SO2, silicate clouds, but no CH4 detected in a warm Neptune

WASP-107b is a warm (approximately 740 K) transiting planet with a Neptune-like mass of roughly 30.5 M⊕ and Jupiter-like radius of about 0.94 RJ (refs. 1,2), whose extended atmosphere is eroding3. Previous observations showed evidence for water vapour and a thick, high-altitude condensate layer in the atmosphere of WASP-107b (refs. 4,5). Recently, photochemically produced sulfur dioxide (SO2) was detected in the atmosphere of a hot (about 1,200 K) Saturn-mass planet from transmission spectroscopy near 4.05 μm (refs. 6,7), but for temperatures below about 1,000 K, sulfur is predicted to preferably form sulfur allotropes instead of SO2 (refs. 8-10). Here we report the 9σ detection of two fundamental vibration bands of SO2, at 7.35 μm and 8.69 μm, in the transmission spectrum of WASP-107b using the Mid-Infrared Instrument (MIRI) of JWST. This discovery establishes WASP-107b as the second irradiated exoplanet with confirmed photochemistry, extending the temperature range of exoplanets exhibiting detected photochemistry from about 1,200 K down to about 740 K. Furthermore, our spectral analysis reveals the presence of silicate clouds, which are strongly favoured (around 7σ) over simpler cloud set-ups. Furthermore, water is detected (around 12σ) but methane is not. These findings provide evidence of disequilibrium chemistry and indicate a dynamically active atmosphere with a super-solar metallicity.

15NH3 in the atmosphere of a cool brown dwarf

Brown dwarfs serve as ideal laboratories for studying the atmospheres of giant exoplanets on wide orbits, as the governing physical and chemical processes within them are nearly identical1,2. Understanding the formation of gas-giant planets is challenging, often involving the endeavour to link atmospheric abundance ratios, such as the carbon-to-oxygen (C/O) ratio, to formation scenarios3. However, the complexity of planet formation requires further tracers, as the unambiguous interpretation of the measured C/O ratio is fraught with complexity4. Isotope ratios, such as deuterium to hydrogen and 14N/15N, offer a promising avenue to gain further insight into this formation process, mirroring their use within the Solar System5-7. For exoplanets, only a handful of constraints on 12C/13C exist, pointing to the accretion of 13C-rich ice from beyond the CO iceline of the disks8,9. Here we report on the mid-infrared detection of the 14NH3 and 15NH3 isotopologues in the atmosphere of a cool brown dwarf with an effective temperature of 380 K in a spectrum taken with the Mid-Infrared Instrument (MIRI) of JWST. As expected, our results reveal a 14N/15N value consistent with star-like formation by gravitational collapse, demonstrating that this ratio can be accurately constrained. Because young stars and their planets should be more strongly enriched in the 15N isotope10, we expect that 15NH3 will be detectable in several cold, wide-separation exoplanets.

Active focal-plane coronagraphy with liquid-crystal spatial-light modulators: broadband contrast performance in the visible

The technological progress in spatial-light modulator (SLM) technology has made it possible to use those devices as programmable active focal-plane phase coronagraphic masks, opening the door to novel versatile and adaptive high-contrast imaging observation strategies. However, the scalar nature of the SLM-induced phase response is a potential hurdle when applying the approach to wideband light, as is typical in astronomical imaging. For the first time, to our knowledge, we present laboratory results with broadband light (up to ∼12% bandwidth) for two commercially available SLM devices used as active focal-plane phase masks in the visible regime (640 nm). It is shown that under ideal or realistic telescope aperture conditions, the contrast performance is negligibly affected in this bandwidth regime, reaching a sufficient level for ground-based high-contrast imaging, which is typically dominated by atmospheric residuals.

Implementing focal-plane phase masks optimized for real telescope apertures with SLM-based digital adaptive coronagraphy

Direct imaging of exoplanets or circumstellar disk material requires extreme contrast at the 10^-6 to 10^-12 levels at < 100 mas angular separation from the star. Focal-plane mask (FPM) coronagraphic imaging has played a key role in this field, taking advantage of progress in Adaptive Optics on ground-based 8 + m class telescopes. However, large telescope entrance pupils usually consist of complex, sometimes segmented, non-ideal apertures, which include a central obstruction for the secondary mirror and its support structure. In practice, this negatively impacts wavefront quality and coronagraphic performance, in terms of achievable contrast and inner working angle. Recent theoretical works on structured darkness have shown that solutions for FPM phase profiles, optimized for non-ideal apertures, can be numerically derived. Here we present and discuss a first experimental validation of this concept, using reflective liquid crystal spatial light modulators as adaptive FPM coronagraphs.

Expression of tissue IGF 1, TGFbeta and EGFR in the sequential steps of intestinal adaptation in a rat model of short bowel syndrome

BACKGROUND

The long-term morphological changes and the expression of tissue growth factors IGF 1, TGFbeta and EGFR in the gut mucosa, during the process of intestinal adaptation were examined.

