Sulfur and carbon isotope measurements of carbonyl sulfide (COS) from small air samples using GC-IRMS

Carbonyl sulfide (COS) is the most abundant sulfur-containing trace gas in the atmosphere, with an average mixing ratio of 500 parts per trillion (ppt). It has a relatively long lifetime of about 2 years, which permits it to travel into the stratosphere. There, it likely plays an important role in the formation of stratospheric sulfur aerosols (SSA), which have a cooling effect on the Earth’s climate. Furthermore, during photosynthetic uptake by plants, COS follows essentially the same pathway as CO2, and therefore COS could be used to estimate gross primary production (GPP). Unfortunately, significant uncertainties still exist in the sources, sinks and global cycling of COS, which need to be overcome. Isotopic measurements of COS could be a promising tool for constraining the COS budget, as well as for investigating its role in the formation of stratospheric sulfur aerosols. Within the framework of the COS-OCS project, we developed a measurement system at Utrecht University using GC-IRMS that can measure δ33S and δ34S from S+ fragment ions of COS from small air samples of 2 to 5 L. This system was recently expanded to also measure δ13C from the CO+ fragment ions of COS, which has never been measured before. We will present the preliminary results from a plant chamber experiment conducted at Wageningen University, in which one of the goals was to quantify the COS uptake and isotopic fractionation factors of different C3 and C4 plants

Surgical quality and prospective quality control of the D2-gastrectomy for gastric cancer in the multicenter randomized LOGICA-trial

Background: Quality of gastric cancer surgery is crucial for favorable prognosis. Generally, prospective trials lack quality control measures. This study assessed surgical quality and a novel D2-lymphadenectomy photo-scoring in the LOGICA-trial. Methods: The multicenter LOGICA-trial randomized laparoscopic versus open total/distal D2-gastrectomy for resectable gastric cancer (cT1-4aN0-3M0) in 10 Dutch hospitals. During the trial, two reviewers prospectively analyzed intraoperative photographs of dissected nodal stations for quality control, and provided centers weekly feedback on their D2-lymphadenectomy, as continuous quality-enhancing incentive. After the trial, these photographs were reanalyzed to develop a photo-scoring for future trials, rating the D2-lymphadenectomy dissection quality (optimal-good-suboptimal-unevaluable). Interobserver variability was calculated (weighted kappa). Regression analyses related the photo-scoring to nodal yield, recurrence and 5-years survival. Results: Between 2015 and 2018, 212 patients underwent total/distal D2-gastrectomy (n = 122/n = 90), and 158 (75%) received neoadjuvant chemotherapy. R0-resection rate was 95%. Rate of ≥15 retrieved lymph nodes was 95%. Moderate agreement was obtained in stations 8 + 9 (κ = 0.522), 11p/11d (κ = 0.446) and 12a (κ = 0.441). Consensus was reached for discordant cases (30%). Stations 8 + 9, 11p/11d and 12a were rated ‘optimal’ in 76%, 63% and 68%. Laparoscopic photographs could be rated better than open (2% versus 12% ‘unevaluable’; 73% versus 50% ‘optimal’; p = 0.042). The photo-scoring did not show associations with nodal yield (p = 0.214), recurrence (p = 0.406) and survival (p = 0.988). Conclusions: High radicality and nodal yield demonstrated good quality of D2-gastrectomy. The prospective quality control probably contributed to this. The photo-scoring did not show good performance, but can be refined. Laparoscopic D2-gastrectomy was better suited for standardized surgical photo-evaluation than open surgery.</p

Body Composition Is a Predictor for Postoperative Complications After Gastrectomy for Gastric Cancer:a Prospective Side Study of the LOGICA Trial

