Real-time polymerase chain reaction (RT-PCR) is used to rule out SARS-CoV-2 prior to surgery, however few studies have evaluated patients with negative testing after surgery. Some 499 patients with ...negative tests were followed for 14 days after surgery, 39 were retested but none developed positive RT-PCR after operation. The risk of developing a positive RT-PCR after surgery was 0.74 per cent.
Corona-virus Disease 2019 (COVID-19) has had a huge impact on the delivery of healthcare worldwide, particularly elective surgery. There is a lack of data regarding risk of postoperative COVID-19 ...infection in children undergoing elective surgery, and regarding the utility of pre-operative COVID-19 testing, and preoperative “cocooning” or restriction of movements. The purpose of this present study was to examine the safety of elective paediatric Otolaryngology surgery during the COVID-19 pandemic with respect to incidence of postoperative symptomatic COVID-19 infection or major respiratory complications.
Prospective cohort study of paediatric patients undergoing elective Otolaryngology surgery between September and December 2020. Primary outcome measure was incidence of symptomatic COVID-19 or major respiratory complications within the 14 days after surgery. Parents of prospectively enrolled patients were contacted 14 days after surgery and enquiry made regarding development of postoperative symptoms, COVID-19 testing, or diagnosis of COVID-19.
302 patients were recruited. 125 (41.4%) underwent preoperative COVID-19 RT-PCR testing. 66 (21.8%) restricted movements prior to surgery. The peak 14-day COVID-19 incidence during the study was 302.9 cases per 100,000 population. No COVID-19 infections or major respiratory complications were reported in the 14 day follow-up period.
The results of our study support the safety of elective paediatric Otolaryngology surgery during the pandemic, in the setting of community incidence not exceeding that observed during the study period.
•Corona-virus Disease 2019 had had a major impact on healthcare delivery globally.•It is safe to proceed with elective paediatric surgery during the current pandemic when community transmission levels are low.•Further work is required to elucidate the exact role of ‘cocooning’/self-isolating in the role of disease prevention.
Background
Colon cancer is a disease with a worldwide spread. Surgery is the best option for the treatment of advanced colon cancer, but some aspects are still debated, such as the extent of ...lymphadenectomy. In Japanese guidelines, the gold standard was D3 dissection to remove the central lymph nodes (203, 213, and 223), but in 2009, Hoenberger et al. introduced the concept of complete mesocolic excision, in which surgical dissection follows the embryological planes to remove the mesentery entirely to prevent leakage of cancer cells and collect more lymph nodes. Our study describes how lymphadenectomy is currently performed in major Italian centers with an unclear indication on the type of lymphadenectomy that should be performed during right hemicolectomy (RH).
Methods
CoDIG 2 is an observational multicenter national study that involves 76 Italian general surgery wards highly specialized in colorectal surgery. Each center was asked not to modify their usual surgical and clinical practices. The aim of the study was to assess the preference of Italian surgeons on the type of lymphadenectomy to perform during RH and the rise of any new trends or modifications in habits compared to the findings of the CoDIG 1 study conducted 4 years ago.
Results
A total of 788 patients were enrolled. The most commonly used surgical technique was laparoscopic (82.1%) with intracorporeal (73.4%), side-to-side (98.7%), or isoperistaltic (96.0%) anastomosis. The lymph nodes at the origin of the vessels were harvested in an inferior number of cases (203, 213, and 223: 42.4%, 31.1%, and 20.3%, respectively). A comparison between CoDIG 1 and CoDIG 2 showed a stable trend in surgical techniques and complications, with an increase in the robotic approach (7.7% vs. 12.3%).
Conclusions
This analysis shows how lymphadenectomy is performed in Italy to achieve oncological outcomes in RH, although the technique to achieve a higher lymph node count has not yet been standardized.
Trial registration (ClinicalTrials.gov) ID: NCT05943951.
The nutrient loads of water draining forested watersheds are generally lower than the loads in water draining basins with other dominant land uses. Commercial forest management activities including ...timber harvesting, site preparation, road construction, and maintenance can alter the chemical properties of headwater forest streams, and there are concerns this can result in cumulative effects at downstream locations. Monthly water samples were collected from 1992 to 2006 in the Mica Creek Experimental Watershed (MCEW) in northern Idaho. This period of record included a pre-treatment time interval from 1992 to 1997; post-road construction period from 1997 to 2001; and post-harvest period from 2001 to 2006. Samples were analyzed for total Kjeldahl nitrogen (TKN), total ammonia nitrogen (TAN), nitrate
+
nitrite (NO
3
+
NO
2), total phosphorus (TP), and orthophosphate (OP). Statistically significant increases (
p
<
0.001) were observed in NO
3
+
NO
2 concentrations following both clearcut and partial cut harvest practices. Downstream of the clearcut harvest activity, mean monthly increases of 0.29
mg-N
L
−1 were observed. Statistically significant increases were also observed at sites further downstream, but changes were smaller than those immediately below the harvest sites and reflected dilution and possibly instream processing and/or uptake. Continued monitoring at these sites will help evaluate nutrient concentration trends during stand regrowth and hydrologic recovery.
The OLYMPUS experiment Milner, R.; Hasell, D.K.; Kohl, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
03/2014, Letnik:
741
Journal Article
Recenzirano
Odprti dostop
The OLYMPUS experiment was designed to measure the ratio between the positron–proton and electron–proton elastic scattering cross-sections, with the goal of determining the contribution of two-photon ...exchange to the elastic cross-section. Two-photon exchange might resolve the discrepancy between measurements of the proton form factor ratio, μpGEp/GMp, made using polarization techniques and those made in unpolarized experiments. OLYMPUS operated on the DORIS storage ring at DESY, alternating between 2.01GeV electron and positron beams incident on an internal hydrogen gas target. The experiment used a toroidal magnetic spectrometer instrumented with drift chambers and time-of-flight detectors to measure rates for elastic scattering over the polar angular range of approximately 25°–75°. Symmetric Møller/Bhabha calorimeters at 1.29° and telescopes of GEM and MWPC detectors at 12° served as luminosity monitors. A total luminosity of approximately 4.5fb−1 was collected over two running periods in 2012. This paper provides details on the accelerator, target, detectors, and operation of the experiment.
