Effect of 2% Chlorhexidine on Shear Bond Strength of Composite Resins to Dentin

Abstract Background and Aim: Intracanal medicaments can affect the bond strength of composite to dentin. The aim of this study was to evaluate the effect of 2% chlorhexidine (CHX) gel as an intracanal medicament on shear bond strength of three different composite resins to dentin. Materials and Methods: In this in-vitro study, 60 intact extracted human premolars were utilized. Each tooth was sectioned vertically and dentin of the buccal surface was exposed. Then, specimens were divided into six groups of 10 teeth. In groups 1-3, dentin was exposed to CHX and in groups 4-6, dentin was exposed to saline. All prepared surfaces were rinsed with distilled water and dentin bonding agent specific for each composite was applied on the dentin surfaces. Z100, Z350 and P90 composites were applied to the treated surfaces and cured. The shear bond strength was recorded in Newtons and converted to MPa. Data were analyzed using the Kruskal-Wallis and Dunn tests. Results: The lowest mean shear bond strength was reported for normal saline and Z100 composite group (18.47 MPa) and the highest for CHX and Z350 group (42.26 MPa). No statistically significant difference in bond strength values was found between normal saline and CHX groups (P>0.05). There was a significant difference in bond strength values of different composite resins in normal saline (P<0.05) and also in CHX groups (P<0.05). Conclusion: Application of 2% chlorhexidine gel slightly but not significantly increases the mean shear bond strength of composite to dentin. The type of composite influences the shear bond strength to denti

The effect of endurance training on the level of tissue IL-6 and VEGF in mice with breast cancer

زمینه و هدف: تمرینات ورزش پتانسیلی در جهت پیشگیری از سرطان پستان دارد. هدف پژوهش حاضر بررسی اثرات پیشگیری و کمک درمانی تمرینات ورزشی بر سایتوکاین های درگیر در رگ زایی تومور سرطان پستان وابسته به گیرنده استروژن می باشد. روش بررسی: در این مطالعه مداخله ای 50 سر موش بالب سی ماده به طور تصادفی در چهار گروه قرار گرفتند. پس از آشناسازی با محیط دو گروه از موش ها به مدت 8 هفته تمرین استقامتی تداومی را انجام دادند و سپس سلول های سرطانی وابسته به استروژن (MC4-L2) به همه موش ها تزریق گردید. پس از آن یک گروه از موش های تمرین کرده و یک گروه از موش های تمرین نکرده به مدت 6 هفته، 5 روز در هفته تمرینات استقامتی را انجام دادند. حجم تومور به صورت هفتگی با کولیس دیجیتالی اندازه گیری شد. در پایان موش ها قربانی شدند و بافت تومور برداشته و سطوح سایتوکاین های اینترلوکین 6 (IL-6) و فاکتور رشد اپی تلیال عروق (VEGF) با روش الایزا اندازه گیری شد. یافته ها: بین گروه ها در میزان مقادیر IL-6 و VEGF و میزان رشد تومور تفاوت معناداری وجود داشت (001/0PP). نتیجه گیری: با توجه به افت مقادیر IL-6 و VEGF در گروه هایی که قبل از سرطانی شدن و پس از سرطانی شدن تمرینات ورزشی را انجام دادند؛ می توان گفت که تمرینات ورزشی علاوه بر نقش پیشگیرانه بسیار موثر، دارای نقش درمانی در تومورهای وابسته به گیرنده استروژن نیز می باشند

Symmetry‐Induced Selective Excitation of Topological States in Su–Schrieffer–Heeger Waveguide Arrays

The investigation of topological state transition in carefully designed photonic lattices is of high interest for fundamental research, as well as for applied studies such as manipulating light flow in on-chip photonic systems. Herein, the topological phase transition between symmetric topological zero modes (TZM) and antisymmetric TZMs in Su–Schrieffer–Heeger mirror symmetric waveguides is reported. The transition of TZMs is realized by adjusting the coupling ratio between neighboring waveguide pairs, which is enabled by selective modulation of the refractive index in the waveguide gaps. Bidirectional topological transitions between symmetric and antisymmetric TZMs can be achieved with proposed switching strategy. Selective excitation of topological edge mode is demonstrated owing to the symmetry characteristics of the TZMs. The flexible manipulation of topological states is promising for on-chip light flow control and may spark further investigations on symmetric/antisymmetric TZM transitions in other photonic topological frameworks

