Neurosurgical intervention for the Meckel-Gruber Syndrome: A systematic review.

INTRODUCTION: Meckel-Gruber Syndrome (MKS) is an autosomal recessive genetic disorder, notable for its triad of occipital encephalocele, polycystic renal dysplasia, and postaxial polydactyly. Identified by Johann Friederich Meckel in 1822, MKS is categorized as a ciliopathy due to gene mutations. Diagnosis is confirmed by the presence of at least two key features. The condition is incompatible with life, leading to death in the womb or shortly after birth. Recent studies have largely focused on the genetic aspects of MKS, with limited information regarding the impact of neurosurgical approaches, particularly in treating encephaloceles. METHODS: A systematic review was performed according to the PRISMA statement. The PubMed, Embase, and Web of Science databases were consulted for data screening and extraction, which was conducted by two independent reviewers. The search strategy aimed to encompass studies documenting cases of MKS with published reports of encephalocele excisions, and the search strings for all databases were: Meckel-Gruber syndrome OR Meckel Gruber syndrome OR Meckel-gruber OR Meckel Gruber. RESULTS: The study included 10 newborns with MKS associated with occipital encephalocele or meningocele, all of whom underwent surgical repair of the occipital sac. The mean gestational age at birth was 36 (± 2) weeks. The mean of birth weight was 3.14 (± 0.85) kilograms. The average head circumference at birth was 33.82 cm (± 2.17). The mean diameter of the encephalocele/meningocele was 5.91 (± 1.02) cm. Other common central nervous system abnormalities included hydrocephalus, Dandy-Walker malformation, and agenesis of the corpus callosum. 40% required shunting for hydrocephalus. Surgery to remove the occipital sac occurred at a median age of 2.5 days (1.5-6.5). The most common post-surgical complication was the need for mechanical ventilation. The most common cause of death was pneumonia and the median age at death was 6.66 (0.03-18) months. CONCLUSION: Our findings suggest that neurosurgical intervention, especially for managing encephaloceles, may offer some improvement in survival, albeit within a context of generally poor prognosis. However, these results should be interpreted with caution.

Thermoelectric properties of topological chains coupled to a quantum dot.

Topological one-dimensional superconductors can sustain zero energy modes protected by different kinds of symmetries in their extremities. Observing these excitations in the form of Majorana fermions is one of the most intensive quests in condensed matter physics. We are interested in another class of one-dimensional topological systems in this work, namely topological insulators. Which present symmetry-protected end modes with robust properties and do not require the low temperatures necessary for topological superconductivity. We consider a device in the form of a single electron transistor coupled to the simplest kind of topological insulators, namely chains of atoms with hybridized sp orbitals. We study the thermoelectric properties of the device in the trivial, non-trivial topological phases and at the quantum topological transition of the chains. We show that the device's electrical conductance and the Wiedemann-Franz ratio at the topological transition have universal values at very low temperatures. The conductance and thermopower of the device with diatomic sp-chains, at their topological transition, give direct evidence of fractional charges in the system. The former has an anomalous low-temperature behavior, attaining a universal value that is a consequence of the double degeneracy of the system due to the presence of zero energy modes. On the other hand, the system can be tuned to exhibit high values of the thermoelectric figure of merit and the power factor at high temperatures.

Adiabatic charge and spin pumping through interacting quantum dots.

In this paper we investigate adiabatic charge and spin pumping through interacting quantum dots using non-equilibrium Green's function techniques and the equation-of-motion method. We treat the electronic correlations inside the dot using a Hartree-Fock approximation and succeed in obtaining closed analytic expressions for the Keldysh Green's functions. These allow us to compute charge and spin currents through the quantum dot. Depending on the parameters of the quantum dot and its coupling to the reservoirs, we show that it can be found in two different regimes: the magnetic regime and the non-magnetic regime. In the magnetic regime we find a non-vanishing spin current in addition to the charge current present in both cases.

Idade, tabagismo, hipertensão arterial, altura e sexo feminino são determinantes de envelhecimento vascular avaliados pela segunda derivada da fotopletismografia digital / Age, tabagism, arterial hypertension, height and feminine sex are determinants of vascular aging evaluated by the second derivative of the digital photoplethysmogram

Avaliar os fatores de risco cardiovascular (RCV) determinantes dosíndices de função arterial obtidos pela segunda derivada da fotopletismografia digital (SDPTG) em uma população de funcionários de uma instituição de ensino privado da cidade de São Paulo. MÉTODOS: Foram obtidos dados antropométricos e clínicos, medidas de pressão arterial (PA) com aparelho automático Microlife em 238 ndivíduos de 23 a 72 anos (média 40,1 ± 9), 105 mulheres / 133 homens. A SDPTG foi registrada automaticamente pelo dispositivo ...

To evaluate the cardiovascular risk (CR) determinants of the arterialfunction indices obtained by the second derivative photopletysmogram (SDPTG) in a agentpopulation from a private teaching institution of São Paulo. Methods: antropometric and clinicaldata, arterial pressure (AP) by na automatic device Microlife were obtained from 238 individualsfrom 28 to 72 years (mean 40,1 ± 9), 105 women / 133 men. The SDPTG was automaticallyregistered by the Dynapulse device through its sensor placed on the 2nd finger of the right hand...