Sub-nanosecond Raman fiber amplifier based red-orange light source.

We introduce a fully-integrated two-color sub-nanosecond fiber laser system that incorporates a backward-pumped polarization-maintaining (PM) Raman phosphosilicate fiber amplifier (RFA) followed by two fully-integrated fiber-coupled second harmonic generator (SHG) modules. The RFA is pumped by a continuous-wave (CW) Yb laser operating at 1116 nm. The pulsed signals are generated by gain-switched distributed feedback (DFB) laser diodes at 1178 nm and 1310 nm, respectively. The output pulsed DFB signals are independently or simultaneously amplified in the RFA. This amplification is achieved using both the broad SiO2 (∼13.2 THz) and relatively narrow P2O5 (39.9 THz) Stokes shifts. The laser system produces sub-nanosecond pulses at 589 and 655 nm, featuring repetition rates ranging from 40 to 100 MHz and an average power of up to 3 W (limited by the SHG crystal damage threshold) at each wavelength. The diffraction-limited output beams maintain an M2 value of < 1.05 across the entire range of output powers and repetition rates for both wavelengths.

Which caval diameter? Clarification manufacturer's instructions for inferior vena cava filter use and implications for practice.

AIM: To clarify manufacturer's instructions for inferior vena cava (IVC) filter use and implications for practice. MATERIALS AND METHODS: Three vendors of IVC filters were contacted for clarification, with all stating that caval diameter limits are to be true maximum and true minimum cross-sectional diameters. To determine the implications of this, measurements were performed on 302 abdominal computed tomography studies in four transaxial dimensions perpendicular to the long axis including true maximum and minimum diameters, and measurements reflecting those typically taken on fluoroscopic cavography. RESULTS: Based on the true maximum and true minimum caval diameter limits as clarified by vendors, 22% of patients who would typically be considered suitable for IVC filter insertion based on frontal and lateral fluoroscopic cavography would be contraindicated, and 40% of patients who would typically be considered suitable for IVC filter insertion based on only frontal fluoroscopic cavography (as lateral projection is often not performed) would be contraindicated. CONCLUSION: There is a marked discordance between the vendor-clarified caval diameter limits of three common IVC filter devices and real-world caval geometry. Given the rarity of complications, this suggests a pressing need for revision of manufacturers' instructions for use statements to better reflect current safe routine clinical use, particularly from a medicolegal perspective.

Efficient Classical Algorithm for Boson Sampling with Partially Distinguishable Photons.

We demonstrate how boson sampling with photons of partial distinguishability can be expressed in terms of interference of fewer photons. We use this observation to propose a classical algorithm to simulate the output of a boson sampler fed with photons of partial distinguishability. We find conditions for which this algorithm is efficient, which gives a lower limit on the required indistinguishability to demonstrate a quantum advantage. Under these conditions, adding more photons only polynomially increases the computational cost to simulate a boson sampling experiment.

Detector-Independent Verification of Quantum Light.

We introduce a method for the verification of nonclassical light which is independent of the complex interaction between the generated light and the material of the detectors. This is accomplished by means of a multiplexing arrangement. Its theoretical description yields that the coincidence statistics of this measurement layout is a mixture of multinomial distributions for any classical light field and any type of detector. This allows us to formulate bounds on the statistical properties of classical states. We apply our directly accessible method to heralded multiphoton states which are detected with a single multiplexing step only and two detectors, which are in our work superconducting transition-edge sensors. The nonclassicality of the generated light is verified and characterized through the violation of the classical bounds without the need for characterizing the used detectors.

Metamorphosis enhances the effects of metal exposure on the mayfly, Centroptilum triangulifer.

The response of larval aquatic insects to stressors such as metals is used to assess the ecological condition of streams worldwide. However, nearly all larval insects metamorphose from aquatic larvae to winged adults, and recent surveys indicate that adults may be a more sensitive indicator of stream metal toxicity than larvae. One hypothesis to explain this pattern is that insects exposed to elevated metal in their larval stages have a reduced ability to successfully complete metamorphosis. To test this hypothesis we exposed late-instar larvae of the mayfly, Centroptilum triangulifer, to an aqueous Zn gradient (32-476 µg/L) in the laboratory. After 6 days of exposure, when metamorphosis began, larval survival was unaffected by zinc. However, Zn reduced wingpad development at concentrations above 139 µg/L. In contrast, emergence of subimagos and imagos tended to decline with any increase in Zn. At Zn concentrations below 105 µg/L (hardness-adjusted aquatic life criterion), survival between the wingpad and subimago stages declined 5-fold across the Zn gradient. These results support the hypothesis that metamorphosis may be a survival bottleneck, particularly in contaminated streams. Thus, death during metamorphosis may be a key mechanism explaining how stream metal contamination can impact terrestrial communities by reducing aquatic insect emergence.

