Erigeron breviscapus (Vant.) Hand-Mazz, has anti-inflammatory activity and ability to inhibit tumor cell growth, migration, and invasion. However, the combined role of SCU and BLM treatment in tumor is unclear. This study aimed to investigate the possible effect and related mechanisms of BLM combined with SCU in the treatment of tumor through in vivo and in vitro experiments. In vivo experiments showed that BLM combined with SCU in the treatment of mice bearing H22 ascites tumor prolonged the survival time, alleviated BLM-induced pulmonary fibrosis, reduced the production of TNF-α; IL-6, and the levels of MDA and MPO. BLM combined with SCU increased the apoptotic rate of H22 ascites cells and the levels of cleaved-caspases-3 and -8. Furthermore, BLM combined with SCU increased the protein expression of p53 and gene expression of miR-29b, and decreased the expression of TGF-β1. In vitro experiment results showed that BLM combined with SCU inhibited the viability of H22 cells and MRC-5 cells, promoted H22 cell apoptosis, up-regulated the protein expression of p53 and down-regulated the protein expression of α-SMA and collagen-I in MRC-5 cells. These experimental results suggested that SCU could enhance the anti-tumor effect of BLM and reduce BLM-induced pulmonary fibrosis, indicating SCU as a potential adjuvant for BLM in the future.Bleomycin (BLM) is a broad spectrum anti-tumor drug and inducing pulmonary fibrosis. As an anti-tumor drug without immunosuppression, it is urgent to find a drug that reduces the side effects of BLM. Scutellarin (SCU), a flavone extracted from  Bleomycin (BLM) is a common drug used for the treatment of several types of neoplasms, such as skin carcinoma, ovarian cancer, esophageal carcinomas, and so on . BLM is Erigeron breviscapus (Vant.) Hand-Mazz, is clinically used to treat patients with ischemic heart diseases and paralysis caused by cerebrovascular diseases in China. Recent studies have reported that SCU can be used for the treatment of hypertension, Alzheimer’s disease, Parkinson’s disease, and neurodegenerative diseases and also for the prevention of cerebral thrombosis, cerebral hemorrhage, and ischemic injury through animal models (Scutellarin (SCU), a flavone extracted from l models . Few expl models . In addil models . Howeverin vivo and in vitro. For in vivo experiments, we used the typical H22 tumor-bearing mice model to investigate our opinion. For in vitro experiments, we used MRC-5 and H22 cell lines to probe whether SCU can strengthen the efficacy of BLM treatment and reduce BLM-induced side effects of pulmonary fibrosis.In this study, we sought to investigate the synergistic and attenuated effects and possible underlying mechanism of SCU on BLM both Scutellarin was purchased from Shanghai Rong Wo Pharmaceutical Technology Co. (China). BLM hydrochloride was obtained from Haizheng Pharmaceuticals . Interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) ELISA kits were obtained from eBioscience . Myeloperoxidase (MPO) and malondialdehyde (MDA) Colorimetric Activity Assay Kits were obtained from Jiancheng Institution of Biotechnology . Annexin V-fluorescein isothiocyanate (FITC) apoptosis kit was purchased from KeyGen Biotech . TRIzol reagent was obtained from Invitrogen Life Technologies . All other chemicals and reagents used in the study were of analytical grade.2 at 37°C.Mouse liver cancer H22 cells (H22) and Human Embryonic Lung fibroblasts MRC-5 cells (MRC-5) were obtained from American Type Culture Collection . H22 cells were cultured in RPMI 1640 medium  with 10% fetal bovine serum  and 1% penicillin–streptomycin . MRC-5 cells were incubated in DMEM medium  containing 10% FBS and 1% penicillin–streptomycin. All cells were incubated in a humidified atmosphere of 5% COSPF male Kun Ming (KM) mice, weighting 18–22 g, were provided by the Experimental Animal Center, Institute of Guangzhou University of Chinese Medicine . The animals were housed in a 12-h light/dark cycle under a constant temperature of 24°C and relative humidity of 65 ± 15% and fed with standard diet and tap water. The animal experiments were conducted according to the guidelines established by the NIH Guide for the Care and Use of Laboratory Animals. All experimental protocols were followed Animal Care and Use Committee at Guangzhou University of Chinese Medicine.6 cells/ml) were inoculated into the abdomen of male KM mice and the ascites cells were passaged three times in the mice, after 1 week, the ascites was collected and diluted with normal saline; the cell concentration was adjusted to 2 × 106 cells/ml and injected into each mouse. After 5 days, 90 mice were randomly divided into nine groups of 10 mice. The control group: intraperitoneal (ip) injection of normal saline, model group: normal saline, ip; BLM alone group: BLM , BLM alone group , SCU-M alone group , and BLM  combined with SCU-M  group. Each group of mice was administered once a day as describe above for seven consecutive days. The weight of the mice and the abdominal diameter were measured every day. All mice were sacrificed on day 8 to collect ascites and lung tissues for the subsequent tests. The volume of ascites was measured at the time of collection. The lung tissues were quickly removed and washed with cold normal saline. A portion of the ascites was solubilized in the TRIzol regent for the extraction of total RNA, and the other portion was used for Western blotting analysis. The lung tissue stored in a -80°C refrigerator until further analysis.5 cells/ml) were plated in 96-well plates with 200 μl in each well. RPMI 1640 medium was added into the blank group without cells, the control group with only cells, and the experimental group containing BLM , SCU  and BLM combined with SCU . After culturing for 24 and 48 h, 20 μl of MTS was added to each well. The cells then incubated continuously for 4 h, and the optical density (OD) was measured with micro-plate reader at a wavelength of 490 nm. (MTS)  assay was used to measure the inhibition rate of SCU, BLM, and SCU combined with BLM in H22 cells. H22 cells  method published by Chou and Talalay , 2010. C4 cells/ml) were seeded into 96-well plates at 200 μl per well. One day after seeding, the cells were dealt with fresh DMEM medium. In BLM and SCU alone group, after the cell density reaches 60–70% confluence, the DMEM medium was removed and 200 μl fresh DMEM containing BLM , and SCU  were added to the wells. The culture was continuously incubated for 24 h (48 h), and then 20 μl MTS was added to each well. The OD was measured at a wavelength of 490 nm after 4 h in a micro-plate reader. In the BLM combined with SCU group, after the cell density reaches 60–70% confluence, the old culture medium was removed and 200 μl fresh DMEM containing BLM (30 μM) was added to the wells. After culturing for another 24 h, the DMEM medium was removed and the cells were treated with new medium containing SCU . After incubation for 24 h (48 h), 20 μl MTS was added to each well. After 4 h incubation, the OD value was measured at a wavelength of 490 nm in a micro-plate reader.MRC-5 cells  for staining. After 5 min incubation at 4°C in the dark, the samples were then immediately analyzed by flow cytometry .Apoptosis was evaluated by staining the cells with Annexin V-FITC apoptosis. Ascites was centrifuged  and then washed twice with cold PBS. After that, the cell concentration was adjusted to 1 × 105 cells/ml) were seeded into 6-well plates with 2 ml in each well. RPMI 1640 medium containing BLM(30 μM), SCU (25 μM), BLM (30 μM) combined with SCU (25 μM) were immediately added to the culture. After 48 