[Application of single anterior teeth defect with computer-aided design and computer-aided manufacturing polymethyl methacrylate single-retainer resin-bonded fixed dental prosthesis in children].

Objective: To explore the clinical effect of computer-aided design and computer-aided manufacturing (CAD/CAM) polymethyl methacrylate (PMMA) single-retainer resin-bonded fixed dental prosthesis (RBFDP) for single anterior teeth defect. Methods: A total of 14 children between 10-14 years old (male 8, female 6) who visited the Department of Pediatric Dentistry, School of Stomatology, The Fourth Military Medical University from March to December 2022 with single anterior teeth loss were enrolled in this study. The intraoral scanner was used to obtain their digital impressions, and then the data were imported into CAD software. The single-retainer RBFDP was designed by the CAD software and was manufactured by milling equipment using CAD/CAM PMMA disk. The prosthesis was then tried-in and bonded to the abutment teeth with resin cement and evaluated in a 12 month follow-up observation. The marginal discoloration, marginal adaptation, color match, secondary caries, the occurrence of fractures and loose of abutment tooth were examined on the basis of the modified United States Public Health Services evaluation system. The evaluation was divided into three scores, in which score A indicated ideal restoration effect, score B means that the restoration effect was acceptable (evaluation of restoration integrity, loose of abutment teeth and secondary caries excluded), and score C indicates that the restoration effect is not good. Results: All the 14 CAD/CAM PMMA single-retainer RBFDP had good marginal adaptation and color match with no marginal discoloration, no secondary caries, no fracture of restorations and no abnormal loose of the abutment teeth. All of the six criteria achieved score A evaluation after a three month follow-up observation. One restoration was classified as score B for fracture after a six month follow-up observation, while two restoration were classified as score B for marginal discoloration after 12 month follow-up observation. Conclusions: The CAD/CAM PMMA single-retainer RBFDP was clinically effective in restoration of single anterior teeth defect in children.

Implementation of leakage elimination operators and subspace protection.

Decoherence-induced leakage errors can potentially damage physical or logical qubits embedded in a subspace of the entire Hilbert space by coupling them to other system levels. Here we report the first experimental implementation of Leakage Elimination Operators (LEOs) that aims to reduce this undermining. LEOs are a type of dynamical decoupling control that have been previously introduced to counteract leakage from a chosen subspace into the rest of a Hilbert space, and have been widely explored theoretically. Different from other error correction strategies, LEOs are compatible with any gate sequence in a code space, and thus, compatible with universal quantum computation. Using IBM's cloud quantum computer (QC), we design three potentially applicable examples of subspaces in two- and three-qubit Hilbert spaces and derive the explicit forms of the corresponding LEOs for these subspaces. For the first time, we experimentally demonstrate that these LEOs significantly suppress leakage. The results also show that the LEO time-scale condition can be satisfied with noise in the IBM's cloud QC and pave a way for quantum setups to get rid of leakage trouble.

Site-specific function and regulation of Osterix in tooth root formation.

Congenital diseases of tooth roots, in terms of developmental abnormalities of short and thin root phenotypes, can lead to loss of teeth. A more complete understanding of the genetic molecular pathways and biological processes controlling tooth root formation is required. Recent studies have revealed that Osterix (Osx), a key mesenchymal transcriptional factor participating in both the processes of osteogenesis and odontogenesis, plays a vital role underlying the mechanisms of developmental differences between root and crown. During tooth development, Osx expression has been identified from late embryonic to postnatal stages when the tooth root develops, particularly in odontoblasts and cementoblasts to promote their differentiation and mineralization. Furthermore, the site-specific function of Osx in tooth root formation has been confirmed, because odontoblastic Osx-conditional knockout mice demonstrate primarily short and thin root phenotypes with no apparent abnormalities in the crown (Journal of Bone and Mineral Research 30, 2014 and 742, Journal of Dental Research 94, 2015 and 430). These findings suggest that Osx functions to promote odontoblast and cementoblast differentiation and root elongation only in root, but not in crown formation. Mechanistic research shows regulatory networks of Osx expression, which can be controlled through manipulating the epithelial BMP signalling, mesenchymal Runx2 expression and cellular phosphorylation levels, indicating feasible routes of promoting Osx expression postnatally (Journal of Cellular Biochemistry 114, 2013 and 975). In this regard, a promising approach might be available to regenerate the congenitally diseased root and that regenerative therapy would be the best choice for patients with developmental tooth diseases.

