Bigger Difference Research Articles

How much variability is there in children's experiences with different educators?

Early childhood education and care settings consist of educators clustered into classrooms, clustered into centers. Yet, little empirical research has examined variance in the interaction styles of full-time educators who work in the same classroom. In this study we engage in preliminary work to examine variability in children's experiences with different educators. The sample consisted of 172 full-time educators from 86 classrooms. We conducted hierarchical linear modeling using the difference in the interaction styles of the two educators in each classroom as the outcome. Educators’ interaction styles were measured using the Responsive Interactions for Learning (RIFL-E) scale. Approximately 58% of the variance was accounted for at the classroom level and 42% at the center level. Educators with similar interaction styles tended to be grouped together in classrooms. Classrooms where educators had smaller discrepancies in interaction styles had higher overall quality and a higher percentage of educators with early childhood education degrees, but a bigger difference between educator's highest level of education. These findings highlight the importance of considering educator-level variance in conceptualizing and measuring quality. Implications for how quality of educator/child interaction is conceptualized and measured, and research and policy on oversight and quality improvement are discussed.

Investigation on subsurface vortices within a closed pump intake under different pressure conditions

An experimental study to investigate various features of subsurface vortices and their evolutions inside a closed pump intake under different pressure conditions at free surface, and to analyze the influence of a pipe bell with different mean axial velocities at the same water level on flow patterns is presented. For all cases, three different flow regimes are closely observed: various side-wall attached, back-wall attached and submerged vortices structures, and their evolutions are subject to the free-surface pressure for a critical flow rate, the number and strength of all these vortex rise as the absolute value of the pressure increases for a higher flow rate, for a lower flow rate, whether the side-wall vortices occur or not is related closely to the pressure magnitude, and there are no vortices for lower absolute pressure values, the number and the strength of the side-wall vortices increase as the absolute pressure values increase. Besides, based on statistical analyses, the side-wall vortex probability on the right side along the stream-wise direction is much higher than that on the opposite side for all operation cases, particularly single vortex probability, and the back-wall vortex probabilities are quite higher with values of more than 90%, meanwhile, the multi-vortices probability is much higher than that of the single-vortex. The captured vortices have been qualitatively classified into different “vortex zones”: no vortex zones and vortex zones including transition, single- and multi-vortex. The Reynolds number and the absolute value pressure are the most important parameters which influence the existence and the number of these vortices, and the increase of the two parameters reduces the no vortex transition zone and causes bigger difference in the back-wall and side-wall vortex zones.

Configuration effect and bandgap mechanism of quasi-one-dimensional periodic lattice structure

Considering the extensive application of periodic structure and bandgap feature of periodic elastic metamaterial, this paper presents the bandgap mechanism and characteristics of two types of complex periodic lattices for vibration attenuation. Specifically, the function of the spring and mass elements acting on the bandgap in periodic system is studied to understand the coupling mechanism of the lattice structure with complex configuration. The analytical expressions of the critical values for the mass, stiffness and configuration angle of the lattice to ensure the existence of the bandgap are obtained. The parameter effects on the bandgap width are studied as the bigger difference between the masses in the two chains, the larger the stiffness ratio, the smaller the angle α(α ≠ 0), the wider the bandgap. The bandgaps of the proposed Models 1 and 2 are 64.8% and 75.9% wider than that of the classical Model T.

Urban-rural carbon footprint disparity across China from essential household expenditure: Survey-based analysis, 2010–2014

Household activities have become an increasingly important driver of carbon emission in China during economic transition. In quest of a more coordinated and efficient mitigation strategy, it is crucial to track the dynamics of carbon footprint discrepancy between urban and rural households across various regions. In this study, combing household-level expenditure survey with multi-regional input-output model, we quantify the urban-rural carbon footprint disparity originated from six essential expenditure categories, they are food, clothing, housing, utility, transport, and post and telecommunication. We assess the roles these essential consumptions play in contributing to carbon footprint disparity across different provincial regions in China during 2010–2014. The results show that the overall per capita household carbon footprint in China increased by 202% during this period, but the annual growth rate actually decreased from 27.5% to 11.4%. Despite urban-rural disparity expanded by 155% over 2010–2014, the annual changing rate slowed down (from 14.9% to 8.2%). Although the per capita carbon footprints in some less-developed regions such as northwest, northeast and central provinces are relatively small, they tend to have a bigger difference between urban and rural households than other more-developed provinces. The expenditure on utility and food plays a major part in urban-rural carbon footprint disparity for most regions, and their share has been increasing over time. Though historically, income inequality tends to be lower with increase in household income and footprint, this lifting effect becomes more uncertain when regions are moving towards a more developed stage.