h, suspended cells were collected and washed twice with cold PBS. PBS was removed, the cell concentration was adjusted to 1 × 106 cells/ml and 400 μl of 1× Annexin V staining buffer and 5 μl Annexin V-FITC were added to the above cell suspension and incubated for 15 min at 4°C in the dark. Then 10 μl PI staining solution was added to the cell suspension and incubated for 5 min at 4°C in the dark. Cells were analyzed using flow cytometry.H22 cells  according to the manufacturer’s instructions. The related caspase activities can be quantified by spectrophotometric detection of free pNA (λ = 405 nm) after cleavage from the peptide substrate (amino acid sequence DEVD-pNA for caspase-3 and sequence IETD-pNA for caspase-8), using a spectrophotometer.The lung tissues were fixed in 10% buffered formalin, and embedded in paraffin. Paraffin sections (4 μm thick) were stained with hematoxylin and eosin (H&E) and Masson’s Trichrome and examined under light microscope to determine lung tissue inflammation or collagen deposition. The lung histological changes were evaluated according to the published methods . (a) Intg, 4°C, 10 min). The expression levels of TNF-α and IL-6 were detected using TNF-α and IL-6 ELISA kit according to the manufacturer’s instructions.Saline was added to the lung tissues (0.3 g) a ratio of 1:9. Hereafter, samples were homogenized  and centrifuged  for 24 h and then treated with SCU (25 μM). After 24 h, the cells were washed three times with cold PBS, fixed with 4% paraformaldehyde for 15 min, washed with PBS for three times, 3 min each, and then permeabilized in 0.5% Triton X-100  at room temperature for 20 min. After that, the slides were washed with PBS for three times, 3 min each, and then closed with normal goat serum at room temperature. After 30 min, the cells were incubated overnight with anti-α-SMA  at 4°C. Next day after washing with PBS three times, the cells were incubated for 1 h at 20–37°C with DyLight 594 AffiniPure goat Anti-Mouse IgG (H+L) . Then the cells were washed three times with PBS, and incubated with 4′-6-diamidino-2-phenylindole (DAPI) . Cell fluorescence was then observed under a fluorescence microscope.H22 cells were plated into 6-well plates with 2 ml per well. Control group and the experiment group were treated with 1640 medium and 1640 medium containing BLM (30 μM), SCU (25 μM), or BLM (30 μM) combined with SCU (25 μM). After 24 h, the cells were washed for three times by cold PBS and were collected. The MRC-5 cells were seeded into 6-well plate with slides of 2 ml in each well. After the cells reached 70–80% confluence, the cells were treated with BLM (30 μM) for 24 h and then treated with SCU (25 μM). The culture was then incubated for 24 h again. The cells were washed three times with cold PBS and then were collected.g, 5 min, 4°C), and then the supernatant was collected. 200 μl RIPA buffer was added, and then centrifuged at 12,000 ×g for 5 min at 4°C. The above steps are operated on ice. The cell plasma and nuclear proteins were collected by cell plasma protein and nucleus protein kits. The protein concentration was measured by BCA method. Equal amounts of proteins were separated using 10% SDS polyacrylamide gel electrophoresis and then transferred onto polyvinylidene fluoride (PVDF) membranes. After blocking for 1 h in PBS containing 5% non-fat dry milk and incubating overnight at 4°C with primary antibodies specific for TGF-β1 , p53 , α-smooth muscle actin (α-SMA)  and type I collagen (collagen-I) , and Actin . The membranes were washed three times with TBST containing a secondary antibody and then incubated for 2 h at room temperature. The super signal west Pico chemiluminescent substrate was used to detect the protein bands.The total protein was collected. The collected ascites cells, H22 cells, MRC-5 cells and the lung tissues were washed three times with cold PBS, centrifuged  - (Ct Control - Ct β-actin).Total RNA of the H22 ascites fluid and lung tissues were extracted using TRIzol reagent. Then 1.5 μg total RNA was reverse transcribed by cDNA reverse transcription according to the kit instruction . The reaction was carried out using Applied Bio Systems Step-one Fast Real-Time PCR system under the following conditions: 50°C for 2 min, 95°C for 10 min, followed by 40 cycles for 15 s (95°C) and 1 min (60°C), then annealed at 60°C for 60 s and extended for 40 s at 72°C with a final extension for 7 min at 72°C. Real-time qPCR products were analyzed following the amplification of the products and their respective primers were presented in t-test, one-way ANOVA and Least Significant Difference (LSD), followed by Tukey’s post hoc test. Log-rank (Mantel-Cox) test was applied to analyze the comparison of survival curves. P-value < 0.05 was considered as statistically significant. Graph were drawn in the GraphPad Prism software (version 6).All data were expressed as mean ± standard deviation (SD). Data analyses were performed using SPSS 23.0 software. Data analyses of different groups were performed using Student’s Figure 1A, compared with model group, the anti-tumor effect of SCU  alone group showed no obvious survival in mice (p > 0.05), but vice versa are the results in BLM alone group (p < 0.05). Moreover, mice treated with BLM (7.5 mg/kg) + SCU-M, H  significantly prolonged the survival time when compared with BLM alone group (p < 0.05). These results indicated that SCU-M, H  could improve the anti-tumor effects of BLM. Hence, SCU at a dose of 60 mg/kg was used in the following experiments.To study the anti-tumor effects of SCU, BLM and their combination in ascites tumor-bearing mice, we observed the survival time of the mice. As shown in Figures D also displayed the synergistic effects of BLM combined with SCU (60 mg/kg) in the treatment of tumors. Compared with control group, the weight gain , abnormal diameter  and volume of ascites degree of change  were seen. While compared with the model group, the above three indicators in the BLM alone group and BLM combined with SCU (60 mg/kg) group were significantly decreased (p < 0.05). In addition, the mice in the treatment group showed a more vigorous state, while the mice in the BLM combined with SCU (60 mg/kg) group showed better response. However, when compared with the model group, weight, volume of ascites and abdominal diameter of SCU (60 mg/kg) alone group showed no difference. These results suggested that SCU (60 mg/kg) could improve the anti-tumor effect of BLM when combined, but SCU (60 mg/kg) alone perhaps had little anti-tumor effect.in vitro, we measured the inhibition rate of SCU combined with BLM in H22 cells. Figure 2 showed the effect of BLM, SCU and the combination of the two in H22 cells. Compared with the control group, the inhibition rate of H22 cells treated with BLM  was significantly increased with the increased concentration. In the combination group , the rate of inhibition was significantly higher than that of the BLM and SCU alone. Data in the graph showed that BLM and SCU alone could inhibit the growth of H22 tumor cells in vitro, and inhibited when combined. In addition, the combination of BLM and SCU  showed a synergistic effect with CI < 1 . The pre test results are shown in the Supplementary Figure To verify the synergistic effects of SCU on BLM in vivo and in vitro experiments, flow cytometer was used to analyze the apoptotic rate of H22 ascites cells in each group. Figures 3A,C showed H22 cell apoptotic rate in ascites and Figures 3B,D showed H22 cell apoptosis in in vitro cultured H22 cells. Results showed that in the BLM alone group and BLM+SCU combined group, the apoptotic rate