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Mechanically connected precast piles are a type of precast piles that utilise snap-type mechanical connectors to restrain the pile ends of two identical or different precast piles at the top and bottom so as to quickly realise the purpose of the connection. However, the gap problem in the connectors of mechanically connected piles can lead to uneven and uniform deformation of the piles under horizontal loading, resulting in additional displacements and rotation angles of the piles at the connection. Solving the problem of calculating the internal force response of discontinuous deformed piles is a prerequisite for promoting and applying mechanically connected precast piles. Firstly, the theoretical derivation of mechanically connected piles with fixed constraints at the pile bottom is carried out. Secondly, the pile response equations of mechanically connected piles are established, and the theoretical solutions of pile displacement and internal force response of mechanically connected piles under horizontal loading are derived. Thirdly, the pile-soil model of the test pile is established using ABAQUS software (ABAQUS 2016) in combination with the design data of the test pile. The numerical simulation displacements and angles of rotation are compared with the test results. Finally, the theoretical and numerical simulation displacements and internal forces of the ordinary pile and the mechanically connected pile are compared. The relative errors of the displacements and angles of rotation of the established pile-soil model are less than 10%, indicating that the established model has good accuracy. The relative errors of the theoretical and numerical simulation displacements and internal forces of the mechanically connected pile are less than 10%, proving the correctness of the theoretical calculation by the m-method. This study can provide effective theoretical support and methodological guidance for the displacement and internal force response of discontinuous piles. [ABSTRACT FROM AUTHOR]

An indoor vibrational dissolution scouring test was designed to investigate the effects of vibrational frequency, vibrational acceleration, environmental temperature, and dissolution medium on the dissolution characteristics of cement-stabilized macadam base material during water erosion. The results showed that the dissolution damage effect exists in cement-stabilized macadam, and dissolution is an important evaluation index of its base failure. The amount of calcium ion (Ca2+) dissolution and pH of cement stabilized gravel increased with increasing vibrational time. When the vibrational frequency was in the range of 80–180 Hz , the amount of dissolved Ca2+ and the pH of the solution first increased, and then decreased with the vibrational frequency. The Ca2+ concentration and pH of the solution reached their maximum at 140 Hz for 10 h. Of the four vibrational dissolution factors considered, vibrational acceleration produced the largest degree of dissolution of cement-stabilized macadam. The leached Ca2+ concentration increased with increasing temperature of the dissolution medium and the concentration of ammonium chloride (NH4Cl) solution, while increasing pH decreased dissolution. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the efficacy of surgery combined with triamcinolone acetonide injection in managing the difficult problem of keloid formation after syndactyly release. Twenty-two patients with keloid formation after syndactyly release were retrospectively reviewed. They were divided into a simple surgery group and a surgery plus injection group. Complications, web quality, scar score and satisfaction were assessed and compared. In the surgery plus injection group, three patients (3/13) experienced recurrence and ten webs were good, whereas in the simple surgery group, seven patients (7/9) experienced recurrence and five webs were poor. The mean Vancouver Scar Scale score was significantly lower (4.3 versus 7.8) and the mean Faces Questionnaire satisfaction score was higher (4.2 versus 2.6) in the surgery plus injection group. Combining surgical excision with early and repeated intralesional injection can achieve better results with low recurrence rate and side effects. Level of evidence: IV [ABSTRACT FROM AUTHOR]

Correction of unequal radial polydactyly in which neither thumb duplicates possess both well-developed proximal and distal components, remains challenging. Current techniques using on-top plasty techniques require circumferential incisions, often resulting in postoperative swelling and dorsal scars. We described our experience using a volar approach to achieve better aesthetic and functional results. Twenty-one patients underwent this surgery between 2008 and 2018, with a mean follow-up of 5.1 years. The mean flexion–extension arc for the metacarpophalangeal joint was 75° and that of the interphalangeal joint was 43°. Mean percentage of key, tripod and tip pinch strength were 77%, 79% and 77%, respectively, when compared with the contralateral side. The Vancouver Scar Scale showed an average score of 1.2. We conclude from our study that the volar approach to on-top plasty is a good technique for the correction of unequal radial polydactyly, with good functional and aesthetic results. Level of evidence: IV [ABSTRACT FROM AUTHOR]

