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.

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.

Erectile dysfunction in patients in a cardiac rehabilitation program.

INTRODUCTION AND OBJECTIVES: Erectile dysfunction is common in patients with coronary heart disease. The aim of this study was to investigate the incidence of, etiological factors associated with, and treatment results obtained in this condition in patients participating in a cardiac rehabilitation program. METHODS: The study included 420 male patients with heart disease who were taking part in a multicomponent therapeutic program that involved physical exercise, psychological techniques and risk factor reduction. RESULTS: Overall, erectile dysfunction was present in 216 patients (52.6%) and there were clear associations with age (P< .001), diabetes mellitus (P< .001), arterial hypertension (P=.029), cigarette smoking (P=.044) and treatment with angiotensin-converting enzyme inhibitors (P=.003) and diuretics (P< .001). However, there were no links to treatment with beta-blockers, calcium antagonists, statins or antiplatelet agents. There were direct associations with trait anxiety (P=.009) and state anxiety (P=.006) and with depression (P=.003). The final multivariate analysis model included diabetes mellitus, smoking, diuretic use, state anxiety and age as significant variables. Only 59 patients agreed to treatment with a phosphodiesterase-5 inhibitor, with positive results in 45 (76.27%). Treatment was contraindicated in 41 patients because they were taking nitrates for myocardial ischemia. The remaining patients expressed no interest, had relationship problems or were worried about complications. CONCLUSIONS: The incidence of erectile dysfunction was substantial. The condition was directly associated with risk factors for atherosclerosis, treatment, and psychological disorders (i.e., anxiety and depression). Relationship problems and the fear of complications may explain why many patients refused to take phosphodiesterase-5 inhibitors.

[Neonatal pelvic ectasia: long-term outcome and association with ureterovesical anomalies]. / Ectasia piélica neonatal: evolución a largo plazo y asociación a anomalías vesicoureterales.

OBJECTIVE: To analyze the outcome of neonatal pelvic ectasia (PE) and the association between this entity and vesicoureteral reflux and/or other urinary tract abnormalities. PATIENTS AND METHODS: We performed a retrospective study of 255 children (205 boys, 50 girls) with an ultrasonographic diagnosis of PE in the first month of life. The initial ultrasonographic examination was indicated by urinary tract infection in 30 neonates, abnormalities in the prenatal ultrasonographic examination in 150 and by other reasons in 75. Pelvic ectasia was classified in four stages according to anteroposterior pelvic diameter: I < 1 cm, II 1-1.5 cm, III 1.6-2 cm, and IV > 2 cm. RESULTS: Pelvic ectasia was bilateral in 153 children (60 %) and unilateral in 102 (left side in 81.4 % and right side in 18.6 %). Stage I was found in 75.49 %, stage II in 20.34 %, stage III in 3.9 % and stage IV in 0.24 %. The mean follow-up was 32.6 +/- 25.2 months. At the end of the first year, the results of renal ultrasound were normal in 70.2 % of left-sided PE and in 55.9 % of right-sided PE, but 46 patients (18 %) showed worsening of PE between the first and second ultrasound scans. Voiding cystourethrography was performed in 79.6 % of the children and some abnormalities were found in 50 (24.6 %): urethral dilatations in two patients and vesicoureteral reflux in 48. No correlation was found between vesicoureteral reflux and the degree of ectasia (74 % had an anteroposterior diameter of < or = 1 cm). Urinary tract infection was present in 24.3 % of the children and 13 required surgery (eight pyeloplasties, four urethral reimplantations and two resections of type III urethral valves). CONCLUSIONS: Neonatal PE was more prevalent in boys (4:1) and was more frequently located on the left side in both sexes. Associated vesicourethral reflux was found in 23.64 % with no correlation between the degree of dilation and the presence or degree of reflux. Consequently, cystourethrography should be performed in any child with pelvic ectasia, regardless of stage, side or sex.

Synthesis and enzymatic stability of phosphodiester-linked peptide-oligonucleotide hybrids.

Nucleopeptides Ac-Tyr(p3' dACGT)-Ala-Phe-Gly-NH2, Ac-Thr(p3'dACGT)-Ala-Phe-Gly-OH, Ac-Ser(p3'dACGT)-Ala-Phe-Gly-OH, and Phac-Hse(p3'dACGT)-Ala-Phe-Gly-OH, in which the 3'-end of a tetradeoxyribonucleotide is linked by a phosphodiester bond to a hydroxylated amino acid, were synthesized using a stepwise solid-phase methodology to study the influence of the linking amino acid on their stability to 3'-exonucleases. HPLC analysis of the reaction crudes after treatment of each nucleopeptide with snake venom phosphodiesterase showed that the lability of the amino acid-nucleoside linkage increases in the order Thr < Ser < Hse < Tyr.

A series of hexahydro[1,4]oxazino[3,4-a]isoquinolines as potential neuroleptics.

The synthesis and stereochemistry of trans-N,N-diethyl-9,10-dimethoxy-1,3,4,6,7,11b-hexahydro[1,4]oxazino[3,4-a]isoquinoline-3-carboxamide hydrochloride (16) and a series of analogues are described. 16 and its (+) isomer had neuroleptic properties in the Sidman avoidance test in gerbils. A few closely related amides of the trans series were active but cis amides were inactive as neuroleptics.