of H22 ascites cells was increased when compared with model group or control group . The apoptotic rate of H22 cells was increased in BLM (7.5 mg/kg) + SCU (60 mg/kg) combined group when compared with BLM alone group (p < 0.05). All these data suggested that SCU combined with BLM could induce apoptosis of H22 cells, meaning that SCU can enhance the anti-tumor effects of BLM.For Figure 4 showed that the activities of cleaved-caspase-3  and cleaved-caspase-8  were enhanced in BLM alone group (p < 0.05) and SCU (60 mg/kg) alone group when compared with model group. The activities of cleaved-caspase-3 and cleaved-caspase-8 in SCU (60 mg/kg) and BLM (7.5 mg/kg) combined group were more significantly up-regulated when compared with BLM alone group (p < 0.05). Experimental results indicated that when SCU combined with BLM, the effect of BLM on the activities of cleaved-caspase-3 and cleaved-caspase-8 was enhanced. So, the combination of SCU and BLM promoted the apoptosis of tumor cells.The caspase family has long been considered to be closely related to apoptosis, especially cleaved-caspase-3 and -8. So, to demonstrate that SCU can enhance the anti-tumor effects of BLM by promoting tumor cell apoptosis, we measured cleaved-caspase-3 and cleaved-caspase-8 activities. Figure 5 revealed no appearance of inflammation or collagen deposition in the lung tissue of the control group. However, when compared with control group, the lung tissue of the model group and SCU (60 mg/kg) alone group did not differ much from the control groups, but the BLM (7.5 mg/kg) alone group showed inflammatory cell infiltration and vascular congestion in H&E staining. And the lung injury scores of all samples were shown in Table 2. Masson’s staining demonstrated collagen deposition in the lung interstitium and around bronchioles. In contrast, compared with BLM alone group, the inflammation and collagen deposition of BLM (7.5 mg/kg) combined with SCU (60 mg/kg) group were reduced. All these results suggested that BLM combined with SCU for tumor treatment; significantly alleviated pulmonary fibrosis.Figure 6, we observed that BLM  can reduce the cell viability of MRC-5 cell when compared with control group (p < 0.05). However, when the MRC-5 cells were treated with SCU , the cell viability remained the largest. Then, the cell viability was gradually decreased. These data showed that SCU could inhibit the viability of MRC-5 cells at a range of concentrations in vitro. The pre test results are shown in the Supplementary Figure MTS assay was used to measure the effect of SCU and BLM on MRC-5 cell viability. In Figure 7, when compared with the model group, the levels of TNF-α  and IL-6  in the BLM alone group were increased significantly (p < 0.05). In contrast, the levels of TNF-α and IL-6 in the SCU (60 mg/kg) and BLM (7.5 mg/kg) combined group were decreased significantly compared with BLM (7.5 mg/kg) alone group (p < 0.05). These results suggested no significant difference in the levels of TNF-α and IL-6 between the model group and the SCU (60 mg/kg) alone group.The extent of inflammation could generally be reflected by the level of cytokines produced. So, we measured the levels of TNF-α and IL-6 to evaluate the extent of inflammation in the lung tissues. As shown in Figure 8A) and MDA  were assayed. In Figure 8, when compared with model group, the levels of MPO and MDA in BLM (7.5 mg/kg) alone group were significantly increased (p < 0.05). However, compared with BLM alone group, the levels of MPO and MDA in BLM (7.5 mg/kg) and SCU (60 mg/kg) combined group were remarkably decreased (p < 0.05). The above results suggested that the protective effects of SCU against BLM-induced lung injury may be related to antioxidant activity.To study whether SCU attenuation on BLM-induced pulmonary fibrosis was associated with antioxidant effects, the levels of MPO . As shown in Figure 10C, when compared with BLM alone group, the SCU and BLM combined group significantly inhibited TGF-β1 expression in H22 cells and induced the expression of p53 in H22 cells (both p < 0.05). Furthermore, in Figure 10D, compared with control group, the expression levels of TGF-β1, p53, α-SMA, collagen-I in the BLM group were increased significantly (both p < 0.05) in MRC-5 cells. And the expression of TGF-β1, α-SMA, collagen-I in BLM combined with SCU group were significantly lower than that of the BLM alone group (both p < 0.05). However, the expression of p53 in BLM combined with SCU group was significantly increased, compared with BLM alone group (p < 0.05). The total un-cropped gels were provided in the Supplementary Material Results of protein expression of p53 and TGF-β1 in animal experiment are shown in Figure 11, when compared with the model group, the BLM and SCU (60 mg/kg) alone groups showed no obvious effects on the relative expression of miR-29b (p < 0.05). While the relative expression of miR-29b was significantly increased in the SCU (60 mg/kg) and BLM (7.5 mg/kg) combined group compared with BLM alone group (p < 0.05).Many studies have showed that miR-29b was closely associated with the development of tumors and pulmonary fibrosis . So, ourNowadays, the incidence of cancer is increasing in a higher rate, and the number of cases in China is remains quite large. Tumors grow rapidly with infiltration and destruction of the structure and function of the surrounding tissues and in turn metastasizes, making it difficult to treat. Currently, chemotherapeutic drug therapy remains currently one of the main treatment strategy for cancer, but most of the chemotherapeutic drugs used clinically have varying degrees of immunosuppressive and bone marrow suppression side effects. Fortunately, as a broad-spectrum anti-cancer drug, BLM showed no bone marrow toxicity and immunosuppressive side effects . HoweverErigeron breviscapus (Vant.) Hand-Mazz. Modern pharmacological experiments showed that SCU have anti-inflammatory properties, suppressing the growth, migration, and invasion of cancer cells  and experimental animal models. In addition, we studied that SCU enhanced the anti-tumor efficacy of BLM and reduced the side effects of BLM through regulating TGF-β1 and p53 pathways. However, we have not studied in more detail about how SCU and BLM affect TGF-β1 and p53 signaling. Furthermore, in this study we only measured the expression of miR-29b and did not detect the expression of other miRNAs. Therefore, it is unclear whether combination of BLM and SCU affects the expression of other miRNAs. So further research regarding these issues is needed.Our present experimental results confirmed that SCU can enhance the anti-tumor effects of BLM and alleviate the toxic adverse effects of BLM when combined with SCU for the treatment of tumor. The possible mechanism of SCU may occur through the regulation of balance of p53 and TGF-β pathways to achieve the purpose of increasing the efficiency and reducing the toxicity. These indicate that SCU can be used as an adjuvant in combination with chemotherapeutic agents for the treatment of cancers.Y-CL and Z-RS conceived and designed the experiments. JN, H-MY, C-YS, and Z-BZ performed the experiments. Y-LL and J-YZ analyzed the data. Y-CL, Z-RS, and X-PL were the group leader offering supervision and financial support. JN and Y-CL wrote the paper. JN, H-MY, and Y-CL supplemented the experiments and revised the paper. All authors reviewed the manuscript.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The handling Editor and reviewer AT declared their involvement as co-editors in the Research Topic, and confirm the absence of any other collaboration.