The efficiency of producing biological damage varies with radiation quality. Conventional explanations rely on spatial differences in the radiation track structure; generally however there are also ...very large temporal differences in delivery of the radiation at the cellular level. High-LET radiation normally deposits substantial amounts of energy by individual heavily ionizing tracks on a timescale of the order of picoseconds. By contrast each low-LET radiation track deposits a small amount of energy. Many of these tracks, distributed over the whole cell, are required to deliver an equivalent dose to a high-LET track and they are usually delivered over much longer timescales (typically seconds) during which chemical, biochemical and biological processes are occurring. In this paper the design, characterization and initial application of a high-brightness, laser-plasma ultrasoft x-ray source is described. This has been used to investigate the importance of the temporal differences by irradiating mammalian cells with an energy deposition with spatial properties of low-LET radiation and temporal properties similar to high-LET radiation. The present system delivers a typical dose, to the incident surface of the cells, of 0.12 Gy per pulse delivered in <10 ps. The capabilities of the x-ray source were tested by determining the survival of V79-4 hamster cells irradiated with picosecond pulses of ultrasoft x-rays under aerobic and anaerobic conditions, which were found to be consistent with previously published non pulsed data with x-rays of similar energy. These results support the expectation that the disappearance of an oxygen effect for high-LET radiation particles is due to their spatial properties rather than the very short timescale of each particle traversal. For other effects, particularly non-targeted phenomena such as induced genomic instability, expectations may be less clear cut.
To compare performance of prospective interpretations of clinical tomosynthesis (digital breast tomosynthesis DBT) plus full-field digital mammography (FFDM) examinations with retrospective readings ...of the corresponding FFDM examinations alone.
Seven Mammography Quality Standard Act-qualified radiologists retrospectively interpreted 10,878 FFDM examinations that had been interpreted by other radiologists during prospective clinical interpretations of DBT plus FFDM. The radiologists were blinded to the Breast Imaging Reporting and Data System (BIRADS) category given during the clinical interpretations and the verified outcome by follow-up and/or any diagnostic workup that may have followed. Ratings (BIRADS 0, 1, or 2) were recorded. Group performance levels in terms of recall rates and attributable cancer detection rates were compared to the prospective clinical interpretations of the same examinations (DBT plus FFDM) using McNemar test (two sided/tailed) with significance level of .05.
During the prospective clinical interpretations of DBT plus FFDM, 588 cases were recalled (588 of 10,878, 5.41%) compared to 888 cases recalled (888 of 10,878, 8.16%) during the FFDM-alone retrospective interpretations (absolute difference, 35%; P<.0001). There were 59 and 38 suspicious abnormalities later verified as cancers detected during the DBT plus FFDM and the FFDM-alone interpretations, respectively (absolute increase, 55%; P<.0001). Invasive cancer detections were 48 and 29, respectively (absolute increase, 66%; P<.0001).
The combination of DBT plus FFDM for screening asymptomatic women resulted in a significant reduction in recall rates and a simultaneous increase in cancer detection rates when compared to retrospective interpretations of corresponding FFDM examinations alone.
Influenza virus is one of the most ubiquitous organisms on the planet, causing illness in much of the population each year. The dynamic nature of the influenza virus requires similarly dynamic ...surveillance and prevention initiatives. The efforts of national surveillance programs, overseen by the World Health Organization and administered by institutions such as the U.S. Centers for Disease Control and Prevention, the U.S. armed forces, and 60 to 70 collaborating laboratories, annually culminate in the development of effective influenza vaccines. The U.S. Air Force's contribution is via Project Gargle, through which bases in various locations worldwide conduct active surveillance and submit throat swab specimens for virus isolation and characterization; the results of these laboratory analyses help determine the composition of the following year's influenza vaccine. These collaborative efforts have resulted in an identical or close antigenic match between vaccine and epidemic strains in 8 of the last 9 influenza seasons.
The OLYMPUS collaboration reports on a precision measurement of the positron-proton to electron-proton elastic cross section ratio, \(R_{2\gamma}\), a direct measure of the contribution of hard ...two-photon exchange to the elastic cross section. In the OLYMPUS measurement, 2.01~GeV electron and positron beams were directed through a hydrogen gas target internal to the DORIS storage ring at DESY. A toroidal magnetic spectrometer instrumented with drift chambers and time-of-flight scintillators detected elastically scattered leptons in coincidence with recoiling protons over a scattering angle range of \(\approx 20\degree\) to \(80\degree\). The relative luminosity between the two beam species was monitored using tracking telescopes of interleaved GEM and MWPC detectors at \(12\degree\), as well as symmetric Møller/Bhabha calorimeters at \(1.29\degree\). A total integrated luminosity of 4.5~fb\(^{-1}\) was collected. In the extraction of \(R_{2\gamma}\), radiative effects were taken into account using a Monte Carlo generator to simulate the convolutions of internal bremsstrahlung with experiment-specific conditions such as detector acceptance and reconstruction efficiency. The resulting values of \(R_{2\gamma}\), presented here for a wide range of virtual photon polarization \(0.456<\epsilon<0.978\), are smaller than some hadronic two-photon exchange calculations predict, but are in reasonable agreement with a subtracted dispersion model and a phenomenological fit to the form factor data.
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