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This paper presents a study of the tensile strength of unsaturated soil by a DEM model in a novel uniaxial tensile test device. For validation and comparison, traditional triaxial shear test of unsaturated soil are also conducted. In the DEM model, the capillary effects and some other cementation effects are modelled by a bond, whose strength is a function of the moisture content and void ratio in uniaxial tensile tests and also the confining pressure in triaxial tests. To compare the DEM simulations with experiments, the bond strength function is calibrated through a quantity measurable in both laboratory and DEM simulations such as the shear strength in triaxial tests or the uniaxial tensile strength in uniaxial tensile tests. The comparison shows that the proposed model is able to capture the phenomena observed in experiments. Most importantly, through investigation of the grain-scale data such as the motion, force chains and development of fractures, it is possible to explain some macroscopic observations such as the form of shear bands in the sample, the influence of the moisture content on the shear and tensile strength, etc. [ABSTRACT FROM AUTHOR]

The purpose of this study was to assess the influence of two suture methods on the postoperative complications of extraction of mandibular third molars (M3M). We searched the MEDLINE (PubMed), Cochrane Library, and Web of Science databases until 18 May 2018 for randomised controlled trials (RCT) that evaluated the influence of any suture techniques on postoperative complications after the removal of impacted M3M. Pain, facial swelling, and trismus were measured for both the early stage (2–3 days) and late stage (5–7 days) after extraction. We identified 655 records, of which five were assessed for eligibility. All trials included had a moderate risk of bias. The analysis showed that the patients whose wounds had been closed primarily had significantly more pain than those whose wounds were closed secondarily (a wedge of mucosa) during the early stage (standardised mean difference (SMD), −0.49; 95% CI −0.71 to −0.27; P < 0.0001) and the late stage (SMD −0.36; 95% CI −0.54 to −0.19; P < 0.0001) after the removal of impacted M3M. Patients whose wounds were closed secondarily had less swelling (mm) at the postoperative early stage (SMD −1.12; 95% CI −1.57 to −0.66; P < 0.00001) and late stage (SMD −0.51; 95% CI −0.68 to −0.33; P < 0.00001). There was more trismus in the primary closure group than in the secondary group during both stages. Our findings suggest that secondary closure causes less pain, facial swelling, and trismus in both early and late stages of surgical removal of impacted M3M, and therefore it improves the quality of life by reducing postoperative discomfort. [ABSTRACT FROM AUTHOR]

Surface sediment samples (n = 92) were collected from Hangzhou Bay to investigate the transport and deposition of polybrominated diphenyl ethers (PBDEs) and to assess the ecological risks in Hangzhou Bay. The concentrations of ∑ 7 PBDEs (sum of BDE-28, 47, 99, 100, 153, 154, 183) and BDE-209 ranged from 3.61 to 91.09 pg g−1 and from non-detectable to 2007.52 pg g−1 (dry weight), respectively. The high values of ∑ 7 PBDEs and BDE-209 were commonly occurred at the northeast of Hangzhou Bay and the Nanhui Spit coast of Shanghai. Compared with the south part of the bay, the dominance of BDE-209 was more prominent and the linear correlations between PBDEs concentrations and TOCs as well as median grain size were more significant in the northern Hangzhou Bay. Hydrodynamic forcing on the transport and deposition of PBDEs is primarily responsible for the discrepancy of this spatial distribution in these two parts. In addition to BDE-209, BDEs-153, 99, 47, and 100 were also the abundant congeners. Three principal components were extracted using principal component analysis (PCA), mainly attributed to human activities, erosion of polluted soils via surface runoff and release from products for PC1, PC2 and PC3, respectively. The calculation results of mass inventories, hazard quotients (HQs) and risk quotients (RQs) indicated that the ecological risk of PBDEs in Hangzhou Bay was low. The multiple effect of hydrodynamic forcing with complicated and large-scope tidal currents made it hard to deposit for organic matters and contaminants in Hangzhou Bay. • BDE-209 was dominant in the north area of Hangzhou Bay. • ∑ 7 PBDEs decreased from coastal areas to the center of Hangzhou Bay. • Hydrodynamic forcing influenced spatial distribution of PBDEs. • Hangzhou Bay is at low risk level at present. • Organic matters and contaminants are hard to deposit in Hangzhou Bay. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to evaluate whether bromelain can decrease trismus, pain, and facial swelling in patients undergoing impacted third molar surgery.Materials and Methods: Three databases were searched to identify relevant studies through November 1, 2017. Randomized controlled trials (RCTs) that compared the effect of bromelain versus placebo after mandibular third molar surgery were included. The main outcome measures, pain, facial swelling, and trismus, were assessed in the early stage (2 to 3 days) and the late stage (7 days) after surgery. Standardized mean differences (SMDs) and weighted mean differences (WMDs) were calculated using fixed-effect models. All statistical analyses were implemented using Review Manager 5.3.Result: Six RCTs were included in this meta-analysis. The pooled results suggested that bromelain appears to be effective for decreasing facial swelling in the early and late stages after surgery (early-stage SMD, -0.24; 95% confidence interval [CI], -0.46 to -0.02; P = .03; late-stage SMD, -0.54; 95% CI, -0.84 to -0.24; P = .0004). Bromelain alleviated postoperative pain 7 days after surgery (SMD, -0.54; 95% CI, -0.87 to -0.20; P = .002), but there was no significant difference in pain levels at the early stage. For trismus, analyses showed that bromelain had no apparent effect on early or late trismus.Conclusion: Bromelain conferred moderate relief of postoperative discomfort after third molar surgery. [ABSTRACT FROM AUTHOR]

