The photon-the quantum excitation of the electromagnetic field-is massless but carries momentum. A photon can therefore exert a force on an object upon collision
. Slowing the translational motion of ...atoms and ions by application of such a force
, known as laser cooling, was first demonstrated 40 years ago
. It revolutionized atomic physics over the following decades
, and it is now a workhorse in many fields, including studies on quantum degenerate gases, quantum information, atomic clocks and tests of fundamental physics. However, this technique has not yet been applied to antimatter. Here we demonstrate laser cooling of antihydrogen
, the antimatter atom consisting of an antiproton and a positron. By exciting the 1S-2P transition in antihydrogen with pulsed, narrow-linewidth, Lyman-α laser radiation
, we Doppler-cool a sample of magnetically trapped antihydrogen. Although we apply laser cooling in only one dimension, the trap couples the longitudinal and transverse motions of the anti-atoms, leading to cooling in all three dimensions. We observe a reduction in the median transverse energy by more than an order of magnitude-with a substantial fraction of the anti-atoms attaining submicroelectronvolt transverse kinetic energies. We also report the observation of the laser-driven 1S-2S transition in samples of laser-cooled antihydrogen atoms. The observed spectral line is approximately four times narrower than that obtained without laser cooling. The demonstration of laser cooling and its immediate application has far-reaching implications for antimatter studies. A more localized, denser and colder sample of antihydrogen will drastically improve spectroscopic
and gravitational
studies of antihydrogen in ongoing experiments. Furthermore, the demonstrated ability to manipulate the motion of antimatter atoms by laser light will potentially provide ground-breaking opportunities for future experiments, such as anti-atomic fountains, anti-atom interferometry and the creation of antimatter molecules.
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GEOZS, IJS, IMTLJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK, ZAGLJ
Identification of patient factors influencing velopharyngeal function for speech following initial cleft palate repair.
A literature search of relevant databases from inception until 2018 was ...performed using medical subject headings and keywords related to cleft palate, palatoplasty and speech assessment. Following three stage screening data extraction was performed.
Systematic review and meta-analysis of relevant literature.
Three hundred and eighty-three studies met the inclusion criteria, comprising data on 47 658 participants.
Individuals undergoing initial palatoplasty.
Studies including participants undergoing initial cleft palate repair where the frequency of secondary speech surgery and/or velopharyngeal function for speech was recorded.
Patient factors reported included cleft phenotype (95% studies), biological sex (64%), syndrome diagnosis (44%), hearing loss (28%), developmental delay (16%), Robin Sequence (16%) and 22q11.2 microdeletion syndrome (11%). Meta-analysis provided strong evidence that rates of secondary surgery and velopharyngeal dysfunction varied according to cleft phenotype (Veau I best outcomes, Veau IV worst outcomes), Robin Sequence and syndrome diagnosis. There was no evidence that biological sex was associated with worse outcomes. Many studies were poor quality with minimal follow-up.
Meta-analysis demonstrated the association of certain patient factors with speech outcome, however the quality of the evidence was low. Uniform, prospective, multi-centre documentation of preoperative characteristics and speech outcomes is required to characterise risk factors for post-palatoplasty velopharyngeal insufficiency for speech.
Registered with PROSPERO CRD42017051624.
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CMK, NUK, OILJ, SAZU, UKNU, UL, UM, UPUK
The positron, the antiparticle of the electron, predicted by Dirac in 1931 and discovered by Anderson in 1933, plays a key role in many scientific and everyday endeavours. Notably, the positron is a ...constituent of antihydrogen, the only long-lived neutral antimatter bound state that can currently be synthesized at low energy, presenting a prominent system for testing fundamental symmetries with high precision. Here, we report on the use of laser cooled Be
ions to sympathetically cool a large and dense plasma of positrons to directly measured temperatures below 7 K in a Penning trap for antihydrogen synthesis. This will likely herald a significant increase in the amount of antihydrogen available for experimentation, thus facilitating further improvements in studies of fundamental symmetries.
Background and aims:
Intra-abdominal septic complications IASC following ileocolonic resection for Crohn’s disease are common. Determining risk factors for these complications can aid pre-operative ...and peri-operative strategies to reduced morbidity. This study aims to determine the incidence and predictors of intra-abdominal septic complications following ileocolonic resection for Crohn’s disease.
