Photonics and fracture toughness of heterogeneous composite materials

Fracture toughness measures the resistance of a material to fracture. This fundamental property is used in diverse engineering designs including mechanical, civil, materials, electronics and chemical engineering applications. In spite of the advancements made in the past 40 years, the evaluation of this remains challenging for extremely heterogeneous materials such as composite concretes. By taking advantage of the optical properties of a thin birefringent coating on the surface of opaque, notched composite concrete beams, here we sense the evolution of the maximum shear stress distribution on the beams under loading. The location of the maximum deviator stress is tracked ahead of the crack tip on the experimental concrete samples under the ultimate load, and hence the effective crack length is characterised. Using this, the fracture toughness of a number of heterogeneous composite beams is evaluated and the results compare favourably well with other conventional methods using combined experimental and numerical/analytical approaches. Finally a new model, correlating the optically measured shear stress concentration factor and flexural strength with the fracture toughness of concretes is proposed. The current photonics-based study could be vital in evaluating the fracture toughness of even opaque and complex heterogeneous materials more effectively in future

Mapping and linking supply- and demand-side measures in climate-smart agriculture. A review

Climate change and food security are two of humanity’s greatest challenges and are highly interlinked. On the one hand, climate change puts pressure on food security. On the other hand, farming significantly contributes to anthropogenic greenhouse gas emissions. This calls for climate-smart agriculture—agriculture that helps to mitigate and adapt to climate change. Climate-smart agriculture measures are diverse and include emission reductions, sink enhancements, and fossil fuel offsets for mitigation. Adaptation measures include technological advancements, adaptive farming practices, and financial management. Here, we review the potentials and trade-offs of climate-smart agricultural measures by producers and consumers. Our two main findings are as follows: (1) The benefits of measures are often site-dependent and differ according to agricultural practices (e.g., fertilizer use), environmental conditions (e.g., carbon sequestration potential), or the production and consumption of specific products (e.g., rice and meat). (2) Climate-smart agricultural measures on the supply side are likely to be insufficient or ineffective if not accompanied by changes in consumer behavior, as climate-smart agriculture will affect the supply of agricultural commodities and require changes on the demand side in response. Such linkages between demand and supply require simultaneous policy and market incentives. It, therefore, requires interdisciplinary cooperation to meet the twin challenge of climate change and food security. The link to consumer behavior is often neglected in research but regarded as an essential component of climate-smart agriculture. We argue for not solely focusing research and implementation on one-sided measures but designing good, site-specific combinations of both demand- and supply-side measures to use the potential of agriculture more effectively to mitigate and adapt to climate change

Rivaroxaban Compared with Standard Anticoagulants for the Treatment of Acute Venous Thromboembolism in Children: a Randomised, Controlled, Phase 3 Trial

Background: Treatment of venous thromboembolism in children is based on data obtained in adults with little direct documentation of its efficacy and safety in children. The aim of our study was to compare the efficacy and safety of rivaroxaban versus standard anticoagulants in children with venous thromboembolism. Methods: In a multicentre, parallel-group, open-label, randomised study, children (aged 0–17 years) attending 107 paediatric hospitals in 28 countries with documented acute venous thromboembolism who had started heparinisation were assigned (2:1) to bodyweight-adjusted rivaroxaban (tablets or suspension) in a 20-mg equivalent dose or standard anticoagulants (heparin or switched to vitamin K antagonist). Randomisation was stratified by age and venous thromboembolism site. The main treatment period was 3 months (1 month in children <2 years of age with catheter-related venous thromboembolism). The primary efficacy outcome, symptomatic recurrent venous thromboembolism (assessed by intention-to-treat), and the principal safety outcome, major or clinically relevant non-major bleeding (assessed in participants who received ≥1 dose), were centrally assessed by investigators who were unaware of treatment assignment. Repeat imaging was obtained at the end of the main treatment period and compared with baseline imaging tests. This trial is registered with ClinicalTrials.gov, number NCT02234843 and has been completed. Findings: From Nov 14, 2014, to Sept 28, 2018, 500 (96%) of the 520 children screened for eligibility were enrolled. After a median follow-up of 91 days (IQR 87–95) in children who had a study treatment period of 3 months (n=463) and 31 days (IQR 29–35) in children who had a study treatment period of 1 month (n=37), symptomatic recurrent venous thromboembolism occurred in four (1%) of 335 children receiving rivaroxaban and five (3%) of 165 receiving standard anticoagulants (hazard ratio [HR] 0·40, 95% CI 0·11–1·41). Repeat imaging showed an improved effect of rivaroxaban on thrombotic burden as compared with standard anticoagulants (p=0·012). Major or clinically relevant non-major bleeding in participants who received ≥1 dose occurred in ten (3%) of 329 children (all non-major) receiving rivaroxaban and in three (2%) of 162 children (two major and one non-major) receiving standard anticoagulants (HR 1·58, 95% CI 0·51–6·27). Absolute and relative efficacy and safety estimates of rivaroxaban versus standard anticoagulation estimates were similar to those in rivaroxaban studies in adults. There were no treatment-related deaths. Interpretation: In children with acute venous thromboembolism, treatment with rivaroxaban resulted in a similarly low recurrence risk and reduced thrombotic burden without increased bleeding, as compared with standard anticoagulants. Funding: Bayer AG and Janssen Research & Development. © 2020 Elsevier Ltd