PURPOSE: There is a lack of prospective studies evaluating the effects of body composition on postoperative complications after gastrectomy in a Western population with predominantly advanced gastric cancer. METHODS: This is a prospective side study of the LOGICA trial, a multicenter randomized trial on laparoscopic versus open gastrectomy for gastric cancer. Trial patients who received preoperative chemotherapy followed by gastrectomy with an available preoperative restaging abdominal computed tomography (CT) scan were included. The CT scan was used to calculate the mass (M) and radiation attenuation (RA) of skeletal muscle (SM), visceral adipose tissue (VAT), and subcutaneous adipose tissue (SAT). These variables were expressed as Z-scores, depicting how many standard deviations each patient’s CT value differs from the sex-specific study sample mean. Primary outcome was the association of each Z-score with the occurrence of a major postoperative complication (Clavien-Dindo grade ≥ 3b). RESULTS: From 2015 to 2018, a total of 112 patients were included. A major postoperative complication occurred in 9 patients (8%). A high SM-M Z-score was associated with a lower risk of major postoperative complications (RR 0.47, 95% CI 0.28–0.78, p = 0.004). Furthermore, high VAT-RA Z-scores and SAT-RA Z-scores were associated with a higher risk of major postoperative complications (RR 2.82, 95% CI 1.52–5.23, p = 0.001 and RR 1.95, 95% CI 1.14–3.34, p = 0.015, respectively). VAT-M, SAT-M, and SM-RA Z-scores showed no significant associations. CONCLUSION: Preoperative low skeletal muscle mass and high visceral and subcutaneous adipose tissue radiation attenuation (indicating fat depleted of triglycerides) were associated with a higher risk of developing a major postoperative complication in patients treated with preoperative chemotherapy followed by gastrectomy. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11605-022-05321-0

Pain and Opioid Consumption After Laparoscopic Versus Open Gastrectomy for Gastric Cancer:A Secondary Analysis of a Multicenter Randomized Clinical Trial (LOGICA-Trial)

Background:Laparoscopic gastrectomy could reduce pain and opioid consumption, compared to open gastrectomy. However, it is difficult to judge the clinical relevance of this reduction, since these outcomes are reported in few randomized trials and in limited detail. Methods: This secondary analysis of a multicenter randomized trial compared laparoscopic versus open gastrectomy for resectable gastric adenocarcinoma (cT1-4aN0-3bM0). Postoperative pain was analyzed by opioid consumption in oral morphine equivalents (OME, mg/day) at postoperative day (POD) 1–5, WHO analgesic steps, and Numeric Rating Scales (NRS, 0–10) at POD 1–10 and discharge. Regression and mixed model analyses were performed, with and without correction for epidural analgesia. Results: Between 2015 and 2018, 115 patients in the laparoscopic group and 110 in the open group underwent surgery. Some 16 patients (14%) in the laparoscopic group and 73 patients (66%) in the open group received epidural analgesia. At POD 1–3, mean opioid consumption was 131, 118, and 53 mg OME lower in the laparoscopic group, compared to the open group, respectively (all p &lt; 0.001). After correcting for epidural analgesia, these differences remained significant at POD 1–2 (47 mg OME, p = 0.002 and 69 mg OME, p &lt; 0.001, respectively). At discharge, 27% of patients in the laparoscopic group and 43% patients in the open group used oral opioids (p = 0.006). Mean highest daily pain scores were between 2 and 4 at all PODs, &lt; 2 at discharge, and did not relevantly differ between treatment arms. Conclusion: In this multicenter randomized trial, postoperative pain was comparable between laparoscopic and open gastrectomy. After laparoscopic gastrectomy, this was generally achieved without epidural analgesia and with fewer opioids. Trial Registration: NCT02248519.</p

Low Red to Far-red ratio increases resistance to CO2 diffusion and reduces photosynthetic efficiency in low light grown tomato plants

Application of light-emitting diode technology has opened opportunities to optimize light spectrum for crop production greenhouses and vertical farms. In addition to photosynthetically active radiation, far-red (FR) light has shown potential for enhancing leaf photosynthesis. However, additional FR also alters the red to far-red ratio (R:FR) and induces a shade-avoidance response (SAR) that changes leaf nitrogen, thickness and mass. These acclimations can potentially also alter the resistance to CO2 diffusion, which can limit photosynthesis. Tomato plants were grown with and without additional FR at two light levels. Changes in photosynthetic responses to light and CO2 diffusion resistance, as well as leaf mass, thickness and nitrogen content were assessed. At low light additional FR strongly reduced leaf maximum photosynthesis, leaf mass, thickness and nitrogen, and increased the resistance to CO2 diffusion. These effects were to a much lesser extent present in plants grown at high light intensity. Tomato leaves grown under low light intensity supplemented with FR, show much stronger SAR and a larger increase in CO2 diffusion resistance than plants grown under high light, which negatively influences their photosynthesis at increasing light intensity. Only if the negative effects of sensitivity to FR and SAR response can be avoided, supplemental FR light may be beneficial to enhance photosynthesis in greenhouse and vertical farm systems

Blood-feeding patterns of Culex pipiens biotype pipiens and pipiens/molestus hybrids in relation to avian community composition in urban habitats