Prediction of Landslide Position of Loose Rock Mass at Mountain Tunnel Exit

Landslide of loose rock mass at mountain tunnel exit occurs easily, and prediction of landslide position is one of the engineering problems to be solved urgently. Currently, existing and used prediction methods, such as field monitoring measurement, numerical analysis, nonlinear theories, and the geometric method, play a very important role and have their limitations. For example, there is a bigger difference between calculation mode by Wang et al.’s method and actual engineering situation; besides, there exists a relatively big discrepancy between the predicted and true position. Aiming to solve this problem, this article combined theoretical analysis and actual engineering situation to establish an optimal calculation mode. At the same time, this article re‐deduced instability criteria based on the stress‐transferring theory and examined the factors that influence solutions. The improved method can predict landslide position more accurately because the parameters (β, s, H, α, γ, c, φ, and T) related to the occurrence of landslide are taken into consideration. It is pointed out that landslide possibly occurs in the case of Δ ≥ 0 and Y ≤ 0. In addition, the equations s1 < s < s2 and 0 ≤ s ≤ H/sin α can determine landslide position accurately. The method is applied to two engineering examples, and the calculation results show that the deviations of predictive position from the actual landslide position are only 0.10% and 0.07%, respectively, indicating that prediction results are accurate and reliable. It is suggested that the proposed method is a useful tool in the design of tunnel engineering.

EXPERIMENTAL AND NUMERICAL RESEARCH ON FLOW IN THE LAST STAGE OF 1090MW STEAM TURBINE

The paper deals with experimental and numerical research in the last stage of real 1090MW steam turbine with the last steel blade length 1220mm placed in nuclear power station. The last stage was equipped with twelve static pressure taps. It was also possible to probe in two planes - before and behind the last stage using pneumatic or optical probes. A number of last stage flow parameters were determined at the root and tip wall for nominal turbine output. Among those parameters are static pressures, Mach and Reynolds numbers, last stage reactions and steam wetness. All the directly measured and evaluated flow parameters are taken from locally measured points and that is why even 3D CFD calculation of the whole system - last stage, diffuser and exhaust hood was implemented. Measured and calculated parameters are compared. Especially static pressures are in very good agreement; the only steam wetness has bigger difference due to different measurement position. Locally measured values are enough to estimate the flow behavior of the last stage. On the other hand, the CFD simulations with well determined boundary conditions, meshes and geometry and is effective tool to simulate even very complicated flow structures in the last stage and exhaust hood.

Comparison of Science Inquiry Ability and Scientific Thinking Ability between Gifted and Non-gifted Students

