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In this study, plasma induced by a nanosecond Nd:YAG laser on thin oil films deposited on a silica wafer was characterized by evaluating the main plasma parameters. Spatially and temporally integrated spectral measurements were performed under experimental conditions optimized for elemental analysis of trace metals in oil. Time-resolved values of the spectral line intensities, electron number density, and plasma temperature were obtained from time-integrated measurements by subtracting averaged spectra recorded at different time delays. The electron number density was estimated using the Stark broadened profile of the hydrogen Balmer alpha line. Ionization temperatures were derived from Mg ionic to atomic line intensity ratios. The obtained apparent values of time-resolved plasma parameters were in the range of 1.1×1017 cm-3 (1.5 μs) to 1.5×1016 cm-3 (4 μs) and 9400 K (3 μs) to 7200 K (5 μs), depending on the delay time. Emission spectra of C2 and CN molecules were used to evaluate the rotational and vibrational temperature.

Background Breast-conserving surgery with adjuvant radiotherapy and mastectomy are currently offered as equivalent surgical options for early-stage breast cancer based on RCTs from the 1970s and 1980s. However, the treatment of breast cancer has evolved and recent observational studies suggest a survival advantage for breast-conserving surgery with adjuvant radiotherapy. A systematic review and meta-analysis was undertaken to summarize the contemporary evidence regarding survival after breast-conserving surgery with adjuvant radiotherapy versus mastectomy for women with early-stage breast cancer. Methods A systematic search of MEDLINE, the Cochrane Central Register of Controlled Trials (CENTRAL), and Embase that identified studies published between 1 January 2000 and 18 December 2023 comparing overall survival after breast-conserving surgery with adjuvant radiotherapy versus mastectomy for patients with unilateral stage 1–3 breast cancer was undertaken. The main exclusion criteria were studies evaluating neoadjuvant chemotherapy, rare breast cancer subtypes, and specific breast cancer populations. The ROBINS-I tool was used to assess risk of bias, with the overall certainty of evidence assessed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) tool. Studies without critical risk of bias were included in a quantitative meta-analysis. Results From 11 750 abstracts, 108 eligible articles were identified, with one article including two studies; 29 studies were excluded from the meta-analysis due to an overall critical risk of bias, 42 studies were excluded due to overlapping study populations, and three studies were excluded due to reporting incompatible results. A total of 35 observational studies reported survival outcomes for 909 077 patients (362 390 patients undergoing mastectomy and 546 687 patients undergoing breast-conserving surgery with adjuvant radiotherapy). The pooled HR was 0.72 (95% c.i. 0.68 to 0.75, P < 0.001), demonstrating improved overall survival for patients undergoing breast-conserving surgery with adjuvant radiotherapy. The overall certainty of the evidence was very low. Conclusion This meta-analysis provides evidence suggesting a survival advantage for women undergoing breast-conserving surgery with adjuvant radiotherapy for early-stage breast cancer compared with mastectomy. Although these results should be interpreted with caution, they should be shared with patients to support informed surgical decision-making. [ABSTRACT FROM AUTHOR]

Non-randomised studies of the effects of interventions are critical to many areas of healthcare evaluation, but their results may be biased. It is therefore important to understand and appraise their strengths and weaknesses. We developed ROBINS-I (“Risk Of Bias In Non-randomised Studies - of Interventions”), a new tool for evaluating risk of bias in estimates of the comparative effectiveness (harm or benefit) of interventions from studies that did not use randomisation to allocate units (individuals or clusters of individuals) to comparison groups. The tool will be particularly useful to those undertaking systematic reviews that include non-randomised studies.

Background: The optimal dose of dexamethasone for severe/critical COVID‐19 is uncertain. We compared higher versus standard doses of dexamethasone in adults with COVID‐19 and hypoxia. Methods: We searched PubMed and trial registers until 23 June 2023 for randomised clinical trials comparing higher (>6 mg) versus standard doses (6 mg) of dexamethasone in adults with COVID‐19 and hypoxia. The primary outcome was mortality at 1 month. Secondary outcomes were mortality closest to 90 days; days alive without life support; and the occurrence of serious adverse events/reactions (SAEs/SARs) closest to 1 month. We assessed the risk of bias using the Cochrane RoB2 tool, risk of random errors using trial sequential analysis, and certainty of evidence using Grading of Recommendations Assessment, Development and Evaluation (GRADE). Results: We included eight trials (2478 participants), of which four (1293 participants) had low risk of bias. Higher doses of dexamethasone probably resulted in little to no difference in mortality at 1 month (relative risk [RR] 0.97, 95% CI: 0.79–1.19), mortality closest to Day 90 (RR 1.01, 95% CI: 0.86–1.20), and SAEs/SARs (RR 1.00, 95% CI: 0.97–1.02). Higher doses of dexamethasone probably increased the number of days alive without invasive mechanical ventilation and circulatory support but had no effect on days alive without renal replacement therapy. Conclusions: Based on low to moderate certainty evidence, higher versus standard doses of dexamethasone probably result in little to no difference in mortality, SAEs/SARs, and days alive without renal replacement therapy, but probably increase the number of days alive without invasive mechanical ventilation and circulatory support. [ABSTRACT FROM AUTHOR]

The analytical capability of laser-produced plasma for the analysis of low alloying elements in cast iron samples has been investigated. The plasma was induced by irradiation of a sample in air at atmospheric pressure using an infrared CO2 laser. Emission spectra were recorded by time-integrated spatially- resolved measurement technique. A set of ten cast iron samples in a powder or particulate form were provided by BAM (Bundesanstalt für Material Forschung und Prüfung, Deutschland), seven of which were used for calibration, and three were treated as unknowns. Linear calibration curves were obtained for copper, chromium, and nickel, with correlation coefficients above 0.99. Precision and accuracy of the LIBS method was evaluated and compared to those obtained by the inductively coupled plasma (ICP) analysis of the same samples. Detection limits for Cu, Cr and Ni were close to those reported in the literature for other comparable iron-based alloys obtained using different LIBS systems. Analytical figures of merit of the studied LIBS system may be considered as satisfying, especially in the light of other advantages of the method, like cost effective and fast analysis with no sample preparation, and with a possibility for real-time on-site analysis. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 172019]

The applicability of nanosecond infrared (IR) transversely excited atmospheric (TEA) CO2 laser, operating at 10.6 μm and 100 ns pulse length (initial spike), induced plasma under reduced air pressure for spectrochemical analysis of bronze and brass samples was investigated. The plasma consisted of two clearly distinguished and spatially separated regions and expanded to a distance of about 10 mm from the surface. Elemental composition of the samples was determined using a time-integrated space-resolved laser-induced plasma spectroscopy (TISR-LIPS) technique. Sharp and well resolved spectral lines mostly atomic, and negligibly low background emission, were obtained from a plasma region 7 mm from the target surface. Good signal to background and signal to noise ratios were obtained. Estimated detection limits for trace elements Mg, Fe, Al and Ca were in the order of 10 ppm in bronze and around 50 ppm in brass. Damage on the investigated samples induced by TEA CO2 laser radiation was negligible. [Projekat Ministarstva nauke Republike Srbije, br. 172019]