Analysis of Machine-made Sand Parameters in Shaanxi

Machine-made sand was significantly different from natural sand in terms of particle gradation, morphology, composition and structure. The concrete composed of mechanical sand and natural sand was greatly influenced by the physical and chemical properties of sand and gravel in terms of its microscopic appearance and macroscopic properties. Therefore, this paper aimed to systematically analyze the big data of machine-made sand performance testing, and focus on the fluctuation of the fineness modulus, stone powder content, and other indicators of machine-made sand particles in various regions of Shaanxi, and solve measures were further discussed

Research and Application of Polycarboxylic Acid Water Reducer with Different Molecular Weight

In this paper, a polycarboxylic water reducing agent was synthesized by using Methylallyl polyethylene glycol (HPEG) with molecular weight of 1200, 2400, 2800 and 3400 under the same conditions, C80 concrete tests were performed on these four molecular weight superplasticizers, verify the effect of different molecular weight polycarboxylic acid water reducer in C80 pumping concrete, finally, a kind of low molecular weight polycarboxylic acid water reducer with viscosity reducing effect in high-grade concrete is obtained, which can promote pumping of high-grade concrete

Research and Application of Polycarboxylic Acid Water Reducer with Different Molecular Weight

In this paper, a polycarboxylic water reducing agent was synthesized by using Methylallyl polyethylene glycol (HPEG) with molecular weight of 1200, 2400, 2800 and 3400 under the same conditions, C80 concrete tests were performed on these four molecular weight superplasticizers, verify the effect of different molecular weight polycarboxylic acid water reducer in C80 pumping concrete, finally, a kind of low molecular weight polycarboxylic acid water reducer with viscosity reducing effect in high-grade concrete is obtained, which can promote pumping of high-grade concrete

Anatomical and Microstructural Features of Rattan (Calamus caesius)

Calamus caesius, one of the most valuable high-quality rattans, has emerged as an economical material for use in commercial products. This study systematically investigated the anatomical and microstructural characteristics of Calamus caesius in terms of the frequency, radial diameter, tangential diameter, and form factor of the vascular bundles in both inner and outer regions, as well as the frequency, proportion, length, diameter, and length-diameter ratio of the vessel elements, and the size, double wall thickness, lumen diameter, and ultrastructure of the fibers. The results revealed that the sizes of both vascular bundles and vessel elements in the inner regions were larger than the outer regions, while the fiber proportions and morphological features remained relatively constant. The fibers have a multi-layered structure, most of which exhibited a four-layered structure in their secondary walls. The properties of various tissue structures reflect rattan’s desirable characteristics for use as high-quality commercial timber

Bamboo Structure and Its Impact on Mechanical Properties: A Case Study of <i>Bambusa arundinaceae</i>

Bamboo is a naturally occurring composite material, which exhibits a decomposable structure with varying composition. The distinct structural features of bamboo contribute to its exceptional strength and flexibility, making it an excellent choice for construction purposes. However, only a limited portion of bamboo species has been studied for its mechanical properties, and research on Bambusa arundinaceae has primarily focused on its pharmaceutical values. Therefore, we investigated the relationship between the structural characteristics of B. arundinaceae and its mechanical properties using axial compression experiments and tangential bending experiments. The results showed that the distribution density of vascular bundles (VBs) of B. arundinaceae ranged from 1.98 to 4.34 pcs/mm2,while the volume fraction of fiber sheaths (FSs) ranged from 35.82 to 42.58%. The average compressive strength, flexural strength, and flexural elasticity modulus were 113.99 MPa, 239.07 MPa, and 17.39 GPa, which were 97.56%, 64.07%, and 66.09% higher than those of moso bamboo (Phyllostachys edulis), respectively. The compressive strength, flexural strengths, and elasticity modulus of B. arundinaceae were positively correlated with both the distribution density of VBs and the volume fraction of FSs. These insights are crucial for the advancement of durable and efficient materials in diverse sectors including construction and manufacturing

Analyzing Fiber and Vascular Bundle Characteristics, and Micro-Mechanical Properties of Oligostachyum sulcatum

The structure of vascular bundles and the mechanical properties of fibers are crucial factors determining the utilization of bamboo. This study investigated the structure of vascular bundles and evaluated the morphological and micromechanical properties of the fibers in Oligostachyum sulcatum. The results showed that the fiber length and width of O. sulcatum meet the requirements of raw materials for the papermaking process. However, the fiber content in O. sulcatum is relatively low, which may increase the cost of papermaking. The vascular bundle growth exhibited non-uniformity, especially at the top part, with no discernible pattern in bundle area changes. The nanoindentation testing demonstrated that the bamboo's indentation modulus of elasticity (IMOE) and hardness values were comparable to those of moso bamboo (Phyllostachys edulis), suggesting its potential as a substitute in engineering applications

Choice of Outcomes Used in Randomized Controlled Trials Measuring the Efficacy and Safety of Massage Therapy for Cervical Spondylotic Radiculopathy