Abstract Scene classification is a significant aspect of computer vision. Convolutional neural networks (CNNs), a development of deep learning, are a well-understood tool for image classification. But training CNNs requires large-scale datasets. Transfer learning addresses this problem and produces a solution for small-scale datasets. Because scene image classification is more complex than common image classification. We propose a novel ResNet based transfer learning model utilizing multi-layer feature fusion, taking full advantage of interlayer discriminating features and fusing them for classification by softmax regression. In addition, a novel data augmentation method with a filter useful for small-scale datasets is presented. New image patches are generated by sliding block cropping of a raw image, which are then filtered to insure that the new images sufficiently represent the original categorization. Our new ResNet based transfer learning model with enhanced data augmentation is evaluated on six benchmark scene datasets (LF, OT, FP, LS, MIT67, SUN397). Extensive experimental results show that on the six datasets our method obtains better accuracy than other state-of-the-art models. [ABSTRACT FROM AUTHOR]

Abstract Titanium possesses a wide prospect due to its attractive combination of mechanical and electrochemical properties, however, the large affinity of hydrogen during industrial application will reduce its service life. Nevertheless, few studies focus on the effect of hydrogenation on microstructure evolution, electrochemical property and deformation behavior of titanium at room temperature. In this work, these effects induced by additional hydrogen were investigated in detail. The results suggest that the additive hydrogen will reduce the grain size, leading to the formation of lamellar or needle structure alpha phase with an increasing volume fraction of titanium hydride. In the meantime, the mechanical properties and corrosion resistances of hydrogenated titanium increase first and then decrease with the increase of hydrogen content. The improvement of mechanical property can be attributed to the occurrence of deformation twins, which will equivalently reduce the grain size, leads to the enhancement of ultimate compressive strength, work hardening rate and dislocation storage capability while the ability of dislocation annihilation diminished, thus results in higher work hardening rate and better compression ratio. Meanwhile, the electrochemical properties of hydrogenated samples enhanced with the increasing corrosion resistance of compact layer, yet, the film structure converts from compact to porous when additive hydrogen content reach to 27.01 at.%, which results in the deterioration of corrosion resistance. Therefore, the work of this research will give some suggestions for the application of titanium. Highlights • A new model demonstrating the structure evolution of titanium during hydrogenation is proposed. • Effects of microstructure evolution and twinning activities on mechanical property are investigated. • Twins will be segmented by the precipitated titanium hydrides. • Electrochemical properties of hydrogenated titanium are first studied. [ABSTRACT FROM AUTHOR]