Diagnostic usefulness of tumor marker levels in pleural effusions of malignant and benign origin

Purpose: The aim of the present study was to determine the usefulness of simultaneous quantification of carbohydrate antigen 19.9 (CA 19.9), carbohydrate antigen 125 (CA 125), neuron specific enolase (NSE), mucinous-carcinoma-associated antigen (MCA), and ferritin in samples of pleural fluids (PF) in order to differentiate malignant from benign pleural effusions (PE). Patients and methods: A total of 61 PE were collected from patients with malignant or benign diseases. The diagnosis of PE was carried out cytologically or histologically by pleural biopsy. Tumor markers were determined in patients with benign or malignant diseases. CA 19.9, CA 125, NSE, and ferritin levels were quantified by the sandwich assay using the streptavidin method (ELISA). MCA was measured by employing a two-side solid phase enzyme immunoassay (EIA) method. PEs, either correctly or incorrectly identified as malignant or nonmalignant were defined as true positive (TP), false positive (FP), true negative (TN), and false negative (FN), the term 'positive' referring to histologically or cytologically proven malignant PE. Sensitivity (S), specificity (s), positive predictive value (PPV), and negative predictive value (NPV) were defined as diagnostic parameters. A cut-off value more than the nonmalignant group mean 2 standard deviation (SD) was considered as positive. Results: The calculated cut-off values were 352 U/ml for CA 125, 54 U/ml for CA 19.9, 555 ng/ml for ferritin, 11.1U/ml for MCA and 8.7 ng/ml for NSE. MCA was found to show the highest S (100%); CA 19.9 displayed the highest s (97%); CA 125, CA 19.9 and MCA showed the highest PPV (95%) and MCA had the highest NPV (100%). The combined measurement of MCA + CA 19.9 + CA 125 slightly increased the S, PPV and NPV. Conclusion: Our results imply that the co-measurement of MCA + CA 19.9 + CA 125 levels may further improve their diagnostic value in malignant PE compared with that of each tumor marker alone and may be useful in distinguishing malignant from benign PE

Diagnostic usefulness of tumour marker levels in pleural effusions of malignant and benign origin

Pleural effusion is a common diagnostic problem. The analysis of serum and body fluids for tumor markers has been intensively applied to clinical diagnosis. The aim of the present study was to determine the usefulness of simultaneous quantification of carbohydrate antigen 19.9, carbohydrate antigen 125, neuron specific enolase, mucinous-carcinoma-associated antigen, and ferritin in samples of pleural fluids in the malign pleural effusion and its differentiation from benign effusions. A total of 61 pleural effusions were collected from the patients, who were subjected either to simple needle aspiration or to tube drainage for the diagnosis of pleural effusion. Tumor markers were determined in benign patient groups with nonspecific pleurisy, tuberculous pleurisy, empyema, congestive heart failure and in malignancy groups consisting of adenocarcinoma, small cell lung carcinoma, mesothelioma, epidermoid lung cancer. The tumor markers CA-19.9, CA-125, NSE, and ferritin levels were quantified by the sandwich assay using the streptavidin technology of ELISA in an ES-300 Boehringer-Mannheim analyser. MCA was measured by employing a two-side solid phase EIA method. MCA measurements were done by the Cobas-Core. For all patients, the effusions correctly or incorrectly identified by the different procedures as being malignant or nonmalignant are defined as true positive, false positive, true negative, and false negative, the term 'positive' referring to histologically proven malignant pleural effusion while nonmalignant effusions are referred to as 'negative'. Therefore, sensitivity, specificity, positive predictive value, and negative predictive value were defined as diagnostic parameters. The cut-off values calculated were 352 U/ml for CA-125, 54 U/ml for CA-19.9. 555 for ferritin, 11.1 for MCA and 8.7 for NSE. In our study, the highest sensitivity is found to be MCA with 100%; specificity, CA-19.9 with 97%; PPV, CA-19.9 and MCA with 95% and NPV, MCA with 100%. Our data imply that the co-measurement of MCA + CA-19.9 + CA-125 levels may further improve their diagnostic value in malignant pleural effusion compared with that of each tumour marker alone and may be useful in distinguishing malignant from benign pleural effusions. (C) 2000 Elsevier Science B.V. All rights reserved

