Instant loading with intraoral welding technique and PRAMA implants: a new prosthetic approach.

When splinting multiple implants passive fit of the framework should be achieved to avoid excessive force distribution on the implants. Recently, a protocol was suggested for immediate loading of multiple implants by welding a titanium bar to implant abutments directly in the oral cavity so as to create a customized, precise and passive metal-reinforced provisional restoration. The intraoral welding technique subsequently proves to be a successful option in the full-arch immediate restorations of the mandible and maxilla. The aim of this article is to present a case report in which a new prosthetic approach, using trans-mucosal implants, is described. Dental implants are instantly loaded with a provisional prosthesis supported by an intraoral welded titanium framework to obtain a precise passive fit of the immediate loaded prosthesis.

Electromagnetically induced transparency in a diamond spin ensemble enables all-optical electromagnetic field sensing.

We use electromagnetically induced transparency (EIT) to probe the narrow electron-spin resonance of nitrogen-vacancy centers in diamond. Working with a multipass diamond chip at temperatures 6-30 K, the zero-phonon absorption line (637 nm) exhibits an optical depth of 6 and inhomogeneous linewidth of ~30 GHz FWHM. Simultaneous optical excitation at two frequencies separated by the ground-state zero-field splitting (2.88 GHz) reveals EIT resonances with a contrast exceeding 6% and FWHM down to 0.4 MHz. The resonances provide an all-optical probe of external electric and magnetic fields with a projected photon-shot-noise-limited sensitivity of 0.2 V/cm/√[Hz] and 0.1 nT/√[Hz], respectively. Operation of a prototype diamond-EIT magnetometer measures a noise floor of ~/<1 nT/√[Hz] for frequencies above 10 Hz and Allan deviation of 1.3±1.1 nT for 100 s intervals. The results demonstrate the potential of diamond-EIT devices for applications ranging from quantum-optical memory to precision measurement and tests of fundamental physics.

Dynamic stabilization of the optical resonances of single nitrogen-vacancy centers in diamond.

We report electrical tuning by the Stark effect of the excited-state structure of single nitrogen-vacancy (NV) centers located ≲100 nm from the diamond surface. The zero-phonon line (ZPL) emission frequency is controllably varied over a range of 300 GHz. Using high-resolution emission spectroscopy, we observe electrical tuning of the strengths of both cycling and spin-altering transitions. Under resonant excitation, we apply dynamic feedback to stabilize the ZPL frequency. The transition is locked over several minutes and drifts of the peak position on timescales ≳100 ms are reduced to a fraction of the single-scan linewidth, with standard deviation as low as 16 MHz (obtained for an NV in bulk, ultrapure diamond). These techniques should improve the entanglement success probability in quantum communications protocols.

Nanophotonics for quantum optics using nitrogen-vacancy centers in diamond.

Optical microcavities and waveguides coupled to diamond are needed to enable efficient communication between quantum systems such as nitrogen-vacancy centers which are known already to have long electron spin coherence lifetimes. This paper describes recent progress in realizing microcavities with low loss and small mode volume in two hybrid systems: silica microdisks coupled to diamond nanoparticles, and gallium phosphide microdisks coupled to single-crystal diamond. A theoretical proposal for a gallium phosphide nanowire photonic crystal cavity coupled to diamond is also discussed. Comparing the two material systems, silica microdisks are easier to fabricate and test. However, at low temperature, nitrogen-vacancy centers in bulk diamond are spectrally more stable, and we expect that in the long term the bulk diamond approach will be better suited for on-chip integration of a photonic network.

Skeletal turnover, bone mineral density, and fractures in male chronic abusers of alcohol.