Symmetry induced selective excitation of topological states in SSH waveguide arrays

The investigation of topological state transition in carefully designed photonic lattices is of high interest for fundamental research, as well as for applied studies such as manipulating light flow in on-chip photonic systems. Here, we report on topological phase transition between symmetric topological zero modes (TZM) and antisymmetric TZMs in Su-Schrieffer-Heeger (SSH) mirror symmetric waveguides. The transition of TZMs is realized by adjusting the coupling ratio between neighboring waveguide pairs, which is enabled by selective modulation of the refractive index in the waveguide gaps. Bi-directional topological transitions between symmetric and antisymmetric TZMs can be achieved with our proposed switching strategy. Selective excitation of topological edge mode is demonstrated owing to the symmetry characteristics of the TZMs. The flexible manipulation of topological states is promising for on-chip light flow control and may spark further investigations on symmetric/antisymmetric TZM transitions in other photonic topological frameworks

Coagulase gene polymorphism of Staphylococcus aureus isolated from clinical and sub-clinical bovine mastitis in Isfahan and Chaharmahal va Bakhtiari provinces of Iran

Mastitis is a common disease in dairy cattle and is an inflammatory response of the breast tissue to bacterial attack to this tissue. Mastitis causes considerable loss to the dairy industry, among the several bacterial pathogens that can cause mastitis; Staphylococcus aureus is probably the most lethal agent because it causes chronic and deep infection in the mammary glands that is extremely difficult to cure. Several virulence factors including coagulase gene are produced by S. aureus and may contribute to its pathogenicity. This study was conducted to investigate the coagulase gene polymorphism of S. aureus isolated from clinical and sub-clinical bovine mastitis milk samples in Isfahan and Chaharmahal va Bakhtiari provinces of Iran. Amplification of the coagulase gene from 86 S. aureus strains isolates by specific primers showed 31 specimens contained 970 bp fragment, and 11 strains contained 730 bp fragment relevant to coa gene (coagulase) in PCR. After enzymatic digestion with AluI, 31 specimens contained three bands: 320, 490, and 160 bp (genotype I) and 11 specimens contained two bands: 490 and 240 bp (genotype VIII) in the RFLP

Mass Spectrometry, Structural Analysis, and Anti-Inflammatory Properties of Photo-Cross-Linked Human Albumin Hydrogels

Albumin-based hydrogels offer unique benefits such as biodegradability and high binding affinity to various biomolecules, which make them suitable candidates for biomedical applications. Here, we report a non-immunogenic photocurable human serum-based (HSA) hydrogel synthesized by methacryloylation of human serum albumin by methacrylic anhydride (MAA). We used matrix-assisted laser desorption ionization-time-of-flight mass spectrometry, liquid chromatography-tandem mass spectrometry, as well as size exclusion chromatography to evaluate the extent of modification, hydrolytic and enzymatic degradation of methacrylated albumin macromer and its cross-linked hydrogels. The impacts of methacryloylation and cross-linking on alteration of inflammatory response and toxicity were evaluated in vitro using brain-derived HMC3 macrophages and Ex-Ovo chick chorioallantoic membrane assay. Results revealed that the lysines in HSA were the primary targets reacting with MAA, though modification of cysteine, threonine, serine, and tyrosine, with MAA was also confirmed. Both methacrylated HSA and its derived hydrogels were nontoxic and did not induce inflammatory pathways, while significantly reducing macrophage adhesion to the hydrogels; one of the key steps in the process of foreign body reaction to biomaterials. Cytokine and growth factor analysis showed that albumin-based hydrogels demonstrated anti-inflammatory response modulating cellular events in HMC3 macrophages. Ex-Ovo results also confirmed the biocompatibility of HSA macromer and hydrogels along with slight angiogenesis-modulating effects. Photocurable albumin hydrogels may be used as a non-immunogenic platform for various biomedical applications including passivation coatings

HAAD: A Quick Algorithm for Accurate Prediction of Hydrogen Atoms in Protein Structures