Does the administration route of leucovorin have any influence on the impairment of colonic healing caused by intraperitoneal 5-fluorouracil treatment?

Intraperitoneal chemotherapy with li-fluorouracil (5-FU) is a new, promising alternative in adjuvant treatment of advanced colorectal cancer. Leucovorin (LV), a biomodulator of 5-FU, potentiates the antineoplastic effect of 5-FU. The aim of this study was to determine whether the administration routes of LV had any influence on the impairment of colonic healing caused by intraperitoneal 5-FU treatment. 48 male Wistar rats were subjected to left colonic resection and anastomosis, and randomized to 1 of 4 groups: control group (receiving intraperitoneal NaCl, intravenous NaCl); ipFU group (receiving intraperitoneal 5-FU, intravenous NaCl); ipFU+ivLV group (receiving intraperitoneal 5-FU, intravenous LV), and ipFU+LV group (receiving intraperitoneal 5-FU+LV, intravenous NaCl). Treatment was started after surgery and continued for 5 days with daily injections. The animals were sacrificed on the 7th day postoperatively. Anastomotic complications were more common in the ipFU, ipFU+ivLV, and ipFU+LV groups (p < 0.05) compared to the control group. The anastomotic breaking strength was significantly reduced in the ipFU, ipFU+ivLV, ipFU+LV groups (p < 0.05) than in the control group, but it did not differ between the ipFU, ipFU+ivLV, and ipFU+LV groups. The hydroxyproline content of the anastomotic segment was also significantly reduced in the ipFU, ipFU+ivLV and ipFU+LV groups (p < 0.05) compared to the control group. However, there was no difference between the anastomotic hydroxyproline content of the ipFU, ipFU+ivLV, and ipFU+LV groups. In this experiment, colonic healing was impaired after intraperitoneal 5-FU administration as judged by the higher rates of anastomotic complications, reductions in anastomotic breaking strength and hydroxyproline content; but LV administration either intravenously or intraperitoneally did not cause further deterioration in colonic healing. Copyright (C) 2001 S. Karger AG, Baser

Bone mineral density and biochemical markers of bone in patients with idiopathic hypercalciuria

In this study, we determined the prevalence of idiopathic hypercalciuria (IH) in patients with renal lithiasis, and measured the bone mineral density (BMD) and biochemical markers of bone metabolism in patients with IH. Among 85 consecutive patients with urolithiasis (40 men, 30 postmenopausal and 15 premenopausal women), hypercalciuria (urinary calcium excretion >4 mg/kg per day) was observed in 22 (11 men, 8 postmenopausal and 3 premenopausal women). These 22 patients were then classified as having absorptive or fasting hypercalciuria. In 19 of the 22 hypercalciuric patients (I I men and 8 postmenopausal women), BMD was measured by dual-energy x-ray absorptiometry and serum levels of calcium, alkaline phosphatase, parathyroid hormone, osteocalcin (OC), and urinary deoxypyridinoline (DPD) were determined. When compared with age- and sex-matched control subjects (volunteers from hospital personnel), OC and urinary DPD levels were significantly higher in the renal lithiasis patients when compared with control subjects. Ward's triangle BMD in women and lumbar BMD in men were significantly lower when compared with sex- and age-matched control subjects. Lumbar, Ward's triangle, and femoral neck BMD measurements were inversely correlated with the duration of renal lithiasis in male patients. Males also had a significant negative correlation between lumbar BMD and the urinary DPD. BMD decreases significantly in male and postmenopausal female patients with IH. Patients with renal lithiasis should be evaluated for IH, and those with IH should be screened for osteoporosis. Studies determining the clinical and lifestyle consequences of IH and its related osteoporosis should be performed