Optimisation of diamond quantum processors

Diamond quantum processors consisting of a nitrogen-vacancy (NV) centre and surrounding nuclear spins have been the key to significant advancements in room-temperature quantum computing, quantum sensing and microscopy. The optimisation of these processors is crucial for the development of large-scale diamond quantum computers and the next generation of enhanced quantum sensors and microscopes. Here, we present a full model of multi-qubit diamond quantum processors and develop a semi-analytical method for designing gate pulses. This method optimises gate speed and fidelity in the presence of random control errors and is readily compatible with feedback optimisation routines. We theoretically demonstrate infidelities approaching $\sim 10^{-5}$ for single-qubit gates and established evidence that this can also be achieved for a two-qubit CZ gate. Consequently, our method reduces the effects of control errors below the errors introduced by hyperfine field misalignment and the unavoidable decoherence that is intrinsic to the processors. Having developed this optimal control, we simulated the performance of a diamond quantum processor by computing quantum Fourier transforms. We find that the simulated diamond quantum processor is able to achieve fast operations with low error probability.Comment: Published version. Updated references, additional analysis for the infidelities of CZ gate. Two new appendices on discussing the effects of time-ordering in the quantum evolution and examining the effects of the secular approximation and hyperfine field misalignments on gate fidelities. Adjusted the discussions and claims accordingl

Detection and modeling of hole capture by single point defects under variable electric fields

Understanding carrier trapping in solids has proven key to semiconductor technologies but observations thus far have relied on ensembles of point defects, where the impact of neighboring traps or carrier screening is often important. Here, we investigate the capture of photo-generated holes by an individual negatively-charged nitrogen-vacancy (NV) center in diamond at room temperature. Using an externally gated potential to minimize space-charge effects, we find the capture probability under electric fields of variable sign and amplitude shows an asymmetric-bell-shaped response with maximum at zero voltage. To interpret these observations, we run semi-classical Monte Carlo simulations modeling carrier trapping through a cascade process of phonon emission, and obtain electric-field-dependent capture probabilities in good agreement with experiment. Since the mechanisms at play are insensitive to the trap characteristics, the capture cross sections we observe - largely exceeding those derived from ensemble measurements - should also be present in materials platforms other than diamond

Isolation and Characterization of Microsatellite Loci in Pistacia weinmannifolia (Anacardiaceae)

Fourteen polymorphic microsatellite loci were isolated from the genomic DNA of Pistacia weinmannifolia, using the Fast Isolation by AFLP of Sequences Containing repeats (FIASCO) method, and screened on 12 individuals from each of two wild populations. The 14 polymorphic loci had an average of 4.1 alleles per locus varying from 1 to 9. The observed (Ho) and expected (He) heterozygosities across the two populations ranged from 0.000 to 0.933 and from 0.000 to 0.906, respectively. Tests for departure from Hardy-Weinberg equilibrium (HWE) and genotypic linkage disequilibrium (LD) were conducted for each of the two populations separately. It was found that no locus significantly deviated from HWE proportions and no significant LD was detected between loci (p < 0.001). In the test of cross-species utility, we successfully amplified nine (64.2%) of 14 loci in P. chinensis and four (28.6%) in P. mexicana. The relatively high level of polymorphism for these markers will facilitate further studies of gene flow, population structure and evolutionary history of P. weinmannifolia and its congeners

The BMP inhibitor follistatin-like 1 (FSTL1) suppresses cervical carcinogenesis

Follistatin-like 1 (FSTL1) is a cancer-related matricellular secretory protein with contradictory organ-specific roles. Its contribution to the pathogenesis of cervical carcinoma is still not clear. Meanwhile, it is necessary to identify novel candidate genes to understand cervical carcinoma’s pathogenesis further and find potential therapeutic targets. We collected cervical carcinoma samples and matched adjacent tissues from patients with the locally-advanced disease and used cervical carcinoma cell lines HeLa and C33A to evaluate the effects of FSTL1 on CC cells. The mRNA transcription and protein expression of FSTL1 in cervical carcinoma tumor biopsy tissues were lower than those of matched adjacent tissues. Patients with a lower ratio of FSTL1 mRNA between the tumor and its matched adjacent tissues showed a correlation with the advanced cervical carcinoma FIGO stages. High expression of FSTL1 markedly inhibited the proliferation, motility, and invasion of HeLa and C33A. Regarding mechanism, FSTL1 plays its role by negatively regulating the BMP4/Smad1/5/9 signaling. Our study has demonstrated the tumor suppressor effect of FSTL1, and these findings suggested a potential therapeutic target and biomarker for cervical carcinoma

Comparison of clinical efficiency between intra-articular injection of platelet-rich plasma and hyaluronic acid for osteoarthritis: a meta-analysis of randomized controlled trials

Background: Platelet-rich plasma (PRP) and hyaluronic acid (HA) are non-surgical treatments for osteoarthritis (OA), but the comparison of their efficiency is still inconclusive. Objectives: The objectives of this study were to compare the efficacy of PRP and HA in the treatment of OA by meta-analysis and to explore the effects of different injection times and leukocyte concentration on the efficacy of PRP. Design: Meta-analysis and subgroup analysis were conducted. The data were analyzed by Review Manager v5.4.1. Data sources and methods: Articles were retrieved and screened from PubMed, the Cochrane Library, Web of Science, and Embase. The outcome included the total Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the visual analog scale (VAS), adverse events (AEs), the International Knee Documentation Committee (IKDC), and the satisfaction rate. Results: A total of 30 articles involving 2733 patients were included. The total WOMAC score and IKDC score of the PRP group were better than those of the HA group at the last follow-up time, while there was no significant difference in AEs, satisfaction rate, and VAS between the two groups. In our subgroup analysis, there was no significant difference between single-injection PRP and triple-injection PRP. Leukocyte-poor PRP (LP-PRP) was better than leukocyte-rich PRP (LR-PRP) in IKDC, but there was no significant difference between them in the other scores. Conclusions: In the treatment of OA, compared with HA, PRP performed better in the improvement of the patient’s function. There was no significant difference in VAS and AEs between the two groups, and the safety was comparable. LP-PRP looked to be superior to LR-PRP in functional recovery, but there appeared to be no significant difference in pain relief between them. There was no significant difference between single PRP and triple PRP in the subgroup analysis

Design and Implementation of a 3D C-arm Control Service Protocol (RoboLINK) Based on DICOM

3D imaging technology assisted orthopaedic robot for preoperative planning can improve the accuracy and efficiency of surgery. However, traditional surgical navigation systems based on 3D data currently need pre-operative drawing and manual registration. The surgical steps are cumbersome and new errors may be introduced during manual registration, resulting in the reduction of accuracy. To address this need, in this study, we design a remote device control service protocol (RoboLINK) based on the DICOM protocol, which can be used in operation and provides a novel solution to the current problem. Based on supporting data transmission between two medical devices, motion control instructions can also be transmitted to achieve mutual cooperation between devices. In accordance with this design method, the protocol is tested in a shadow medical 3D C-arm experimental environment and a simulated surgical robot. The results indicate that the RoboLINK protocol can effectively complete the tasks of data transmission and equipment control with the advantages of feasibility and security