The earliest known reported occurrence of dentigerous cyst in a six-month-old child.

The earliest reported case of the occurrence of a dentigerous cyst is described; the cyst surrounded an unerupted permanent tooth bud in a 6-month-old infant. Most commonly these lesions present between the second and third decades of life. They rarely occur before 10 years of age and have not been documented prior to 1 year of age. In the case reported here, the treatment instituted was extraction of the adjacent deciduous tooth and enucleation of the cyst along with the permanent molar tooth bud. Clinicians should be aware of the potential for this lesion to occur across a wide range of ages and the importance of prompt diagnosis and treatment to prevent complications and reduce morbidity.

Charge Fluctuations on a Flat Interface between Dielectric and Electrolyte or Dense Plasma.

An interface between a dielectric and a medium containing charge carriers with moderate mobility is considered. In equilibrium, stochastic fluxes of positive and negative particles toward the surface have equal average current density j0, and we suppose that the surface absorbs all falling charges. All over the surface, this results in the emergence of oppositely charged spots of various sizes D fluctuating and interacting with each other. Fourier expansion reduces this collection of interacting spots to the ensemble of independently fluctuating charge density waves. An exact solution of the Poisson equation for a single wave on a flat surface was obtained and provided strict proof that a fluctuating electric field is quite strong just above each charge spot but diminishes exponentially with the distance from the plane. The lifetime τ of a charge spot is inversely proportional to the density j0 of the stochastic current while proportional to j0τ fluctuation's amplitudes independent of j0. The fluctuation's parameter dependence on the charge spot's size D can vary according to the conducting medium properties.

Single-Spin Magnetomechanics with Levitated Micromagnets.

We demonstrate a new mechanical transduction platform for individual spin qubits. In our approach, single micromagnets are trapped using a type-II superconductor in proximity of spin qubits, enabling direct magnetic coupling between the two systems. Controlling the distance between the magnet and the superconductor during cooldown, we demonstrate three-dimensional trapping with quality factors around 1×10^{6} and kHz trapping frequencies. We further exploit the large magnetic moment to mass ratio of this mechanical oscillator to couple its motion to the spin degrees of freedom of an individual nitrogen vacancy center in diamond. Our approach provides a new path towards interfacing individual spin qubits with mechanical motion for testing quantum mechanics with mesoscopic objects, realization of quantum networks, and ultrasensitive metrology.

Initial Safety and Tumor Control Results From a "First-in-Human" Multicenter Prospective Trial Evaluating a Novel Alpha-Emitting Radionuclide for the Treatment of Locally Advanced Recurrent Squamous Cell Carcinomas of the Skin and Head and Neck.

PURPOSE: Our purpose was to report the feasibility and safety of diffusing alpha-emitter radiation therapy (DaRT), which entails the interstitial implantation of a novel alpha-emitting brachytherapy source, for the treatment of locally advanced and recurrent squamous cancers of the skin and head and neck. METHODS AND MATERIALS: This prospective first-in-human, multicenter clinical study evaluated 31 lesions in 28 patients. The primary objective was to determine the feasibility and safety of this approach, and the secondary objectives were to evaluate the initial tumor response and local progression-free survival. Eligibility criteria included all patients with biopsy-proven squamous cancers of the skin and head and neck with either primary tumors or recurrent/previously treated disease by either surgery or prior external beam radiation therapy; 13 of 31 lesions (42%) had received prior radiation therapy. Toxicity was evaluated according to the Common Terminology Criteria for Adverse Events version 4.03. Tumor response was assessed at 30 to 45 days at a follow-up visit using the Response Evaluation Criteria in Solid Tumors, version 1.1. Median follow-up time was 6.7 months. RESULTS: Acute toxicity included mostly local pain and erythema at the implantation site followed by swelling and mild skin ulceration. For pain and grade 2 skin ulcerations, 90% of patients had resolution within 3 to 5 weeks. Complete response to the Ra-224 DaRT treatment was observed in 22 lesions (22/28; 78.6%); 6 lesions (6/28, 21.4%) manifested a partial response (>30% tumor reduction). Among the 22 lesions with a complete response, 5 (22%) developed a subsequent local relapse at the site of DaRT implantation at a median time of 4.9 months (range, 2.43-5.52 months). The 1-year local progression-free survival probability at the implanted site was 44% overall (confidence interval [CI], 20.3%-64.3%) and 60% (95% CI, 28.61%-81.35%) for complete responders. Overall survival rates at 12 months post-DaRT implantation were 75% (95% CI, 46.14%-89.99%) among all patients and 93% (95% CI, 59.08%-98.96%) among complete responders. CONCLUSIONS: Alpha-emitter brachytherapy using DaRT achieved significant tumor responses without grade 3 or higher toxicities observed. Longer follow-up observations and larger studies are underway to validate these findings.