The injury patterns, management and outcomes of retroperitoneal haemorrhage caused by lumbar arterial bleeding at a Level-1 Trauma Centre: A 10-year retrospective review.

PURPOSE: Haemorrhagic shock remains a leading preventable cause of death amongst trauma patients. Failure to identify retroperitoneal haemorrhage (RPH) can lead to irreversible haemorrhagic shock. The arteries of the middle retroperitoneal region (i.e., the 1st to 4th lumbar arteries) are complicit in haemorrhage into the retroperitoneal space. However, predictive injury patterns and subsequent management implications of haemorrhage secondary to bleeding of these arteries is lacking. MATERIALS AND METHODS: We performed a retrospective cohort study of patients diagnosed with retroperitoneal haemorrhage who presented to our Level-1 Trauma Centre (2009-2019). We described the associated injuries, management and outcomes relating to haemorrhage of lumbar arteries (L1-4) from this cohort to assess risk and management priorities in non-cavitary haemorrhage compared to RPH due to other causes. RESULTS: Haemorrhage of the lumbar arteries (LA) is associated with a higher proportion of lumbar transverse process (TP) fractures. Bleeding from branches of these vessels is associated with lower systolic blood pressure, increased incidence of massive transfusion, higher shock index, and a higher Injury Severity Score (ISS). A higher proportion of patients in the LA group underwent angioembolisation when compared to other causes of RPH. CONCLUSION: This study highlights the injury patterns, particularly TP fractures, in the prediction, early detection and management of haemorrhage from the lumbar arteries (L1-4). Compared to other causes of RPH, bleeding of the LA responds to early, aggressive haemorrhage control through angioembolisation. These injuries are likely best treated in Level-1 or Level-2 trauma facilities that are equipped with angioembolisation facilities or hybrid theatres to facilitate early identification and management of thoracolumbar bleeds.

Splenic injury during colonoscopy: modern treatment approach and splenic salvage.

Splenic injury is a rare complication of colonoscopy, estimated to occur in 0.020 to 0.034% of procedures, with a 30-day mortality of 3.6% (1-3). Of the three major severe adverse events during colonoscopy (perforation, bleeding, and splenic injury), splenic injury has the highest mortality but is rarest (1). The spleen is attached to the colonic splenic flexure by the splenocolic ligament, suggesting that manipulation of the colon during colonoscopy may cause direct tension or impaction on the spleen and splenic hilum as the mechanism of injury (2,3). Patients typically present within 24 hours of colonoscopy with severe abdominal pain and peritonism, and may be haemodynamically unstable (2). The majority of published cases of high-grade splenic injury due to colonoscopy have been managed with splenectomy (2,3), however smaller numbers have been managed with embolization and conservative measures (3). Modern treatment options for splenic injury due to colonoscopy can be classified into con- servative, endovascular, and surgical management (3). Conservative management involves inpatient moni- toring, with analgesia, intravenous fluids, and blood transfusion (2,3). Endovascular treatment is splenic artery embolization, typically with deployment of coils into the splenic artery proximal to the splenic hilum or into a single splenic artery branch in cases with an isolated focal injury (2-4). Surgical management is principally laparotomic splenectomy (2,3). In modern treatment protocols, splenectomy is usually reserved for unstable patients who require emergent laparotomy (4). Given the similarity in mechanism between splenic injuries due to blunt trauma and those due to colonoscopy, it may be helpful to conceptualize splenic injuries due to colonoscopy according to the American Association for the Surgery of Trauma (AAST) grading system (5). After institutional ethical approval, electronic medical records over a 10-year period (2012-2022) were searched to identify all patients treated for splenic injury due to colonoscopy, with the following inclusion criteria: • Splenic laceration diagnosed on computed tomography (CT). Colonoscopy within 72 hours of CT diagnosis. • Absence of blunt external traumatic incident between colonoscopy and diagnosis. Patient demographic information, past surgical history, colonoscopy indication, splenic injury grading, treatment and outcome data were analysed. Two males and 3 females were included, with median age of 63 years (range: 40-72), and four had undergone previous abdominal surgery (Table 1) (Figure 1). AAST injury grades were II to V. One patient with an AAST II injury was treated conservatively without requiring embolization or splenectomy. Three patients with AAST III-V injuries were treated primarily with splenic artery embolization, with one patient undergoing splenectomy 2 weeks later due to increased haematoma on CT. One patient with AAST III injury was treated conservatively but then underwent splenectomy 6 days later due to clinical rebleeding. All patients in the cohort survived, and 3 of 5 achieved splenic salvage. The spleen has important immune and non-immune functions, as the main filter of blood-borne pathogens, antigens, and red blood cells and patients post- splenectomy have increased life-long risk of infection(6). Embolization preserves splenic function via collateral arterial supply and splenectomy may therefore be best reserved for patients who require emergent laparotomy or where conservative and endovascular management have failed. In the present cohort, 3 of 5 patients were able to avoid splenectomy, higher than in previous published reports (47-69% splenectomy rate) (2,3). The higher splenectomy and mortality rates in previous reports may be due to publication bias favouring severe cases. As a rare complication of colonoscopy, splenic injury requires prompt diagnosis and management to minimize mortality. All patients in the present cohort survived, 3 of 5 with splenic salvage. A treatment protocol utilizing conservative management for low-grade injuries and embolization for high-grade injuries may optimise rates of splenic salvage with long-term public health benefits. This paper has not been presented previously at a conference and is not under consideration by any other journal for publication. The authors have no conflicts of interest to declare. This research was not supported by any funding.

