Main focus of parents of children with attention deficit hyperactivity disorder and the effectiveness of early clinical screening

BACKGROUND Attention deficit hyperactivity disorder(ADHD)is a common mental and behavioral disorder among children.AIM To explore the focus of attention deficit hyperactivity disorder parents and the effectiveness of early clinical screening METHODS This study found that the main directions of parents seeking medical help were short attention time for children under 7 years old(16.6%)and poor academic performance for children over 7 years old(12.1%).We employed a two-stage experiment to diagnose ADHD.Among the 5683 children evaluated from 2018 to 2021,360 met the DSM-5 criteria.Those diagnosed with ADHD underwent assessments for letter,number,and figure attention.Following the exclusion of ADHD-H diagnoses,the detection rate rose to 96.0%,with 310 out of 323 cases identified.RESULTS This study yielded insights into the primary concerns of parents regarding their children's symptoms and validated the efficacy of a straightforward diagnostic test,offering valuable guidance for directing ADHD treatment,facilitating early detection,and enabling timely intervention.Our research delved into the predominant worries of parents across various age groups.Furthermore,we showcased the precision of the simple exclusion experiment in discerning between ADHD-I and ADHD-C in children.CONCLUSION Our study will help diagnose and guide future treatment directions for ADHD.

Assessment of liquefaction potential based on shear wave velocity:Strain energy approach

Liquefaction assessment based on strain energy is significantly superior to conventional stress-based methods.The main purpose of the present study is to investigate the correlation between shear wave velocity and strain energy capacity of silty sands.The dissipated energy until liquefaction occurs was calculated by analyzing the results of three series of comprehensive cyclic direct simple shear and triaxial tests on Ottawa F65,Nevada,and Firoozkuh sands with varying silt content by weight and relative densities.Additionally,the shear wave velocity of each series was obtained using bender element or resonant column tests.Consequently,for the first time,a liquefaction triggering criterion,relating to effective overburden normalized liquefaction capacity energy(WL=s’c)to effective overburden stresscorrected shear wave velocity(eVs1)has been introduced.The accuracy of the proposed criteria was evaluated using in situ data.The results confirm the ability of shear wave velocity as a distinguishing parameter for separating liquefied and non-liquefied soils when it is calculated against liquefaction capacity energy(WL=s’c).However,the proposed WL=s’c-Vs1 curve,similar to previously proposed cyclic resistance ratio(CRR)-Vs1 relationships,should be used conservatively for fields vulnerable to liquefaction-induced lateral spreading.

Field Evaluation of Alternative Testing Strategies for the Detection of HIV Infection in Beijing

To identify a cost-efficient altemative antibody testing strategy for screening and confirmation of HIV infection by rapid simple tests （RSTs） and enzyme-linked immunosorbent assays （ELISAs）. Methods Four RSTs （RST1, RST2, RST3, and RST4 ） and five ELISAs （ELISA1, ELISA2, ELISA3, ELISA4, and ELISA5） were evaluated in two phases by using banked and serum specimens prospectively collected at regional hospitals and voluntary counseling and testing （VCT） centers in Beijing. A total of 200 banked serum specimens were included in the first phase, including 62 HIV-positive, 127 HIV-negative and 11 indeterminate specimens. All specimens were tested by four RSTs and five ELISAs respectively. The second phase involved prospective testing of 389 routine specimens, including 92 HIV-positive, 287 HIV-negative, and 10 indeterminate specimens. All the specimens were tested by two RSTs （RST2 and RST4） and three ELISAs （ELISA1, ELISA3, and ELISA4）, which were selected for their respective excellent sensitivity and/or specificity. Westem blot （WB） was used as a gold standard for confirming the reactivity of all the specimens. Results Sensitivity, specificity, and efficacy were calculated for each assay in two phases. In the first phase, four assays （ELISA4, RST2, RST3, and RST4） had a specificity of 100%. For the determination of efficacy, ELISA4, RST2, and RST4 were selected in the second phase. ELISA1 and ELISA3 which have a sensitivity of 95.9% and 93.2% respectively also entered this phase. In the second phase, all the five assays （ELISA1, ELISA3, ELISA4, RST2, and RST4） had a sensitivity and specifity of over 90%. ELISA1 had a sensitivity of 99% and ELISA4 a specificity of 99%. Conclusion The sensitivity ELISA1 and the specificit of ELISA4 are comparable to ELISA/WB standard strategy. Application of this alternative testing strategy provides a cost-effective method for determining HIV prevalence in Beijing.