Microscopic Nature of the First-Order Field-Induced Phase Transition in the Strongly Anisotropic Ferrimagnet HoFe_{5}Al_{7}.

We report on x-ray magnetic circular dichroism experiments in pulsed fields up to 30 T to follow the rotations of individual magnetic moments through the field-induced phase transition in the ferrimagnet HoFe_{5}Al_{7}. Near the ground state, we observe simultaneous stepwise rotations of the Ho and Fe moments and explain them using a two-sublattice model for an anisotropic ferrimagnet with weak intersublattice exchange interactions. Near the compensation point, we find two phase transitions. The additional magnetization jump reflects the fact that the Ho moment is no longer rigid as the applied field acts against the intersublattice exchange field.

Sensing Coherent Dynamics of Electronic Spin Clusters in Solids.

We observe coherent spin exchange between identical electronic spins in the solid state, a key step towards full quantum control of electronic spin registers in room temperature solids. In a diamond substrate, a single nitrogen vacancy (NV) center coherently couples to two adjacent S=1/2 dark electron spins via the magnetic dipolar interaction. We quantify NV-electron and electron-electron couplings via detailed spectroscopy, with good agreement to a model of strongly interacting spins. The electron-electron coupling enables an observation of coherent flip-flop dynamics between electronic spins in the solid state, which occur conditionally on the state of the NV. Finally, as a demonstration of coherent control, we selectively couple and transfer polarization between the NV and the pair of electron spins. Our observations enable the realization of fast quantum gate operations and quantum state transfer in a scalable, room temperature, quantum processor.

[Bone augmentation of the extremely atrophic anterior mandible, using allogeneic block grafts, via submental approach].

Edentulous patients with advanced resorption of the mandible (atrophic mandible) suffer major discomfort when using dentures. Furthermore, placing dental implants is impossible due to lack of sufficient bone volume. In the past, several methods of bone grafting to the anterior mandible have been proposed. Most of them were unpredictable in either the short or long-term. In 2002 a technique for bone grafting of the anterior mandible via a submental approach was published. A wide reflection of the soft tissue was followed by implant placement. Autogenous particulate posterior iliac crest bone graft was used. The presence of the implants did not allow for contraction of the soft tissue and bone resorption. The addition of bone volume to the chin improved the facial aesthetics of the patients due to a fuller appearance of the chin and tightening of the skin of the neck. The submental approach changes the spatial orientation of the surgeon and placement of implants in the correct location and angle become challenging. Placement of the implants too far buccally was a prosthetic problem. A major disadvantage of autogenous bone grafting is the necessity to operate a donor site. The increasing experience in use of allogenic bone grafts with resorbable collagen membranes, allowed us to modify the submental approach for bone grafting of the anterior atrophic mandible, avoiding a donor site surgery. We chose to perform the bone graft as a first stage surgery, in which, via a submental approach allogenic bone blocks were adapted and fixated to the anterior mandible with titanium screws, xenograft and resorbable collagen membranes were used. A few months (>4) were allowed for graft consolidation and then a second stage surgery was performed, via an intraoral approach dental implants were placed. In this way we avoided loss of orientation and had a familiar setting for implant location and angulation. Five patients with atrophic mandibles were treated using this surgical protocol. Based on cone beam CT imaging, average bone height in the anterior mandible prior to treatment was 5.52 mm. After bone graft, the average gain in bone height was 12.74 mm. No major post-operative complications were noted. After bone graft consolidation, 4 or 5 dental implants were placed, most of the implants used were longer than 11.5 mm. 22 implants were placed, out of which 21 integrated (95.5%). Some of the patients were rehabilitated with overdentures and locators and some with PFM bridges. All patients were followed up for more than a year and no implant failure was recorded. Bone grafting to the anterior mandible using allogenic blocks with collagen membranes via a submental approach with second stage implant placement seems to be a viable solution for rehabilitation of the atrophic mandible.