Quantum interference enables constant-time quantum information processing.

It is an open question how fast information processing can be performed and whether quantum effects can speed up the best existing solutions. Signal extraction, analysis, and compression in diagnostics, astronomy, chemistry, and broadcasting build on the discrete Fourier transform. It is implemented with the fast Fourier transform (FFT) algorithm that assumes a periodic input of specific lengths, which rarely holds true. A lesser-known transform, the Kravchuk-Fourier (KT), allows one to operate on finite strings of arbitrary length. It is of high demand in digital image processing and computer vision but features a prohibitive runtime. Here, we report a one-step computation of a fractional quantum KT. The quantum d-nary (qudit) architecture we use comprises only one gate and offers processing time independent of the input size. The gate may use a multiphoton Hong-Ou-Mandel effect. Existing quantum technologies may scale it up toward diverse applications.

Wernicke's encephalopathy after laparoscopic cardiomyotomy for achalasia.

Achalasia is an incurable neuromuscular disorder of the esophagus, resulting from destruction of the esophageal myenteric plexus. This leads to aperistalsis and failure of the lower esophageal sphincter to relax after swallowing. Symptoms of achalasia are gradual in onset and include dysphagia, regurgitation, and weight loss. Severe malnutrition can ensue. Wernicke's encephalopathy (WE) is a serious, potentially fatal, neurologic disorder caused by thiamine deficiency (vitamin B(1)), classically described as presenting with a triad of ocular abnormalities, ataxia, and confusion. The incidence is uncertain, and many cases likely go unrecognized. It is usually diagnosed in the alcoholic population. We describe its onset after the successful surgical treatment of achalasia.

Identification of nonclassical properties of light with multiplexing layouts.

In Sperling et al. [Phys. Rev. Lett. 118, 163602 (2017)], we introduced and applied a detector-independent method to uncover nonclassicality. Here, we extend those techniques and give more details on the performed analysis. We derive a general theory of the positive-operator-valued measure that describes multiplexing layouts with arbitrary detectors. From the resulting quantum version of a multinomial statistics, we infer nonclassicality probes based on a matrix of normally ordered moments. We discuss these criteria and apply the theory to our data which are measured with superconducting transition-edge sensors. Our experiment produces heralded multiphoton states from a parametric down-conversion light source. We show that the known notions of sub-Poisson and sub-binomial light can be deduced from our general approach, and we establish the concept of sub-multinomial light, which is shown to outperform the former two concepts of nonclassicality for our data.

Combined antioxidant therapy reduces pain and improves quality of life in chronic pancreatitis.

Patients with chronic pancreatitis (CP) typically suffer intractable abdominal pain that is resistant to most analgesic strategies. Recent research indicates that the pain of CP may be in part due to oxygen free radical induced pancreatic damage. Using a randomized, double-blind, placebo-controlled crossover trial, we evaluated the efficacy of a combined antioxidant preparation in the management of CP. Patients with confirmed chronic pancreatitis (N = 36) were randomized to receive treatment with either Antox, which contains the antioxidants selenium, betacarotene, L-methionine, and vitamins C and E, or placebo for 10 weeks. Each group of patients then switched to receive the alternative treatment for a further 10 weeks. Markers of antioxidant status were measured by blood sampling, whereas quality of life and pain were assessed using the SF-36 questionnaire. Nineteen patients completed the full 20 weeks of treatment. Treatment with Antox was associated with significant improvements in quality of life in terms of pain (+17 antioxidant vs. -7 placebo), physical (+9 vs. -3) and social functioning (+8 vs. -7), and general health perception (+10 vs. -3). We conclude that treatment with antioxidants may improve quality of life and reduce pain in patients suffering from chronic pancreatitis.