본 연구에서는 영재 학생과 일반 학생의 과학 탐구 능력과 과학적 사고력을 비교하였다. 연구 대상은 중학교 1 학년 재학 중인 과학 영재 학생 50 명과 일반 학생 64명이었다. 과학 탐구 능력을 검사하는 도구로 김수경 외 (2007) 가 개발한 ‘중학생의 과학 탐구 능력 측정을 위한 평가 도구’를 사용하였고 과학적 사고력을 검사하는 도구로 김소연 (2018)이 개발한 ‘과학 글쓰기를 활용한 과학적 사고력 평가 도구’ 중 ‘광합성’을 주제로 한 평가 도구를 사용하였다. 과학 탐구 능력 검사 결과, 총 26점 중 영재 학생의 평균은 24.26이고 일반 학생의 평균은 16.78로 .001 수준에서 유의한 차이가 나타났고, 기초 탐구 기능에 비해 통합 탐구 기능에서 더 큰 차이를 보였다. 요소별 비교를 한 결과, 기초 탐구 기능의 ‘측정’과 통합 탐구 기능의 ‘변인 통제’에서 두 집단 모두 평균이 낮았고, 기초 탐구 기능의 ‘의사소통’과 통합 탐구 기능의 ‘가설 설정’에서 두 집단 모두 평균이 높았다. 과학적 사고력 검사에서 총 36 점 중 영재 학생의 평균은 23.38이고 일반 학생은 14.66으로 .001 수준에서 유의한 차이가 있었고, 하위 영역인 귀납적, 연역적, 비판적, 창의적 사고력에서도 유의한 차이가 나타났다. 귀납적 사고력을 요구하는 문항에서는 영재 학생과 일반 학생 모두 하나의 근거만 제시하였다. 연역적 사고력을 요구하는 문항에서는 두 집단 모두 두 가지 이상의 근거를 제시하였으나 결론과 설명이 명확하지 않았다. 비판적 사고력을 요구하는 문항에서 영재 학생과 일반 학생 모두, 주장과 근거에 대한 설명과 부연 그 리고 반증이 부족하였다. 창의적 사고력을 요구하는 문항에서 영재 학생의 ‘ 독창성’ 요소의 점수가 다른 요소에 비해 상대적으로 낮았다. 과학 탐구 능력의 일부 요소의 경우 점수가 낮게 나타난 것을 볼 때 , 과학 탐구 능력의 요소별로 명시적으로 안내하고 연습할 기회를 제공할 필요가 있다. 그리고 과학적 사고력을 향상시키기 위해 주장에 대한 근거, 설명 부연, 반증을 하는 능력과 독창성에 중점을 두어 지도할 필요가 있다.In this study, science inquiry ability and scientific thinking ability of gifted students and non-gifted students were compared. The subjects of this study were 50 science gifted students and 64 non-gifted students in the first grade of middle school. ‘Test of science inquiry skills for middle school students’ developed by Kim et al.(2007) and ‘Evaluation instruments for scientific thinking ability using science writing’ developed by Kim(2018) were administered. In the science inquiry ability test, the mean of gifted students was 24.26 out of 26 points, and that of non-gifted students was 16.78. There was a significant difference at .001 level, and there was a bigger difference in integrated process skill compared to basic process skill. In both ‘measurement’ and ‘controling variables’, the means of the two groups were low, but in both ‘communication’ and ‘hypothesizing’, those of the two groups were high. In the scientific thinking ability test, the mean of gifted students was 23.38 out of 36 points and that of non-gifted students was 14.66. There was a significant difference at .001 level, and also significant differences in the sub-area ‘inductive’, ‘deductive’, ‘critical’, and ‘creative’ thinking. For the question requiring inductive thinking ability, both gifted students and non-gifted students presented only one data. In the question requiring deductive thinking ability, both groups provided more than two data, but the claim and explanation were not clear. They wrote the answers with lacked explanation, backing, and rebuttal for the question requiring critical thinking ability. The score of ‘originality’ element of gifted students was relatively lower than that of other elements in the question requiring creative thinking ability. It is necessary to provide the opportunities to guide and practice on the elements of science inquiry ability explicitly, and to emphasize on the data, explanation, backing, rebuttal of the claim and originality in order to improve scientific thinking ability.

Abnormal Anionic Porphyrin Sensing Effect for HER2 Gene Related DNA Detection via Impedance Difference between MWCNTs and Single-Stranded DNA or Double-Stranded DNA

Human epidermal growth factor receptor 2 (HER2) is a key tumor marker for several common and deadly cancers. It is of great importance to develop efficient detection methods for its over-expression. In this work, an electrochemical impedance spectroscopy (EIS) method adjustable by anionic porphyrin for HER2 gene detection has been proposed, based on the impedance difference between multi-walled carbon nanotubes (MWCNTs) and DNA. The interesting finding herein is that with the addition of anionic porphyrin, i.e., meso-tetra(4-sulfophenyl)-porphyrin (TSPP), the impedance value obtained at a glass carbon electrode (GCE) modified with MWCNTs and a single stranded DNA (ssDNA), the probe DNA that might be assembled tightly onto MWCNTs through π-π stacking interaction, gets a slight decrease; however, the impedance value from a GCE modified with MWCNTs and a double stranded DNA (dsDNA), the hybrid of the probe DNA with a target DNA, which might be assembled loosely onto MWCNTs for the screening effect of phosphate backbones in dsDNA, gets an obvious decrease. The reason may be that on the one hand, being rich in negative sulfonate groups, TSPP will try to push DNA far away from CNTs surface due to its strong electrostatic repulsion towards DNA; on the other hand, rich in planar phenyl or pyrrole rings, TSPP will compete with DNA for the surface of CNTs since it can also be assembled onto CNTs through conjugative interactions. In this way, the “loosely assembled” dsDNA will be repelled by this anionic porphyrin and released off CNTs surface much more than the “tightly assembled” ssDNA, leading to a bigger difference in the impedance value between dsDNA and ssDNA. Thus, through the amplification effect of TSPP on the impedance difference, the perfectly matched target DNA could be easily determined by EIS without any label. Under the optimized experimental conditions, this electrochemical sensor shows an excellent linear response to target DNA in a concentration range of 2.0 × 10−11–2.0 × 10−6 M with a limit of detection (LOD) of 6.34 × 10−11 M (S/N = 3). This abnormally sensitive electrochemical sensing performance resulting from anionic porphyrin for DNA sequences specific to HER2 gene will offer considerable promise for tumor diagnosis and treatment.

