (66), (39.56±12.67) years old diagnosed with DE were examined. SⅠt without anesthesia was performed firstly, and 15 minutes later, it was applied again in the same person after topical anesthesia with 0.5% proparacaine hydrochloride eye drops. The wetting strips counted <10mm per 5 minutes were defined positive, while ≤5mm per 5 minutes were defined strong positive. ·RESULTS:The wetting length in SⅠt after topical anesthesia was significantly lower than that in SⅠt without anesthesia(P < 0.001). The positive rate and strong positive rate of SⅠt after topical anesthesia were significantly higher than that of SⅠt without anesthesia (P <0.001). The positive rate and strong positive rate of SⅠt without anesthesia and the strong positive rate of SⅠt after topical anesthesia in patients with aqueous-deficiency dry eye (ADDE) were significantly higher than those in total patients whereas those in patients with evaporative dry eye (EDE) were significantly lower than those in total patients (P <0.001). ·CONCLUSION:SⅠt after topical anesthesia with 0.5% proparacaine hydrochloride eye drops is more objective and reliable than that without anesthesia in reflecting the status of DE, and its diagnostic value in patients with ADDE was even higher, making itself a meaningful evidence for the diagnosis and treatment of DE.
基金supported by the Innovation Fund Research Project of State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology(Grant No.SKLGDUEK202201)the Foundation for the Opening of State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology(Grant No.SKLGDUEK2129)the Open Research Fund of State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences(Grant No.Z020007)。
文摘In recent years,there is a scenario in urban tunnel constructions to build super-large-span tunnels for traffic diversion and route optimization purposes.However,the increased size makes tunnel support more difficult.Unfortunately,there are few studies on the failure and support mechanism of the surrounding rocks in the excavation of supported tunnel,while most model tests of super-large-span tunnels focus on the failure characteristics of surrounding rocks in tunnel excavation without supports.Based on excavation compensation method(ECM),model tests of a super-large-span tunnel excavation by different anchor cable support methods in the initial support stage were carried out.The results indicate that during excavation of super-large-span tunnel,the stress and displacement of the shallow surrounding rocks decrease,following a step-shape pattern,and the tunnel failure is mainly concentrated on the vault and spandrel areas.Compared with conventional anchor cable supports,the NPR(negative Poisson’s ratio)anchor cable support is more suitable for the initial support stage of the super-large-span tunnels.The tunnel support theory,model test materials,methods,and the results obtained in this study could provide references for study of similar super-large-span tunnels。
基金Under the auspices of National Natural Science Foundation of China(No.52279016,51909106,51879108,42002247,41471160)Natural Science Foundation of Guangdong Province,China(No.2020A1515011038,2020A1515111054)+1 种基金Special Fund for Science and Technology Development in 2016 of Department of Science and Technology of Guangdong Province,China(No.2016A020223007)the Project of Jinan Science and Technology Bureau(No.2021GXRC070)。
文摘Huaihe River Basin(HRB) is located in China’s north-south climatic transition zone,which is very sensitive to global climate change.Based on the daily maximum temperature,minimum temperature,and precipitation data of 40 meteorological stations and nine monthly large-scale ocean-atmospheric circulation indices data during 1959–2019,we present an assessment of the spatial and temporal variations of extreme temperature and precipitation events in the HRB using nine extreme climate indices,and analyze the teleconnection relationship between extreme climate indices and large-scale ocean-atmospheric circulation indices.The results show that warm extreme indices show a significant(P < 0.05) increasing trend,while cold extreme indices(except for cold spell duration) and diurnal temperature range(DTR) show a significant decreasing trend.Furthermore,all extreme temperature indices show significant mutations during 1959-2019.Spatially,a stronger warming trend occurs in eastern HRB than western HRB,while maximum 5-d precipitation(Rx5day) and rainstorm days(R25) show an increasing trend in the southern,central,and northwestern regions of HRB.Arctic oscillation(AO),Atlantic multidecadal oscillation(AMO),and East Atlantic/Western Russia(EA/WR) have a stronger correlation with extreme climate indices compared to other circulation indices.AO and AMO(EA/WR) exhibit a significant(P < 0.05) negative(positive)correlation with frost days and diurnal temperature range.Extreme warm events are strongly correlated with the variability of AMO and EA/WR in most parts of HRB,while extreme cold events are closely related to the variability of AO and AMO in eastern HRB.In contrast,AMO,AO,and EA/WR show limited impacts on extreme precipitation events in most parts of HRB.
文摘To make oral test accurately reflect the actual English spoken ability of candidates and play its role in guiding and promoting the improvement of English learners in the teaching, we must ensure that the design of scientific questions, the feasibility and validity of judgments to make an accurate and fair measurement of testers' language ability.