Perspectives on expedited partner therapy for chlamydia: a survey of health care providers.

There is a lack of research on health care providers' use of and perspectives on expedited partner therapy in a state where expedited partner therapy is not prohibited or explicitly allowed. The aim of our study was to understand if and how health care providers use expedited partner therapy, if specific demographic factors and knowledge contribute to increased use of expedited partner therapy, and to describe barriers and facilitators to the use of expedited partner therapy in Pittsburgh, Pennsylvania. A convenience sample of 112 health care providers from diverse disciplines who treat young women at risk for chlamydia completed an online survey. About 11% of health care providers used expedited partner therapy consistently. Those who self-reported that they were knowledgeable about expedited partner therapy were more likely to use expedited partner therapy (73% vs. 49%, p = .009) as were those who said no or were unsure about their institution's guidelines for expedited partner therapy (35% vs. 22%, p = 0.01) (62% vs. 57%, p = 0.01). The most commonly reported facilitator of expedited partner therapy was having clear legal guidelines (86%). This study finds that in a setting where expedited partner therapy is not expressly permitted, health care providers still use the practice but also experience barriers that limit uptake. Legislation expressly endorsing expedited partner therapy in the state and in medical institutions is needed to increase expedited partner therapy use.

The influence of filament elasticity on transients after sudden alteration of length of muscle or load.

The duration of phase 2 of a transient after sudden reduction of the length of a muscle or a load on it decreases rapidly with increasing amplitude of the jump. This is mainly due to the increasing role of the superfast relaxation processes with a characteristic time of about 0.1 ms. Mainly in order to explain this effect, Huxley and Simmons proposed their famous model of force generation in 1971. The present paper examines the effect of elasticity of filaments on relaxation processes. It is shown that if the filaments are not perfectly elastic, the superfast tension transient may result from a delay of redistribution of stresses within actin and/or myosin filaments at the beginning of phase 2. Corresponding redistribution of deformations within the actin filaments leads to non-uniform shifts of the attached myosin heads and changes in the X-ray diffraction pattern. Additionally, we discuss a change in the experimental technique that allows suppression of the elastic vibrations that obscure the contributions of other sources to the superfast tension transient.

An enhanced model of cross-bridge operation with internal elasticity.

A recent study has shown (as reported by Rosenfeld, Eur Biophys J 41:733-753, 2012) that an apparatus consisting of a cycling pump, a lever, and charged beads is able to generate force in accordance with Hill's force-velocity relation. Here, we show that a spring integrated into this microscopic model of a myosin motor allows reproducing, in general terms, the muscle fiber responses to sudden changes in fiber length. The time course of relaxation is governed by the same hindering force that determines the maximal value of muscle contraction velocity. Any single one of the exceptionally simple parts of the proposed model device corresponds to some element of the real myosin head and interacts with any other part in accordance with the laws of Newton, Coulomb, and Hooke. In essence, the model demonstrates that Coulomb repulsion should be understood as the physical source of muscle force. Accordingly, some fictitious master equation with ad hoc postulated rate constants is not needed to explain the essential mechanical characteristics of a muscle. The current model still contains no mechanism that could account for superfast relaxations within periods of about 0.1 ms.

How perfect are you with defective probes? Information on the results of the mini-trial on technical quality assurance during the "Ultraschall 2012" conference in Davos.

This article deals with the technical quality assurance of ultrasound B-systems. As part of a mini-trial during the Dreiländertreffen in Davos "Ultrasound 2012", we addressed the question as to whether physicians can detect faulty probes spontaneously during live scanning B-mode. For this purpose a special diagnostic device had been prepared so that groups of piezoelectric elements in the array were without function. Then the images had to be characterized by test persons without knowledge of the faulty elements. The results show that a deterioration of the image could be detected starting at five disabled elements. Due to the small number of test persons, our statements are only preliminary.

The interrelation between mechanical characteristics of contracting muscle, cross-bridge internal structure, and the mechanism of chemomechanical energy transduction.