METHODS

Four groups of rats were used: a. Sham rats (n = 10) underwent bowel transection and reanastomosis, b. SBS rats underwent an 80% small bowel resection: group A rats (n = 10) were sacrificed 15 days after surgery, group B (n = 10), 30 days after surgery, and group C (n = 10), 60 days after surgery. Morphological small bowel parameters (villus height, lumen diameter and others) of adaptation were examined sequentially. Tissue samples were studied immunohistochemically for the detection of IGF 1, TGFbeta, and EGFR.

RESULTS

There was a significant increase in all morphological parameters at day 15, in the intestinal samples; a further increase followed at day 30 and day 60 (p < 0.0001). Accordingly, an increase in the expression of IGF 1, TGFbeta and EGFR was noted at day 15 (p < 0.05), and at day 30 (NS).

CONCLUSION

Intestinal adaptation is an ongoing process lasting more than 2 months after massive small bowel resection. Peptide growth factors are expressed in the intestine continuously during this period, but the first two weeks are the most critical for the mucosal growth.

Primary tumors of the spleen

Tumors of the spleen are rare compared to the incidence of such tumors in other parenchymatous organs. Their classification has varied with both time and author. They can be divided into two main categories: nonlymphoid and lymphoid. The most common nonlymphoid tumors are the vascular tumors which include benign and malignant haemangiomas, littoral cell angiomas, lymphangiomas and haemangioendotheliomas. The remaining nonlymphoid tumors, such as fibrosarcoma, neurinoma, and lipoma are very uncommon. The lymphoid tumors include Hodgkin's and non Hodgkin's lymphoma, histiocytic lymphoma and plasmacytoma. Metastatic tumors to the spleen mainly originate from melanoma, breast and lung lesions. However, metastases to the spleen are rare compared to those of other parenchymatous organs.

Prosthetic repair of incisional hernia combined with elective bowel operation

BACKGROUND AND AIMS

Incisional hernia repair with mesh is considered a clean operation and it is not recommended to be perfomed at the same time with a potentially contaminated operation. The aim of this study is to assess the short-term results of a group of patients who underwent a colon operation and simultaneous incisional hernia repair with an onlay polypropylene mesh technique.

PATIENTS AND METHODS

From Novemberto June 2006, 19 patients underwent incisional hernia repair with polypropylene mesh, with simultaneous colonic operation. In 13 patients reestablishment of bowel continuity after a Hartmann procedure was done, whereas in four patients a loop colostomy was closed. Two patients underwent colectomy for cancer.

RESULTS

Post-operatively one patient had a seroma and two others had wound infections which required mesh removal. The mean follow-up was 70.15 +/- 48.40 months (range 3 to 142 months). During this period five patients died, four from progression of malignancy and one from myocardial infarction. Three patients (15.78%) developed recurrence, two patients with previous Hartmann's operation for complicated diverticulitis and wound infection and the third patient due to inappropriate mesh fixation with buttonhole hernia development.

CONCLUSION

Prosthetic repair of incisional hernias can be safely performed simultaneously with a colonic operation, with an acceptable rate of infectious complications and recurrence. It is unjustifiable to avoid the use of mesh in a potentially contaminated field when an appropriate technique is used.

[Hospital anxiety and depression scale (HADS): Validation in a Greek general hospital sample]

The Hospital Anxiety and Depression Scale (HADS) has been translated and widely used in several countries to assess anxiety and depression in general hospital patients with good results. Material-Method The HADS was administered to 521 participants (275 controls and 246 inpatients and outpatients of Internal Medicine and Surgical Departments). The Beck Depression Inventory (BDI) and the State-Trait Anxiety Inventory (STAI) were used as "gold standards" for depression and anxiety respectively. Results The HADS presented high internal consistency; Cronbach's α=0.884 (0.829 for anxiety and 0.840 for depression) and stability (test-retest Intraclass Correlation Coefficient 0.944). Factor analysis showed a two-factor structure. The HADS showed high concurrent validity; the correlations of the scale and its subscales with the BDI and the STAI were high (0.722-0.749).

CONCLUSIONS

The Greek version of HADS showed good psychometric properties and could prove as a good tool for clinicians to assess anxiety and depression in general hospital patients.