Abstract The objective of this study was to comprehensively assess the use of tranexamic acid (TXA) during orthognathic surgery. A systematic review and meta-analysis of randomized controlled trials addressing these issues were carried out. Three electronic databases, included PubMed, Web of Science, and Cochrane Library, were searched until April 30, 2018. Eligible studies were restricted to randomized, controlled trials (RCTs). Weighted mean differences (WMD) for blood loss, operation time, haematocrit, quality of surgical field, and odds ratio (OR) for transfusion rates were pooled for the included studies. Eight randomized, controlled trials were included for analysis. Compared with the control group, the TXA group showed a reduction in intraoperative blood loss of 165.03 ml (p < 0.00001; 95% CI, −200.93 to −129.13 ml), a reduction in the drop of haematocrit of 2.32 g/dl (p < 0.00001; 95% CI, −3.38 to −1.26 g/dl), and an improved quality of surgical field (p < 0.00001; MD, −1.01; 95% CI, −1.23 to −0.80). Tranexamic acid has a limited effect on reducing operative time (p < 0.00001; MD, −16.18 min; 95% CI, −19.60 to −12.75 min) and on decreasing the transfusion rates (p = 0.02; OR = 0.33; 95% CI, 0.13 to 0.83). [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to evaluate whether the anesthetic efficiency of articaine is superior to that of lidocaine during lower third molar extraction (LTME).Materials and Methods: Three electronic databases (PubMed, Cochrane, and Web of Science) were searched to identify randomized controlled trials up to December, 31 2017. Five evaluation indexes were extracted, namely success rate of anesthesia, subjective onset time of anesthesia, objective onset time of anesthesia, duration time of anesthesia, and intraoperative pain assessment, to assess the anesthesia efficiency of the 2 solutions. All data analyses were conducted using Review Manager (version 5.3; The Cochrane Collaboration, London, United Kingdom).Results: Nine studies were included in this review. The sample was composed of 770 LTMEs from 493 patients, with 382 LTMEs in the lidocaine group and 388 LTMEs in the articaine group. Compared with lidocaine, 4% articaine with 1:100,000 epinephrine showed a higher success rate of anesthesia (risk ratio, 1.10; 95% confidence interval [CI], 1.01 to 1.21; P = .03), shorter subjective onset time of anesthesia (standardized mean difference, 1.20; 95% CI, 0.50 to 1.89; P = .0007), and longer duration time of anesthesia (mean difference, 0.83 hours; 95% CI, 0.59 to 1.07 hours; P < .00001); however, for intraoperative pain assessment (mean difference, 3.12 mm; 95% CI, -0.13 to 6.37 mm; P = .06) and objective onset time of anesthesia (standardized mean difference, 0.44; 95% CI, -0.39 to 1.26; P = .30), there was no significant difference between the 2 solutions.Conclusions: The results of this study suggest that 4% articaine with 1:100,000 epinephrine possesses superior anesthetic efficiency relative to lidocaine for inferior alveolar nerve blocks during LTME. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to provide an evidence-based evaluation of the impact of surgical drainage after the removal of mandibular third molars.Materials and Methods: The Medline (PubMed), Cochrane Library, and Web of Science databases were searched to identify randomized controlled trials up to September 1, 2017. Postoperative variables, including facial swelling, trismus, and pain, were calculated early (2 to 3 days) and late (5 to 7 days) after the removal of impacted mandibular third molars. Weighted mean differences for trismus and standardized mean differences (SMDs) for swelling and pain were pooled for the included studies.Results: The samples consisted of 592 extractions (297 with surgical drainage and 295 controls) in 409 participants. The included studies were published from 1988 to 2016. Participants who received surgical drainage had significantly less facial swelling during the early stage (SMD, -0.46; 95% confidence interval [CI], -0.67 to -0.26; P < .0001) and the late stage (SMD, -0.36; 95% CI, -0.55 to -0.16; P = .0004) after the removal of an impacted mandibular third molar. They also had better mouth opening than controls during the early and late stages (early MD, 5.55 mm; 95% CI, 2.31-8.79; P = .0008; late MD, 2.38 mm; 95% CI, 1.47-3.29; P < .0001). The level of pain was significantly different between the 2 groups in the early stage (SMD, -0.55; 95% CI, -1.00 to -0.10; P = .01); however, there were no significant differences in the late stage (SMD, -0.13; 95% CI, -0.38 to 0.12; P = .30).Conclusion: The use of surgical drainage has an obviously positive effect on postoperative reactions after the removal of a mandibular third molar. Given the need for additional time for clinic visits, surgical drainage presents an alternative for the perioperative management of impacted mandibular third molar surgery, especially in cases of a fully bony tooth with poor drainage. [ABSTRACT FROM AUTHOR]