Graphene Photonics and Optoelectronics

The richness of optical and electronic properties of graphene attracts enormous interest. Graphene has high mobility and optical transparency, in addition to flexibility, robustness and environmental stability. So far, the main focus has been on fundamental physics and electronic devices. However, we believe its true potential to be in photonics and optoelectronics, where the combination of its unique optical and electronic properties can be fully exploited, even in the absence of a bandgap, and the linear dispersion of the Dirac electrons enables ultra-wide-band tunability. The rise of graphene in photonics and optoelectronics is shown by several recent results, ranging from solar cells and light emitting devices, to touch screens, photodetectors and ultrafast lasers. Here we review the state of the art in this emerging field.Comment: Review Nature Photonics, in pres

Should all acutely ill children in primary care be tested with point-of-care CRP: A cluster randomised trial

Background: Point-of-care blood C-reactive protein (CRP) testing has diagnostic value in helping clinicians rule out the possibility of serious infection. We investigated whether it should be offered to all acutely ill children in primary care or restricted to those identified as at risk on clinical assessment. Methods: Cluster randomised controlled trial involving acutely ill children presenting to 133 general practitioners (GPs) at 78 GP practices in Belgium. Practices were randomised to undertake point-of-care CRP testing in all children (1730 episodes) or restricted to children identified as at clinical risk (1417 episodes). Clinical risk was assessed by a validated clinical decision rule (presence of one of breathlessness, temperature ≥ 40 °C, diarrhoea and age 12-30 months, or clinician concern). The main trial outcome was hospital admission with serious infection within 5 days. No specific guidance was given to GPs on interpreting CRP levels but diagnostic performance is reported at 5, 20, 80 and 200 mg/L. Results: Restricting CRP testing to those identified as at clinical risk substantially reduced the number of children tested by 79.9 % (95 % CI, 77.8-82.0 %). There was no significant difference between arms in the number of children with serious infection who were referred to hospital immediately (0.16 % vs. 0.14 %, P = 0.88). Only one child with a CRP < 5 mg/L had an illness requiring admission (a child with viral gastroenteritis admitted for rehydration). However, of the 80 children referred to hospital to rule out serious infection, 24 (30.7 %, 95 % CI, 19.6-45.6 %) had a CRP < 5 mg/L. Conclusions: CRP testing should be restricted to children at higher risk after clinical assessment. A CRP < 5 mg/L rules out serious infection and could be used by GPs to avoid unnecessary hospital referrals

Expanding the Repertoire of Modified Vaccinia Ankara-Based Vaccine Vectors via Genetic Complementation Strategies

nkara (MVA) is a safe, highly attenuated orthopoxvirus that is being developed as a recombinant vaccine vector for immunization against a number of infectious diseases and cancers. However, the expression by MVA vectors of large numbers of poxvirus antigens, which display immunodominance over vectored antigens-of-interest for the priming of T cell responses, and the induction of vector-neutralizing antibodies, which curtail the efficacy of subsequent booster immunizations, remain as significant impediments to the overall utility of such vaccines. Thus, genetic approaches that enable the derivation of MVA vectors that are antigenically less complex may allow for rational improvement of MVA-based vaccines. during infection, and that the processes governing the generation of antiviral antibody responses are more readily saturated by viral antigen than are those that elicit CD8+ T cell responses. deletion, enables the generation of novel replication-defective MVA mutants and expands the repertoire of genetic viral variants that can now be explored as improved vaccine vectors