Limberg flap reconstruction for the treatment of pilonidal sinus disease

Pilonidal disease is a common chronic disorder of the sacrococcygeal area affecting young people. Recent reports have advocated different surgical approaches, such as open or closed technique, but recurrence complicates all forms of treatment. We conducted this case review to evaluate the validity of Limberg flap reconstruction method in the treatment of chronic recurrent pilonidal disease. In the period between September 2003 and December 2004, 32 male patients with complicated/recurrent pilonidal disease were operated on using the Limberg flap reconstruction method. The patients' mean age was 26.4 + 1.6 years (range 19-47 years). All patients fared well, had a satisfactory wound healing, had minimal pain and were mobilized immediately after surgery. They stayed at hospital for 6 to 32 hours. No patient had serious wound infection or flap ischemia. They all returned to normal activity within 4 to 12 days. Follow-up ranged between 14 and 28 months. No patient had recurrence during the above period. Limberg flap reconstruction has several advantages compared to the classical surgical methods for the treatment of pilonidal disease. The patients have a short hospital stay, are mobilized soon after surgery and have a minimal morbidity and recurrence rate.

Effects of acetylsalicylic acid on experimental atherogenesis induced in rabbits

AIM

Inflammation related processes play a key role in the current etiologic model of atherosclerosis and its acute complications. In addition, platelet-derived growth factors stimulate the neointimal proliferation of restenosis after coronary interventions. Reducing platelet accumulation at treated sites may attenuate restenosis. The purpose of this experimental study was to investigate the effect of acetylsalicylic acid (ASA), a widely used anti-platelet and anti-inflammatory agent on the development and extent of atherosclerosis.

METHODS

Fourty-eight male white New Zealand rabbits were separated in 4 groups (12 animals each group). Group I received a diet of 2% cholesterol and 6% corn oil for 3 months. Group II received a diet of 2% cholesterol and 6% corn oil and in addition received 3 mg of ASA/kg daily intramuscular (i.m.) for 3 months. Group III received the same diet, and in addition received 10 mg of ASA/kg daily i.m. for 3 months. Group IV received the same diet and in addition received 50 mg of ASA/kg daily i.m. for 3 months. Animals were sacrificed after 3 months.

RESULTS

ASA reduced the serum levels of total cholesterol, total lipids, triglycerides and LDL cholesterol. There was significant difference in the extent of atherosclerotic lesions between animals which received different doses of ASA and that animals which did not received any ASA. High dose ASA treatment resulted in an increase in fasting plasma glucose, associated with a reduction in total cholesterol and triglycerides.

CONCLUSION

Our results suggest that there is a protective effect on atherosclerosis development of ASA down stream from where it lowers plasma fatty acid concentrations. However, further studies are required to verify that effect.

Ampullary carcinoid and jejunal stromal tumour associated with von Recklinghausen's disease presenting as gastrointestinal bleeding and jaundice

We report a very rare case of a 36-year-old woman with von Recklinghausen's disease, synchronous carcinoid of the ampulla of Vater and stromal tumour of the jejunum, who presented with gastrointestinal bleeding and jaundice.

Therapeutic drug monitoring of tacrolimus in clinical transplantation

Initial clinical trials of FK did not incorporate available FK levels, and difficulties were quickly experienced particularly with neurotoxicity and nephrotoxicity. The introduction of routine assay allowed broad parameters to be identified, which assisted in evaluating effective therapeutic parameters. Levels approximately 20 ng/ml were frequently associated with toxicity and the initial therapeutic range between 10-25 ng/ml was probably excessive. Reliable effective assay > 5 ng/ml using the Abbott IMx is not available, and many patients will have excellent hepatic or renal function with what are currently undetectable levels of FK. However, IncStar have an ELISA assay with a sensitivity of 0.5 mg/ml. Clinical practice does not, at this time, dictate elevation of FK, although careful monitoring continues. Education of oral administration from 0.15 mg/kg to 0.1 mg/kg in combination therapy with steroids and 0.05 mg/kg with azathioprine and steroids has led to revision of therapeutic parameters, e.g., 5-15 ng/ml is now widely used. Therapeutic drug monitoring is important to avoid unnecessary toxicity, but the lower limit has not been fully defined. Clearly, many patients with < 5 ng/ml have excellent hepatic function.

Seasonal variation in the incidence of ruptured abdominal aortic aneurysm

This retrospective study was performed in order to correlate the season with the risk of rupture of an abdominal aortic aneurysm (AAA). From December 1968 to December 1990, 224 patients, 203 males (90.63%) and 21 females (9.37%), mean age 71 years, underwent surgery either urgently because of rupture or expansion (group A, 66 patients, 22.46%) or electively (group B, 158 patients, 70.53%) for AAA. Of the 66 patients in group A, 61 were male (92.4%) and five female (7.55%) with a mean age of 73 years. Of the 158 patients in group B, 142 were male (89.8%) and 16 female (10.1%). The frequency distribution of electively admitted and operated cases of AAA was shown to be similar during all seasons but the admissions of ruptured AAA were shown by non-parametric statistical analysis to increase during the autumn (p less than 0.05) with 43.9% of the cases being admitted during September, October and November. The male to female ratio and the ratio of the number of aneurysms ruptured to the total number of aneurysms did not change significantly. The explanation of this phenomenon is obscure and needs further epidemiological investigation to assess the seasonal variability or various parameters such as hypertension.