Spectrally Sharp Near-Field Thermal Emission: Revealing Some Disagreements between a Casimir-Polder Sensor and Predictions from Far-Field Emittance.

Near-field thermal emission largely exceeds blackbody radiation, owing to spectrally sharp emission in surface polaritons. We turn the Casimir-Polder interaction between Cs(7P_{1/2}) and a sapphire interface into a sensor sharply filtering, at 24.687 THz, the near-field sapphire emission at ∼24.5 THz. The temperature evolution of the sapphire mode is demonstrated. The Cs sensor, sensitive to both dispersion and dissipation, suggests the polariton to be redshifted and sharper, as compared, up to 1100 K, to predictions from far-field sapphire emission, affected by birefringence and multiple resonances.

Linear Probing of Molecules at Micrometric Distances from a Surface with Sub-Doppler Frequency Resolution.

We report on precision spectroscopy of subwavelength confined molecular gases. This was obtained by rovibrational selective reflection of NH_{3} and SF_{6} gases using a quantum cascade laser at λ≈10.6 µm. Our technique probes molecules at micrometric distances (≈λ/2π) from the window of a macroscopic cell with submegahertz resolution, allowing molecule-surface interaction spectroscopy. We exploit the linearity and high resolution of our technique to gain novel spectroscopic information on the SF_{6} greenhouse gas, useful for enriching molecular databases. The natural extension of our work to thin cells will allow compact frequency references and improved measurements of the Casimir-Polder interaction with molecules.

Development and internal validation of clinical prediction models for outcomes of complicated intra-abdominal infection.

BACKGROUND: Complicated intra-abdominal infections (cIAIs) are associated with significant morbidity and mortality. The aim of this study was to describe the clinical characteristics of patients with cIAI in a multicentre study and to develop clinical prediction models (CPMs) to help identify patients at risk of mortality or relapse. METHODS: A multicentre observational study was conducted from August 2016 to February 2017 in the UK. Adult patients diagnosed with cIAI were included. Multivariable logistic regression was performed to develop CPMs for mortality and cIAI relapse. The c-statistic was used to test model discrimination. Model calibration was tested using calibration slopes and calibration in the large (CITL). The CPMs were then presented as point scoring systems and validated further. RESULTS: Overall, 417 patients from 31 surgical centres were included in the analysis. At 90 days after diagnosis, 17.3 per cent had a cIAI relapse and the mortality rate was 11.3 per cent. Predictors in the mortality model were age, cIAI aetiology, presence of a perforated viscus and source control procedure. Predictors of cIAI relapse included the presence of collections, outcome of initial management, and duration of antibiotic treatment. The c-statistic adjusted for model optimism was 0.79 (95 per cent c.i. 0.75 to 0.87) and 0.74 (0.73 to 0.85) for mortality and cIAI relapse CPMs. Adjusted calibration slopes were 0.88 (95 per cent c.i. 0.76 to 0.90) for the mortality model and 0.91 (0.88 to 0.94) for the relapse model; CITL was -0.19 (95 per cent c.i. -0.39 to -0.12) and - 0.01 (- 0.17 to -0.03) respectively. CONCLUSION: Relapse of infection and death after complicated intra-abdominal infections are common. Clinical prediction models were developed to identify patients at increased risk of relapse or death after treatment, these now require external validation.

Clinical significance of pulmonary nodules in decision-making and management of patients diagnosed with esophageal cancer.

In esophageal cancer, metastatic spread to the lungs is detected in 4-9.7% of cases. During staging investigations, 22% of patients have pulmonary nodules detected on cross-sectional imaging. The purpose of this study is to elucidate the clinical importance of these incidentally found pulmonary nodules, in patients with clinically localized esophageal cancer. A retrospective cohort study was conducted from January 2008 to December 2012 in a tertiary esophagogastric referral center. One-hundred and forty-nine patients were included in the study. All patients underwent dedicated staging followed by neoadjuvant chemotherapy and surgery as indicated. Thirty-three (22.1%) patients had pulmonary nodules found in their preoperative staging. Only three (9%) patients proved to develop metastatic pulmonary disease on follow-up. Interestingly, in all three patients, the nodules were negative on initial 18-fluorodeoxyglucose positron emission tomography. Incidentally found pulmonary nodules in newly diagnosed patients with esophageal cancer during staging investigations are rarely metastases. Such nodules, in isolation, should not preclude patients from radical treatment.