Anticandidal activity and biocompatibility of a rechargeable antifungal denture material.

OBJECTIVES: Candida-associated denture stomatitis is a recurrent and debilitating oral mucosal disease. Development of anticandidal denture materials represents a promising strategy to manage this condition. We have previously shown that miconazole incorporated in methacrylic acid (MAA) copolymerized diurethane dimethacrylate (UDMA) denture materials has long-term anticandidal activity. In this study, we examined the ability of culture medium conditioned with drug-free- or miconazole-MAA-UDMA discs to prevent Candida infection in an in vitro oral epithelial cell/Candida albicans coculture system. MATERIALS AND METHODS: Candida albicans (C. albicans)-induced OKF6/TERT-2 cell damage was quantified by the release of lactate dehydrogenase from epithelial cells, cytokine production was quantified using protein cytokine arrays, and the expression of C. albicans genes was measured by RT-qPCR. RESULTS: Candida albicans had limited growth with altered expression levels of secreted aspartyl proteinase-2 and -5 in culture medium conditioned by miconazole-MAA-UDMA discs. Significantly, the ability of C. albicans to induce oral epithelial cell damage and trigger epithelial proinflammatory cytokine production was also inhibited by miconazole disc conditioned media. CONCLUSION: Miconazole released from MAA-UDMA denture materials effectively prevents the development of candidal infection in an in vitro oral epithelial system. Further characterization of this drug-rechargeable denture material is warranted.

The association of preterm birth and small birthweight for gestational age on childhood disability screening using the Ten Questions Plus tool in rural Sarlahi district, southern Nepal.

CONTEXT: The Ten Questions tool was developed in 1984 as a low-cost, simple screen for childhood disability and referral for diagnosis in low-resource settings, and its use in Nepal has not been previously evaluated. Preterm birth and intrauterine growth restriction are potential risk factors for child disability and loss of developmental potential, but there are few studies examining this relationship from developing settings. OBJECTIVE: To examine the associations of small for gestational age and preterm birth as predictors of Ten Questions Plus positivity. DESIGN, SETTING AND PARTICIPANTS: The Ten Questions Plus questionnaire was administered to caregivers of 680 children between 2 and 5 years of age from August 2007 to March 2008 in rural Sarlahi, southern Nepal. Participants had previously been enrolled in a randomized trial of chlorhexidine cleansing at birth. At 1 month of age, children were then enrolled into a randomized 2 × 2 factorial trial of daily iron and zinc supplementation between October 2001 and January 2006. INTERVENTION: None. MAIN OUTCOME MEASURE: Positive screen on the Ten Questions Plus tool defined as a positive response to one or more questions. RESULTS: Of preterm children, 37 (33.6%) had a positive response to at least one question on the Ten Questions Plus and were considered at risk for disability. One hundred and seventy term children (29.8%) were at risk for disability. CONCLUSIONS: The Ten Questions Plus tool can be used in this rural Nepali setting to identify children at increased risk for mental and physical disability to be targeted for further examination. The prevalence of parent-reported disabilities is high in this population (almost one-third of children); children who are both preterm and small-for-gestational age are at increased risk for motor milestone delay, reported learning difficulty, speech and behavioural problems. Intrauterine growth restriction may affect child development and result in disabilities later in childhood.

Micro-computerized tomography analysis of alveolar bone loss in ligature- and nicotine-induced experimental periodontitis in rats.