The influence of the DMS chain length and crosslinking density of the DMS@POSS on membrane properties were studied. The membranes revealed characteristic structure-property relation towards both glass transition and gases transport. Specifically, clear dependence of properties from the length of DMS units  was revealed. Gas transport properties, when compared to state-of-art polydimethylsiloxane and commercial silicone rubber, demonstrated significantly higher selectivity of DMS@POSS for carbon dioxide (in CO2/N2), hydrogen (in H2/N2) and oxygen (in O2/N2) but lowered permeability, proportional to the amount of POSS in the material. With a precise control over mechanical and thermal properties compared to conventional silicone rubbers, described materials could be considered as materials of choice in niche gas separation or other applications.The transport of small gases (H Among the huge structural diversity of siloxane derivatives, polyhedral oligomeric silsesquioxane (POSS) molecules, which possess discrete nanocage structures, have been attracting significant fundamental and industrial interest . DistincRecently, the necklace-shaped polymers, in which a “hard and bulky” unit and a “soft” chain such as POSS and dimethyloligosiloxane (DMS) respectively, are alternately bonded in the polymer main chain, have attracted much attention as a primary polymer design leading to well-balanced nano-fusion. We have reported the alternating siloxane copolymers consisted of a bifunctional POSS cage and a flexible linear DMS chain segment ,7,8. The® MH 1657). They demonstrated a two-fold increase in CO2 permeability without significant influence on selectivity while other composite (with Pebax® 2533) showed enhancement in both selectivity and permeability upon up to 30 wt% POSS incorporation [Several studies on gas permeation using polymer membranes containing POSS units have been reported. For instance, Rahman et al. prepared nanocomposite membranes by incorporation of poly(ethylene glycol) functionalized POSS (PEG-POSS) in commercial poly(ether-block-amide)  and siloxane (R2SiO). Due to utilization of DMS connection between POSS particles, the necklace-shaped DMS@POSS polymer materials that we developed are even closer to the family of the polydimethylsiloxanes. Therefore, knowledge of gas permeation in these hybrids is of high importance. Precise understanding of the relationship of a structure and gas permeability property can show the way towards mechanically and thermally stable membrane materials. Few studies have reported the composite materials that are based on combination of POSS and PDMS. Chen et al. [2, O2 and N2 decreased, while CO2/N2 and O2/N2 selectivities demonstrated an increase in selectivity. Interestingly, when the amine functionalized POSS was introduced in similar PDMS-PU matrix both permeability and selectivity decreased with the content of POSS-amine from 5% to 25% [2 and CO2 permeabilities was observed in the work of Rezakazemi [As outlined by Madhavan et al. , in regan et al.  used divn et al. . Several% to 25% . The deczakazemi  who usedIn this work, the transport of small gases through the series of cross-linked polymer membranes based on necklace-shaped DMS@POSS polymers  using a scanning FTIR Microscope . The test was conducted in the attenuated total reflectance (ATR) mode using actual membranes for analysis in the scanning range of 4000–650 cm®, NETZSCH, Selb, Germany) under a nitrogen atmosphere (50 mL·min−1). The samples in an aluminum pan (mass ~3 mg) were cooled below the glass transition point (Tg) and re-heated to well above Tg. The heating and cooling rate was set to 30 °C·min−1 with an empty aluminum pan used as a reference. The Tg value was determined as the midpoint value between the onset and the end of a step transition using the NETZSCH analysis software .Differential scanning calorimetry (DSC) was carried out using a NETZSCH instrument (DSC 204 F1 Phoenix®) to provide an open circle of 2 cm diameter (a respective active surface area ~ 3.14 cm2) as schematically shown in For the gas permeation measurements, the polymer membranes were masked with alumina tape (Bytacp) in barrer units (1 barrer = 10−10 cm3(STP)·cm/cm2·s·cmHg) was calculated and is reported. The ideal selectivity between two different gases in a composite membrane was calculated by taking the ratio of the permeabilities of different gases, αij = pi/pj, where pi and pj are the permeabilities of fast gas i and slow gas j, respectively.Thickness of the membranes was measured by digital micrometer  and was in the range 120–160 µm. A commercial silicone rubber membrane  with thickness of 500 µm was used as a reference. Gas permeation was measured for pure gases purchased from  and each membrane sample was measured in several replicates (5–15). Average values of permeability (3 stretching (around 2960 cm−1), symmetric CH3 deformations (1258 cm−1) Si-C stretching (790 cm−1), Si-O-Si stretching (1010 and 1075 cm−1). Additionally, the −1), C-C stretching in the aromatic ring (1600 cm−1 and 1430 cm−1), in-plane CH bending (shoulders around 1000 and 1070 cm−1), out of plane CH bending (shoulder around 740 cm−1), as well as more complex Si-O-Si signals in the range of 650–900 cm−1 characteristic to POSS cages. Qualitatively, all samples used in the work give similar FTIR spectral results, proving that, structurally, materials are similar to each other. Other spectra are therefore not shown for clarity in this work.g) were measured by thermal mechanical analysis (TMA), in which Tg is detected using the indentation probe during the material gradual heating [g of the actual membrane samples. The result, given in g value is proportional to the amount of POSS in materials  This structure-property relation provides an important demonstration of the control over thermal properties one obtains by changing the way how material is synthesized.In our earlier work, glass transition temperatures , O2/N2 (oxygen enrichment/ nitrogen purification), and H2/N2 (hydrogen purification) as gas pairs for separation. e so far , togethee so far .2/N2 separation by 2 for all membranes (α~25) compared to conventional PDMS [A detailed result for the COnal PDMS  and commmaterial ; therefo2/N2 pair separation, we can say that One more observation that is given in eability . Overall2/N2 pair separation, all tested 2/N2 data we do see some influence of crosslinking on the gas permeation for 2 which didn’t demonstrate such behavior.For the case of O2/N2 separation given in 2 can penetrate the POSS cages as the smallest gas because in such case we should have observed much better permeability expected for materials with fine micropores [Finally, for the Hcropores .2), and largest for the largest (N2); that is why the separation of H2 and N2 is most improved for this pair compared to ordinary PDMS, as shown in In order to clarify the dependence of gases permeability in the fabricated Finally, permeability and selectivity dependences on siloxane linker length (DMS mass content) were built and are shown in 2 and N2 permeability of three g) and rubbery conditions (T > Tg) of the polymers. Results of both gases and selectivity dependence on temperature are given in P) are much higher for both nitrogen and carbon dioxide compared to PDMS [A unique feature of the used DMS@POSS materials is their glass transition temperatures as given in  to PDMS ,22 (deta2 philic polymers (Pebax® MH 1657 and Pebax® 2533) [Few studies that have investigated the gas permeability in the POSS-containing composite materials can be found in the literature. To the best of our knowledge, our study is the first report of the gas permeability of the hybrids containing higher amount of POSS compared to amount of polymeric linkers. In the ultimate case, our ) matrix , the loax® 2533) . 2 permeability with the increased loading of the POSS increasing in the range from 5 to 25 wt% [2 philic polymer [Regarding the gas permeability in the POSS-containing materials, membranes comprising CyPOSS in PDMS-PU demonstrated a similar trend as observed in our study, i.e., significant decrease of the COo 25 wt%  as well o 25 wt% ,15. Unfoo 25 wt%  suggesti polymer . In our 2 permeability change was only correlated to the degree of crystallinity of the POSS containing composite and no influence of the molecular structure and the type of modification was observed [Based on the presented experimental data, the transport of the gas molecules in current DMS@POSS composites takes place in the confined space filled with siloxane. Confined space adds significantly to the size sieving phenomena, allowing faster diffusion of small molecules. As a result, in the materials presented, two factors are defining the properties: size sieving around the densely packed POSS particles and solution-diffusion through the siloxane that links POSS particles together. Therefore, we have to conclude that the mass (volume) content of the siloxane in the material was the most significant factor for the gas permeation. Similarly, in the work of Guerrero et al. COobserved . Investigation of gas transport in the novel terature ,11,21, iembranes . We also


