Realizing quantum speedup for practically relevant, computationally hard problems is a central challenge in quantum information science. Using Rydberg atom arrays with up to 289 qubits in two spatial ...dimensions, we experimentally investigate quantum algorithms for solving the Maximum Independent Set problem. We use a hardware-efficient encoding associated with Rydberg blockade, realize closed-loop optimization to test several variational algorithms, and subsequently apply them to systematically explore a class of graphs with programmable connectivity. We find the problem hardness is controlled by the solution degeneracy and number of local minima, and experimentally benchmark the quantum algorithm's performance against classical simulated annealing. On the hardest graphs, we observe a superlinear quantum speedup in finding exact solutions in the deep circuit regime and analyze its origins.
Chronic HBV infection is a global public health burden estimated to impact nearly 300 million persons worldwide. Despite the advent of potent antiviral agents that effectively suppress viral ...replication, HBV cure remains difficult to achieve because of the persistence of covalently closed circular DNA (cccDNA), HBV‐DNA integration into the host genome, and impaired immune response. Indefinite treatment is necessary for most patients to maintain level of viral suppression. The success of direct‐acting antivirals (DAAs) for hepatitis C treatment has rejuvenated the search for a cure for chronic hepatitis B (CHB), though an HBV cure likely requires an additional layer: immunomodulators for restoration of robust immune responses. DAAs such as entry inhibitors, capsid assembly modulators, inhibitors of subviral particle release, cccDNA silencers, and RNA interference molecules have reached clinical development. Immunomodulators, namely innate immunomodulators (Toll‐like receptor agonists), therapeutic vaccines, checkpoint inhibitors, and monoclonal antibodies, are also progressing toward clinical development. The future of the HBV cure possibly lies in triple combination therapies with concerted action on replication inhibition, antigen reduction, and immune stimulation. Many obstacles remain, such as overcoming translational failures, choosing the right endpoint using the right biomarkers, and leveraging current treatments in combination regimens to enhance response rates. This review gives an overview of the current therapies for CHB, HBV biomarkers used to evaluate treatment response, and development of DAAs and immune‐targeting drugs and discusses the limitations and unanswered questions on the journey to an HBV cure.
One of the key issues with geological sequestration of carbon dioxide in coal seams is change of permeability caused by carbon dioxide (CO2) injection, and especially any resulting reduction in ...injectivity. Injection causes changes in pressure and effective stress, with further changes caused by coal matrix swelling associated with adsorption of CO2. In this paper we aim to study how the change in effective stress and coal swelling may influence the gas permeability in brown coal using natural coal and reconstituted coal specimens. Tests were conducted at different confining pressures to represent conditions at different depths. Different gas injection pressures were also employed at each confining stress stage. The test results clearly depicted an exponential reduction of coal permeability to CO2 gas when effective stress increases. Based on the experimental results, an empirical correlation to represent the effect of stress on permeability was developed. The results also showed that increase in pore pressure can induce further swelling of the coal specimens, and this can lead to further decrease in permeability which can have important impact on field injectivity. Test results for natural brown coal specimens were compared with results of tests on reconstituted coal specimens made from compaction of coal particles obtained from crushing of blocks of natural coal. Observed permeability behaviour of gas in reconstituted coal was similar to the natural coal specimen permeability trend, when effective stress increases.
Directions of rectification and photocurrent in a ferroelectric BiFeO3 crystal can be switched by applying high‐voltage pulses at room temperature. The switching is highly repeatable though cycling ...and also stable with time. This switchable photocurrent and diode effect results from the combination of polarization flipping and electromigration of oxygen vacancies.
Aim
Quality of life (QoL) and functional outcomes are at risk of being impaired after rectal surgery, but there has been no large prospective study to thoroughly assess QoL according to surgical ...approach. We have investigated the impact of laparoscopic and robotic total mesorectal excision (TME) on QoL and functional outcomes.
Method
Patients undergoing laparoscopic or robotic TME for rectal cancer between 2009 and 2013 were prospectively included in this questionnaire‐based survey of QoL together with variations in urinary and sexual function. A propensity score analysis was retrospectively conducted to compare outcomes between groups in a cohort matched 1:1 for age, sex, body mass index, preoperative chemoradiation status and tumour height. The survey was performed preoperatively and 3, 6 and 12 months after surgery.
Results
Global health status/QoL was similar between the two groups for 130 matched pairs, but the robotic group showed better role, emotional and social functioning and experienced less fatigue and financial difficulty. International Prostatic Symptom Scores in men increased postoperatively, with significantly less impairment in the robotic group at 6 months. These scores were comparable to preoperative scores at 6 months in the robotic group and at 12 months in the laparoscopic group. Of 48 sexually active men in each group, International Index of Erectile Function‐5 scores decreased postoperatively, returning to preoperative levels at 6 months in the robotic group and at 12 months in the laparoscopic groups.
Conclusion
The robotic approach for TME was associated with less impairment of urinary and sexual function; QoL was comparable to the laparoscopic approach.
