1,188 research outputs found
Role of the microbiota in the modulation of vaccine immune responses
The human immune system and the microbiota co-evolve, and their balanced relationship is based on crosstalk between the two systems through the course of life. This tight association and the overall composition and richness of the microbiota play an important role in the modulation of host immunity and may impact the immune response to vaccination. The availability of innovative technologies, such as next-generation sequencing (NGS) and correlated bioinformatics tools, allows a deeper investigation of the crosstalk between the microbiota and human immune responses. This review discusses the current knowledge on the influence of the microbiota on the immune response to vaccination and novel tools to deeply analyze the impact of the microbiome on vaccine responses
The Raman Fingerprint of Graphene
Graphene is the two-dimensional (2d) building block for carbon allotropes of
every other dimensionality. It can be stacked into 3d graphite, rolled into 1d
nanotubes, or wrapped into 0d fullerenes. Its recent discovery in free state
has finally provided the possibility to study experimentally its electronic and
phonon properties. Here we show that graphene's electronic structure is
uniquely captured in its Raman spectrum that clearly evolves with increasing
number of layers. Raman fingerprints for single-, bi- and few-layer graphene
reflect changes in the electronic structure and electron-phonon interactions
and allow unambiguous, high-throughput, non-destructive identification of
graphene layers, which is critically lacking in this emerging research area
Single-atom vibrational spectroscopy in the scanning transmission electron microscope
Vibrational spectroscopy can achieve high energy resolution, but spatial resolution of unperturbed vibrations is more difficult to realize. Hage et al. show that a single-atom impurity in a solid (a silicon atom in graphene) can give rise to distinctive localized vibrational signatures. They used high-resolution electron energy-loss spectroscopy in a scanning transmission electron microscope to detect this signal. An experimental geometry was chosen that reduced the relative elastic scattering contribution, and repeated scanning near the silicon impurity enhanced the signal. The experimental vibration frequencies are in agreement with ab initio calculations.Science, this issue p. 1124Single-atom impurities and other atomic-scale defects can notably alter the local vibrational responses of solids and, ultimately, their macroscopic properties. Using high-resolution electron energy-loss spectroscopy in the electron microscope, we show that a single substitutional silicon impurity in graphene induces a characteristic, localized modification of the vibrational response. Extensive ab initio calculations reveal that the measured spectroscopic signature arises from defect-induced pseudo-localized phonon modestextemdashthat is, resonant states resulting from the hybridization of the defect modes and the bulk continuumtextemdashwith energies that can be directly matched to the experiments. This finding realizes the promise of vibrational spectroscopy in the electron microscope with single-atom sensitivity and has broad implications across the fields of physics, chemistry, and materials science
Nutritional surveillance in Tuscany: maternal perception of nutritional status of 8-9 y-old school-children
Introduction. Overweight and obesity in the developmental age has become a public health problem. For this reason, prevention projects must be developed in advance with the aim to involve not only children, but their parents as well.
Our objective is to evaluate the accuracy of the mothers? perceptions of adolescent nutritional status.
Methods. Cross-sectional study. We selected a statistical sample of 3,076 subjects (1,583 males, 1,493 females), 8-9 y-old school-children of 164 3rd-grade elementary school classes from throughout Tuscany, as well as their mothers.
The mothers? information was gathered via self-administered questionnaires, while the children were given an eating behaviour survey under the supervision of qualified personnel. Mothers? education level (self-reported) height and weight were collected; children?s height and weight were measured. The former were asked how they perceived their children?s body image.
Results. A correlation exists between the mothers? perceptions of the nutritional state of their children via the silhouettes and the BMI classes of the children, which is equal to 80% with a k-Cohen for agreement equal to 0.58 (SE = 0.02; P : 0.0001). However, no correlation exists between the mothers? responses
to the question ?In your opinion, is your child ??? and the child?s actual BMI class (the exact percentage correlation is equal to 75%, with a k-Cohen for agreement equal to 0.43 SE = 0.014; P : 0.0001).