Different antibiotic treatments for group A streptococcal pharyngitis

Background: Antibiotics provide only modest benefit in treating sore throat, although effectiveness increases in participants with positive throat swabs for group A beta-haemolytic streptococci (GABHS). It is unclear which antibiotic is the best choice if antibiotics are indicated. Objectives: We assessed the comparative efficacy of different antibiotics on clinical outcomes, relapse, complications and adverse events in GABHS tonsillopharyngitis. Search methods: We searched The Cochrane Library, Cochrane Central Register of Controlled Trials (CENTRAL 2010, Issue 3) which includes the Acute Respiratory Infections Group's Specialised Register, MEDLINE (1966 to July Week 4, 2010) and EMBASE (1974 to August 2010). Selection criteria: Randomised, double-blind trials comparing different antibiotics reporting at least one of the following: clinical cure, clinical relapse, complications, adverse events. Data collection and analysis: Two authors independently screened trials for inclusion and extracted data. Main results: Seventeen trials (5352 participants) were included; 16 compared with penicillin (six with cephalosporins, six with macrolides, three with carbacephem and one with sulfonamides), one trial compared clindamycin and ampicillin. Randomisation reporting, allocation concealment and blinding were poor. There was no difference in symptom resolution between cephalosporins and penicillin (intention-to-treat (ITT) analysis; N = 5; n = 2018; odds ratio for absence of resolution of symptoms (OR) 0.79, 95% confidence interval (CI) 0.55 to 1.12). Clinical relapse was lower with cephalosporins (N = 4; n = 1386; OR 0.55, 95% CI 0.31 to 0.99); overall number needed to treat to benefit (NNTB) 50), but found only in adults (OR 0.42, 95% CI 0.20 to 0.88; NNTB 33). There were no differences between macrolides and penicillin. Carbacephem showed better symptom resolution post-treatment (N = 3; n = 795; OR 0.70, 95% CI 0.49 to 0.99; NNTB 14), but only in children (N = 2; n = 233; OR 0.57, 95% CI 0.33 to 0.99; NNTB 8.3). Children experienced more adverse events with macrolides (N = 1, n = 489; OR 2.33; 95% CI 1.06 to 5.15). Authors' conclusions: Evidence is insufficient for clinically meaningful differences between antibiotics for GABHS tonsillopharyngitis. Limited evidence in adults suggests cephalosporins are more effective than penicillin for relapse, but the NNTB is high. Limited evidence in children suggests carbacephem is more effective for symptom resolution. Data on complications are too scarce to draw conclusions. Based on these results and considering the low cost and absence of resistance, penicillin can still be recommended as first choice. Plain Language Summary: Different antibiotics for group A streptococcal pharyngitis Pharyngitis or tonsillitis, a throat infection that usually presents with a sore throat, is a common upper respiratory tract infection. Most sore throats are caused by viruses, but sometimes bacteria are involved. Many people carry bacteria in their throat without becoming ill. However, sometimes a bacterial throat infection can occur. Infection with a specific type of bacteria, group A beta-haemolytic streptococci (GABHS) is linked to serious complications such as acute rheumatic fever or kidney disease (post-streptococcal glomerulonephritis). In order to prevent these complications antibiotics are often prescribed to treat patients presenting to their doctor with a sore throat. A previous Cochrane review found that there is only a modest benefit of antibiotics for treating an acute sore throat, even if group A beta-haemolytic streptococci (GABHS) are present. Most throat infections, even with bacteria, are self-limiting and the risk of complications is extremely low in most populations studied (in low-income countries). However, sometimes antibiotics may be indicated. We found 17 trials with a total of 5352 participants that studied the effects of different classes of antibiotics on resolution of symptoms in patients with a sore throat and a positive culture for GABHS. Our review found that the effects of these antibiotics are very similar. All antibiotics studied also cause undesired side effects (such as nausea and vomiting, rash), but there was no strong evidence for meaningful differences between the antibiotics. The studies did not report on long-term complications and therefore it is unclear if any class of antibiotics is better in preventing these serious but rare complications. As all the identified studies were carried out in populations in high-income countries with a low risk of streptococcal complications, there is a need for trials in populations where this risk is still very high (low-income countries and Aboriginal communities). Penicillin has been used for a very long time but resistance of the GABHS to penicillin has never been reported. Also, penicillin is a cheap antibiotic. Our review therefore supports the use of penicillin as a first choice antibiotic in patients with acute throat infections caused by GABHS

Different antibiotic treatments for group A streptococcal pharyngitis (Review)