Methods:
A single-centre, retrospective study was conducted. The clinical case notes of patients with histopathologically proven Crohn’s disease, who underwent an ileocolonic resection as a one-stage or two-stage procedure, were reviewed. The primary endpoint was the formation of intra-abdominal septic complications within a 30-day post-operative time frame.
Results:
Overall 163 patients underwent 175 ileocolonic procedures. Post-operative intra-abdominal septic complications were demonstrated in 9% 13/142 of one-stage procedures and 12% 4/33 of two-stage procedures p = 0.2. Post-operative IASCs following a one-stage procedure demonstrated associations with smokers p = 0.004, intraoperative abdominal sepsis p = 0.005, concomitant upper gastrointestinal Crohn’s p = 0.015, the presence of peri-operative anaemia p = 0.037, hypoalbuminaemia < 25g/l p = 0.04, and histologically involved margins p = 0.001. Multivariate analysis demonstrated the presence of intra-abdominal sepsis (hazard ratio HR 8.6, 95% confidence interval CI: 1.2 60.1 and the use of peri-operative biologicals HR 24.6, 95% CI: 2.0–298 as independent predictors of post-operative intra-abdominal septic complications.
Conclusions:
This study highlights specific variables that may be contributory to poor outcome. These findings may be important when optimising patients for surgery, as well as planning an appropriate operative strategy. Further prospective studies and a larger sample size are required to validate these findings.
Aim
Laparoscopic surgery is well established for colon cancer, with defined benefits. Use of laparoscopy for the performance of restorative proctocolectomy (RPC) with ileoanal anastomosis is more ...controversial. Technical aspects include difficult dissection of the distal rectum and a potentially increased risk of anastomotic leakage through multiple firings of the stapler. In an attempt to overcome these difficulties we have used the technique of transanal rectal excision to perform the proctectomy. This paper describes the technique, which is combined with an abdominal approach using a single‐incision platform (SIP).
Method
Data were collected prospectively for consecutive operations between May 2013 and October 2015, including all cases of restorative proctocolectomy with ileoanal pouch anastomosis performed laparoscopically. Only patients having a transanal total mesorectal excision (TaTME) assisted by SIP were included. The indication for RPC was ulcerative colitis (UC) refractory to medical treatment.
Results
The procedure was performed on 16 patients with a median age of 46 (26–70) years. The male:female ratio was 5:3 and the median hospital stay was 6 (3–20) days. The median operation time was 247 (185–470) min and the overall conversion rate to open surgery was 18.7%. The 30‐day surgical complication rate was 37.5% (Clavien–Dindo 1 in four patients, 2 in one patient and 3 in one patient). One patient developed anastomotic leakage 2 weeks postoperatively.
Conclusion
This initial study has demonstrated the feasibility and safety of TaTME combined with SIP when performing RPC with ileal pouch–anal anastomosis for UC.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
In early 2019 in the UK, concern about the risk of COVID-19 transmission to surgeons who operate near to the airway led to wide scale adoption of different masks, including valved types used in ...industry. It was noted early on that although these masks protect clinicians, they may represent a risk to the patient due to unfiltered air being directed towards them during close contact1 and the National Health Service circulated guidance to that effect2.
Subsequently, an increased incidence of surgical site infection (SSI) was noticed, postulated to be due to contamination of the surgical field by microbial particles from valved masks or hoods leading to a National Patient Safety Alert3. A study recommended that a surgical mask be placed over the exhaust valves of these mask types4.
We reviewed the literature using the key words surgical masks, power hoods, FFP3 masks and surgical site infection. Most studies showed no reduction in the incidence of SSI with surgical masks5, but some showed an increase6. There were no studies comparing bacterial contamination of the surgical site with different types of masks.
A pilot study was designed to evaluate if FFP3 respirators and powerhoods allowed bacterial contamination of the surgical field in comparison with standard surgical masks and no masks.