Optimal regulation of bipedal walking speed despite an unexpected bump in the road.

Bipedal locomotion may occur over imperfect surfaces with bumps or other features that disrupt steady gait. An unexpected bump in the road is generally expected to slow down most types of locomotion. On wheels, speed may be regained quite readily with “cruise control” performed in continuous time. But legged locomotion is less straightforward, because the stance leg may be under-actuated, and the continuous-time dynamics are periodically disrupted by discrete ground contact events. Those events may also afford good control opportunities, albeit subject to the delay between discrete opportunities. The regulation of walking speed should ideally use these opportunities to compensate for lost time, and with good economy if possible. However, the appropriate control strategy is unknown. Here we present how to restore speed and make up for time lost going over a bump in the road, through discrete, once-per-step control. We use a simple dynamic walking model to determine the optimal sequence of control actions—pushing off from the leg at the end of each stance phase—for fast response or best economy. A two-step, deadbeat sequence is the fastest possible response, and reasonably economical. Slower responses over more steps are more economical overall, but a bigger difference is that they demand considerably less peak power. A simple, reactive control strategy can thus compensate for an unexpected bump, with explicit trade-offs in time and work. Control of legged locomotion is not as straightforward as with wheels, but discrete control actions also allow for effective and economical reactions to imperfect terrain.

Examination of static and dynamic balance of brain injured patients in elastic space

The partial or complete loss of static and dynamic balance after vascular or traumatic brain injury is an important dysfunction in neurorehabilitation. The balance skills significantly contribute to gait ability, which determines the patient's living conditions and return to normal daily activities. The recovery of standing stability and walking ability are the most important elements of rehabilitation after brain injury. The purpose of this examination is to show the key elements of core stabilization, postural control, balance and coordination exercises with the use of vertical suspension and to analyze the effects with some tests among hemiparetic and ataxic patients. Twenty patients were assigned for follow-up study in 2 treatment groups (10 hemiparetic, 10 ataxic) and they completed average 30 minutes of special treatment (exercises in elastic space), 5 times a week over a period of 6 weeks. During the research the previously used conventional therapies were unchanged. In order to document the changes in the state of locomotion we used the following: transfers and locomotion items of the Functional Independence Measure (FIM), Fugl–Meyer Balance, Scale for the Assessment and Rating of Ataxia and Stabilometer device. Therapeutic exercises in elastic space were useful for both groups with regard to static and dynamic balance and stability of standing, however, better results were observed in the group of ataxic patients. The bigger difference over the obtained outcomes was demonstrated rather in the locomotion item of FIM and in the measurements of Stabilometer. The stability provided by springs and elastic ropes significantly contributes to proprioception and accurate body awareness in space. Based on our observations the elastic space formed with vertical suspension continuously stimulates the sensory system, which can develop new neuromuscular connections that can greatly improve balance, postural control and gait.