The incidence of endodontic infections is high. The contribution of Endodontics to the global problem of antibiotic resistance could be significant. The ESE, together with the World Health Organization, are promoting the World Antibiotic Awareness Week (13-19 November 2017) to promote the appropriate use of systemic antibiotics in Endodontics. The objective of this study was to determine the prescription pattern of antibiotics in the treatment of endodontic infections of Spanish dentists attending specialization programs in Endodontics.Dentists from five Spanish endodontic postgraduate programs were requested to answer a one-page questionnaire surveying about antibiotics indications. Seventy-three dentists were required to participate in this investigation, and 67 (91.2%) fulfilled satisfactorily the survey and were included in the study. Data were analyzed using descriptive statistics and chi square test.The average duration of antibiotic therapy was 6.8±1.2 days. All respondents chose amoxicillin as first choice antibiotic in patients with no medical allergies, alone (40%) or associated to clavulanic acid (60%). The first drug of choice for penicillin allergic patients was clindamycin (72%). For cases of irreversible pulpitis, 22% of respondents prescribed antibiotics. For the scenario of a necrotic pulp, symptomatic apical periodontitis and no swelling, 37% prescribed antibiotics. A quarter of dentists prescribed antibiotics for necrotic pulps with asymptomatic apical periodontitis and a sinus tract.The results of this study show that postgraduate training in Endodontics provides greater awareness of the correct indications of antibiotics. Dentists who have received specialized training in Endodontics have a prescription pattern of antibiotics more adjusted to the guidelines recommended by international organizations and by scientific societies. Key words:Antibiotics, apical periodontitis, dental curriculum, endodontic infections, postgraduate endodontic training. The need for expertise in Endodontics should be met through a harmonized effort in development of basic educational programmes at undergraduate level and, furthermore, programmes at postgraduate levels . The ESEAt postgraduate level, endodontic trainees must have an understanding of the relevant aspects of the clinical pharmacology and therapeutics in relation to the treatment of endodontic infections . Consequet al. , were requested to answer a one-page questionnaire on the indications for systemic antibiotics in the treatment of endodontic infections.-QuestionnaireThe questions Fig.  were bas-Data collection and statistical analysis.p < 0.05.A database was created for further analysis using Excel . Data description was carried out by frequency tables. When obtaining the numerical representation by percentages, the total number of answers for each query was taken into account. Data were analysed using descriptive statistics and chi square test. ANOVA and the Tukey test for independent samples were used to assess differences between dental schools. Significant differences were considered when -Participation and profile of respondentsSeventy-three dentists were required to participate in the investigation and 67 (91.2%)  fulfilled satisfactorily the survey and were included. The demographics of the 67 respondents are described in -Duration of antibiotic treatmentp > 0.05).The average duration proposed for antibiotic therapy was 6.8 ± 1.2 days, 7 days being the more frequently selected duration (81%) . Dentists attending the endodontic program in Santiago prescribed amoxicillin associated to clavulanic acid with a frequency significantly higher than those of Barcelona (p < 0.05), Valencia (p < 0.01) and Zaragoza (p < 0.05). No dentists selected clindamycin, azithromycin or metronidazole-spiramycin as first choice antibiotic for non-allergic patients.Amoxicillin was chosen by all respondents as first choice antibiotic in patients with no medical allergies , either p = 0.0001). Dentists attending the endodontic program in Barcelona prescribed azithromycin with a frequency (77%) significantly higher than those of Santiago , Sevilla , Valencia  and Zaragoza .For penicillin allergic patients, the greatest majority of the respondents (72%) selected clindamycin 300 mg, and 28% selected azithromycin . There w-Antibiotic prescription in each clinical situationp = 0.012). Dentists attending the endodontic program in Barcelona prescribed antibiotics with a frequency (38.5%) significantly higher than those of Santiago  and Zaragoza  , but there were no significant differences between the faculties compared two to two.In the second clinical situation, irreversible pulpitis with symptomatic apical periodontitis and moderate/severe symptoms, 22% of respondents would prescribe antibiotics. The percentages of dentists who would prescribe AB in this clinical situation were very high in Valencia (42.9%), Barcelona (38.5%) and Santiago (33.3%)   would prescribe AB in this clinical situation, without there being differences between the five dental schools (3.1% woulp = 0.015), being the percentages of respondents who would prescribe AB in this clinical situation significantly higher in the dentists of Barcelona (61.5%) and Valencia (57.1%) compared to those of Zaragoza (6.7%) (p < 0.05)  Fig. , bottom.p = 0.0007)  and Sevilla .For the fifth scenario, necrotic pulp, asymptomatic apical periodontitis, but with the presence of a sinus tract, 25% of dentists would prescribed antibiotics. Again, there were significant differences amongst the universities (p = 0.005) , Sevilla , Valencia  and Barcelona .Finally, in the clinical situation of a necrotic pulp, symptomatic apical periodontitis, swelling, and other moderate/severe symptoms, 96% of dentists prescribed antibiotics. There were significant differences amongst the dental schools (05) Fig. , bottom.The objective of this study was to analyse the antibiotic prescription habits of Spanish dentists attending postgraduate training in Endodontics when treating endodontic infections. To the best of our knowledge, this is the first survey analysing the pattern of antibiotic prescription of dentists attending specialization programs in Endodontics. The questions that were included in the survey, as well as the different endodontic clinical situations proposed, were based on the previously published surveys in the United States ,22 and S-Main resultThe survey responses demonstrate that all the respondents selected the proper antibiotic (amoxicillin) for the treatment of endodontic infections. However, still some of them indicated antibiotics inappropriately for the treatment of pulpitis and apical periodontitis.-Choice of subjectsThe population sampled was Spanish dentists attending specialization programs in Endodontics. Dentists were recruited from five endodontic postgraduate programs developed in five different Spanish Dental Schools, from different regions of the country. The percentage of students included in the study and the overall response rate (91%) was high. The sample (n = 67) can be considered representative of the Spanish dentists attending endodontic programs. Other published surveys, conducted under equivalent conditions, have also shown very high response rates ,24,15.The sample size (n = 67) is smaller than those of previous publications ,23-25, w-First choice antibiotics and treatment duration Dentist proposed for antibiotic therapy a duration of 6.8 ± 1.2 days, being 7 days the mode (81%), without significant differences amongst the universities enrolled in the study. Similar results have been reported in the surveys carried out amongst Spanish endodontists  and oralAll respondents selected amoxicillin as the first choice antibiotic for non-allergic patients. This is in agreement with the previous results of surveys carried out amongst the members of the Spanish Endodontics Society, who selected amoxicillin as the first-choice antibiotic (82%) , and witSurveys carried out in other European countries ,14,27,28For β-lactam allergic patients, the first choice antibiotic was clindamycin 300 mg (72%), followed by azithromicyn (28%). These results are in accordance with the results of the surveys conducted previously in Spain amongst endodontists (63% clindamycin)  and oral-Prescription of antibiotics in the suggested clinical situations and comparison with previous surveysThe results of the present study demonstrate that postgraduate training in Endodontics improves dentists’ knowledge of indications of antibiotics in the treatment of endodontic infections. The pattern of antibiotic prescription of dentists attending specialization programs on Endodontics, found in this study, fits better to the correct guidelines  than thoThe two first clinical situations are both cases of irreversible pulpitis, the pulp is still vital, with no signs of systemic involvement. Therefore, antibiotics are not indicated in these situations -8,33. HoThe third clinical situation is a necrotic pulp in a healthy patient with no signs of systemic involvement. Neither in this case are antibiotics indicated ,14, whatNeither the fourth nor the fifth case, necrotic pulp with symptomatic apical periodontitis with moderate/severe symptoms and no swelling, and necrotic pulp with asymptomatic apical periodontitis with sinus tract, respectively, requires antibiotics. Nonsurgical root canal treatment and analgesics are sufficient ,8. HowevFinally, the last clinical scenario, a necrotic pulp with symptomatic apical periodontitis and systemic involvement (swelling and moderate/severe symptoms), indicates antibiotics in addition to root canal treatment, incision and drainage -8. EffecThe comparison of the results of this survey (dentists of postgraduate training programs in endodontics) with the results of previous surveys carried out on undergraduate students  or gener-Differences amongst training programsParticularly striking is the differences observed between endodontic training programs: dentists trained in Barcelona and Valencia have high percentages of antibiotic over-prescription. On the contrary, dentists from the endodontic programs in Sevilla and Zaragoza show lower percentages of antibiotic prescription.The differences observed between the programs could be explained by the different importance given, within each of the programs, to the medical aspects of endodontics. Some endodontic programs focus, perhaps too much, on the technical and technological aspects of endodontics, dedicating less importance to its basic, medical and pharmacological aspects. Possibly, the formation and the research field of the professors of each program have a great influence on this.Another factor that may explain the high percentage of prescription of antibiotics observed in some of the programs may be the type of population served. The pressure imposed by the community and the unreasonable demand for antibiotics by patients is a key factor in over-prescription, and may vary from one region to another.The European Society of Endodontology published the guidelines for Accreditation of postgraduate speciality training programs in Endodontology  with theAlthough the minimum criteria for training specialists in Endodontology within Europe remark that endodontic trainees must have an understanding of the relevant aspects of the clinical pharmacology and therapeutics in relation to the treatment of endodontic infections , the resThe results of this study show that postgraduate training in Endodontics provides greater awareness of the correct indications of antibiotics. Dentists who have received specialized training in Endodontics have a prescription pattern of antibiotics more adjusted to the guidelines recommended by international organizations and by scientific societies. However, there is still a significant percentage of dentists with specialized training in Endodontics who prescribe antibiotics in clinical situations where they are not indicated. Therefore, campaigns must still be carried out to promote the appropriate use of systemic antibiotics in Endodontics, preventing their misuse and protecting patients against unnecessary antibiotics.