Comparison of invasive methods and two different stool antigen tests for diagnosis of H pylori infection in patients with gastric bleeding

AIM： To compare two different H pylori stool antigen tests as noninvasive diagnostic methods. METHODS： The study population consisted of 22 upper gastrointestinal system bleeding patients. Urea breath test （UBT）, rapid urease test （RUT） and histopathological examination were applied to all patients. Stool specimens from these patients were examined by rapid STPIP!HpSA and one step simple H pylori antigen cassette test for the detection of Hpylori antigens. RESULTS： For these 22 patients, 15 （68.2%） were diagnosed as positive and seven （31.8%） were diagnosed negative for H pylori infection by the gold standard methods. Whereas 10 （45.5%） were positive and 12 （54.5%） were diagnosed negative by the rapid STPIP!HpSA test. The sensitivity, specificity, positive and negative predictive values were 60%, 86%, 90% and 50%, respectively. When compared to the gold standard methods, these differences were not significant. However, six patients （27.3%） were positive, and 16 （72.7%） were negative by the simple H pylori stool antigen cassette test. The sensitivity, specificity, positive and negative predictive values were 33%, 86%, 83% and 38%, respectively. Compared to the gold standard methods, the simple H pylori stool antigen cassette test results were significantly different （P = 0.012）. CONCLUSION： Rapid STRIP!HpSA test could be used as a routine diagnostic tool in the microbiology laboratory for assessing clinical significance and eradication control of H pylori in upper gastrointestinal system bleeding patients.

Design and verification of portable direct shear tester with application to remolded colluvium geomaterials

The mechanical properties of colluvium strongly govern the stability of colluvial slopes, and they arc essential for the related analysis and design. Nevertheless, their measurement is not easy on account of heterogeneity in property and difficulty of sampling. This study attempted to evaluate the shear strength of remolded colluvium by means of a simple direct shear test in the field. A portable direct shear tester was designed to overcome the inconvenience and expensiveness of the conventional large-scale in-situ direct shear test. It can be easily assembled and applied for the silnplc field direct shear test. For calibration, the results of the portable direct shear tester were compared with the results of the laboratory direct shear tester for four different types of soil samples, i.e. standard sand, slate debris, arenaceous shale debris and mixture of gravel and sand. Correlation formulas were established based on the calibration, enabling the portable direct shear tester to measure and estimate the shear strength of remoldcd colluvium in field. This study primarily focuses on the colluvium in Central Taiwan, including the lateritic Dadu Terrace and the arcnaceous shale of Taiping-Wufcng mounts. The portable direct shear tester was applied to sites selected in these areas, and the results were furthcr analyzed and discussed.

基于响应面法的不同配比沥青混凝土性能平衡优化设计

采用4种不同标号沥青及3种油石比制备12组沥青混合料,通过车辙试验、Overlay Tester(OT)试验以及动态模量试验评价其高温性能、低温性能和力学性能。采用响应面法对不同沥青混合料的高温性能、低温抗裂性能、疲劳性能和力学性能进行平衡性分析。结果表明,采用高油石比和低标号沥青可显著提高混合料的高温性能及力学性能且具有一定的抗裂性能,根据性能叠加图推荐了满足高模量沥青混凝土高温性能、抗裂性能与力学性能标准的沥青标号与油石比范围,其结果对于合理进行不同标号沥青混凝土配合比设计具有较大的参考价值。

An elasto-plastic constitutive model incorporating strain softening and dilatancy for interface thin-layer element and its verification

The mechanical behaviors of the interface between coarse-grained soil and concrete were investigated by simple shear tests under condition of mixed soil slurry (bentonite mixed with cement grout).For comparison,the interfaces both without slurry and with bentonite slurry were analyzed.The experimental results show that different slurries exert much influence on the strength and deformation of soil/structure interface.Under mixed soil slurry,strain softening and shear dilatation are observed,while shear dilatation appears under the small normal stress of the interface without slurry,and shear contraction is significant under the condition of the bentonite slurry.The thickness of the interface was determined by analyzing the disturbed height of the sample with both simple shear test and particle flow code (PFC).An elasto-plastic constitutive model incorporating strain softening and dilatancy for thin layer element of interface was formulated in the framework of generalized potential theory.The relation curves of shear stress and shear strain,as well as the relation curves of normal strain and shear strain,were fitted by a piecewise function composed by hyperbolic functions and resembling normal functions.The entire model parameters can be identified by tests.The new model is verified by comparing the measured data of indoor cut-off wall model tests with the predictions from finite element method (FEM).The FEM results indicate that the stress of wall calculated by using Goodman element is too large,and the maximum deviation between the test data and prediction is about 45%.While the prediction from the proposed model is close to the measured data,and the error is generally less than 10%.