The biocompatibility of polyaniline and polypyrrole: A comparative study of their cytotoxicity, embryotoxicity and impurity profile

Conducting polymers (CP), namely polyaniline (PANI) and polypyrrole (PPy), are promising materials applicable for the use as biointerfaces as they intrinsically combine electronic and ionic conductivity. Although a number of works have employed PANI or PPy in the preparation of copolymers, composites, and blends with other polymers, there is no systematic study dealing with the comparison of their fundamental biological properties. The present study, therefore, compares the biocompatibility of PANI and PPy in terms of cytotoxicity (using NIH/3T3 fibroblasts and embryonic stem cells) and embryotoxicity (their impact on erythropoiesis and cardiomyogenesis within embryonic bodies). The novelty of the study lies not only in the fact that embryotoxicity is presented for the first time for both studied polymers, but also in the elimination of inter-laboratory variations within the testing, such variation making the comparison of previously published works difficult. The results clearly show that there is a bigger difference between the biocompatibility of the respective polymers in their salt and base forms than between PANI and PPy as such. PANI and PPy can, therefore, be similarly applied in biomedicine when solely their biological properties are considered. Impurity content detected by mass spectroscopy is presented. These results can change the generally accepted opinion of the scientific community on better biocompatibility of PPy in comparison with PANI.

Primerjava običajnih in faktorskih modelov pri statističnem strojnem prevajanju iz angleščine v slovenščino z orodjem Moses

Strojno prevajanje je področje računalniške lingvistike, ki raziskuje uporabo programske opreme za prevajanje besedila iz enega jezika v drugega. Faktorsko statistično strojno prevajanje je različica statističnega, pri katerem besedilu dodamo jezikoslovne oznake na ravni besed in jih spremenimo v vektorje. Tako želimo izboljšati kakovost dobljenih prevodov. V prispevku opišemo uporabo odprtokodnega sistema Moses za faktorsko statistično strojno prevajanje iz angleščine v slovenščino. Iz besedilnega korpusa smo ustvarili več faktorskih in nefaktorskih prevajalnih modelov. Z njimi smo prevedli dve besedili s področja informacijskih tehnologij. Prvo je usmerjeno tržno in ima kompleksnejšo zgradbo, drugo pa je bolj tehnične narave. Prevode, ki smo jih dobili, smo na dva načina primerjali z dvema neodvisnima človeškima prevodoma in s prevodom, ki smo ga ustvarili s storitvijo Google Translate. Za prvi način primerjave smo uporabili metriko BLEU, za drugega pa so prevode pregledali človeški pregledovalci in podali subjektivno oceno, ki je pri prevajanju še vedno zelo pomembna. Čeprav rezultatov ne moremo primerjati neposredno zaradi različnih metrik, se gibanje ocen kakovosti pri obeh besedilih dobro ujema. Edina občutna razlika med računalniško in človeško oceno se pojavi pri prehodu na faktorske modele pri drugem besedilu. Analizirali smo zanesljivost ocenjevalcev in rezultate ocenjevanja. Ugotovili smo, da so naši modeli primernejši za tehnična besedila in da uporaba faktorskih modelov vidneje izboljša prevajanje kompleksnejših besedil.

Insula-Retrosplenial Cortex Overconnectivity Increases Internalizing via Reduced Insight in Autism

BackgroundInternalizing symptoms like anxiety and depression are common and impairing in autism spectrum disorder (ASD). Here, we test the hypothesis that aberrant functional connectivity among three brain networks (salience network [SN], default mode network [DMN], and frontoparietal network [FPN]) plays a role in the pathophysiology of internalizing in ASD. MethodsWe examined the association between resting-state functional connectivity and internalizing in 102 adolescents and young adults with ASD (n = 49) or typical development (n = 53). Seed-to-target functional connectivity was contrasted between adolescents and young adults with ASD and typically developing subjects using a recent parcellation of the human cerebral cortex, and connections that were aberrant in ASD were analyzed dimensionally as a function of parent-reported internalizing symptoms. ResultsThree connections demonstrated robust overconnectivity in ASD: 1) the anterior insula to the retrosplenial cortex (i.e., SN-DMN), 2) the anterior insula to the frontal pole (i.e., SN-FPN), and 3) the dorsolateral prefrontal cortex to the retrosplenial cortex (i.e., FPN-DMN). These differences remained significant after controlling for age, and no age-related effects survived correction. The SN-DMN connection was associated with greater internalizing in ASD, mediated by a bigger difference between self- and parent-reported internalizing. Control analyses found that the other two connections were not associated with internalizing, and SN-DMN connectivity was not associated with a well-matched control measure (externalizing symptoms). ConclusionsThe present findings provide novel evidence for a specific link between SN-DMN overconnectivity and internalizing in ASD. Further, the mediation results suggest that intact anterior insula-retrosplenial connectivity may play a role in an individual’s generating insight into his or her own psychopathology.

