Nearly all the sky is covered by Lyman-α emission around high-redshift galaxies.

Galaxies are surrounded by large reservoirs of gas, mostly hydrogen, that are fed by inflows from the intergalactic medium and by outflows from galactic winds. Absorption-line measurements along the lines of sight to bright and rare background quasars indicate that this circumgalactic medium extends far beyond the starlight seen in galaxies, but very little is known about its spatial distribution. The Lyman-α transition of atomic hydrogen at a wavelength of 121.6 nanometres is an important tracer of warm (about 104 kelvin) gas in and around galaxies, especially at cosmological redshifts greater than about 1.6 at which the spectral line becomes observable from the ground. Tracing cosmic hydrogen through its Lyman-α emission has been a long-standing goal of observational astrophysics1-3, but the extremely low surface brightness of the spatially extended emission is a formidable obstacle. A new window into circumgalactic environments was recently opened by the discovery of ubiquitous extended Lyman-α emission from hydrogen around high-redshift galaxies4,5. Such measurements were previously limited to especially favourable systems6-8 or to the use of massive statistical averaging9,10 because of the faintness of this emission. Here we report observations of low-surface-brightness Lyman-α emission surrounding faint galaxies at redshifts between 3 and 6. We find that the projected sky coverage approaches 100 per cent. The corresponding rate of incidence (the mean number of Lyman-α emitters penetrated by any arbitrary line of sight) is well above unity and similar to the incidence rate of high-column-density absorbers frequently detected in the spectra of distant quasars11-14. This similarity suggests that most circumgalactic atomic hydrogen at these redshifts has now been detected in emission.

Author Correction: Nearly all the sky is covered by Lyman-α emission around high-redshift galaxies.

Change history: In this Letter, author M. Akhlaghi should be associated with affiliation (2) rather than (3). This error has been corrected online.

Evaluation of optimum classification measures used to define textbook outcome among patients undergoing curative-intent resection of gastric cancer.

BACKGROUND: Textbook outcome (TO) is a composite measure reflecting various aspects of services provided to patients with solid malignancies. We sought to evaluate the importance of various TO components previously proposed for gastric cancer. METHODS: Prospectively maintained electronic databases of 1,743 patients treated in two academic surgical centres were reviewed. Six candidate definitions of TO were evaluated based on their ability to accurately predict patients' prognosis by Cox proportional hazards modelling. RESULTS: TO definition combining 10 measures corresponding to complete tumour resection with an uneventful postoperative course showed the best goodness of fit by achieving the lowest values of Akaike (AIC) and Bayesian (BIC) information criteria and the best predictive performance based on the highest value of c-index. The overall median survival was significantly longer for patients with than without textbook outcome (69.0 vs 20.1 months, P < 0.001). TO maintained its prognostic value in a multivariate model controlling for age, sex, comorbidities, treatment, and tumour related variables and was associated with a 39% lower risk of death (HR 0.61, 95%CI 0.51 - 0.73, P < 0.001). Nine variables identified as predictors of TO were used to develop a nomogram showing very good correlation between the predicted and actual probability of achieving TO. The AUC of ROC obtained from the nomogram was 0.752 (95% CI 0.727 to 0.781). CONCLUSIONS: A uniform definition of textbook outcome provides clinically relevant prognostic information and could be used in quality improvement programs for gastric cancer patients.

Antarctic Polyester Hydrolases Degrade Aliphatic and Aromatic Polyesters at Moderate Temperatures.

Polyethylene terephthalate (PET) is one of the most widely used synthetic plastics in the packaging industry, and consequently has become one of the main components of plastic waste found in the environment. However, several microorganisms have been described to encode enzymes that catalyze the depolymerization of PET. While most known PET hydrolases are thermophilic and require reaction temperatures between 60°C and 70°C for an efficient hydrolysis of PET, a partial hydrolysis of amorphous PET at lower temperatures by the polyester hydrolase IsPETase from the mesophilic bacterium Ideonella sakaiensis has also been reported. We show that polyester hydrolases from the Antarctic bacteria Moraxella sp. strain TA144 (Mors1) and Oleispira antarctica RB-8 (OaCut) were able to hydrolyze the aliphatic polyester polycaprolactone as well as the aromatic polyester PET at a reaction temperature of 25°C. Mors1 caused a weight loss of amorphous PET films and thus constitutes a PET-degrading psychrophilic enzyme. Comparative modeling of Mors1 showed that the amino acid composition of its active site resembled both thermophilic and mesophilic PET hydrolases. Lastly, bioinformatic analysis of Antarctic metagenomic samples demonstrated that members of the Moraxellaceae family carry candidate genes coding for further potential psychrophilic PET hydrolases. IMPORTANCE A myriad of consumer products contains polyethylene terephthalate (PET), a plastic that has accumulated as waste in the environment due to its long-term stability and poor waste management. One promising solution is the enzymatic biodegradation of PET, with most known enzymes only catalyzing this process at high temperatures. Here, we bioinformatically identified and biochemically characterized an enzyme from an Antarctic organism that degrades PET at 25°C with similar efficiency to the few PET-degrading enzymes active at moderate temperatures. Reasoning that Antarctica harbors other PET-degrading enzymes, we analyzed available data from Antarctic metagenomic samples and successfully identified other potential enzymes. Our findings contribute to increasing the repertoire of known PET-degrading enzymes that are currently being considered as biocatalysts for the biological recycling of plastic waste.