Discussion. Mothers have an accurate perception of the nutritional status of their children, correctly choosing the silhouette that corresponds to the child?s BMI profile without variation by gender.
We can assume that mothers in our sample have a good concept about healthy nutritional status
Phonon dispersion and lifetimes in MgB2
We measure phonon dispersion and linewidth in a single crystal of MgB_2 along
the Gamma-A, Gamma-M and A-L directions using inelastic X-Ray scattering. We
use Density Functional Theory to compute the effect of both electron-phonon
coupling and anharmonicity on the linewidth, obtaining excellent agreement with
experiment. Anomalous broadening of the E_2g phonon mode is found all along
Gamma-A. The dominant contribution to the linewidth is always the
electron-phonon coupling.Comment: 4 pages, 3 figure
Risk calculator for prediction of treatment-related urethroplasty failure in patients with penile urethral strictures
Purpose To design a dedicated risk calculator for patients with penile urethra stricture who are scheduled to urethroplasty that might be used to counsel patients according to their pre-operative risk of failure. Methods Patients treated with penile urethroplasty at our center (1994-2018) were included in the study. Patients received 1-stage or staged penile urethroplasty. Patients with failed hypospadias repair, lichen sclerosus or incomplete clinical records were excluded. Treatment failure was defined as any required postoperative instrumentation, including dilation. Univariable Cox regression identified predictors of post-operative treatment failure and Kaplan-Meier analysis plotted the failure-free survival rates according to such predictors. Multivariable Cox regression-based risk calculator was generated to predict the risk of treatment failure at 10 years after surgery. Results 261 patients met the inclusion criteria. Median follow-up was 113 months. Out of 216 patients, 201 (77%) were classified as success and 60 (23%) failures. Former smoker (hazard ratio [HR] 2.12, p = 0.025), instrumentation-derived stricture (HR 2.55, p = 0.006), and use of grafts (HR 1.83, p = 0.037) were predictors of treatment failure. Model-derived probabilities showed that the 10-year risk of treatment failure varied from 5.8 to 41.1% according to patient's characteristics. Conclusions Long-term prognosis in patients who underwent penile urethroplasty is uncertain. To date, our risk-calculator represents the first tool that might help physicians to predict the risk of treatment failure at 10 years. According to our model, such risk is largely influenced by the etiology of the stricture, the use of graft, and patient's smoking habits
Repair of sphincter urethral strictures preserving urinary continence: surgical technique and outcomes
Introduction Repair of post-TURP sphincter urethral strictures represents challenging problem, due to the risk of urinary incontinence after the repair. We described a surgical technique we use to repair these strictures preserving urinary continence in patients with incompetent bladder neck. Materials and methods An observational, retrospective, study was conducted to include patients with post-TURP urethral strictures in the area of distal sphincter. We included only patients with complete clinical data and follow-up who previously underwent TURP or HOLEP or TUIP, and subsequently developed proximal bulbar urethral strictures close to the membranous urethra and the related distal urethral sphincter. Patients were included, if they were fully continent after TURP or other procedures to treat BPH. The primary outcome of the study was treatment failure, defined as the need for any post-operative instrumentation. Secondary outcome was post-urethroplasty urinary continence. Patients showing stricture recurrence or post-operative incontinence were classified as failure. Results Overall, 69 patients were included in the study. Median patient's age was 67 years; median stricture length was 4 cm. Thirty-tree patients (47.8%) underwent previous urethrotomy. Median follow-up was 52 months. Out of 69 patients, 55 (79.7%) were classified as success and 14 (20.3%) as failure. Out of the whole cohort, thus, 11/69 (16%) have a risk of recurrent strictures and 3/69 (4.3%) have incontinence. Conclusions The use of modified ventral onlay graft urethroplasty, using particular non-aggressive steps, is a suitable surgical technique for repair of sphincter urethral stricture in patients who underwent BPH transurethral surgery, using different procedures (TURP, HOLEP, TUIP)
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