ЗНАЧАЈ РАЗЛИЧИТИХ ФАКТОРА АТРАКТИВНОСТИ У ЛЕТЊИМ ТУРИСТИЧКИМ ДЕСТИНАЦИЈАМА ЗА ТУРИСТЕ

Summer tourist destinations attract touristS for various attractions and developed product content. This paper focuses on how various attraction factors are important for tourists. The most used model for analysis of the attraction factors is the Ritchie Crouch model, that defines several attractions categories. The paper stars with a modified Ritchie Crouch model with basic attraction factors in the focus within summer destinations. These factors have been taken into consideration having in mind the specifics of summer destinations and their products. The research methodology is based on the AHP model Analytic Hierarchy Process)). In this model, each interviewee compares different alternatives, and in this case assesses the value of individual attraction factors for the decision making process about a summer destination. On the basis of the results, three segments have been identified, followed by testing the significance of the differences between attraction factors among the defined segments. After this, a hypothesis has been tested that there is a bigger difference among the segments defined according to attraction factors preferences than among the traditionally defined segments.

Friction effect of stator in a multi-walled CNT-based rotation transmission system

The rotation transmission system (RTS) made from co-axial multi-walled nanotubes (MWNTs) has the function of regulating the input rotation from a nanomotor. The mechanism for the regulation is that the friction among the tubes during rotation governs the rotation of the rotors in the nanosystem. By integrating a rotary nanomotor and a nanobearing into an MWNT-based RTS, it is discovered that the stator (outer tube) provides relatively greater friction on the rotors by penetrating the motor tube, which has a higher stable rotational frequency. And the output rotation of the rotors in the system depends significantly on the temperature of the system, as the rotor tubes are slightly longer than the motor tube. Briefly, at low temperatures, say 8 K, the rotors rotate synchronously with the motor. However, at high temperatures, the rotors rotate slower than the motor with a bigger difference between their rotational frequencies. Hence, the output rotational frequencies can be adjusted by changing the temperature as well as the input rotational frequency.

Making a difference to employability through assessment

Students will know some of the benefits and costs of an undergraduate degree. They will be told of the degree 'premium' and that, over a lifetime, they can expect to be better off. A university education will open doors to professions that will seem distant when completing school education. They will anecdotally hear stories about employers expecting a first or upper second. They will also know that some students will never pay back their loans. The reality is that an undergraduate degree can lead to a good job but this is not the case for all students as finding graduate level employment will be very challenging for some. We argue that courses should continually look at ways to enhance the employability of their students.It is understandable that students will see good grades from assessment as the route to a good degree and ultimately to a good job. If assessment can also develop and evidence the skills valued by others, particularly employers, then further benefits are added. There are a number of ways that student employability can be supported, including: careers advice; jobs fairs; visiting speakers and possibly a placement opportunity. We argue that, additionally, assessment can make a difference and with thoughtful design can make an even bigger difference. It is the author's experience that if students are asked what they learnt on their course, they are likely to talk about the outcomes of assessment. If these outcomes also evidence the skills valued by the employer, then this will present a more persuasive response. Assessment is critical for all courses. If assessment can leave the student with outcomes, experience or artefacts that evidence a 'can-do' ability then we argue this must positively impact on employability.

Effects of Ti target current on properties of TiSiN coatings

TiSiN coatings were deposited on WC/TiC/Co substrates using a combined method of arc ion plating and medium-frequency magnetron sputtering. Effects of Ti target currents on coating's properties were studied. Results showed that with Ti target current increasing from 55 to 95 A, surface roughness significantly increased and Si content decreased from 9.87 to 3.22 at.-%. The preferred orientation was TiN (200) below Ti current of 85 A, but changed into TiN (111) at 95 A. As Ti current increased, the hardness increased first and then decreased. The maximum value (39.6 GPa) was achieved at 65 A with the Si content of 8.2 at.-%. Edge effect happened on all samples, which exhibited large differences in Si content and hardness between edge and central regions. The increase in Ti current enhanced the edge effect with a bigger difference in Si contents and a larger affected region.

Programmable i-motif DNA folding topology for a pH-switched reversible molecular sensing device.