The permeability coefficient of concrete was tested by self-made falling water test device, and the relationship between porosity and permeability coefficient was analyzed. Based on the design of plugging test, the influence of different particle size blockers on concrete plugging and the plugging process of yellow mud that is sticky on concrete were studied. The results demonstrate that there is a high linear relationship between the porosity and the permeability coefficient; when facing the same size of blocker. the anti-clogging ability of concrete with different voids is different, the size of blockage sensitive particle of concrete with 15% porosity is 0.15~0.3 mm and 0.3~0.6 mm, while that of concrete with 20% and 25% porosity is 0.3~0.6 mm and 0.6~1.18 mm; the concrete with different voids was blocked seriously by graded gravel, the sticky blocker such as yellow mud would lead to the rapid plugging of permeable concrete. [ABSTRACT FROM AUTHOR]

Hand burns are frequently seen in children, often resulting in digital flexion contractures. Traditional split‐thickness or full‐thickness skin grafts leave notably different skin texture and hyperpigmentation. The purpose of this study was to describe our operation for treating digital flexion contractures with full‐thickness plantar skin grafts, and to evaluate the appearance and function outcomes. Hematoxylin and eosin staining, Masson trichrome staining and Melan A (marker of melanocyte) staining were used to evaluate palmar skin, plantar skin, groin skin and burn scars. Full‐thickness plantar skin grafts were performed between 2008 and 2015 in 24 hand burn patients with digital flexion contracture. The average age at the time of surgery was 39.3 months and the average follow‐up period was 5.5 years. The functional and cosmetic results were assessed. Plantar skin shared similar attributes with palmar skin histologically. Both plantar skin and palmar skin did not express melan A. All of the skin grafts survived well without hematoma, infection and necrosis. The grafts resembled the adjacent normal skin in regards to appearance and texture. The average TAM (total active movement) degree for the fingers was improved from 152.3° to 238.5°. The average VSS (Vancouver Scar Scale) score decreased dramatically from 10.4 to 1.1. Twenty one of twenty four patients (21/24, 87.5%) were very satisfied with function and appearance, and three in twenty four (3/24, 12.5%) were somewhat satisfied. This study indicates that full‐thickness plantar skin grafts can achieve a satisfactory appearance and good function for hand burn child patients with digital flexion contractures. [ABSTRACT FROM AUTHOR]

The aim of this research is to evaluate the effect of polyphosphoric acid (PPA) on the mechanical performance of styrene–butadiene–styrene (SBS) and styrene–butadiene–rubber (SBR) modified asphalt. Conventional properties, multiple stress creep recovery (MSCR), bending beam rheometer (BBR), and linear amplitude sweep (LAS) tests were conducted to evaluate the performance characteristics of asphalt at different PPA inclusions. Gel‐permeation chromatography (GPC), saturates, aromatics, resins, and asphaltenes (SARA), and Fourier transform infrared (FTIR) were carried to reveal the molecular weight, component and infrared spectra of asphalt. Results showed that PPA hardened the asphalt, improved the rutting and fatigue performances of polymer modified asphalt (PMA) binder, but weakened the anti‐cracking performances. Besides, storage stability had a significant improvement as the addition of PPA. The addition of PPA brought more macromolecules into asphalt and led to more high‐average molecular weight compounds. Furthermore, PPA changed four component ratios of asphalt. Both PMA with or without PPA have similar absorption peaks. This may be due to absorption peak of PMA covered the changes in PPA modification process as the low content of PPA. 0.8% dosage of PPA may be considered optimum for composite modified binder combining the above experimental results for this binder source. [ABSTRACT FROM AUTHOR]

The objective of this research is to investigate the physiochemical and rheological properties of waste cooking oil (WCO)/styrene‐b‐butadiene‐b‐styrene/ethylene vinyl acetate (SBS/EVA) composite modified asphalt. A petroleum asphalt composite modified with SBS/EVA and oil/SBS/EVA were prepared to undergo the physical, rheological, and microscopic experiments. Comparing these tests results with the properties of unmodified petroleum asphalt, SBS and EVA cause an improvement in pavement performance, but weaken the storage stability. Although the high‐temperature performance undermined by the addition of WCO, the thermal stability, fatigue property, and low temperature crack resistance improved obviously. In addition, WCO mainly composed by low‐weight components, and these can supplement the light components in the polymer‐modified asphalt. EVA could increase the percentage of large molecular size of asphalt, while WCO relieves this trend. The reactions between WCO and these polymers (SBS and EVA) are physical reactions. Atomic force microscopy morphology results reflect that SBS and EVA increase the surface complexity and roughness, and WCO makes the asphalt surface smooth. This indicates WCO increases the dispersion of polymers in asphalt. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48828. [ABSTRACT FROM AUTHOR]

