Strength of sandy and clayey soils cemented with single and double fluid jet grouting

Abstract Innovations in jet grouting technology have primarily focused on the cutting efficiency of the jets, with the aim of creating larger columns and increasing the productivity of construction sites. Relatively little attention has been paid to the consequences of the grouting system on the mechanical properties of the formed material. This paper investigates this aspect by analysing the results of two field trials carried out in both sandy and clayey soils, where single and double fluid jet grouting were simultaneously performed, with varied grout composition and injection parameters. Parallel uniaxial compressive tests on samples cored from the columns show that the material formed with the double system is systematically lower in strength than the material formed using the single fluid system. The mineralogical composition of samples cored from the columns was analysed by performing parallel Scanning Electron Microscopy (SEM), X-ray diffraction analysis (XRD), Differential Thermal Analysis (DTA) and Thermo-Gravimetric Analyses (TGA) to determine the reasons for this difference. A lower proportion of cementitious products, an accelerated carbonation of portlandite and a less homogeneous distribution of cement hydration products was found on the surface of the soil particles of the double samples than for the single fluid columns

EGFR and HER2 expression in primary cervical cancers and corresponding lymph node metastases: Implications for targeted radiotherapy

<p>Abstract</p> <p>Background</p> <p>Proteins overexpressed on the surface of tumor cells can be selectively targeted. Epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) are among the most often targeted proteins. The level and stability of expression in both primary tumors and corresponding metastases is crucial in the assessment of a receptor as target for imaging in nuclear medicine and for various forms of therapy. So far, the expression of EGFR and HER2 has only been determined in primary cervical cancers, and we have not found published data regarding the receptor status in corresponding metastatic lesions. The goal of this study was to evaluate whether any of these receptors are suitable as target for clinical diagnosis and therapy.</p> <p>Methods</p> <p>Expression of EGFR and HER2 was investigated immunohistochemically in both lymph node metastases and corresponding primary cervical cancers (n = 53). HER2 and EGFR expression was scored using HercepTest criteria (0, 1+, 2+ or 3+).</p> <p>Results</p> <p>EGFR overexpression (2+ or 3+) was found in 64% (35/53) of the primary cervical tumors and 60% (32/53) of the corresponding lymph node metastases. There was a good concordance between the primary tumors and the paired metastases regarding EGFR expression. Only four patients who had 2+ or 3+ in the primary tumors changed to 0 or 1+ in lymph node metastases, and another two cases changed the other way around. None of the primary tumors or the lymph node metastases expressed HER2 protein.</p> <p>Conclusion</p> <p>The EGFR expression seems to be common and stable during cervical cancer metastasis, which is encouraging for testing of EGFR targeted radiotherapy. HER2 appears to be of poor interest as a potential target in the treatment of cervical cancer.</p

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P &lt; 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

Effect of initial water content and pore water chemistry on intrinsic compression behavior

The effect of initial water content (w0) and pore water chemistry on the intrinsic compression curve of clays was investigated experimentally. The test results indicate that w0 had a considerable effect on the intrinsic compression curve of a clay, and the degree of the effect is a function of pore water chemistry. The fundamental mechanism of the effect of w0 and pore water chemistry on the intrinsic compression curve is through its influence on the microstructure of clays. For relatively stable flocculated microstructures, the effect of w0 will disappear under a small value of effective vertical consolidation stress, σ′v, for example, σ′v  1,000 kPa. Furthermore, it has been shown that when σ′v is larger than the remolded yield stress, almost all the test data follow the intrinsic compression line (ICL) proposed by Burland. Finally, based on the test data, a new equation for estimating void ratio () under σ′v = 100 kPa on ICL from the void ratio (el) corresponding to the liquid limit water content has been proposed

Concrete wedge and coarse sand coating shear connection system in GFRP concrete composite deck