Four types of concrete mixtures, containing 0 wt.%, 1 wt.%, 2 wt.%, and 4 wt.% of NS were prepared. The development of flexural and compressive strengths was determined for up to 90 days of curing. In addition, transport properties and microstructural properties were determined, with the use of RapidAir, mercury intrusion porosimetry (MIP), and scanning electron microscopy (SEM) techniques. The experimental results showed that NS has remarkable effects on the mechanical and transport properties of LWACs, even in small dosages. A significant improvement in strength and a reduction of transport properties, in specimens with an increased NS content, was observed. However, the positive effects of NS were more pronounced when a higher amount was incorporated into the mixtures (>1 wt.%). NS contributed to compaction of the LWAC matrix and a modification of the air-void system, by increasing the amount of solid content and refining the fine pore structure, which translated to a noticeable improvement in mechanical and transport properties. On the other hand, NS decreased the consistency, while increasing the viscosity of the fresh mixture. An increment of superplasticizer (SP), along with a decrement of stabilizer (ST) dosages, are thus required.This study presents the results of an experimental investigation of the effects of nanosilica (NS) on the strength development, transport properties, thermal conductivity, air-void, and pore characteristics of lightweight aggregate concrete (LWAC), with an oven-dry density <1000 kg/m However, as a result of its low density and high porosity, attributed to the intrinsic nature of lightweight aggregate or foaming agents, a weak LWC microstructure is produced. Thus, the mechanical performance of LWCs is significantly worse than that of normal-weight concretes [Lightweight concrete (LWC), often utilized in structural and masonry elements, is a versatile construction material with reduced dry density and low thermal conductivity. Moreover, because of the lower thermal conductivity of LWC, compared with normal-weight concrete, LWCs with low densities are widely used as heat and acoustic insulating elements. LWC owes its properties to the presence of natural or artificial aggregates with low specific densities , or the induction of air-voids in concrete or mortar . Depending on its density and the purpose of its use, lightweight concrete can be categorized in three ways: (I) low density concrete with a density lower than 800 kg/moncretes . HoweverIn recent years, increased interest has thus focused on the development of LWC with satisfactory mechanical and durability performance, through the optimization of packing densities and the incorporation of the proper aggregate type, fillers, and cement additives (mainly ground granulated blast furnace slag (GGBFS), fly ash (FA), and silica fume (SF)) . In addi3) showed that an optimal amount of NS  contributed to an improvement in compressive strength development from one day of hydration, as well as to decreased water permeability and chloride penetration. Atmaca et al. [As far as the authors of this paper are aware, only a limited number of papers have been devoted to a characterization of the effects of NS on the properties of LWACs. Du et al.  have evaa et al.  have anaa et al.  have shoa et al.  have ana3. This study thus proposes and demonstrates several techniques for evaluating the effects of NS on various material properties of LWAC, with a density ranging between 900 and 1000 kg/m3. These properties include strength development, thermal conductivity, transport properties , and evaluation of the air-void system and pore characteristics.Previous studies have mainly focused only on the effects of NS on material properties of normal-weight concrete. However, more detailed investigation of the effects of different NS dosages on the properties of LWAC is highly needed, so as to establish a precise relationship between NS dosage and the fresh and early/long term hardened properties of concrete. Besides, most of the available studies have evaluated the properties of lightweight concretes with densities >1000 kg/m3. To produce the concrete, a commercially available colloidal silica suspension (NS) (Levasil CB8), with a density of 1.4 g/cm3, containing 50 wt.% of solid material, was used. The liquid phase in the NS suspension was also considered to be a part of the mixing water, used for the cement paste preparation (see This research work studies the influence of nanosilica (NS) addition on the properties of lightweight aggregate concrete (LWAC), with dry density ranges between 900 and 1000 kg/mtion see . Scannin3. One of the main problems of lightweight concrete is its sensitivity to compaction and vibration, which can lead to concrete bleeding. A polycarboxylate ether-based superplasticizer (Sika VC 2014), provided by Sika, Germany, was thus used to achieve high workability of the produced concrete; that is, a slump flow >500 mm, according to EN 12350-8. Moreover, owing to the differences in density between the aggregates and the cement paste, segregation is prone to occur in lightweight concrete mixtures and, as such, a viscosity-enhancing admixture (Sika stabilizer ST 10160317) was added to the mixture. The particle size distributions of the concrete constituents as well as measured physical properties of the used expanded glass aggregates are given in Blast furnace cement, CEM III/A 42.5 N, provided by HeidelbergCement , was used in the study. The physical and chemical properties of the cement are summarized in 3, and thus lightweight aggregate, rather than normal-weight coarse aggregate, was used. In order to minimize concrete density, it is important to increase the volume of the lightest component in the mixture, which is expanded glass. This can be ensured by applying a packing density concept, without significantly altering the other properties of the lightweight concrete. By applying packing density theory in the mix design, aggregate particles can be packed efficiently in a specific volume while minimizing the gaps between the particles and, consequently, decreasing the amount of paste required to fill voids. The following formula, developed by Andreasen and Andersen [Several parameters significantly affect the characteristics and stability of lightweight aggregate concrete. In this research, the targeted dry density was about 1000 kg/mAndersen , was useribution ,19. The water absorption of lightweight aggregate is a significant parameter that can affect the properties of concrete, in both fresh and hardened states. To avoid this negative influence, the water absorption of the expanded glass (Liaver) used was determined after 60 min, according to EN 1097-6. The results are presented in To compare the influence of NS on the properties of LWAC, four mixes were planned and prepared, as presented in 3 cubical steel molds were filled with concrete to determine its compressive strength, dry density, thermal conductivity, and capillary water porosity. Moreover, 4 × 4 × 16 cm3 prisms were also cast to measure the flexural strength and water absorption of the concrete. After casting, the concrete specimens were stored in a laboratory at a controlled humidity and temperature equal to 99% and 20 ± 1 °C, respectively. The samples were demolded after 24 h and cured under water until the day of testing, according to EN 12390-2.A standard concrete mixer with a capacity of 50 liters was used to mix the concrete components as follows. The aggregates, cement, and fine sand were initially dry mixed for 30 s. Next, water, nanosilica, stabilizer, and two-thirds of superplasticizer were added to the mixer, with the mixing process continuing for an additional 3 min. The mixer was then stopped for one minute to control agglomeration and to remove concrete stuck to the bottom of the mixer. Finally, the mixture was mixed for an additional short period of time (30 s), after which the remaining superplasticizer and stabilizer were added, to achieve the target consistency. After mixing, the properties of the fresh concrete were measured for fresh density and consistency. For the hardened concrete, several 10 × 10 × 10 cmThe oven-dry densities of the specimens were measured after 28 days of curing, according to EN 12390-7. Three samples of each case were oven-dried at 105 °C until reaching a constant mass, with the mean value being selected as the dry density. In this investigation, flexural and compressive strength of the produced lightweight concrete were measured at the age of 7, 28, and 90 days to compare the mechanical performance of LWCs with different NS contents. To determine the strengths of the specimens, compression and flexural testing machines , conforming to EN 12390-3 and EN 196-1, respectively, were used. At the testing day, samples were taken from the curing chamber, and the surface of concrete was dried completely in order to prevent the influence of wetted surfaces on the test results. From each mix, three samples were tested and the mean value was considered.3 specimens, using the transient plane source method , conforming to ISO 22007-2 . Then, the surfaces of the samples were dried, and the mass of the saturated sample is determined (msat). The samples were dried at 105 °C to constant mass and weighed (mdry). From the knowledge of these masses, the effective water porosity can be calculated using the following formula (Equation (2)):Effective water porosity, in this experiment, is described as the pores that are accessible by water. It was measured simply using the water displacement method. The test was carried out on 10 × 10 × 10 cm3 prisms with the partial immersion method, conforming to EN ISO 15148. Prior to the test, specimens were dried to a constant mass, with the sides sealed with hot paraffin wax. During measurement, the water level was kept constant, at about 5 mm above the highest point of the bottom side of the prism (The water absorption coefficient (water uptake) of the specimens was determined on 4 × 4 × 160 cmhe prism . The maiTo evaluate the air-void characteristics of the concrete specimens, automated image analysis systems based on a linear traverse method (conforming EN 480-11) were performed, with the use of a RapidAir 