In order to analyze the rationality of evaluation indexes HI1, HI2, HI3, HI4 and HI5 based on rheological properties for self-healing performance of asphalt, DSR (dynamic shear rheometer) is used to test the relationship between the complex modulus and loading times of virgin asphalt, SBS modified asphalt and rubber modified asphalt. Based on four-point bending fatigue test, the fatigue-self-healing properties of virgin asphalt mixture, SBS modified asphalt mixture and rubber modified asphalt mixture are studied. The results demonstrate that evaluate the self-healing performance of asphalt with different indicators may obtain different results, the order of self-healing ability of virgin asphalt, SBS modified asphalt and rubber modified asphalt is inconsistent, and the evaluation result of HI5 index on self-healing ability of three asphalts is consistent with mixtures, the self-healing ability of rubber modified asphalt and SBS modified asphalt is better than virgin asphalt obviously. [ABSTRACT FROM AUTHOR]

In this paper, fluorescence microscope was used to analyze microstructure of A-70' asphalt, SBS modified asphalt and rubber modified asphalt, and DSR was used to test and evaluate self-healing properties. The results show that the higher the temperature is, the more the SBS modifier, rubber powder and matrix asphalt tend to be phase soluble, and the solubility of SBS and 70' asphalt is better than that of rubber powder. The self-healing capacity of SBS modified asphalt and rubber modified asphalt is comparable and better than that of A-70' road petroleum asphalt. The self-healing property of asphalt material is inversely proportional to the degree of injury. The greater the degree of injury, the less significant the self-healing ability. The self-healing energy barrier of rubber modified asphalt is the largest, followed by SBS modified asphalt, and 70' asphalt is the smallest. The self-healing effect of rubber asphalt requires higher temperature conditions and heat supply. [ABSTRACT FROM AUTHOR]

Background: Macrodactyly is a congenital malformation characterized by aggressive overgrowth of multiple tissues, including subcutaneous fat, nerves, and bones in digits or limbs. In type II macrodactyly, the peripheral nerve is enlarged; however, the morphological and functional characteristics of the affected peripheral nerves have rarely been evaluated. Methods: In this research, six macrodactyly patients and three polydactyly patients (control) were studied. Pre-operative sensory nerve action potential and intra-operative nerve action potential tests were performed. The microstructure and ultrastructure of the enlarged nerves were observed and neurofilament (NF) expression was evaluated using immunofluorescent staining. Results: Axon impairment of the digital nerves originating from the median nerve (MN) was observed. A compensatory reinnervation from the ulnar nerve (UN) was found in two of the six patients, and significant morphological changes were observed in the enlarged nerve. The myelinated nerve fibers decreased, the lamellar structure of the myelin sheath changed, and the density of the NFs of the unmyelinated fibers decreased. There was aberrant distribution of NFs in the macrodactylous nerve tissues. In patients with compensatory UN reinnervation, the number of myelinated and unmyelinated fibers increased to normal levels; however, the diameter of the myelinated fibers apparently decreased. Conclusions: The morphology and function of the macrodactylous enlarged nerve was impaired in type II macrodactyly patients; however, the unaffected UN partially compensated for the lost function of the affected MN under specific situations. Electrophysiological tests should be performed to determine the function of the affected nerve and surgical treatment for type II macrodactyly could be refined. [ABSTRACT FROM AUTHOR]

The waste engine oil (WEO) on the rheological characteristics of asphalt were studied. Two types of asphalt binders and five WEO contents (2%, 4%, 6%, 8%, and 10% wt. %) were selected to prepare WEO modified asphalt samples. Results indicated that both WEO modified asphalt had lower elastic portion, thermal susceptibility, Zero shear viscosity (ZSV), and rutting resistance, but had higher fatigue resistance and temperature sensitivity. Moreover, the effect of waste engine oil on pure asphalt is more significant than SBS modified asphalt. [ABSTRACT FROM PUBLISHER]