Electron quantum metamaterials in van der Waals heterostructures

In recent decades, scientists have developed the means to engineer synthetic periodic arrays with feature sizes below the wavelength of light. When such features are appropriately structured, electromagnetic radiation can be manipulated in unusual ways, resulting in optical metamaterials whose function is directly controlled through nanoscale structure. Nature, too, has adopted such techniques -- for example in the unique coloring of butterfly wings -- to manipulate photons as they propagate through nanoscale periodic assemblies. In this Perspective, we highlight the intriguing potential of designer sub-electron wavelength (as well as wavelength-scale) structuring of electronic matter, which affords a new range of synthetic quantum metamaterials with unconventional responses. Driven by experimental developments in stacking atomically layered heterostructures -- e.g., mechanical pick-up/transfer assembly -- atomic scale registrations and structures can be readily tuned over distances smaller than characteristic electronic length-scales (such as electron wavelength, screening length, and electron mean free path). Yet electronic metamaterials promise far richer categories of behavior than those found in conventional optical metamaterial technologies. This is because unlike photons that scarcely interact with each other, electrons in subwavelength structured metamaterials are charged, and strongly interact. As a result, an enormous variety of emergent phenomena can be expected, and radically new classes of interacting quantum metamaterials designed

The role of neutralizing antibodies in prevention of HIV-1 infection: what can we learn from the mother-to-child transmission context?

International audienceIn most viral infections, protection through existing vaccines is linked to the presence of vaccine-induced neutralizing antibodies (NAbs). However, more than 30 years after the identification of AIDS, the design of an immunogen able to induce antibodies that would neutralize the highly diverse HIV-1 variants remains one of the most puzzling challenges of the human microbiology. The role of antibodies in protection against HIV-1 can be studied in a natural situation that is the mother-to-child transmission (MTCT) context. Indeed, at least at the end of pregnancy, maternal antibodies of the IgG class are passively transferred to the fetus protecting the neonate from new infections during the first weeks or months of life. During the last few years, strong data, presented in this review, have suggested that some NAbs might confer protection toward neonatal HIV-1 infection. In cases of transmission, it has been shown that the viral population that is transmitted from the mother to the infant is usually homogeneous, genetically restricted and resistant to the maternal HIV-1-specific antibodies. Although the breath of neutralization was not associated with protection, it has not been excluded that NAbs toward specific HIV-1 strains might be associated with a lower rate of MTCT. A better identification of the antibody specificities that could mediate protection toward MTCT of HIV-1 would provide important insights into the antibody responses that would be useful for vaccine development. The most convincing data suggesting that NAbs migh confer protection against HIV-1 infection have been obtained by experiments of passive immunization of newborn macaques with the first generation of human monoclonal broadly neutralizing antibodies (HuMoNAbs). However, these studies, which included only a few selected subtype B challenge viruses, provide data limited to protection against a very restricted number of isolates and therefore have limitations in addressing the hypervariability of HIV-1. The recent identification of highly potent second-generation cross-clade HuMoNAbs provides a new opportunity to evaluate the efficacy of passive immunization to prevent MTCT of HIV-1

Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease

Background: Experimental and clinical data suggest that reducing inflammation without affecting lipid levels may reduce the risk of cardiovascular disease. Yet, the inflammatory hypothesis of atherothrombosis has remained unproved. Methods: We conducted a randomized, double-blind trial of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1β, involving 10,061 patients with previous myocardial infarction and a high-sensitivity C-reactive protein level of 2 mg or more per liter. The trial compared three doses of canakinumab (50 mg, 150 mg, and 300 mg, administered subcutaneously every 3 months) with placebo. The primary efficacy end point was nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. RESULTS: At 48 months, the median reduction from baseline in the high-sensitivity C-reactive protein level was 26 percentage points greater in the group that received the 50-mg dose of canakinumab, 37 percentage points greater in the 150-mg group, and 41 percentage points greater in the 300-mg group than in the placebo group. Canakinumab did not reduce lipid levels from baseline. At a median follow-up of 3.7 years, the incidence rate for the primary end point was 4.50 events per 100 person-years in the placebo group, 4.11 events per 100 person-years in the 50-mg group, 3.86 events per 100 person-years in the 150-mg group, and 3.90 events per 100 person-years in the 300-mg group. The hazard ratios as compared with placebo were as follows: in the 50-mg group, 0.93 (95% confidence interval [CI], 0.80 to 1.07; P = 0.30); in the 150-mg group, 0.85 (95% CI, 0.74 to 0.98; P = 0.021); and in the 300-mg group, 0.86 (95% CI, 0.75 to 0.99; P = 0.031). The 150-mg dose, but not the other doses, met the prespecified multiplicity-adjusted threshold for statistical significance for the primary end point and the secondary end point that additionally included hospitalization for unstable angina that led to urgent revascularization (hazard ratio vs. placebo, 0.83; 95% CI, 0.73 to 0.95; P = 0.005). Canakinumab was associated with a higher incidence of fatal infection than was placebo. There was no significant difference in all-cause mortality (hazard ratio for all canakinumab doses vs. placebo, 0.94; 95% CI, 0.83 to 1.06; P = 0.31). Conclusions: Antiinflammatory therapy targeting the interleukin-1β innate immunity pathway with canakinumab at a dose of 150 mg every 3 months led to a significantly lower rate of recurrent cardiovascular events than placebo, independent of lipid-level lowering. (Funded by Novartis; CANTOS ClinicalTrials.gov number, NCT01327846.

Demographic, clinical and antibody characteristics of patients with digital ulcers in systemic sclerosis: data from the DUO Registry

OBJECTIVES: The Digital Ulcers Outcome (DUO) Registry was designed to describe the clinical and antibody characteristics, disease course and outcomes of patients with digital ulcers associated with systemic sclerosis (SSc). METHODS: The DUO Registry is a European, prospective, multicentre, observational, registry of SSc patients with ongoing digital ulcer disease, irrespective of treatment regimen. Data collected included demographics, SSc duration, SSc subset, internal organ manifestations, autoantibodies, previous and ongoing interventions and complications related to digital ulcers. RESULTS: Up to 19 November 2010 a total of 2439 patients had enrolled into the registry. Most were classified as either limited cutaneous SSc (lcSSc; 52.2%) or diffuse cutaneous SSc (dcSSc; 36.9%). Digital ulcers developed earlier in patients with dcSSc compared with lcSSc. Almost all patients (95.7%) tested positive for antinuclear antibodies, 45.2% for anti-scleroderma-70 and 43.6% for anticentromere antibodies (ACA). The first digital ulcer in the anti-scleroderma-70-positive patient cohort occurred approximately 5 years earlier than the ACA-positive patient group. CONCLUSIONS: This study provides data from a large cohort of SSc patients with a history of digital ulcers. The early occurrence and high frequency of digital ulcer complications are especially seen in patients with dcSSc and/or anti-scleroderma-70 antibodies

National Geographic : understand civil engineering differently

Our undergraduate civil engineering students have access to a rich and diverse bank of textual and graphical knowledge concerning their chosen profession. However, over a number of decades, commentators have raised concerns that our students have insufficient understanding of the role of civil engineering in society. Indeed, the call for universities to educate ‘global engineers’ emphasises the need for our students to be schooled in the humanities, in parallel with their core computational studies. Unfortunately, engineering students in particular, are not accustomed to regular exploratory reading. This paper considers the use of the National Geographic magazine as a means to ignite our students’ curiosity with the world around them. The results from a pilot study and a content analysis of a number of editions from over a decade shows that this periodical regularly carries themes directly concerning the impact of civil engineering in society, be it political , financial environmental , social or ecological

Implementation of a method to visualize noise-induced hearing loss in mass stranded cetaceans