Mediastinal herniation of the biliary tract leading to bile duct: obstruction following oesophagectomy.

Surgical management of oesophageal and gastro-oesophageal junction malignancies is one of the most challenging situations confronting the surgeon. Attaining a complete circumferential resection margin of lower-third oesophageal and gastro-oesophageal junction locally advanced carcinomas requires en-bloc resection of the hiatus and all the peri-oesophageal tissue and pleura. This results in an increased risk of herniation of the abdominal organs through the enlarged hiatus, which carries significant risk of morbidity and mortality. The incidence of this complication is higher than has been reported. Surgical management of symptomatic hernias is the standard treatment while criteria for managing asymptomatic hernias are less clear. We report a rare case of a late mediastinal herniation of the pancreas and bile duct, leading to obstructive jaundice following oesophagectomy which was treated successfully in our unit.

Hepatocolonic fistula: a rare consequence of retained gallstones after laparoscopic cholecystectomy.

Spillage of gallstones during laparoscopic cholecystectomy occurs in up to 30% of cases but complications due to stone retention are less frequent. We report the first case of a hepatocolonic fistula as a consequence of a retained gallstone.

Rb optical resonance inside a random porous medium.

We studied resonant laser interaction with Rb atoms confined to the interstitial cavities of a random porous glass. Due to diffusive light propagation, the effect of atomic absorption on the light scattered by the sample is almost entirely compensated by atomic fluorescence at low atomic densities. For higher densities, radiation trapping increases the probability of nonradiative decay via atom-wall collisions. A simple connection of the fluorescence/absorption yield to the sample porosity is given.

Integrated magneto-optical traps on a chip using silicon pyramid structures.

We have integrated magneto-optical traps (MOTs) into an atom chip by etching pyramids into a silicon wafer. These have been used to trap atoms on the chip, directly from a room temperature vapor of rubidium. This new atom trapping method provides a simple way to integrate several atom sources on the same chip. It represents a substantial advance in atom chip technology and offers new possibilities for atom chip applications such as integrated single atom or photon sources and molecules on a chip.

Alpine skiing injuries. A nine-year study.

Injury patterns in alpine skiing have changed over time as ski, boot, binding, and slope-grooming technologies have evolved. We retrospectively examined injury patterns in alpine skiers over a 9-year period at the Mammoth and June mountains (California) ski area. A total of 24,340 injuries were reported for the 9 seasons studied, and total lift tickets sold numbered 9,201,486. The overall injury rate was 2.6 injuries per 1,000 skier days and increased slowly over the period studied. The knee was the most frequently injured area at 35% of all injuries. Increasing trends (P < .05) were noted for the rates of lower extremity injuries (37%) and knee injuries (45%). A decreasing trend was noted for the rate of lacerations (31% decrease). Slight increases were noted in upper extremity and axial injury rates. Skiing injuries continue to be a worrisome recreational problem despite improvements in ski equipment and slope-grooming techniques. The increasing trend in lower extremity, particularly knee, injury rates highlights the need for continued skier education and equipment innovation.

Snowboarding injuries, a four-year study with comparison with alpine ski injuries.

Snowboarding is a rapidly growing winter sport. Its unorthodox maneuvers and young participants raise many safety concerns. We examined injury patterns in recreational snowboarders, comparing these patterns with those found in alpine skiers. Snowboarding and skiing injury patterns differed significantly (P < .05) for the following categories: 49% of injured snowboarders were beginners versus 18% of skiers. Snowboarders were more likely to suffer wrist (19% versus 2%) and ankle (16% versus 6%) injuries, but less likely to sustain knee (17% versus 39%) or thumb (2% versus 4%) injuries than skiers. For snowboarders, wrist injuries were most common in beginners (30%), knee injuries in low intermediates (28%), ankle injuries in intermediates (17%), and shoulder or clavicle injuries in advanced snowboarders (14%). Most snowboarders (90%) wore soft-shelled boots, 73% of lower extremity injuries occurred to the lead-foot side, and 73% of wrist injuries occurred during backward falls; 67% of knee injuries occurred during forward falls. Of all injuries, 8% occurred while loading onto or unloading from a ski lift. The sport of snowboarding brings with it a different set of injuries from those seen in alpine skiing. The data focus attention on improvements such as wrist guards or splints, releasable front-foot bindings, and better instruction for beginner snowboarders to improve the safety of this sport. Finally, the data confirm that snowboarders and skiers may be safely combined on the same slopes.