BACKGROUND AND OBJECTIVE: Nicotine reportedly is a risk factor for periodontitis, but accurate data regarding nicotine-induced alveolar bone loss is lacking. The aim of this study was to quantitatively assess alveolar bone loss in ligature- and nicotine-induced periodontitis in rats using micro-computerized tomography (micro-CT). MATERIAL AND METHODS: Thirty-six adult male rats were treated by placing silk ligatures around the cervixes of the right second maxillary molar; the contralateral tooth was untreated. After ligation, the animals were randomly divided into three groups: group A received intraperitoneal injections of saline solution, group B received 0.83 mg of nicotine/kg/d, and group C received 1.67 mg of nicotine/kg/d. Six animals in each group were killed on days 14 and 28 after ligature placement, and then micro-CT examinations were conducted. RESULTS: In all groups, bone mineral density (BMD), bone volume fraction (BVF), trabecular number (Tb.N) and trabecular thickness (Tb.Th) values of the ligated sides were significantly lower than those of the unligated sides (p < 0.001), whereas alveolar bone height loss (ABHL) and trabecular separation (Tb.Sp) of the ligated sides were significantly higher than those of the unligated sides (p < 0.001). Compared with the control group, nicotine administration increased the ABHL value and decreased the BMD, BVF and Tb.Th values of both sides in a dose-dependent manner (p < 0.05). CONCLUSION: Our results confirmed that ligature could cause significant loss in the trabecula of alveolar bone, and daily administration of nicotine resulted in further bone loss and microstructure deterioration.

Activation of GABAergic neurons following tooth pulp stimulation.

The functional impact of GABA (gamma-aminobutyric acid)ergic neurons in nociceptive transmission of the spinal trigeminal nucleus is not fully established. Using both the glutamic acid decarboxylase (GAD)(67)-green fluorescence protein (GFP) knock-in mouse and the tooth pulp stimulation model, we performed double-immunofluorescent histochemistry to determine the characteristics of GABAergic neuron activation in the spinal trigeminal nucleus. The number of Fos-positive GABAergic neuronal profiles was significantly increased 2 hrs after tooth pulp stimulation. The Fos/GFP double-labeled neurons were mainly present in superficial laminae of the spinal trigeminal subnucleus interpolaris-caudalis transition (Vi/Vc) and subnucleus caudalis (Vc) on the side ipsilateral to the stimulation. Subsequently, the number of double-labeled neurons decreased gradually and became comparable with that of the controls by 48 hrs. Our results provide direct morphological evidence that a subset of GABAergic neurons in the spinal trigeminal system was activated during tooth pulp stimulation.

Holonomic quantum computation in decoherence-free subspaces.

We show how to realize, by means of non-Abelian quantum holonomies, a set of universal quantum gates acting on decoherence-free subspaces and subsystems. In this manner we bring together the quantum coherence stabilization virtues of decoherence-free subspaces and the fault tolerance of all-geometric holonomic control. We discuss the implementation of this scheme in the context of quantum information processing using trapped ions and quantum dots.

Quantum phase transitions and bipartite entanglement.

We develop a general theory of the relation between quantum phase transitions (QPTs) characterized by nonanalyticities in the energy and bipartite entanglement. We derive a functional relation between the matrix elements of two-particle reduced density matrices and the eigenvalues of general two-body Hamiltonians of d-level systems. The ground state energy eigenvalue and its derivatives, whose nonanalyticity characterizes a QPT, are directly tied to bipartite entanglement measures. We show that first-order QPTs are signaled by density matrix elements themselves and second-order QPTs by the first derivative of density matrix elements. Our general conclusions are illustrated via several quantum spin models.

Dressed qubits.

Inherent gate errors can arise in quantum computation when the actual system Hamiltonian or Hilbert space deviates from the desired one. Two important examples we address are spin-coupled quantum dots in the presence of spin-orbit perturbations to the Heisenberg exchange interaction, and off-resonant transitions of a qubit embedded in a multilevel Hilbert space. We propose a "dressed qubit" transformation for dealing with such inherent errors. Unlike quantum error correction, the dressed qubit method does not require additional operations or encoding redundancy, is insensitive to error magnitude, and imposes no new experimental constraints.

Efficient universal leakage elimination for physical and encoded qubits.

Decoherence-induced leakage errors can couple a physical or encoded qubit to other levels, thus potentially damaging the qubit. They can therefore be very detrimental in quantum information processing and require special attention. Here we present a general method for removing such errors by using simple decoupling and recoupling pulse sequences. The proposed gates are experimentally accessible in a variety of promising quantum-computing proposals.

Polynomial-time simulation of pairing models on a quantum computer.

We propose a polynomial-time algorithm for simulation of the class of pairing Hamiltonians, e.g., the BCS Hamiltonian, on an NMR quantum computer. The algorithm adiabatically finds the low-lying spectrum in the vicinity of the gap between the ground and the first excited states and provides a test of the applicability of the BCS Hamiltonian to mesoscopic superconducting systems, such as ultrasmall metallic grains.