Clinical characteristics and outcome of patients over 60 years with Hodgkin lymphoma treated in Switzerland.

Hodgkin lymphoma (HL) in older patients appears to be a different disease compared with younger patients with historically lower survival rates. This is related to a variety of factors, including increased treatment-related toxicity, the presence of comorbidities, and biologic differences. In order to better assess the clinical characteristics, treatment strategies, and outcome of this particular population, we conducted a population-based, retrospective analysis including 269 patients with HL older than 60 years (median age 71 years, range 60-94), treated between 2000 and 2017 in 15 referral centers across Switzerland. Primary endpoints were overall survival (OS), progression-free survival (PFS), and cause-specific survival (CSS). The vast majority of patients were treated with curative intent, either with a combined modality approach (chemotherapy followed by radiation therapy) or with systemic therapy. At a median follow-up of 6.6 years (95% confidence interval [CI], 6.0-7.6), 5-year PFS was 52.2% (95% CI, 46.0-59.2), 5-year OS was 62.5% (95% CI, 56.4-69.2), and 5-year CSS was 85.1.8% (95% CI, 80.3-90.1) for the entire cohort. A significant difference in terms of CSS was observed for patients older than 71 years in comparison to patients aged 60-70 years (hazard ratio 2.6, 1.3-5.0, p = 0.005). Bleomycin-induced lung toxicity (BLT) was documented in 26 patients (17.7%) out of the 147 patients exposed to this compound and was more frequent in patients older than 71 years (15/60, 25%). Outcome of HL pts older than 71 years appeared to decrease substantially in comparison to the younger counterpart. Treatment-related toxicities appeared to be relevant, in particular, BLT. New, potentially less toxic strategies need to be investigated in prospective clinical trials in this particular frail population.

Cement augmentation of the proximal femur nail antirotation: is it safe?

BACKGROUND: Cement augmentation of the proximal femur nail antirotation (PFNA; Fa. DePuy Synthes) showed good biomechanical and clinical results regarding increased stability and functional outcome [Linden et al. in J Orthop Res 24:2230-2237, 2006;Kammerlander et al. in Injury 49:1436-1444, 2018;]. Cement-associated complications are well known in orthopedic procedures like hip arthroplasty, vertebra- and kyphoplasty. This study investigates outcome and safety of augmentation of the proximal femur nail blade. MATERIALS AND METHODS: The retrospective review of the 299 patients (mean age 80 ± 13 years; 205 women and 94 men) focused on perioperative complications after augmentation which was performed with Traumacem V+ Cement (Fa. DePuy Synthes) in 152 cases. The decision for augmentation of the blade was made by the attending surgeon and based on the factors age, bone quality, and fracture pattern. Primary outcome measures were changes in blood pressure, heart rate or oxygen saturation, and the number of needed vasoactive drugs during augmentation. Secondary outcome measures where the rate of cement leakage into the joint, mechanical failure, and perioperative complications like pulmonary embolism, stroke, or heart attack. RESULTS: In 152 augmented cases, no leakage of cement into the joint could be detected. No signs of mechanical failure like cut-out of the blade were seen after 6 weeks and 3 months. Also, augmentation did not show a higher rate of mortality or postoperative complications like stroke, heart attack, embolism, or infection. 57 of 152 augmented cases received an intraoperative intervention with vasoactive medication at the time of augmentation either prophylactically or because of a blood pressure fall. Out of the non-augmented cases, 21 of 147 needed vasoactive medication in the second half of the operation. The difference between these groups was significant (p < 0.05). In the cases without an intervention, there was a significant blood pressure fall of about 8 ± 7.4 mmHg during the augmentation (p < 0.001). Still, none of the augmented cases showed a change in heart rate or oxygen saturation. CONCLUSION: The augmentation of the PFNA blade proved to be a safe procedure. Cement augmentation will not increase postoperative complications or mortality. The risk for leakage of cement into the joint is low and mechanical cut-out might be prevented. The decision for augmentation should be made carefully and always be declared loud and in advance to allow the anesthetist to prepare, because blood pressure changes can occur.