基金Supported partly by Indian Council of Medical Research(ICMR)
文摘AIM: To determine the role of subjective assessment using Mc Monnies dry eye questionnaire in diagnosing dry eye disease and its association with clinical tests.METHODS: There were 500 patients screened for dry eye using Mc Monnies dry eye questionnaire between May to October 2013 at the outpatient Department of Ophthalmology of a medical college hospital. All 500 patients were subjected to clinical tests. Dry eye was defined as having one or more symptoms often or all the time. Positive signs were if one or both eyes revealed tear film breakup time(TBUT) of ≤10s, a Schirmer test score of ≤10 mm, a Rose Bengal staining score of ≥1, a Lissamine green staining score of ≥1 or existence of meibomian gland disease(≥grade 1). Statistical analysis was performed to describe the distribution of symptoms and signs, to assess the correlations between Mc Monnies score(MS) and variable clinical signs of dry eye, and to explore the association between dry eye symptoms and variable clinical signs. Analysis was performed using software package Epi info. A Probability(P) value using Chi-square test of 【0.005 was taken as significant.· RESULTS: Dry eye prevalence with symptoms(questionnaire), Schirmer test, TBUT, Rose Bengal staining and Lissamine green staining was 25.6%,15.20%, 20.80%, 23.60%, and 22.60% respectively. Among those with severe symptoms(MS】20), 75.86% had a low TBUT(【10s), 58.62% had a low Schirmer’s I test(≤10 mm),86.20% had Rose Bengal staining score of ≥1, 79.31%had Lissamine green staining score of ≥1. We found statistically significant associations between positive Schirmer test and arthritis(P 【0.002), dryness elsewhere(P 【0.001), contact lens use(P 【 0.002), systemic medication(P 【0.0001), sleeping with eyes partly open(P 【0.002), history of dry eyes treatment(P 【0.0001),environmental factors(P 【0.001), swimming(P 【0.001).· CONCLUSION: Subjective assessment plays an important role in diagnosing dry eye disease. There is strong correlation between MS and Schirmer test, TBUT,Rose Bengal staining and Lissamine green staining in normal as well as marginal and pathological dry eye.
文摘AIM To assess the diagnostic accuracy of a new fecal test for detecting Helicobacter pylori(H. pylori), using ^(13)Curea breath test as the reference standard, and explore bacterial antibiotic resistance. METHODS We conducted a prospective two-center diagnostic test accuracy study. We enrolled consecutive people≥ 18 years without previous diagnosis of H. pylori infection, referred for dyspepsia between February and October 2017. At enrollment, all participants underwent 13 C-urea breath test. Participants aged over 50 years were scheduled to undergo upper endoscopy with histology. Participants collected stool samples 1-3 d after enrollment for a new fecal investigation(THD fecal test). The detection of bacterial 23 S rRNA subunit gene indicated H. pylori infection. We also used the index diagnostic test to examine mutations conferring resistance to clarithromycin and levofloxacin. Independent investigators analyzed index test and reference test standard results blinded to the other test findings. We estimated sensitivity, specificity, positive(PPV) and negative(NPV) predictive value, diagnostic accuracy, positive and negative likelihood ratio(LR), together with 95% confidence intervals(CI).RESULTS We enrolled 294 consecutive participants(age: Median 37.0 years, IQR: 29.0-46.0 years; men: 39.8%). Ninetyfive(32.3%) participants had a positive ^(13)C-urea breath test. Twenty-three(7.8%) participants underwent upper endoscopy with histology, with a full concordance between ^(13)C-urea breath test and histology in detecting H. pylori infection. Four(1.4%) out of the 294 participants withdrew from the study after the enrollment visit and did not undergo THD fecal testing. In the 290 participants who completed the study, the THD fecal test sensitivity was 90.2%(CI: 84.2%-96.3%), specificity 98.5%(CI:96.8%-100%), PPV 96.5%(CI: 92.6%-100%), NPV 95.6%(CI: 92.8%-98.4%), accuracy 95.9%(CI: 93.6%-98.2%), positive LR 59.5(CI: 19.3-183.4), negative LR 0.10(CI: 0.05-0.18). Out of 83 infected participants identified with the THD fecal test, 34(41.0%) had bacterial genotypic changes consistent with antibiotic-resistant H. pylori infection. Of these, 27(32.5%) had bacterial strains resistant to clarithromycin, 3(3.6%) to levofloxacin, and 4(4.8%) to both antibiotics. CONCLUSION The THD fecal test has high performance for the non-invasive diagnosis of H. pylori infection while additionally enabling the assessment of bacterial antibiotic resistances.
基金supported by National Natural Science Foundation of China (Grant No. 50535030)National Basic Research Program of China (973 Program, Grant No. 2006CB300407)
文摘Mechanical properties of structural materials are particularly important for design, performance realization and reliability analysis of microelectromechanical systems (MEMS). Furthermore, accurate database of mechanical properties at the micro scale can provide indispensable reference for establishing MEMS standard. Electroplated nickel film is one of the most favored structural materials used in MEMS, thus its mechanical properties has been studied for many years. However, the measured values show large scatter in Yotmg's modulus of nickel film. Young's modulus and yield stress of electroplated nickel film are measured by using a micro-tensile testing instrument. The tensile load applied on the specimen is measured by a load cell with accuracy 0.25 mN directly, without additional friction. Through measuring the axial stiffness coefficient of the tensile instnunent in situ, the tensile strain of the specimen is obtained by using two-serial spring model. The electroplated nickel films were fabricated from sulfarnate baths, and the gauge section is 500μm long and 10μm wide nominally, and thickness range between 25 μm and 50μm. The obtained Young's modulus from tensile testing is 83+6 GPa for nickel specimens electroplated at current density of 20 mA/cm2 and it increases to 124+5 GPa as current density is decreased to 10 mA/cm2. The phenomena are interpreted in terms of porosity of microstructure. The higher current density produced rnicrostucture with low density and high volume fraction of pores, and the microstructure of high porosity corresponds to a lower modulus. The measured values of Young's modulus are consistent with those of calculated from the exponential empirical formula between Young's modulus and porosity. The micro-tensile testing instrument can also be used for mechanical measurement of other MEMS films.