457 Automated-Air-Void-Analyzer produced by Germann Instruments A/S, Copenhagen Denmark a. This mPore structure characteristics were determined with the use of the mercury intrusion porosimetry (MIP) method. MIP measurement made it possible to focus on pore sizes <10 µm. In general, it is known that MIP has disadvantages when measuring relatively large voids ; it is tLWAC is highly sensitive to any changes in its constituents. Increasing the water or superplasticizer dosages can lead to segregation and bleeding. In the experimental part of this research, superplasticizer dosages were adopted and adjusted to achieve the required consistency class, without negatively affecting concrete homogeneity and stability. As can be seen from Flexural strength and compressive strength results are depicted in In the case of compressive strength, the incorporation of NS at all dosages had a beneficial effect on all concretes tested b. StrengThe relationship between the amount of NS used and the air-void characteristics was determined on the basis of a 2D image analyzing technique, with the use of a RapidAir 457 testing device. The air-void characteristics are presented in It can be seen that the total porosities a of the As the RapidAir device is well suited to evaluating the air-void characteristics of concrete, the mercury intrusion porosimetry (MIP) method can be successfully applied to evaluating the pore size distribution and the fine pore structure of cement matrices, thus providing insight into their microstructural characteristics, which are responsible for the durability and transport-related properties of concrete. For a further understanding of the role of NS in the refinement of LWAC’s microstructure, a SEM analysis was also undertaken. The measurements were performed on concrete samples at the age of 28 days. 3) initially required a higher amount of superplasticizer than pristine concrete, but in turn, no bleeding in NS-modified mixtures was observed. On the basis of the results presented above, it can be concluded that NS significantly modifies the plastic and hardened properties of LWACs. A beneficial effect on mechanical and transport properties was clearly observed. However, the incorporation of NS requires certain mixture modifications, to produce concrete with satisfactory plastic properties, so as to obtain the appropriate hardened properties. Generally speaking, the effect of NS on the fresh properties of normal-weight concrete has been studied widely by several researchers ,26,27. IChanges in mixture design, through the incorporation of NS, did not contribute to a noticeable alteration of either fresh or dry specimen densities. Similarly, no noticeable differences between thermal conductivity or specific heat values were observed. As has been widely reported, thermal conductivity is highly related to LWAC density, with mixture composition having only a minor effect on this parameter ,30,31. HIn the case of the hardened properties of LWAC, it was observed that even small NS dosages (1 wt.%) were beneficial in improving overall concrete performance, with increments in NS content leading to considerable improvements. The beneficial effect of NS on strength development can be attributed to the nano-filling and nucleating effects, as well as to the pozzolanic activity of silica nanoparticles, which results in an acceleration of cement hydration, the production of a higher amount of dense calcium–silicate–hydrate (C-S-H) phase, a refinement in microstructure, and an improvement in the interfacial transition zone (ITZ) between the cement matrix and the aggregate ,37,38,39The improved mechanical performance of LWAC can also be attributed to an alteration in void characteristics, when NS was present in the mixture. The incorporation of NS contributed to decreasing the total number of voids in the mixes and to an increase in the production of voids with a slightly larger diameter. This resulted in maintaining relatively similar total porosity, along with increased average chord length and spacing factor, thus resulting in the production of robust structures with increased mechanical performance. In addition, incorporation of NS significantly contributed to the refinement of the pore structure in the capillary range. Previous studies ,44,45 haOn the basis of the results obtained in this work, it is clear that the incorporation of NS has a beneficial effect on the mechanical and transport properties of LWAC. However, to utilize NS beneficially in the production of LWACs, a proper mix design—with the optimal amounts of NS, SP, and ST meeting both economic and mechanical/durability requirements—is required. Superplasticizer dosage required to achieve the targeted consistency increases with the nanosilica content owing to the large surface area and small nanosilica particles.NS has a beneficial effect on the early flexural and compressive strengths of LWACs, with the effect increasing with NS dosage. When a lower amount of NS is incorporated (1 wt.%), strength improvement is relatively limited.NS added at a dosage of >1 wt.% effectively increases the 28 day flexural and compressive strengths. After 90 days, further strength improvements were not observed.The remarkable decrement of effective water porosity and the water absorption coefficient was analyzed in specimens containing NS. This effect increased with an increment in NS content, and best performance was exhibited by specimen containing 4 wt.%.The incorporation of NS leads to compaction and refinement of air-void structures in LWAC; thus more robust lightweight concrete structures are obtained. In addition, the presence of NS in the mixture refines the fine pore structure, resulting in an improvement in transport properties.From the results obtained, the following conclusions can be drawn:


Our objectives were (1) to systematically map the contours of the European evidence base on labour trafficking, identifying its key characteristics, coverage, gaps, strengths and weaknesses and (2) to synthesise key scientific research.We took a two-phase approach: a systematic map followed by a detailed synthesis of key scientific research evidence. Our search strategy included 15 databases, hand searches of additional journals, backwards searches, snowball searches and expert recommendations. We identified and screened 6106 records, mapped 152 and synthesised eight.Overall, the literature was limited and fragmented. Reports produced by official agencies dominated; academic authorship and peer-reviewed outputs were comparatively rare. Few publications met minimum scientific standards. Qualitative designs outweighed quantitative ones. Publications typically described trafficking’s problem profile and/or discussed interventions; they rarely assessed trafficking’s impacts or evaluated interventions. Even among the key scientific research, the quality of evidence was variable and often low. Particular weaknesses included poor methods reporting, unclear or imprecise results and conclusions not properly grounded in the data. The synthesised studies were all exploratory, also sharing other design features. Common themes identified included: poor treatment of victims; diversity of sectors affected and commonalities among victims; inadequacies of current responses; and barriers to interventions.There is a lack of high-quality studies into European labour trafficking. Methodological opacity, insufficient rigour and publication in non-indexed locations impede the identification, assessment and synthesis of evidence. Adherence to higher reporting standards would further the field’s development and particular research gaps should be addressed.The online version of this article (10.1007/s11292-017-9321-3) contains supplementary material, which is available to authorized users. Human trafficking, sometimes known as modern slaverySystematic reviews of any aspect of the trafficking literature are rare; notable exceptions have focused on trafficking’s health impacts , the predominance of purely descriptive work, methodological opacity, weak research design , sampling biases (a common shortcoming when working with hidden populations), ill-founded inferences, a tendency to be emotionally and/or politically charged and lack balance, and poor-quality statistics  , as recommended for reviews like ours that deal with broad topics and poorly-charted domains What can we learn from key scientific research evidence about the scale, nature and impacts of labour trafficking affecting Europe and on-the-ground counter-measures? (Synthesis)We defined ‘human trafficking’ in accordance with international law as:the recruitment, transportation, transfer, harbouring or receipt of persons, by means of the threat or use of force or other forms of coercion, of abduction, of fraud, of deception, of the abuse of power or of a position of vulnerability or of the giving or receiving of payments or benefits to achieve the consent of a person having control over another person, for the purpose of exploitation. Exploitation shall include, at a minimum, the exploitation of the prostitution of others or other forms of sexual exploitation, forced labour or services, slavery or practices similar to slavery, servitude or the removal of organs.  