Solar 3D printing of lunar regolith Meurisse, A.; Makaya, A.; Willsch, C. ...
Acta astronautica,
November 2018, 2018-11-00, 20181101, Volume:
152
Journal Article
Peer reviewed
Open access
The authors demonstrated the feasibility of sintering lunar regolith layer-by-layer solely using concentrated sunlight. First trials using actual concentrated sunlight led to an inhomogeneous ...sintering of individual layers of lunar regolith simulant, due to the significant flux density variations caused by atmospheric fluctuations. Tests focusing Xenon light demonstrated however the concept with the manufacturing of the first solar 3D printed brick made of lunar regolith simulant. The use of artificial light enabled steady illumination conditions over several hours as required to sinter lunar regolith layer-by-layer. Actual compressive strength of the sintered bricks, below 5 MPa, might be currently too low for a direct lunar application. High porosity levels and weak layer-to-layer bonding were observed on the micro-scale, but ways of improving the technology were found by reducing the thermal gradient and the cooling time between consecutive layers, thus showing the potential of the process. Adaptation of the technology on the Moon is presented to illustrate the suitability of solar additive manufacturing on the lunar surface, as a possible technique for shielding habitats and building roads prior to arrival of the astronauts.
•A novel 3D printing technique using only sunlight and lunar soil is presented.•The lunar soil is sintered layer-by-layer by concentrated sunlight.•A brick was solar 3D-printed using Xenon light and JSC-2A lunar simulant.•Characterisation indicates a compression strength of the solar sintered parts smaller than 5 MPa.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The European Astronaut Centre (EAC) is currently constructing the European Lunar Exploration Laboratory (LUNA), a large training and operations facility to be located adjacent to EAC at the DLR ...(German Aerospace Centre) campus in Cologne, Germany. With an estimated representative lunar testbed area of approximately 660 m
, a large volume of lunar regolith simulant material is needed for this purpose. In this study, a basanitic sandy silt from a quarry located in the Siebengebirge Volcanic Field is evaluated as a large-volume source of material. The focus of this project has been to conduct a physical and chemical characterisation of the fine-grained material to be used in LUNA; the European Astronaut Centre lunar regolith simulant 1 (EAC-1 A). The physical characterisation tests undertaken include sphericity, density measurements, cohesion and static angle of repose, with mineralogical investigations via petrographical analysis with optical microscope and SEM, XRF, XRD and DSC measurements. The results of the EAC-1A tests are compared to published data on existing widely used lunar regolith simulants, namely JSC-1A, JSC-2A, NU-LHT-3M, DNA and FJS-1.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
RAS mutations are currently sought for in tumor samples, which takes a median of almost 3weeks in western European countries. This creates problems in clinical situations that require urgent ...treatment and for inclusion in therapeutic trials that need RAS status for randomization. Analysis of circulating tumor DNA might help to shorten the time required to determine RAS mutational status before anti-epidermal growth factor receptor antibody therapy for metastatic colorectal cancer. Here we compared plasma with tissue RAS analysis in a large prospective multicenter cohort.
Plasma samples were collected prospectively from chemotherapy-naive patients and analyzed centrally by next-generation sequencing (NGS) with the colon lung cancer V2 Ampliseq panel and by methylation digital PCR (WIF1 and NPY genes). Tumoral RAS status was determined locally, in parallel, according to routine practice. For a minimal κ coefficient of 0.7, reflecting acceptable concordance (precision±0.07), with an estimated 5% of non-exploitable data, 425 subjects were necessary.
From July 2015 to December 2016, 425 patients were enrolled. For the 412 patients with available paired plasma and tumor samples, the κ coefficient was 0.71 95% confidence interval (CI), 0.64–0.77 and accuracy was 85.2% (95% CI, 81.4% to 88.5%). In the 329 patients with detectable ctDNA (at least one mutation or one methylated biomarker), the κ coefficient was 0.89 (95% CI, 0.84–0.94) and accuracy was 94.8% (95% CI, 91.9% to 97.0%). The absence of liver metastases was the main clinical factor associated with inconclusive circulating tumor DNA results odds ratio=0.11 (95% CI, 0.06–0.21). In patients with liver metastases, accuracy was 93.5% with NGS alone and 97% with NGS plus the methylated biomarkers.
This prospective trial demonstrates excellent concordance between RAS status in plasma and tumor tissue from patients with colorectal cancer and liver metastases, thus validating plasma testing for routine RAS mutation analysis in these patients.
Clinicaltrials.gov, NCT02502656.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
AbstractThe authors investigate mechanical properties of sintered lunar regolith. Using JSC-1A and DNA lunar simulants, they study the influence of changes in glass content, main plagioclase series, ...and ilmenite content on a defined sintering process and on the mechanical properties of resulting sintered samples. Ilmenite addition up to 20 wt% of the regolith showed a negligible effect on the sintered product. The anorthite plagioclase endmember cannot be replaced by albite, responsible for the low sintering temperature of DNA and covering up the effect of the glass phase. The vacuum environment was revealed to have a positive effect on JSC-1A sintering: the grains bond at lower temperature than in air, thus preventing the formation of additional porosity and increasing the compression strength up to 152 MPa compared with only 98 MPa for sintering JSC-1A in air.
5-Fluorouracil (5-FU) and platinum-based perioperative chemotherapy is standard of care for resectable gastric adenocarcinoma (RGA). Nanoparticle albumin-bound (Nab-) paclitaxel is active in advanced ...disease but has never been evaluated in the perioperative setting. The objective was to evaluate the efficacy of Nab-paclitaxel in combination with FOLFOX for RGA patients.