Abstract Background Culex pipiens sensu stricto (s.s.) is considered the primary vector of Usutu virus and West Nile virus, and consists of two morphologically identical but behaviourally distinct biotypes (Cx. pipiens biotype pipiens and Cx. pipiens biotype molestus) and their hybrids. Both biotypes are expected to differ in their feeding behaviour, and pipiens/molestus hybrids are presumed to display intermediate feeding behaviour. However, the evidence for distinct feeding patterns is scarce, and to date no studies have related differences in feeding patterns to differences in host abundance. Methods Mosquitoes were collected using CO2-baited traps. We collected blood-engorged Cx. pipiens/torrentium specimens from 12 contrasting urban sites, namely six city parks and six residential areas. Blood engorged Cx. pipiens/torrentium mosquitoes were identified to the species and biotype/hybrid level via real-time polymerase chain reaction (PCR). We performed blood meal analysis via PCR and Sanger sequencing. Additionally, avian host communities were surveyed via vocal sounds and/or visual observation. Results We selected 64 blood-engorged Cx. pipiens/torrentium mosquitoes of which we successfully determined the host origin of 55 specimens. Of these, 38 belonged to biotype pipiens, 14 were pipiens/molestus hybrids and the identity of three specimens could not be determined. No blood-engorged biotype molestus or Cx. torrentium specimens were collected. We observed no differences in feeding patterns between biotype pipiens and pipiens/molestus hybrids across different habitats. Avian community composition differed between city parks and residential areas, whereas overall avian abundance did not differ between the two habitat types. Conclusions Our results show the following: (1) Cx. pipiens s.s. feeding patterns did not differ between city parks and residential areas, regardless of whether individuals were identified as biotype pipiens or pipiens/molestus hybrids. (2) We detected differences in host availability between city parks and residential areas. (3) We show that in both urban habitat types, biotype pipiens and pipiens/molestus hybrids fed on both mammalian and avian hosts. This underscores the potential role in arbovirus transmission of biotype pipiens and pipiens/molestus hybrids. Graphical Abstrac

Distribution of Culex pipiens life stages across urban green and grey spaces in Leiden, The Netherlands

Abstract Background There is an urgent need for cities to become more climate resilient; one of the key strategies is to include more green spaces in the urban environment. Currently, there is a worry that increasing green spaces might increase mosquito nuisance. As such, this study explores a comprehensive understanding of how mosquitoes utilise contrasting grey and green habitats at different life stages and which environmental factors could drive these distributions. Methods We used a setup of six paired locations, park (green) vs. residential (grey) areas in a single model city (Leiden, The Netherlands), where we sampled the abundances of different mosquito life stages (eggs, larvae, adults) and the local microclimatic conditions. In this study, we focused on Culex pipiens s.l., which is the most common and abundant mosquito species in The Netherlands. Results Our results show that while Cx. pipiens ovipositioning rates (number of egg rafts) and larval life stages were far more abundant in residential areas, adults were more abundant in parks. These results coincide with differences in the number of suitable larval habitats (higher in residential areas) and differences in microclimatic conditions (more amenable in parks). Conclusions These findings suggest that Cx. pipiens dispersal may be considerably more important than previously thought, where adult Cx. pipiens seek out the most suitable habitat for survival and breeding success. Our findings can inform more targeted and efficient strategies to mitigate and reduce mosquito nuisance while urban green spaces are increased, which make cities more climate resilient. Graphical Abstrac

Sulfur and carbon isotope measurements of carbonyl sulfide (COS) from small air samples using GC-IRMS

Carbonyl sulfide (COS) is the most abundant sulfur-containing trace gas in the atmosphere, with an average mixing ratio of 500 parts per trillion (ppt). It has a relatively long lifetime of about 2 years, which permits it to travel into the stratosphere. There, it likely plays an important role in the formation of stratospheric sulfur aerosols (SSA), which have a cooling effect on the Earth’s climate. Furthermore, during photosynthetic uptake by plants, COS follows essentially the same pathway as CO2, and therefore COS could be used to estimate gross primary production (GPP). Unfortunately, significant uncertainties still exist in the sources, sinks and global cycling of COS, which need to be overcome. Isotopic measurements of COS could be a promising tool for constraining the COS budget, as well as for investigating its role in the formation of stratospheric sulfur aerosols. Within the framework of the COS-OCS project, we developed a measurement system at Utrecht University using GC-IRMS that can measure δ33S and δ34S from S+ fragment ions of COS from small air samples of 2 to 5 L. This system was recently expanded to also measure δ13C from the CO+ fragment ions of COS, which has never been measured before. We will present the preliminary results from a plant chamber experiment conducted at Wageningen University, in which one of the goals was to quantify the COS uptake and isotopic fractionation factors of different C3 and C4 plants