The cross-bridge working stroke is regarded as a continuous (without jumps) change of myosin head internal state under the action of a force exerted within the nucleotide-binding site. Involvement of a concept of continuous cross-bridge conformation enables discussion of the nature of the force propelling muscle, and the Coulomb repulsion of like-charged adenosine triphosphate (ATP) fragments ADP(2-) and P (i) (2-) can quite naturally be considered as the source of this force. Two entirely different types of working stroke termination are considered. Along with the fluctuation mechanism, which controls the working stroke duration t (w) at isometric contraction, another interrupt mechanism is initially taken into account. It is triggered when the lever arm shift amounts to the maximal value S ≈ 11 nm, the back door opens, and P(i) crashes out. As a result, t (w) becomes inversely proportional to the velocity v of sliding filaments t (w) ≈ S/v for a wide range of values of v. Principal features of the experimentally observed dependences of force, efficiency, and rate of heat production on velocity and ATP concentration can then be reproduced by fitting a single parameter: the velocity-independent time span t (r) between the termination of the last and beginning of the next working stroke. v becomes the principal variable of the model, and the muscle force changes under external load are determined by variations in v rather than in the tension of filaments. The Boltzmann equation for an ensemble of cross-bridges is obtained, and some collective effects are discussed.

Investigation of the suitability of tissue phantoms for testing the constancy of ultrasonic transducer arrays in quality assurance.

PURPOSE: To ensure high quality ultrasound diagnostics, proper functioning of the devices used is a necessary prerequisite. Ultrasound transducers have proven to be the most failure-prone part of the signal chain. Their technical monitoring is possible in principle with the help of tissue phantoms. The background of the present study is to determine which type of phantoms and which measurement parameters are best suited to a consistency test as part of routine quality assurance of ultrasound imaging systems. MATERIALS AND METHODS: A classic wire-type phantom (ATS Mod. 539, ATS Labs Bridgeport, USA) and a 3 D cyst phantom (TCC, Timelkam, Austria) were used for the studies and comparative tests were conducted between intact transducers and those in which faults had been simulated. The collected measurement data show a relatively large scatter. Therefore, statistical analysis methods were used, and the discrimination analysis proved to be a useful tool. RESULTS: Local failures which arise, e. g. due to the breakdown of individual piezoelectric elements or element groups in the transducer array, can be detected with the help of the gray value targets of the ATS phantom, but only in those cases in which the error-affected sound field part actually overlaps with the target under consideration. The TCC phantom is not suitable for the detection of such errors. Global transducer failures, i. e. those that affect the entire array, can even be detected with both types of phantoms. CONCLUSION: When the emphasis of quality assessment is on the detection of local defects in the array that make up the largest part of the transducer faults, studies with conventional phantoms are only of limited value.

Physical activity and gestational weight gain: a meta-analysis of intervention trials.

BACKGROUND: high gestational weight gain (GWG) has been found to be associated with a number of adverse perinatal and long-term outcomes. OBJECTIVES: we aimed to perform a systematic review and meta-analysis to find out whether physical activity in pregnancy might help avoid high GWG. SEARCH STRATEGY: a literature search in relevant databases and an additional search by hand through bibliographies of various publications were performed. SELECTION CRITERIA: we included randomised controlled trials on healthy women, with increased physical activity as the only intervention. GWG had to be documented for the intervention and control group separately. DATA COLLECTION AND ANALYSIS: two reviewers independently extracted data and performed quality assessment. Data from the included trials were combined using a random-effects model. The effect size was expressed as mean difference (MD). MAIN RESULTS: of 1380 studies identified, 12 trials met the inclusion criteria. In seven trials, GWG was lower in the exercise group compared with the control group, whereas five trials showed a lower GWG in the control groups. The meta-analysis resulted in an MD of GWG of -0.61 (95% CI: -1.17, -0.06), suggesting less GWG in the intervention groups compared with the control groups. We found no indication for publication bias or dose effects. AUTHOR'S CONCLUSIONS: in summary, our analyses suggest that physical activity during pregnancy might be successful in restricting GWG.

High yield expression of biologically active recombinant full length human tuftelin protein in baculovirus-infected insect cells.