Background: Antibiotics provide only modest benefit in treating sore throat, although effectiveness increases in participants with positive throat swabs for group A beta-haemolytic streptococci (GABHS). It is unclear which antibiotic is the best choice if antibiotics are indicated. Objectives: We assessed the comparative efficacy of different antibiotics on clinical outcomes, relapse, complications and adverse events in GABHS tonsillopharyngitis. Search strategy: We searched The Cochrane Library, Cochrane Central Register of Controlled Trials (CENTRAL 2010, Issue 3) which includes the Acute Respiratory Infections Group's Specialised Register, MEDLINE (1966 to July Week 4, 2010) and EMBASE (1974 to August 2010). Selection criteria: Randomised, double-blind trials comparing different antibiotics reporting at least one of the following: clinical cure, clinical relapse, complications, adverse events. Data collection and analysis: Two authors independently screened trials for inclusion and extracted data. Main results: Seventeen trials (5352 participants) were included; 16 compared with penicillin (six with cephalosporins, six with macrolides, three with carbacephem and one with sulfonamides), one trial compared clindamycin and ampicillin. Randomisation reporting, allocation concealment and blinding were poor. There was no difference in symptom resolution between cephalosporins and penicillin (intention-to-treat (ITT) analysis; N = 5; n = 2018; odds ratio for absence of resolution of symptoms (OR) 0.79, 95% confidence interval (CI) 0.55 to 1.12). Clinical relapse was lower with cephalosporins (N = 4; n = 1386; OR 0.55, 95% CI 0.31 to 0.99); overall number needed to treat to benefit (NNTB) 50), but found only in adults (OR 0.42, 95% CI 0.20 to 0.88; NNTB 33). There were no differences between macrolides and penicillin. Carbacephem showed better symptom resolution post-treatment (N = 3; n = 795; OR 0.70, 95% CI 0.49 to 0.99; NNTB 14), but only in children (N = 2; n = 233; OR 0.57, 95% CI 0.33 to 0.99; NNTB 8.3). Children experienced more adverse events with macrolides (N = 1, n = 489; OR 2.33; 95% CI 1.06 to 5.15). Authors' conclusions: Evidence is insufficient for clinically meaningful differences between antibiotics for GABHS tonsillopharyngitis. Limited evidence in adults suggests cephalosporins are more effective than penicillin for relapse, but the NNTB is high. Limited evidence in children suggests carbacephem is more effective for symptom resolution. Data on complications are too scarce to draw conclusions. Based on these results and considering the low cost and absence of resistance, penicillin can still be recommended as first choice

Antibiotics for clinically diagnosed acute rhinosinusitis in adults (Review)

In primary care settings, the diagnosis of rhinosinusitis is generally based on clinical signs and symptoms. Technical investigations are not routinely performed, nor recommended. Individual trials show a trend in favour of antibiotics, but the balance of benefit versus harm is unclear. To assess the effect of antibiotics in adults with clinically diagnosed rhinosinusitis in primary care settings. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 2, 2012), MEDLINE (January 1950 to February week 4, 2012) and EMBASE (January 1974 to February 2012). Randomised controlled trials (RCTs) of antibiotics versus placebo in participants with rhinosinusitis-like signs or symptoms. Two authors independently extracted data and assessed the risk of bias. We contacted trial authors for additional information. We collected information on adverse effects from the trials. We included 10 trials involving 2450 participants. Overall, the risk of bias in these studies was low. Irrespective of the treatment group, 47% of participants were cured after one week and 71% after 14 days. Antibiotics can shorten the time to cure, but only five more participants per 100 will cure faster at any time point between 7 and 14 days if they receive antibiotics instead of placebo (number needed to treat to benefit (NNTB)) 18 (95% confidence interval (CI) 10 to 115, I(2) statistic 0%, eight trials). Purulent secretion resolves faster with antibiotics (odds ratio (OR) 1.58 (95% CI 1.13 to 2.22)), (NNTB 11, 95% CI 6 to 51, I(2) statistic 0%, three trials). However, 27% of the participants who received antibiotics and 15% of those who received placebo experienced adverse events (OR 2.10, 95% CI 1.60 to 2.77) (number needed to treat to harm (NNTH)) 8 (95% CI 6 to 13, I(2) statistic 13%, seven trials). More participants in the placebo group needed to start antibiotic therapy because of an abnormal course of rhinosinusitis (OR 0.49, 95% CI 0.36 to 0.66), NNTH 20 (95% CI 14 to 35, I(2) statistic 0%, eight trials). Only one disease-related complication (brain abscess) occurred in a patient treated with antibiotics. The potential benefit of antibiotics in the treatment of clinically diagnosed acute rhinosinusitis needs to be seen in the context of a high prevalence of adverse events. Taking into account antibiotic resistance and the very low incidence of serious complications, we conclude that there is no place for antibiotics for the patient with clinically diagnosed, uncomplicated acute rhinosinusitis. This review cannot make recommendations for children, patients with a suppressed immune system and patients with severe disease, as these populations were not included in the available trials