Assessment of the impact of noise over-exposure in stranded cetaceans is challenging, as the lesions that lead to hearing loss occur at the cellular level and inner ear cells are very sensitive to autolysis. Distinguishing ante-mortem pathology from post-mortem change has been a major constraint in diagnosing potential impact. Here, we outline a methodology applicable to the detection of noise-induced hearing loss in stranded cetaceans. Inner ears from two mass strandings of long-finned pilot whales in Scotland were processed for scanning electron microscopy observation. In one case, a juvenile animal, whose ears were fixed within 4¿hours of death, revealed that many sensory cells at the apex of the cochlear spiral were missing. In this case, the absence of outer hair cells would be compatible with overexposure to underwater noise, affecting the region which transduces the lowest frequencies of the pilot whales hearing spectrum. Perfusion of cochlea with fixative greatly improved preservation and enabled diagnostic imaging of the organ of Corti, even 30¿hours after death. This finding supports adopting a routine protocol to detect the pathological legacy of noise overexposure in mass stranded cetaceans as a key to understanding the complex processes and implications that lie behind such stranding events.Postprint (published version

Intenções reprodutivas e práticas de regulação da fecundidade entre universitários Reproductive intentions and fertility regulation practices among university students

OBJETIVO: Identificar as intenções reprodutivas e caracterizar as práticas de regulação da fecundidade, abarcando a contracepção e o aborto, entre um grupo de adolescentes e jovens de alta escolaridade. MÉTODOS: Os dados foram levantados a partir de um estudo amplo quali-quantitativo com estudantes de graduação com idade de até 24 anos, de uma universidade pública estadual localizada na cidade de São Paulo. A população estudada foi constituída de 952 estudantes que freqüentavam disciplinas sorteadas pelo método de sorteio aleatório; e numa segunda etapa foram realizadas 33 entrevistas em profundidade com alunos voluntários. Na primeira etapa, os alunos foram entrevistados em sala de aula, através de um questionário auto-aplicável e, na segunda etapa, foram gravadas entrevistas em profundidade, realizadas em um local previamente combinado. RESULTADOS: O padrão de família idealizado pelo grupo era pequeno, com até dois filhos. A idade considerada ideal no nascimento do primeiro filho seria próxima aos 30 anos. Os estudantes referiram uma alta proporção de uso de contraceptivos - sobretudo do condom e da pílula. Ao lado disso, observa-se uma alta proporção de gestações finalizadas pelo aborto. Como resultante desse quadro, a fecundidade é bastante baixa no grupo, ou seja, 27 estudantes referiram uma ou mais gestações. Os dados qualitativos não foram objeto de análise. CONCLUSÕES: Embora o tamanho idealizado para a família reflita uma tendência geral presente na sociedade brasileira, constata-se que o grupo adia a maternidade/paternidade em função de um projeto de vida orientado para a conclusão de um curso superior e a inserção no mercado de trabalho. Ainda assim, a contracepção e a prevenção das doenças sexualmente transmissíveis são vivenciadas precariamente.<br>OBJECTIVE: To identify reproductive intentions and fertility regulation practices, including contraception and abortion, in a group of high schooling adolescents and young adults. METHODS: The data were gathered from a large quali-quantitative study carried out among University of São Paulo undergraduate students aged up to 24 years. The study sample consisted of 952 students who attended the university courses and were randomly drawn. In this first step, a self-administered questionnaire was applied to the students in the classroom. On the next step, in-depth interviews were applied to 33 volunteer students in a preset place. RESULTS: It was observed that the students' idealized family model is to have up to two children. The optimal age for having a first child is close to 30. The students referred high contraceptive use, especially condoms and the pill. High proportion of abortion was also observed. Consequently, fertility is considerably low in the study group, i.e., 27 students reported having one or more pregnancies. Qualitative data were not analyzed. CONCLUSIONS: Although the idealized family size reflects a general trend in the Brazilian society, it can be noted that the group delays maternity/paternity for the sake of a life project of getting a university degree and having autonomy. Despite that, contraception and prevention of sexually transmitted diseases are poor