BACKGROUND: Chronic alcohol abuse is a risk factor for osteoporosis and fractures, whose pathogenesis is still unclear. We investigated the influence of alcoholism and other risk factors on calcium and skeletal metabolism, bone mineral density (BMD), and fractures. MATERIALS AND METHODS: In 51 chronic male alcoholics without liver failure and 31 healthy controls, serum total and ionised calcium, phosphate, creatinine, 25-hydroxy vitamin D (25OHD), PTH, total (ALP) and bone-specific (BALP) alkaline phosphatase, osteocalcin (BGP), carboxy-terminal telopeptide of type I collagen (beta-CTx), osteoprotegerin (OPG) and receptor activator of nuclear factor kappa B ligand (RANKL) were assessed. In patients only, we also measured serum testosterone, 17-beta estradiol, LH, and IGF-I. BMD was measured by dual energy x-ray absorptiometry at lumbar spine (LS-) and femur [neck (FN-) and total hip (TF-)]. Vertebral fractures were identified by a semiquantitative method on thoraco-lumbar spine x-ray, non-vertebral fractures (as life-style factors) by history. RESULTS: Alcoholics were leaner, had significantly higher ALP and BALP, and lower BGP and 25OHD levels than controls. No significant difference in other calcium and bone metabolism parameters was found. OPG/RANKL ratio was significantly higher in alcoholics. Beta-CTx negatively correlated with abuse duration. OPG positively correlated with daily alcohol assumption and with indexes of liver cytolysis. Though LS-, FN- and TF-BMD of alcoholics and controls did not significantly differ, patients had a much higher prevalence of vertebral fractures. The same was found considering both vertebral and non-vertebral fractures. CONCLUSIONS: Ethanol-induced skeletal damage seems mainly dependent on negative effects on bone formation. Lifestyle factors and traumas likely contribute to the high fracture incidence of alcohol abusers, independently of BMD.

Regulated and entangled photons from a single quantum Dot

We propose a new method of generating nonclassical optical field states. The method uses a semiconductor device, which consists of a single quantum dot as active medium embedded in a p- i- n junction and surrounded by a microcavity. Resonant tunneling of electrons and holes into the quantum dot ground states, together with the Pauli exclusion principle, produce regulated single photons or regulated pairs of photons. We propose that this device also has the unique potential to generate pairs of entangled photons at a well-defined repetition rate.

Kangaroo (skin-to-skin) care with a postpartum woman who felt depressed.

The mother in this case study had numerous known risk factors for postpartum depression and was in rehabilitation for drug abuse. She was crying at 2 hours postbirth and expressing feelings of sadness as her baby was being unwrapped for her first kangaroo care (KC) experience. Thereafter, during our research protocol, her self-reported depression scores decreased rapidly and had disappeared by 32 hours postbirth. A benefit of KC requiring systematic study is that KC may lessen maternal depression. There is new knowledge that some functions of the maternal HPA axis become dampened during the last trimester of pregnancy as the placenta increases its secretion of corticotrophin-releasing hormone. The sudden loss of the placenta following delivery, accompanied by a suppressed HPA axis, may have an effect on mood during the immediate postpartum period. Perhaps appropriate reactivation of the maternal HPA axis can be triggered following birth by the stimulation inherent in KC, thereby minimizing risk for postpartum depression.

Kangaroo skin-to-skin care for premature twins and their adolescent parents.

Risk factors associated with prematurity and adolescent parenting greatly increase when combined with multiple birth. Kangaroo care (KC) for preterm infants is well documented, although KC with twins or with adolescent parents is mentioned only briefly. In this case study, adolescent parents experience KC with their 32-week twin sons beginning 19 hours postbirth. These young parents interacted with, responded to, and took responsibility for their newborn sons, behaviors that are sometimes difficult for adolescent parents. Thus, KC appeared to be an effective intervention for these adolescent parents. Additionally, three kinds of KC with twins were identified: separate, sequential, and shared.

Dehydroepiandrosterone sulfate and bone resorption rates as reflected by serum levels of C-terminal telopeptide of type I collagen: a study in healthy men.

Sex steroid hormones contribute to the physiological regulation of bone turnover in males. To address this issue, we investigated serum estradiol (E2), total testosterone (T), and DHEAS concentrations, along with serum levels of carboxy-terminal telopeptide of type I collagen (sCTx), in a sample of 76 healthy men aged 23 to 87. The concentration of sCTx declined with age. Both T and DHEAS, at variance with E2, showed a significant age-related decline. T, DHEAS and sCTx significantly (p<0.01) correlated with each other. DHEAS and T were significantly associated after correcting for age (r=0.35, p=0.002) or body mass index (r=0.65, p<0.0001). DHEAS, but not T, significantly correlated with sCTx after correcting for age (r=0.26, p=0.026, and r=0.20, p=0.08, respectively). Stepwise multiple regression analysis showed that only DHEAS (but not T or E2) was a significant independent predictor of sCTx (p=0.0001). Our results show that adrenal androgens play a crucial role in regulating bone resorption in aging men.

Triggered single photons from a quantum dot.

We demonstrate a new method for generating triggered single photons. After a laser pulse generates excitons inside a single quantum dot, electrostatic interactions between them and the resulting spectral shifts allow a single emitted photon to be isolated. Correlation measurements show a reduction of the two-photon probability to 0.12 times the value for Poisson light. Strong antibunching persists when the emission is saturated. The emitted photons are also polarized.