Four-stranded DNAs including G-quadruplexes and i-motifs are formed from four stretches of identical bases (G or C). A challenge remains in controlling the intermolecular folding of different G-rich or C-rich strands due to the self-association of each component. Here, we introduce a well-designed bimolecular i-motif that does not allow the dimerization of the same strand, and illustrate its usefulness in a pH-switched ATP-sensing DNA molecular device. We analyze two groups of i-motif DNAs containing two stretches of different C-residues (Cn-1TmCn and CnTmCn-1; n = 3−6, m = 1, 3) and show that their bimolecular folding patterns (L- and H-form) noticeably differs in the thermal stability. The L-form structures generally display a relatively low stability, with a bigger difference from that of conventional i-motifs formed by CnTmCn. It inspires us to at utmost improving the structural stability by extending the core of L-form bimolecular i-motifs with a few flanking noncanonical base pairs, and therefore to avoid the dimeric association of each component. This meaningful bimolecular i-motif is then incorporated into a three-way junction (3WJ) and a four-way junction (4WJ) functionalized with two components of a ATP-binding split DNA aptamer, allowing the pH-triggered directional assembly of 3WJ and 4WJ into the desired (3+4)WJ structure that is verified by gel electrophoresis. It therefore enables the ATP-induced association of the split aptamer within the (3+4)WJ structure, as monitored by fluorescence quenching. In this way, the designed DNA system behaves as a pH-switched reversible molecular device, showing a high sensitivity and selectivity for fluorescent ATP analysis. The i-motif folding topology-programmed DNA nanoassembly may find more applications in the context of larger 2D/3D DNA nanostructures like lattices and polyhedra.

Advances in the treatment of Orthopaedic diseases with Bone Marrow Mesenchymal Stem Cells

Bone Marrow Mesenchymal Stem Cells (BMSCs) are ideal seed cells for cell therapy, which have been through many long-term studies of in vitro and animal disease model treatment and have been widely used in preventing and treating a variety of clinical diseases caused by aging and other damage, including bone injury and regeneration, neural degenerative and injury, myocardial injury, liver cirrhosis, diabetes, lung disease and so on. BMSCs application in the treatment of orthopaedic disease is the most common and effective. By retrospective literature review, we summarize the BMSCs transplantation application in Orthopaedic disease treatment. As an ideal cell source, BMSCs was first applied in bone tissue engineering, mainly used in the treatment of long bone defect and bone nonunion; Recently, the research trends of clinical BMSCs application turned to treat degenerative diseases and genetic disorders because of its great potential, including osteoarthrits, femoral head necrosis, disc degeneration, spinal cord injury, knee varus, osteogenesis hypoplasia, hypophosphatasia and so on. The safety and efficacy of BMSCs treatment are the key issues in clinical cell therapy. There is no side effects and complications after BMSCs treatment, prove its clinical application is safe. But due to type and degree of disease and individual differences, therapeutic methods including injection method, effective concentrations, treatment window selection, cycle and therapeatic effects have a bigger difference. There is still no uniform of recognized operation standards for the treatment of the same type of disease. So BMSCs transplantation requires effective control during whole medical process and its application in orthopedic diseases is still lack of large-scale multicenter clinical study. Therefore, this review focuses on induction, summary and analysis in the research status of BMSCs in bone disease treatment, and provide new ideas and methods for BMSCs transplantation in orthopaedic disease prevention and treatment.

Morphological Asymmetry of the Superior Cervical Facets from C3 through C7 due to Degeneration.

Introduction Knowledge about facet morphology has already been discussed extensively in literature but is limited regarding asymmetry and its relation to facet degeneration. Method Facet dimensions, surface area, curvature, and degeneration of the superior facets were measured in 85 dried human vertebrae from the anatomical collection of the Vrije Universiteit Brussel. The vertebrae were analysed using the Microscribe G2X digitizer (Immersion Co., San Jose, CA) and a grading system for the evaluation of cervical facet degeneration. Coordinates were processed mathematically to evaluate articular tropism. The statistical analysis includes the paired t-test and the Pearson correlation. Results On average, no systematic differences between the left and right facets were found concerning morphology and degeneration. However, there were significant differences regardless of the side-occurrence. There was a significant correlation between the dimensions of the total facet surface and the degree of degeneration but not for the recognizable joint surface. Conclusions Facet tropism of the upper joint facets occurred often in the cervical spine but without side preference. A bigger difference in degeneration asymmetry was associated with a bigger difference in facet joint dimension asymmetry.