The results appeared to confirm our methodology and suggested that reusable valved FFP3 masks are associated with bacterial dissemination. Subsequent examination of these masks identified a potential mechanism for this bacterial contamination. A larger scale study is needed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Aim: Potential screening modalities for early diagnosis of squamous cell anal cancer (SCC) in HIV patients include digital anorectal examination (DARE), anal Papanicolaou testing (Pap test), human ...papilloma virus (HPV) co-testing, and high-resolution anoscopy. The aim of this study was to demonstrate the results of a five-year screening program for SCC in HIV patients. Materials and Methods: We conducted a retrospective study on 204 HIV patients who underwent a screening program for SCC from October 2010 to January 2015. All patients were screened by DARE, anal Pap test, including HPV test and cytology, and high-resolution video-proctoscopy (HR-VPS) with and without acetic acid 3%. Depending on macroscopic appearance and biopsies, patients underwent observation or treatment. Median follow-up was 36 months. Results: Cytologic abnormalities (Cyt+) for high-risk HPV genotypes were recorded in 34% of patients. HR-VPS was positive in 59 patients (29%), of whom 13 patients (22%) were positive for warts; the rest have typical features of anal intraepithelial neoplasia (AIN). Sixteen (8%) patients had AIN (AIN I-III) and underwent wide local excision, ablation, or imiquimod. Absence of progression was recorded. Fourteen patients (7%) had SCC: eight (57%) with no evidence of recurrence, two (14%) had recurrence, and four (29%) died from metastatic disease. Conclusions: Our data demonstrated a successful screening program in preventing SCC in HIV patients. We demonstrate the advantages of progression towards SCC. Moreover, we used a new screening tool, the HR-VPS, a low-cost and manageable instrument to collect patients' long-term data.
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DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We describe a novel use of an Amplatzer III plug device (St. Jude Medical, St. Paul, Minn) in the treatment of a traumatic arteriovenous fistula between the innominate vein and the origin of the left ...common carotid artery causing symptomatic right heart failure. A review of the literature indicates this is the first case to describe the use of the Amplatzer III device in this way. We demonstrate immediate closure of fistula radiologically and complete symptomatic resolution at short-term follow-up.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Aim
Use of open abdomen (OA) remains an important life‐saving manoeuvre in the management of trauma and the abdominal catastrophe. The National Open Abdomen Audit (NOAA) is an audit project ...investigating the indications, management, and subsequent outcomes of OA treatment throughout the UK. The aim is to generate a snapshot of practice which will inform the management of future patients and potentially reduce the significant harm that can be associated with OA.
Methods and analysis
NOAA is a collaborative, prospective observational audit recruiting patients from across Great Britain and Ireland. The study will open from July 2023 with rolling recruitment across participating sites. All adult patients who leave theatre with an OA will be included and followed‐up for 90 days. The primary objective is to prospectively audit the national variability in the management of the OA. Secondary outcomes include the treatment modality used for OA, indication, outcome of treatment and complications, including mortality and development of intestinal failure. All data will be recorded and managed using the secure REDCap electronic data capture and analysed using Stata (version 16.1). Results will be reported in accordance with the STROBE statement.
Conclusion
Results will be used to formulate a practical clinical guideline on when to implement an OA along with a stepwise management plan once initiated to reduce the associated morbidity and mortality. It is hoped that participation in this study will facilitate education of surgeons with a “trickle down” effect on all members of the surgical team and remove variability in the management.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Aim
Ileocolonic resection is reserved for patients with moderate to severe Crohn's disease. Postoperative clinical recurrence can occur in up to 55% of patients within 5 years. Predicting the risk of ...recurrence is key in deciding upon appropriate treatment strategies. This study aims to determine the incidence of postoperative clinical recurrence and predictors of recurrence in a specialist institution.
Method
The clinical case records of 142 patients who underwent either a one‐stage or two‐stage procedure for ileocolonic Crohn's disease from 1 January 2005 to 31 December 2010 were reviewed. Preoperative, perioperative and postoperative variables were extracted. Postoperative clinical recurrence was defined as an initiation or change in medical treatment for recurrent symptoms with endoscopic or radiological evidence of active disease. Time to clinical recurrence was measured in months after surgery. Univariate and multivariate analyses were performed.
Results
Over the 6‐year period, follow‐up data were obtained on 142 patients over a median of 28.5 months. Clinical recurrence was demonstrated in 59 (41.5%) patients. The proportion of patients with clinical recurrence at 5 years was 48.2%. Predictors of recurrence included a re‐resection for recurrent disease hazard ratio (HR) 1.9; 95% CI 1.1–3.3; P = 0.02 and ileocolonic disease (HR 1.7; 95% CI 1.0–2.9; P = 0.05).
Conclusion
Identifying the predictors for postoperative clinical recurrence is important for determining the postoperative strategy. This study provides a unique perspective on the incidence of recurrence and associated predictors from the perspective of a specialist unit.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
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