Tuftelin is an acidic protein expressed at very early stages of mouse odontogenesis. It was suggested to play a role during epithelial-mesenchymal interactions, and later, when enamel formation commences, to be involved in enamel mineralization. Tuftelin was also detected in several normal soft tissues of different origins and some of their corresponding cancerous tissues. Tuftelin is expressed in low quantities, and undergoes degradation in the enamel extracellular matrix. To investigate the structure and function of tuftelin, the full length recombinant human tuftelin protein was produced. The full length human tuftelin cDNA was cloned using Gateway recombination into the Bac-to-Bac system compatible transfer vector pDest10. This vector adds a hexahistidine tag to the N-terminus of the expressed protein, enabling one-step affinity purification on nickel column. The recombinant human tuftelin protein was transposed into the bacmid and expressed in Spodoptera frugiperda (Sf9) insect cells. The yield of the purified, his-tagged recombinant full length human Tuftelin (rHTuft+) was 5-8 mg/L culture. rHTuft+ was characterized by SDS-PAGE, Western blot, ESI-TOF spectrometry, restriction mapping and MS/MS sequencing. The availability of the purified, full length recombinant human tuftelin protein opened up the possibility to investigate novel functions of tuftelin. Application of rHTuft+ agarose beads onto embryonic mouse mandibular explants caused changes in the surrounding epithelial cells, including morphology, orientation and spatial organization. Further studies using DiI labeling, revealed that rHTuft+, placed on the tooth germ region, brought about recruitment of adjacent embryonic mesenchymal cells. These findings support the hypothesis that tuftelin plays an important role during embryogenesis.

Anaerobic cells of Bacillus cereus F4430/73 respond to low oxidoreduction potential by metabolic readjustments and activation of enterotoxin expression.

In the present study, a food-borne pathogen strain of Bacillus cereus (F4430/73) was anaerobically grown in controlled-batch conditions under low initial oxidoreduction potential (ORP=-148 mV) using hydrogen gas as reducing agent. Its physiological characteristics, including growth, glucose fermentation capacity and enterotoxin production, were compared with anaerobic conditions generated by nitrogen gas (ORP=+ 45 mV). The results showed that low ORP affected growth mainly during the early stages. Maximal specific rates of growth and glucose consumption were reduced, and drastic changes in time profiles of fermentation product concentration were observed. Production of lactate was promoted at the expense of acetate. Nevertheless, low ORP did not affect final biomass yield. Under both ORP conditions, Non-haemolytic enterotoxin (Nhe) was produced early during the exponential growth phase as a first enterotoxin and Haemolysin BL (Hbl) later during the early stationary growth phase as a second enterotoxin. The major effect of low ORP was the strong stimulation of Hbl production and, to a lesser extent, Nhe production. This control was complex, involving different levels of regulation. We discussed the regulation of enterotoxin expression and the involvement of the pleiotropic regulator PlcR.

[Non-thermal non-cavitational effects of ultrasound]. / Nicht-thermische, nicht-kavitative Wirkungen von Ultraschall.

The non-thermal, non-cavitational (NTNC-) effects of medical ultrasound are based essentially on the direct and indirect effects of the sound radiation pressure. This article introduces the biophysics of the basic mechanisms and describes possible clinical implications using selected examples. It has been determined that generally no additional risks ensue through the effects of NTNC used purely for diagnostic purposes. Significant effects can only be detected under the conditions which prevail during therapeutic exposure. The question as to whether the pulse Doppler technique is completely harmless cannot be answered conclusively at this time. The synergetic effects between ultrasound and contrast media have not yet been examined thoroughly.

The human tuftelin gene and the expression of tuftelin in mineralizing and nonmineralizing tissues.

Tuftelin has been suggested to play an important role during the development and mineralization of enamel, but its precise function is still unclear. This article reviews major milestones in the discovery, structural characterization, expression, localization, and conservation of tuftelin in different vertebrate species. It focuses on the structure of the human tuftelin gene, which has recently been deciphered [12]. It describes the exon-intron organization, sizes and structure, the promoter structure, and the newly discovered alternatively spliced human tooth-bud tuftelin mRNA transcripts. It also examines information on the structural motifs in the human-derived tuftelin protein and how they relate to tuftelin from other species. It reviews our recent results on the transcription of tuftelin mRNA and protein expression in several nonmineralizing soft tissues, using reverse-transcription polymerase chain reaction (RT-PCR) followed by DNA cloning and sequencing, indirect immunohistochemistry, immunohistochemistry combined with confocal microscopy, and in situ hybridization. These results and earlier Northern blot results show that tuftelin, in addition to being expressed in the developing and mineralizing tooth, is also expressed in several nonmineralizing soft tissues, suggesting that tuftelin has a universal function and/or a multifunctional role.