and/or within the household (domestic servitude). Our review definition of labour trafficking was that implicitly used in the UK for data collection and case monitoring : exploitation of any bodily labour except sexual services and domestic servitude. This definition covers labour in both legal and illegal industries but excludes domestic servitude. Analysis of UK trafficking data has revealed statistically significant differences between victims of domestic servitude and labour trafficking , Malta, Moldova, Monaco, Montenegro, Netherlands, Norway, Poland, Portugal, Romania, Russian Federation, San Marino, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey, Ukraine and the UK.We defined ‘Europe’ as all European Union (EU) member states, candidates and potential candidates plus additional countries not affiliated with the EU but located within the geographical territory commonly understood as Europe . The full list of countries covered is:Ethical approval was not required for this project. We registered our review prospectively in the PROSPERO International Prospective Register of Systematic Reviews  to ensure external scrutiny, draw on their diverse perspectives and experiences and maximise the review’s relevance and practical application Continental Europe DatabaseCriminal Justice DatabaseEast Europe, Central Europe DatabaseERIC (Education Resources Information Center)IBSS NCJRS  Abstracts DatabaseProquest theses and dissertationsPsycINFOPsycEXTRASCOPUSSocial Policy and PracticeSocial Science DatabaseSociological AbstractsWeb of Science.We used varied and complementary search strategies, designed to retrieve relevant publications from both the academic and grey literatures. First, we ran keyword searches of the following fifteen databases: Brown Journal of World Affairs; Criminology and Public Policy; Policing: A Journal of Policy and Practice; Health and Human Rights; International Health; and Journal of Immigrant and Minority Health. Third, we ran backwards searches on the contents of two major bibliographies we found that catalogued publications on human trafficking  indexed in the above databases. They were:The range of issues that labour trafficking encompasses and the lack of definitional consistency and clarity meant we needed broad and varied search terms. Our search terms Appendix  were desWe uploaded search results to specialist systematic review software (EPPI 4 Reviewer). Most of our results came from database searches and were returned in a format suited to screening on title and abstract; this worked as an initial sift before full text screening. Results from other sources typically lacked abstracts and so we proceeded directly to full text screening. We used the sequence of inclusion criteria detailed in Table n = 216) of the total records screened on title and abstract. The results indicated strong consistency between coders  of texts. A comparison of the exact codes assigned showed a high degree of consistency between coders (86%).We mapped the full texts using a detailed data extraction form Appendix . A singlThe systematic map highlighted the methodological weaknesses of the literature, which influenced how we targeted our synthesis. We selected studies for inclusion using the criteria in Table Eight publications met the inclusion criteria for synthesis. They varied in their design, methods and foci and included substantial qualitative material. Consequently, we designed our data extraction form Appendix  to be brGiven the anticipated nature of the literature, we chose to assess the quality of the studies based on the best methodological approach possible under the circumstances of their designs, rather than the risk of bias inherent in these designs in the first place  was the same and there was 88% overall agreement between coders. All discrepancies, none of which were larger than one point, were discussed and resolved.reported in the publications. It remains a possibility that at least some of the publications with underdeveloped or missing methods section were less methodologically weak in practice than in their reporting.We present results from the systematic map and synthesis in turn. We use examples from publications to substantiate certain findings: these were selected for context and illustrative purposes and are neither exhaustive nor intended to ‘name and shame’. Our coding was necessarily based on what was Although the empirical evidence base on labour trafficking is underdeveloped, the issue has been addressed in the context of numerous and diverse European countriesn = 105) of publications appeared from January 2009 to July 2015 (approximately 40% of the study period). During screening, we noted that certain countries’ annual reports of human trafficking originally dealt exclusively with sex trafficking: in Sweden and the Netherlands, for example, labour trafficking was first included respectively in the ninth  and multiple countries . There were striking methodological gaps in 9% of publications (n = 13) around precisely which countries were covered in all or part of their enquiries. Finally, multiple-country enquiries generally dealt with each country in isolation and international comparative analyses were rare: notable exceptions include Rijken . Reports were by far the most common publication format, accounting for 77% (n = 117) of the sample. The remainder was comprised of books or book chapters , theses  and miscellaneous formats . We noted that reports were often extremely long: the median was 84 pages (interquartile range of 112) and the longest ran to 644 pages.There were remarkably few journal articles in the sample: just 12% (n = 5340), they contributed just 25% (n = 38) of the publications mapped. Most  came instead from backwards searches, snowballing and requests to stakeholders.A related issue was publication in non-indexed locations; although the database searches yielded the vast majority of our initial results  featured the combination of a literature review and other non-scientific enquiry.Figure n = 18) of publications contained anything that met our definition of scientific research, despite the standards for this being fairly rudimentary  in design than exclusively quantitative . Although mixed methods enquiries were common , within them, qualitative methods dominated and the quantitative contribution rarely exceeded the description of basic numerical data. Again highlighting the methodological weaknesses of the overall evidence base, 11% (n = 16) of publications contained insufficient information even to establish whether the design was qualitative, quantitative or both.Far more of the publications were exclusively qualitative  and/or a discussion of interventions .n = 10) or of interventions . Five of those that assessed labour trafficking’s impacts met our criteria for scientific research, including a small but noteworthy set of studies addressing health impacts  since it limits their external validity.Second, all studies used non-random sampling. This is particularly noteworthy for those studies involving quantitative enquiries    , we made sure to pilot our codebooks, assess for inter-rater reliability (results showed good consistency) and encourage the coders to seek a second opinion where unsure. We double-coded the quality assessment of the studies in the synthesis. Some of the coding categories in the rest of the synthesis were open-ended and narrative in nature. Although unavoidable, as they are appropriate to the review of qualitative literature, such categories introduce greater subjectivity and with it a risk of bias. For validation and quality control, a second coder reviewed and commented on the main coder’s outputs here.Despite increased prioritisation of labour trafficking in European counter-trafficking policy and practice de Jonge , our resWhile publication in a journal does not guarantee quality, the peer-review process is widely seen as a quality-control measure that promotes rigour and transparency. Yet, the majority of mapped publications were reports: a format that is generally neither well-indexed nor subject to rigorous quality control. The preponderance of grey literature raises concerns about the visibility, accessibility and quality of the evidence on labour trafficking. Digestibility is another consideration: the tendency towards very lengthy publications may limit their dissemination, consumption and, ultimately, impact.The knowledge-production process was dominated by official agencies, with comparatively little input from academics and other independent parties. Of course, different authorships have different strengths. Robust outputs from practitioners, for example, can capitalise on valuable experiential knowledge and hard-to-access data and sources. In contrast, obvious advantages to academic outputs include the expectation of impartiality, rigorous methods training, strong analytical skills and research experience. The scarcity of academic research may reflect difficulties in securing data access, an oft-cited barrier to trafficking research Feingold .n = 18) of mapped publications met our basic criteria for scientific research. It seems that the problem is less that there is too little information, although there are certainly major gaps, and more that so much of it risks being lost because it exists in states not conducive to meaningful appraisal and synthesis. Many publications that fell short of the inclusion criteria for our synthesis contained material that was interesting, empirically-rich and informative   model of problem-oriented policing  merits further attention. The severity of labour trafficking was reflected both in its association with symptoms of ill health and more general accounts of extremely poor living and working conditions. While it remains to be seen whether and how the experiences and impacts of labour trafficking diverge from, say, sex trafficking, these results speak to a clear need for investment in both support services for victims of labour trafficking and targeted preventative activity. Numerous perceived barriers to intervention were highlighted, ranging from limited awareness to unmet training needs and widespread corruption. While their actual impact was not assessed, it would be useful to consider these factors when designing and evaluating interventions. The results suggest labour trafficking can affect a diverse range of legal and illegal industries. A more differentiated approach to researching and responding to labour trafficking that takes into account similarities and differences between sectors could prove useful in future. Finally, the overlaps between labour trafficking and other labour market issues  highlight the importance of situating research on and responses to labour trafficking within a broader spectrum of interrelated matters: labour trafficking should not be reduced to a criminal justice issue alone  reviews of and commentaries on other aspects to the human trafficking literature. Similar complaints about methodological opacity, lack of rigour, failure to acknowledge and account for limitations and skews in focus and methods have been heard repeatedly for over a decade , responses have rarely been evidence-based and the literature remains notoriously weak