Background Massage is an important treatment for cervical spondylotic radiculopathy (CSR) . As massage-related research advances, numerous randomized controlled trials (RCT) concerning massage therapy in CSR have been published, but high-quality evidence is still limited due to some problems in the choice of outcomes. Objective To evaluate the outcomes used in RCTs in recent 10 years regarding CSR treated using massage, providing a basis for the choice of core outcomes used in studies about massage in CSR. Methods RCTs regarding CSR treated using massage were searched in databases of CNKI, Wanfang Data, CQVIP, SinoMed, PubMed, EMBase and Cochrane Library from January 2011 to May 2021. Literature screening, data extraction, and risk of bias assessment were performed by two researchers separately. A qualitative analysis was conducted to analyze the outcomes used in the RCTs. Results In all, 66 RCTs were included, in which the outcomes were categorized into 7 categories based on functional attributes: quality of life (95 times, 41.48%) , symptoms and signs (64 times, 27.95%) , physical and chemical examinations (39 times, 17.03%) , safety events (12 times, 5.24%) , economic assessment (12 times, 5.24%) , long-term prognosis (5 times, 2.18%) , and TCM symptoms/syndromes (2 times, 0.87%) . The most frequently used five outcomes were overall response rate, Visual Analogue Scale (VAS) score, Neck Disability Index score, adverse reactions and adverse events, symptom and sign score, and the measurement time points for which were 17 in total in a period from one day after treatment to the sixth month of follow-up. The above-mentioned outcome indexes are mainly measured at 14 days (27.08%) , 14 days (26.67%) , 14 days (29.17%) , 28 days (28.57%) and 14 days (33.33%) after treatment. The number of RCTs using one, two, three, and at least four outcomes was 5, 20, 14, and 27, respectively. Forty-eight RCTs reported the overall response rate. Conclusion We found many problems existing in the choice of outcomes used in RCTs assessing massage for CSR. The problems are as follows: primary and secondary outcomes were not defined; alternative outcomes received more attention while endpoint outcomes were neglected; the blinding method was ignored in RCTs using subjective outcomes; there was tremendous heterogeneity between RCTs in the number or combination of outcomes used, composite outcomes were mostly used; there was non-uniformity in measurement times of outcomes. We suggest that further relevant studies should pay attention to sufficient top-level design and preliminary research, and actively take actions to establish a set of core outcomes

Fiber Characteristics and Mechanical Properties of <i>Oxytenanthera abyssinica</i>

Unlike the culm hollow structure of most bamboo species, Oxytenanthera abyssinica has a unique solid or semi-solid culm, which may endow it with superior mechanical performance. In this study, the variation in fiber morphology and micro-mechanical properties across the radial regions of bamboo culm was examined by optical microscopy, scanning electron microscopy, X-ray diffraction, and nanoindentation. Results showed that the mean values of vascular bundle frequency and fiber tissue proportion were 1.76 pcs/mm2 and 21.04%, respectively, both of which increased gradually from inner to outer. The mean length, diameter, and length-diameter ratio of the fiber were 2.10 mm, 21.54 μm, and 101.41 respectively. The mean indentation modulus of elasticity (IMOE) and hardness were 21.34 GPa and 545.88 MPa. The IMOE exhibited a significant increase from the inner to the middle region, and little change was observed from the middle to the outer region. There were slight fluctuations in hardness along the radial direction. The mean crystallinity and microfibril angle(MFA) of the fibers was 68.12% and 11.26 degrees, respectively. There is a positive correlation between cellulose crystallinity and the IMOE and hardness, while there is a negative correlation between the MFA and the IMOE and the hardness

Functional Connectome before and following Temporal Lobectomy in Mesial Temporal Lobe Epilepsy

As mesial temporal lobe epilepsy (mTLE) has been recognized as a network disorder, a longitudinal connectome investigation may shed new light on the understanding of the underlying pathophysiology related to distinct surgical outcomes. Resting-state functional MRI data was acquired from mTLE patients before (n = 37) and after (n = 24) anterior temporal lobectomy. According to surgical outcome, patients were classified as seizure-free (SF, n = 14) or non-seizure-free (NSF, n = 10). First, we found higher network resilience to targeted attack on topologically central nodes in the SF group compared to the NSF group, preoperatively. Next, a two-way mixed analysis of variance with between-subject factor ‘outcome’ (SF vs. NSF) and within-subject factor ‘treatment’ (pre-operation vs. post-operation) revealed divergent dynamic reorganization in nodal topological characteristics between groups, in the temporoparietal junction and its connection with the ventral prefrontal cortex. We also correlated the network damage score (caused by surgical resection) with postsurgical brain function, and found that the damage score negatively correlated with postoperative global and local parallel information processing. Taken together, dynamic connectomic architecture provides vital information for selecting surgical candidates and for understanding brain recovery mechanisms following epilepsy surgery