The current role of staging laparoscopy in oesophagogastric cancer.

INTRODUCTION: Oesophagogastric cancers are known to spread rapidly to locoregional lymph nodes and by transcoelomic spread to the peritoneal cavity. Staging laparoscopy combined with peritoneal cytology can detect advanced disease that may not be apparent on other staging investigations. The aim of this study was to determine the current value of staging laparoscopy and peritoneal cytology in light of the ubiquitous use of computed tomography in all oesophagogastric cancers and the addition of positron emission tomography in oesophageal cancer. METHODS: All patients undergoing staging laparoscopy for distal oesophageal or gastric cancer between March 2007 and August 2013 were identified from a prospectively maintained database. Demographic details, preoperative staging, staging laparoscopy findings, cytology and histopathology results were analysed. RESULTS: A total of 317 patients were identified: 159 (50.1%) had gastric adenocarcinoma, 136 (43.0%) oesophageal adenocarcinoma and 22 (6.9%) oesophageal squamous carcinoma. Staging laparoscopy revealed macroscopic metastases in 36 patients (22.6%) with gastric adenocarcinoma and 16 patients (11.8%) with oesophageal adenocarcinoma. Positive peritoneal cytology in the absence of macroscopic peritoneal metastases was identified in a further five patients with gastric adenocarcinoma and six patients with oesophageal adenocarcinoma. There was no significant difference in survival between patients with macroscopic peritoneal disease and those with positive peritoneal cytology (p=0.219). CONCLUSIONS: Staging laparoscopy and peritoneal cytology should be performed routinely in the staging of distal oesophageal and gastric cancers where other investigations indicate resectability. Currently, in our opinion, patients with positive peritoneal cytology should not be treated with curative intent.

Antibodies against monocytes and endothelial cells in the sera of patients with atherosclerotic peripheral arterial disease.

We looked for antibodies against endothelial cells, monocytes, fibroblasts, lymphocytes and Epstein-Barr virus transformed lymphocytes in the sera of 28 elderly and 18 middle-aged patients with atherosclerotic peripheral arterial disease and 13 controls. Inclusion criteria were symptomatic peripheral arterial disease with intermittent claudication and ankle/radial Doppler pressure ratio less than 0.7 in the patient group and greater than 1 in the controls. The sera were tested using a standard cytotoxic technique against a cell panel of monocytes, T and B lymphocytes from 5 donors, and against endothelial cells, fibroblasts and Epstein-Barr virus transformed lymphocytes from one umbilical cord vein and blood. The sera of 30 of 46 (65.2%) patients showed toxicity against monocytes from at least one member of the cell panel and 12 of 19 sera tested (63%) reacted with endothelial cells. Only one of the control sera was positive against monocytes and none reacted with endothelial cells. None of the sera of either patients or controls contained cytotoxic antibodies against T and B lymphocytes, Epstein-Barr virus transformed lymphocytes or fibroblasts. The selective cytotoxicity suggests that the antibodies detected are not against HLA-antigens (which are expressed by normal lymphocytes and Epstein-Barr virus lymphocytes). Our results suggest that immune phenomena occur in atherosclerosis.

Molecular and genetic ecotoxicologic approaches to aquatic environmental bioreporting.