In recent years, Glass Fiber-Reinforced Polymer (GFRP) has become a widely used material in Fiber-Reinforced Polymer (FRP) composite structures. Several studies have been performed on the bonding methods of FRP sheets and plates, but limited research has been undertaken on the critical shear connection systems for innovative GFRP concrete composite bridge decks structures. Coarse sand coating shear connection systems for GFRP structures show strong bondage in the shear direction but poor grip in the normal direction. An innovative concrete wedge system, supplementary to coarse sand coating overcomes the normal split between GFRP panel and concrete, in composite bridge deck structures. This study presents a finite element (FE) investigation on GFRP concrete composite deck using a concrete wedge shear connection system based on existing experimental evaluation. In this research, the thickness of the GFRP module was varied and the deflection behaviour of GFRP concrete composite deck was furthermore studied. FE results indicate that thickness increments of the GFRP module significantly reduce the mid-span deflection of the composite deck and subsequently increase the ultimate load. In order to investigate the interaction behaviour between GFRP and concrete in the numerical analysis, a structural interface element is proposed for finite element modelling (FEM) analysis. In order to undertake a rapid evaluation of deflection of the composite deck, an equation is proposed to estimate the deflection at the mid-span of the GFRP composite bridge deck based on the FEM results. In addition, the GFRP composite bridge deck was numerically analysed using light-weight concrete (LWC) and results were compared with GFRP composite deck with conventional concrete. The results indicate that using LWC increases the ultimate load proportionally till failure

Characterisation of likelihood of gas hydrates occurrence in the South China Sea based on Bonferroni mean-based TOPSIS and fuzzy set theory

The efficiency of gas hydrate production depends on the success of gas exploration and occurrence evaluation. The existing evaluation models are generally univariate and only applicable to certain geological settings. This study presents a holistic approach to evaluate the likelihood of gas hydrate occurrence by supplying an index for mapping gas hydrate levels with depth. The approach integrates a generalised TOPSIS method with the fuzzy set theory. An expedition of gas hydrate conducted in the Shenhu area of the South China Sea was adopted as a case study to assess the reliability of the proposed index. As a multivariate model, the proposed approach enables the capture of non-linearity associated with gas hydrates in its entirety. The magnitude of the strength of the influential factor varies substantially from one site to another across the Shenhu area. The results also show that no site achieves the highest likelihood ‘Level V’. These results are consistent with the gas saturation values obtained using Archie’s relationship. For example, at SH4 and SH7, the values of the likelihood index are the highest between 170–185 m and 150–165 m, respectively, and the observed saturation at these locations varies from 20% (SH4) to 43% (SH7). The proposed likelihood index yields a prominent ability to quantify the level of occurrence of gas hydrates with depth at different sites. It appears to be an efficient multicriteria system bound to improve the management of the gas production trial stage

Numerical evaluation of the ground response induced by dewatering in a multi-aquifer system

This study presents a numerical investigation of dewatering-induced settlement and wall deflection during pumping tests in Tianjin, China. Based on the measured groundwater head and building settlement during the pumping test, a three-dimensional liquid–solid coupling model is established by using the finite element method (FEM). The void ratio, hydraulic conductivity, and elastic modulus of each layer are back-calculated through the numerical model. The groundwater drawdown, seepage field, ground settlement, horizontal ground displacement, and diaphragm wall lateral deflection are analyzed using the FEM model. The simulated results demonstrate that (i) the maximum ground settlement outside of the excavation reaches to 82 mm due to the leakage effect of aquitards; (ii) large horizontal displacement occurs in the soil during the pumping test with a maximum value of 28.3 mm, and the installation of the diaphragm wall in the aquifer can reduce the horizontal displacement of the ground; (iii) long-term pumping causes a large lateral deflection of the diaphragm wall, and a maximum value of 23.2 mm occurs at the layer where the screens of the wells are located; and (iv) long-term large-scale pumping should be avoided before excavation

A Brief Report of Pingdi Landslide (23 July 2019) in Guizhou Province, China

This short communication reports on a large landslide with a movement of 2 million m3 of soil and rock that occurred on 23 July, 2019 in the village of Pingdi, located in the county of Shuicheng, Guizhou Province, China. This landslide resulted in 42 deaths and 9 missing people. This report describes the preliminary investigation, rescue effort, and possible cause. The total rainfall in the 6 days prior to the landslide was 189.1 mm, which may be held responsible as the major cause. Some recommendations are proposed to reduce human casualties and property losses