The ability to control electronic states at the nanoscale has contributed to our modern understanding of condensed matter. In particular, quantum dot circuits represent model systems for the study of ...strong electronic correlations, epitomized by the Kondo effect. We use circuit quantum electrodynamics architectures to study the internal degrees of freedom of this many-body phenomenon. Specifically, we couple a quantum dot to a high-quality-factor microwave cavity to measure with exceptional sensitivity the dot's electronic compressibility, that is, its ability to accommodate charges. Because electronic compressibility corresponds solely to the charge response of the electronic system, it is not equivalent to the conductance, which generally involves other degrees of freedom such as spin. Here, by performing dual conductance and compressibility measurements in the Kondo regime, we uncover directly the charge dynamics of this peculiar mechanism of electron transfer. The Kondo resonance, visible in transport measurements, is found to be 'transparent' to microwave photons trapped in the high-quality cavity, thereby revealing that (in such a many-body resonance) finite conduction is achieved from a charge frozen by Coulomb interaction. This freezing of charge dynamics is in contrast to the physics of a free electron gas. We anticipate that the tools of cavity quantum electrodynamics could be used in other types of mesoscopic circuits with many-body correlations, providing a model system in which to perform quantum simulation of fermion-boson problems.
Periodontitis is chronic inflammation of the periodontium caused by the host's inflammatory response to plaque biofilm, which destroys tooth‐supporting soft and hard tissues. Periodontitis is a ...complex disease that involves interactions among three main features – microbial challenge, the host immune response, and environmental and genetic risk factors – in its pathogenesis. Although periodontitis has been regarded as the result of hyperimmune or hyperinflammatory responses to plaque bacteria, recent studies indicate that periodontal pathogens are rather poor activators and/or suppressors of the host immune response. This raises the question of how periodontal pathogens cause inflammation. To resolve this issue, in the present review we propose that bacterial invasion into gingival tissue is a key event in the initiation of periodontitis and that the persistence of these bacteria within host tissue results in chronic inflammation. In support of this hypothesis, we present the ways in which microbial, environmental and genetic risk factors contribute to bacterial invasion. It is hoped that the current model will instigate active discussion and new research to complete the puzzle of this complex disease process.
Abstract Introduction Preeclampsia (PE) is a leading cause of maternal and neonatal mortality and morbidity worldwide. However, the pathophysiology of this disease is not yet fully understood. MiRNA ...plays an important role in post-transcriptional gene regulation. Recent studies have suggested that dysregulation of miRNAs in placental tissue is involved in the pathogenesis of PE. Therefore, we investigated miRNA profiles in PE placenta to understand the miRNA function in PE pathogenesis. Methods MiRNA profiling was performed in 20 formalin-fixed and paraffin-embedded samples (10 placentas from severe PE and 10 from a control group). We used a hybridization-based microarray with a PNA-probe comprised of 158 miRNAs. Results Thirteen miRNAs (miR-92b, miR-197, miR-342-3p, miR-296-5p, miR-26b, miR-25, miR-296-3p, miR-26a, miR-198, miR-202, miR-191, miR-95, and miR-204) were significantly overexpressed and two miRNAs (miR-21 and miR-223) were underexpressed in PE compared with the control group. Among 15 differentially expressed miRNAs, miR-26b, miR-296-5p, and miR-223 were found to be consistent with results from previous studies. We identified 893 genes that were predicted by at least three of four computational algorithms. Target genes participated in several signaling pathways, adherens junction, focal adhesion, and regulation of the actin cytoskeleton. Conclusions Several miRNAs are found to be dysregulated in placentas of PE patients and they seem to be closely associated with the early pathogenesis of PE. Further study is necessary to develop tools for early detection and management.
The stress–strain relationship between ferrite and martensite phases in the commercial dual-phase DP980 steel was studied using in situ neutron diffraction and the crystal plasticity finite element ...method (CPFEM). The phase identification method based on the image quality of electron backscatter diffraction and a filtering process was used to obtain information concerning individual crystallographic orientations for ferrite and martensite phases in DP980 steel. The (200) and (211) lattice strains of ferrite and martensite phases were measured along the loading and transverse directions as a function of macroscopic stress using in situ neutron diffraction. A CPFEM based on representative volume elements (RVE) was applied to determine the microscopic hardening parameters for each phase by fitting the measured macroscopic stress and measured (200) and (211) lattice strains. The microscopic hardening parameters for each phase successfully captured the influence of the crystallographic orientation of the ferrite phase on the localization of shear strain and the behavior of ductile failure in RVE of the unit cell during uniaxial tension.
Background
The long-term outcomes of minimally invasive lateral pelvic lymph node dissection (LPND) are not completely known. The aim of this study was to compare long-term outcomes between robotic ...and laparoscopic LPND in low rectal cancer patients with suspected lymph node metastasis in the pelvic sidewall.
Methods
We retrospectively reviewed the records of all rectal cancer patients who had laparoscopic or robotic total mesorectal excision (TME) with LPND between March 2006 and June 2016. Stage IV patients were excluded. The outcomes of patients who had laparoscopic and robotic TME with LPND were compared.
Results
Twenty-nine patients had laparoscopic LPND and 70 had robotic LPND. No significant differences in patient characteristics were observed between the two groups. The urinary retention rate was lower in the robotic group than in the laparoscopic group (7.1% vs. 24.1%;
p
= 0.043). During a median follow-up of 44.3 months, the overall recurrence rates were 48.3% and 31.4% in the laparoscopic and robotic groups, respectively (
p
= 0.175). The 5-year disease-free survival rates were 50.4% and 67.0% in the laparoscopic and robotic groups, respectively (
p
= 0.227). The 5-year overall survival rates were 65.0% and 92.2% in the laparoscopic and robotic groups, respectively (
p
= 0.017).
Conclusions
Robotic TME with LPND is safe and feasible. In particular, it is associated with lower urinary retention. Robotic TME with LPND might yield a similar local recurrence rate and 5-year disease-free survival, but favorable long-term overall survival as compared to the laparoscopic approach. However, considering the retrospective nature and both major variables of TME and LPND involved together, this should be cautiously interpreted.
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