[Dysphagia in cervical spine diseases]. / Dysphagie bei Erkrankungen der Halswirbelsäule.

Dysphagia is a common symptom and can be indicative of a variety of heterogeneous diseases. "Classical" diseases of the head and neck region, such as acute tonsillitis, peritonsillar abscesses, diverticula, and benign or malignant tumors are common causes of dysphagia. However, it can also occur in the context of neurological diseases, e.g., as a result of stroke or as an age-related phenomenon (presbyphagia). Pathologies of the cervical spine can also be a cause of dysphagia. In this context, congenital or acquired diseases, inflammatory or degenerative processes, cervical spine surgery, and (malignant) masses of the cervical spine should be taken into account. Particular dysphagia with a positive history of previous operative interventions on the cervical spine or symptoms such as chronic back pain and trauma should give rise to consideration of a cervical spine-related cause.

The evolution of 3D imaging in orthopedic trauma care.

Three-dimensional (3D) imaging can enhance trauma care by allowing better evaluation of bony detail and implant position compared to conventional fluoroscopy or x­ray. Intraoperative 3D imaging further improves this evaluation by allowing any necessary revisions to be made in the operating room prior to the patient emerging from anesthesia. This revision, if necessary, better achieves the surgical goals and alleviates the stressful situation of obtaining postoperative 3D imaging, where the benefit of revision must be balanced against the cost and risk of returning to the operating room. Improved image volume, resolution, and software capability have allowed surgeons to obtain high-quality, wide field views of bony anatomy that can include the uninjured side as a comparison. In this paper, the evolution of intraoperative 3D imaging over the past 25 years is discussed.

Fighting fish parasites with photodynamically active chlorophyllin.

Water-soluble chlorophyll (chlorophyllin) was used in a phototoxic reaction against a number of fish ectoparasites such as Ichtyobodo, Dactylogyrus, Trichodina, and Argulus. Chlorophyllin is applied to the water at concentrations of several micrograms per milliliter for a predefined incubation time, and afterwards, the parasites are exposed to simulated solar radiation. Application in the dark caused only little damage to the parasites; likewise, light exposure without the addition of the photosensitizer was ineffective. In Ichthyobodo, 2 µg/mL proved sufficient with subsequent simulated solar radiation to almost quantitatively kill the parasites, while in Dactylogyrus, a concentration of about 6 µg/mL was necessary. The LD50 value for this parasite was 1.02 µg/mL. Trichodina could be almost completely eliminated at 2 µg/mL. Only in the parasitic crustacean Argulus, no killing could be achieved by a photodynamic reaction using chlorophyllin. Chlorophyllin is non-toxic, biodegradable, and can be produced at low cost. Therefore, we propose that chlorophyllin (or other photodynamic substances) are a possible effective countermeasure against several ectoparasites in ponds and aquaculture since chemical remedies are either forbidden and/or ineffective.

Treatment of ichthyophthiriasis with photodynamically active chlorophyllin.

Water-soluble chlorophyll (chlorophyllin) exerts pronounced photodynamic activity on fish parasites. In order to determine its potential as a remedy against ectoparasites in fish carps were incubated in water with defined concentrations of chlorophyllin. The main focus of the experiments was on the ciliate Ichthyophthirius multifiliis (Fouquet) which is responsible for considerable losses in livestock in aquaculture. As malachite green, which in the past efficiently cured infected fishes, is banned because of its possible carcinogenicity; no effective remedy is presently available in aquaculture to treat ichthyophthiriasis. Using chlorophyllin, the number of trophonts was significantly reduced (more than 50 %) after 3 h incubation of infested fish at 2 and 4 mg/L and subsequent irradiation with simulated solar radiation. The lack of reinfection after light treatment indicates that also the remaining parasites have lost their multiplication capacity. In the controls (no chlorophyllin and no light, light but no chlorophyllin, or chlorophyllin but no light), no reduction of the I. multifiliis infection was observed. We propose that chlorophyllin (or other photodynamic substances) is a possible effective countermeasure against I. multifiliis and other ectoparasites in aquaculture.