Creating decoherence-free subspaces using strong and fast pulses.

A decoherence-free subspace (DFS) isolates quantum information from deleterious environmental interactions. We give explicit sequences of strong and fast ["bang-bang" (BB)] pulses that create the conditions allowing for the existence of DFSs that support scalable, universal quantum computation. One such example is the creation of the conditions for collective decoherence, wherein all system particles are coupled in an identical manner to their environment. The BB pulses needed for this are generated using only the Heisenberg exchange interaction. In conjunction with previous results, this shows that Heisenberg exchange is by itself an enabler of universal fault-tolerant quantum computation on DFSs.

Reducing constraints on quantum computer design by encoded selective recoupling.

The requirement of performing both single-qubit and two-qubit operations in the implementation of universal quantum logic often leads to very demanding constraints on quantum computer design. We show here how to eliminate the need for single-qubit operations in a large subset of quantum computer proposals: those governed by isotropic and XXZ, XY-type anisotropic exchange interactions. Our method employs an encoding of one logical qubit into two physical qubits, while logic operations are performed using an analogue of the NMR selective recoupling method.

Current role of endomyocardial biopsy in the management of dilated cardiomyopathy and myocarditis.

Dilated cardiomyopathy is a common cause of congestive heart failure. Despite a thorough cardiovascular evaluation, a specific cause is frequently not found, and the disorder then is considered idiopathic. Endomyocardial biopsy (EMB) may yield diagnostic and prognostic information in patients with idiopathic dilated cardiomyopathy; however, the yield of useful information with this procedure among patients with heart failure is low, and the risks of occasional cardiac perforation and death further limit its use. Recent publications in the field of myocarditis and cardiomyopathy have renewed interest in the use of EMB in select patients to diagnose specific and potentially treatable myocarditides; however, the role of EMB in the work-up of patients with dilated cardiomyopathy is not well defined. In this article, we discuss the risks and utility of EMB in the management of patients with dilated cardiomyopathy and specific myocarditides.

Number needed to treat: caveat emptor.

Number needed to treat (NNT)-the inverse of the absolute risk reduction resulting from an intervention-was introduced as a yardstick to describe the harm as well as the benefit of therapeutic maneuvers. Analysis using NNT works well when comparing two or more interventions that have their impact over the same period of time in similar populations or patients. Under other conditions, however, analysis based on NNT can produce results that diverge widely from the impact that the interventions can be expected to have on risk of death. This can happen either for entire populations or for an individual when comparing NNTs for interventions which have their effects on different subsets of the population or when comparing interventions which have their effects over different periods of time. We demonstrate how this can occur by comparing the NNTs and effect of intervention on deaths in a population for automatic implantable cardioverter defibrillators (AICDs), heart transplantation, and cholesterol lowering through nutritional intervention with plant stanol ester.

Efficient femtosecond optical parametric generator with a birefringent delay compensator.

A novel method based on a birefringent crystal is presented to compensate for the group-velocity mismatch between a femtosecond pulsed pump and the signal or idler in an optical parametric generator (OPG). With a thin calcite plate inserted between two beta-barium borate crystals for synchronization, an efficient four-pass OPG pumped by a frequency-doubled ~200-fs Ti:sapphire laser is obtained. The conversion efficiency is almost doubled throughout the whole tunable region compared with a conventional OPG pumped at the same power density, indicating that the total conversion efficiency of femtosecond optical parametric amplifier system can be raised significantly by use of this new four-pass OPG to generate the seed.

Preventing heart disease and stroke: messages from the United States.

After rising steeply in the United States for the first two-thirds of the century, mortality from cardiovascular disease in the United States has declined sharply in the past 40 years. In addition to advances in the treatment of clinically manifest cardiovascular disease, the decline in deaths from cardiovascular disease results from a decline in tobacco consumption, decreased serum cholesterol levels, and improved control of hypertension. However, recent changes in risk factor levels are a cause for concern. These changes include sharp increases in smoking among young adults; increases in obesity and type II diabetes; a decrease in physical activity; and, a decline in hypertension control. In order to reduce the burden of cardiovascular disease in Olmsted County, Minnesota, we organized CardioVision 2020 (www.cardiovision2020.org). CardioVision 2020 is a population-based, multi-faceted, collaborative project based on personal commitment and community action.