Molecular and population genetic ecotoxicologic approaches are being developed for the utilization of arthropods as bioreporters of heavy metal mixtures in the environment. The explosion of knowledge in molecular biology, molecular genetics, and biotechnology provides an unparalleled opportunity to use arthropods as bioreporter organisms. Interspecific differences in aquatic arthropod populations have been previously demonstrated in response to heavy metal insult in the Arkansas River (AR) California Gulch Superfund site (CGSS). Population genetic analyses were conducted on the mayfly Baetis tricaudatus. Genetic polymorphisms were detected in polymerase chain reaction amplified 16S mitochondrial rDNA (a selectively neutral gene) of B tricaudatus using single-strand conformation polymorphism analysis. Genetic differences may have resulted from impediments to gene flow in the population caused by mortality arising from exposure to heavy metal mixture pollution. In laboratory studies a candidate metal-responsive mucinlike gene, which is metal and dose specific, has been identified in Chironomus tentans and other potential AR-CGSS bioreporter species. Population genetic analyses using the mucinlike gene may provide insight into the role of this selectable gene in determining the breeding structure of B. tricaudatus in the AR-CGSS and may provide mechanistic insight into determinants of aquatic arthropod response to heavy metal insult. Metal-responsive (MR) genes and regulatory sequences are being isolated, characterized, and assayed for differential gene expression in response to heavy metal mixture pollution in the AR-CGSS. Identified promoter sequences can then be engineered into previously developed MR constructs to provide sensitive in vitro assays for environmental bioreporting of heavy metal mixtures. The results of the population genetic studies are being entered into an AR geographic information system that contains substantial biological, chemical, and geophysical information. Integrated spatial, structural, and temporal analyses of these parameters will provide invaluable information concerning environmental determinants that restrict or promote gene flow in bioreporter populations.

Effects of extrahepatic obstructive jaundice on Kupffer cell clearance capacity.

Systemic endotoxemia consistently occurs in jaundiced patients undergoing surgery. Kupffer cell dysfunction is implicated in the development of endotoxemia and its postoperative complications. A novel in situ single-pass hepatic perfusion technique using a fluorescein isothiocyanate-labeled latex probe was developed for measuring Kupffer cell clearance capacity and was applied in an animal model of biliary obstruction. Control rats and rats jaundiced for 1, 2, 3, and 4 weeks' duration were studied. Kupffer cell clearance capacity, plasma bilirubin, endotoxin, and anticore glycolipid concentrations were measured. Maximal hyperbilirubinemia preceded reduced Kupffer cell clearance capacity. Rats jaundiced for greater than 2 weeks had a significantly decreased Kupffer cell clearance capacity but significantly higher endotoxin and anticore glycolipid concentrations. Anticore glycolipid concentrations correlated strongly with systemic endotoxemia and both were inversely correlated with duration of jaundice. Impairment of Kupffer cell clearance capacity may contribute to endotoxemia associated with cholestasis.

Older (but not younger) siblings facilitate false belief understanding.

Results from 4 experiments and an analysis in which all data from 444 English and Japanese children are pooled show (a) a linear increase in understanding false belief with the number of older siblings, (b) no such effect for children younger than 3 years 2 months, (c) no helpful effect of younger siblings at any age (despite the large sample), (d) no effect of siblings' gender, and (e) no helpful effect of siblings on a task measuring children's understanding of how they know something. Discussion involves speculation about how older siblings may assist children (e.g., through pretend play and mental state language) and how different aspects of a theory of mind may develop through different means.

Self-expanding stents for malignant dysphagia.

Self-expanding metallic stents have been employed successfully for vascular, urethral, and biliary strictures. In a prospective study we examined the efficacy of the 16 mm Wallstent for palliation of malignant dysphagia. Eight patients with severe dysphagia due to advanced primary (four) or secondary (four) oesophageal malignant disease were recruited and nine Wallstents were inserted (one patient required two). Dysphagia was reduced in all but one patient, who died after oesophageal perforation; a second patient had a self-limiting bout of haematemesis. Two patients required subsequent treatment for tumour ingrowth but five had no further palliative therapy from stent insertion to time of death. With careful patient selection and skillful application, a 16 mm self-expanding metal endoprosthesis affords effective palliation in malignant oesophageal obstruction.

The drawings of children and young people with Down's syndrome: a case of delay or difference?

This study compared the performance of 29 children and young people with Down's Syndrome with the performance of 29 verbal-mental-age-matched children without learning difficulties on four drawing tasks and four picture-selection tasks. All eight tasks involved the graphic depiction of a perceptually-present array in which one object was partially occluded by another object. It was found that all participants performed better on the picture-selection tasks than on the drawing tasks, and that the individuals with Down's Syndrome performed significantly worse than the children without learning difficulties on all eight tasks. However, it was also found that the performance of the children without learning difficulties correlated strongly with their verbal mental age, but that the performance of the individuals with Down's Syndrome did not show the same correlation with verbal mental age. Other systematic differences between the drawings of the individuals with Down's Syndrome and those of the children without learning difficulties also occurred. The findings suggest that the drawing development of children and young people with Down's Syndrome may not just be delayed relative to that of children who do not have learning difficulties but may exhibit a qualitatively different pattern.