Hydrogen constitutes nearly half of all atoms in proteins and their positions are essential for analyzing hydrogen-bonding interactions and refining atomic-level structures. However, most protein structures determined by experiments or computer prediction lack hydrogen coordinates. We present a new algorithm, HAAD, to predict the positions of hydrogen atoms based on the positions of heavy atoms. The algorithm is built on the basic rules of orbital hybridization followed by the optimization of steric repulsion and electrostatic interactions. We tested the algorithm using three independent data sets: ultra-high-resolution X-ray structures, structures determined by neutron diffraction, and NOE proton-proton distances. Compared with the widely used programs CHARMM and REDUCE, HAAD has a significantly higher accuracy, with the average RMSD of the predicted hydrogen atoms to the X-ray and neutron diffraction structures decreased by 26% and 11%, respectively. Furthermore, hydrogen atoms placed by HAAD have more matches with the NOE restraints and fewer clashes with heavy atoms. The average CPU cost by HAAD is 18 and 8 times lower than that of CHARMM and REDUCE, respectively. The significant advantage of HAAD in both the accuracy and the speed of the hydrogen additions should make HAAD a useful tool for the detailed study of protein structure and function. Both an executable and the source code of HAAD are freely available at http://zhang.bioinformatics.ku.edu/HAAD

Phase transition in Random Circuit Sampling

Quantum computers hold the promise of executing tasks beyond the capability of classical computers. Noise competes with coherent evolution and destroys long-range correlations, making it an outstanding challenge to fully leverage the computation power of near-term quantum processors. We report Random Circuit Sampling (RCS) experiments where we identify distinct phases driven by the interplay between quantum dynamics and noise. Using cross-entropy benchmarking, we observe phase boundaries which can define the computational complexity of noisy quantum evolution. We conclude by presenting an RCS experiment with 70 qubits at 24 cycles. We estimate the computational cost against improved classical methods and demonstrate that our experiment is beyond the capabilities of existing classical supercomputers

Global Mortality Estimates for the 2009 Influenza Pandemic from the GLaMOR Project: A Modeling Study

Background: Assessing the mortality impact of the 2009 influenza A H1N1 virus (H1N1pdm09) is essential for optimizing public health responses to future pandemics. The World Health Organization reported 18,631 laboratory-confirmed pandemic deaths, but the total pandemic mortality burden was substantially higher. We estimated the 2009 pandemic mortality burden through statistical modeling of mortality data from multiple countries. Methods and Findings: We obtained weekly virology and underlying cause-of-death mortality time series for 2005–2009 for 20 countries covering ~35% of the world population. We applied a multivariate linear regression model to estimate pandemic respiratory mortality in each collaborating country. We then used these results plus ten country indicators in a multiple imputation model to project the mortality burden in all world countries. Between 123,000 and 203,000 pandemic respiratory deaths were estimated globally for the last 9 mo of 2009. The majority (62%–85%) were attributed to persons under 65 y of age. We observed a striking regional heterogeneity, with almost 20-fold higher mortality in some countries in the Americas than in Europe. The model attributed 148,000–249,000 respiratory deaths to influenza in an average pre-pandemic season, with only 19% in person

Suppressing quantum errors by scaling a surface code logical qubit

Practical quantum computing will require error rates that are well below what is achievable with physical qubits. Quantum error correction offers a path to algorithmically-relevant error rates by encoding logical qubits within many physical qubits, where increasing the number of physical qubits enhances protection against physical errors. However, introducing more qubits also increases the number of error sources, so the density of errors must be sufficiently low in order for logical performance to improve with increasing code size. Here, we report the measurement of logical qubit performance scaling across multiple code sizes, and demonstrate that our system of superconducting qubits has sufficient performance to overcome the additional errors from increasing qubit number. We find our distance-5 surface code logical qubit modestly outperforms an ensemble of distance-3 logical qubits on average, both in terms of logical error probability over 25 cycles and logical error per cycle ($2.914\%\pm 0.016\%$ compared to $3.028\%\pm 0.023\%$). To investigate damaging, low-probability error sources, we run a distance-25 repetition code and observe a $1.7\times10^{-6}$ logical error per round floor set by a single high-energy event ($1.6\times10^{-7}$ when excluding this event). We are able to accurately model our experiment, and from this model we can extract error budgets that highlight the biggest challenges for future systems. These results mark the first experimental demonstration where quantum error correction begins to improve performance with increasing qubit number, illuminating the path to reaching the logical error rates required for computation.Comment: Main text: 6 pages, 4 figures. v2: Update author list, references, Fig. S12, Table I