Macro- and micromechanical evaluation of cyclic simple shear test by discrete element method

Direct simple shear tests are considered to be simple laboratory tests that are capable of imposing a cyclic loading that is analogous to that induced by earthquakes. A realistic evaluation of the test results demands a profound micromechanical investigation of specimens. Three-dimensional discrete element method models of a stacked-ring simple shear test were constructed, in which monotonic and cyclic loadings were applied under constant-volume conditions, and good agreement between the monotonic and cyclic macromechanical behaviors was noted. Micromechanical properties of specimens that were subjected to a cyclic loading are discussed in terms of lateral and intermediate principal stress development, fabric anisotropy, and principal stress rotation. The stress and strain states inside the specimen were investigated and it was shown that despite the uniform stress distribution inside the specimen, the volumetric strain distributes non-uniformly during loading and the non-uniformity grows with cycling, which leads to localized zones of dilative and contractive behavior.

Non-Probabilistic Approach to the Time of Energy Emission in Small Quantum Systems

The energy emitted by an electron in course of its transition between two quantum levels can be considered as a dissipated energy. This energy is obtained within a definite interval of time. The problem of the size of the time interval necessary for transitions is examined both on the ground of the quantum approach as well as classical electrodynamics. It is found that in fact the emission time approaches the time interval connected with acceleration of a classical velocity of the electron particle from one of its quantum levels to a neighbouring one.

Behavior of compacted clay-concrete interface

Tests of interface between compacted clay and concrete were conducted systematically using interface simple shear test apparatus.The samples,having same dry density with different water content ratio,were prepared.Two types of concrete with different surface roughness,i.e.,relatively smooth and relatively rough surface roughness,were also prepared.The main objectives of this paper are to show the effect of water content,normal stress and rough surface on the shear stress-shear displacement relationship of clay-concrete interface.The following were concluded in this study:1)the interface shear sliding dominates the interface shear displacement behavior for both cases of relatively rough and smooth concrete surface except when the clay water content is greater than 16%for the case of rough concrete surface where the shear failure occurs in the body of the clay sample;2)the results of interface shear strength obtained by direct shear test were different from that of simple shear test for the case of rough concrete surface;3)two types of interface failure mechanism may change each other with different water content ratio;4)the interface shear strength increases with increasing water content ratio especially for the case of clay-rough concrete surface interface.

An examination of the mechanical interaction of drilling slurries at the soil-concrete contact

Evidence gained from previous field tests conducted on drilled shaft foundation shows that using drilling slurries to stabilize a borehole during the construction may influence the interfacial shear strength.This paper deals with an exhaustive study of the effects of drilling slurries at the contact between soil and concrete.This study involved adapting a simple shear apparatus and performing approximately 100 experimental tests on the interaction between two types of soils;clay and sandy clay and five specimens of concrete with different surface shapes.It also involved using bentonite and polymer slurries as an interface layer between soil and concrete.Results showed that an interface layer of bentonite slurry between clay and concrete decreases the interfacial shear strength by 23% and as an interface layer between sandy clay and concrete,bentonite increases interfacial shear strength by 10%.Using polymer slurry as an interface layer between clay and concrete decreases the interfacial shear strength by 17% while using it as an interface layer between sandy clay and concrete increases the interfacial shear strength by 10%.Furthermore,the data show that using bentonite and polymer slurry as an interface layer between clay and concrete decreases the sliding ratio by 50% to 60%,while increasing the sliding ratio by 44% to 56% when these are used as an interface layer between sandy clay and concrete.

Nonlinear elastic model for compacted clay concrete interface

In this paper,a nonlinear elastic model was developed to simulate the behavior of compacted clay concrete interface(CCCI)based on the principle of transition mechanism failure(TMF).A number of simple shear tests were conducted on CCCI to demonstrate different failure mechanisms;i.e.,sliding failure and deformation failure.The clay soil used in the test was collected from the"Shuang Jang Kou"earth rockfill dam project.It was found that the behavior of the interface depends on the critical water contents by which two failure mechanisms can be recognized.Mathematical relations were proposed between the shear at failure and water content in addition to the transition mechanism indicator.The mathematical relations were then incorporated into the interface model.The performance of the model is verified with the experimental results.The verification shows that the proposed model is capable of predicting the interface shear stress versus the total shear displacement very well.