We performed a non-randomised, open-label, phase II study. RGA patients were assigned to receive neoadjuvant Nab-paclitaxel (150 mg/m2) and FOLFOX q2w for six cycles. Six additional post-operative cycles were kept at the investigator's discretion. The primary end-point was complete pathological response (tumour regression grade TRG1) rate. According to Fleming design, 49 patients were required to test H0 (10% TRG1) and H1 (25% TRG1). To reject H0, TRG1 had to be achieved in 8 patients.
Forty-nine patients were included. Median number of neoadjuvant chemotherapy cycles was 6 (range, 3–6). Median dose intensity for Nab-paclitaxel, oxaliplatin and 5-FU was 96% (38–103%), 97% (47–103%) and 99% (50–112%), respectively. Surgery could not be performed in 5 (10.2%) patients. Tumour resection was R0 for 42 of 44 (95.5%) patients. Pathological review classified tumours as TRG1 to TRG5 for 8 (16.3%), 11 (22.5%), 4 (8.2%), 18 (36.7%) and 3 (6.1%) patients, respectively. Grade 3 or worse toxicities during neoadjuvant chemotherapy were non-febrile neutropenia (20.4%), nausea (8.2%), diarrhoea (8.2%) and neuropathy (6.1%). Of 44 patients, 14 (31.8%) experienced surgery-related complications and three (6.8%) died of surgical complications.
This regimen shows promising activity. Toxicity is manageable but a meaningful rate of surgical complications was observed. This strategy deserves investigation in phase III studies.
•Neoadjuvant FOXAGAST leads to major cPR rate in resectable oesogastric adenocarcinoma.•Patients treated with FOXAGAST as perioperative regimen show prolonged PFS and OS.•FOXAGAST regimen is associated with a high rate of surgical complications.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Background
Specific surgical and oncological outcomes in patients with rectal cancer surgery after a previous diagnosis of prostate cancer have not been well described. The aim of this study was to ...compare surgical outcomes in patients with rectal cancer with or without a history of prostate cancer.
Methods
Patients who had surgery for rectal cancer with (PC group) or without (no‐PC group) previous curative treatment for prostate cancer were enrolled between January 2001 and December 2015. Comparisons between the two groups were performed by multivariable Cox analysis, and after propensity score matching in a 3 : 1 ratio for demographic and tumour characteristics, and surgical and oncological outcomes.
Results
A total of 944 patients with rectal cancer were enrolled, of whom 10·8 per cent had a history of prostate cancer. After matching, 83 patients who had received treatment for prostate cancer were compared with 249 who had not. The PC and no‐PC groups were similar regarding patient characteristics. Extended total mesorectal excision, conversion to open surgery, transfusion and tumour perforation were more frequent in the PC group than in the no‐PC group. Major surgical morbidity (28 versus 17·2 per cent; P = 0·036), anastomotic leakage (25 versus 13·7 per cent; P = 0·019) and permanent stoma (41 versus 12·4 per cent; P < 0·001) occurred more frequently in the PC group. Local recurrence was increased significantly in the PC group (17 versus 8·0 per cent; P = 0·019), and resulted in a significant decrease in disease‐free and overall survival.
Conclusion
Prostate cancer treatment increases short‐ and long‐term surgical morbidity in patients with rectal cancer, and impairs oncological outcomes.
The present study showed that a past history of prostate radiotherapy or prostatectomy for prostate cancer increased the risk of anastomotic leakage, permanent stoma after rectal resection and shorter survival.
Morbity and outcomes worse
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Sleep apnea (SA) was reported as possibly exacerbating symptoms of COVID-19, a disease induced by SARS-CoV-2 virus. The same comorbidities are common with both pathologies. This study aimed to ...estimate the prevalence, characteristics of SA and variation in AHI three months after severe COVID-19 requiring intensive care unit (ICU) admission.
A prospective cohort of patients admitted to ICU for severe COVID-19 underwent an overnight home polygraphy 3 months after onset of symptoms, as part of a comprehensive follow-up program (pulmonary function tests, 6-minute walk tests and chest CT-scan). Patients with an apnea hypopnea index (AHI) ≥5 were considered as having SA. We performed a comparative descriptive analysis of 2 subgroups according to the existence, severity of SA and indication for effective SA treatment: patients with absent or mild SA (AHI <15) vs patients with moderate to severe SA (AHI ≥15).
Among 68 patients included, 62 (91%) had known comorbidities (34 hypertension, 21 obesity, 20 dyslipidemia, 16 type 2 diabetes). It has been observed a preexisting SA for 13 patients (19.1%). At 3 months, 62 patients (91%) had SA with 85.5% of obstructive events. Twenty-four patients had no or a mild SA (AHI <15) and 44 had moderate to severe SA (AHI ≥15). Ischemic heart disease exclusively affected the moderate to severe SA group. Except for thoracic CT-scan which revealed less honeycomb lesions, COVID-19 symptoms were more severe in the group with moderate to severe SA, requiring a longer curarization, more prone position sessions and more frequent tracheotomy.
SA involved 91% of patients in our population at 3 months of severe COVID-19 and was mainly obstructive type. Although SA might be a risk factor as well as consequences of ICU care in severe COVID-19 infection, our results underline the importance of sleep explorations after an ICU stay for this disease.
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