A two-site Kitaev chain in a two-dimensional electron gas.

Artificial Kitaev chains can be used to engineer Majorana bound states (MBSs) in superconductor-semiconductor hybrids1-4. In this work, we realize a two-site Kitaev chain in a two-dimensional electron gas by coupling two quantum dots through a region proximitized by a superconductor. We demonstrate systematic control over inter-dot couplings through in-plane rotations of the magnetic field and via electrostatic gating of the proximitized region. This allows us to tune the system to sweet spots in parameter space, where robust correlated zero-bias conductance peaks are observed in tunnelling spectroscopy. To study the extent of hybridization between localized MBSs, we probe the evolution of the energy spectrum with magnetic field and estimate the Majorana polarization, an important metric for Majorana-based qubits5,6. The implementation of a Kitaev chain on a scalable and flexible two-dimensional platform provides a realistic path towards more advanced experiments that require manipulation and readout of multiple MBSs.

Realization of a minimal Kitaev chain in coupled quantum dots.

Majorana bound states constitute one of the simplest examples of emergent non-Abelian excitations in condensed matter physics. A toy model proposed by Kitaev shows that such states can arise at the ends of a spinless p-wave superconducting chain1. Practical proposals for its realization2,3 require coupling neighbouring quantum dots (QDs) in a chain through both electron tunnelling and crossed Andreev reflection4. Although both processes have been observed in semiconducting nanowires and carbon nanotubes5-8, crossed-Andreev interaction was neither easily tunable nor strong enough to induce coherent hybridization of dot states. Here we demonstrate the simultaneous presence of all necessary ingredients for an artificial Kitaev chain: two spin-polarized QDs in an InSb nanowire strongly coupled by both elastic co-tunnelling (ECT) and crossed Andreev reflection (CAR). We fine-tune this system to a sweet spot where a pair of poor man's Majorana states is predicted to appear. At this sweet spot, the transport characteristics satisfy the theoretical predictions for such a system, including pairwise correlation, zero charge and stability against local perturbations. Although the simple system presented here can be scaled to simulate a full Kitaev chain with an emergent topological order, it can also be used imminently to explore relevant physics related to non-Abelian anyons.

Singlet and triplet Cooper pair splitting in hybrid superconducting nanowires.

In most naturally occurring superconductors, electrons with opposite spins form Cooper pairs. This includes both conventional s-wave superconductors such as aluminium, as well as high-transition-temperature, d-wave superconductors. Materials with intrinsic p-wave superconductivity, hosting Cooper pairs made of equal-spin electrons, have not been conclusively identified, nor synthesized, despite promising progress1-3. Instead, engineered platforms where s-wave superconductors are brought into contact with magnetic materials have shown convincing signatures of equal-spin pairing4-6. Here we directly measure equal-spin pairing between spin-polarized quantum dots. This pairing is proximity-induced from an s-wave superconductor into a semiconducting nanowire with strong spin-orbit interaction. We demonstrate such pairing by showing that breaking a Cooper pair can result in two electrons with equal spin polarization. Our results demonstrate controllable detection of singlet and triplet pairing between the quantum dots. Achieving such triplet pairing in a sequence of quantum dots will be required for realizing an artificial Kitaev chain7-9.

Quantized Majorana conductance.

Majorana zero-modes-a type of localized quasiparticle-hold great promise for topological quantum computing. Tunnelling spectroscopy in electrical transport is the primary tool for identifying the presence of Majorana zero-modes, for instance as a zero-bias peak in differential conductance. The height of the Majorana zero-bias peak is predicted to be quantized at the universal conductance value of 2e2/h at zero temperature (where e is the charge of an electron and h is the Planck constant), as a direct consequence of the famous Majorana symmetry in which a particle is its own antiparticle. The Majorana symmetry protects the quantization against disorder, interactions and variations in the tunnel coupling. Previous experiments, however, have mostly shown zero-bias peaks much smaller than 2e2/h, with a recent observation of a peak height close to 2e2/h. Here we report a quantized conductance plateau at 2e2/h in the zero-bias conductance measured in indium antimonide semiconductor nanowires covered with an aluminium superconducting shell. The height of our zero-bias peak remains constant despite changing parameters such as the magnetic field and tunnel coupling, indicating that it is a quantized conductance plateau. We distinguish this quantized Majorana peak from possible non-Majorana origins by investigating its robustness to electric and magnetic fields as well as its temperature dependence. The observation of a quantized conductance plateau strongly supports the existence of Majorana zero-modes in the system, consequently paving the way for future braiding experiments that could lead to topological quantum computing.

Retracted: Marchantin M Induces Apoptosis of Prostate Cancer Cells Through Endoplasmic Reticulum Stress.

The Editors of Medical Science Monitor wish to inform you that the above manuscript has been retracted from publication due to concerns with the credibility and originality of the study, the manuscript content, and the Figure images. Reference: Tian-Wei Zhang, Li Xing, Jun-Long Tang, Jing-Xiao Lu, Chun-Xiao Liu. Marchantin M Induces Apoptosis of Prostate Cancer Cells Through Endoplasmic Reticulum Stress. Med Sci Monit, 2015; 21: 3570-3576. DOI: 10.12659/MSM.894476.

[Transurethral bipolar isokinetic anatomical enucleation for giant (> 300 g) prostatic hyperplasia: Report of 5 cases and review of the literature].

OBJECTIVE: To explore the application prospect and clinical efficacy of transurethral plasmakinetic enucleation of the Giant prostatic hyperplasia. METHODS: The clinical data of 5 patients with Giant prostatic hyperplasia treated by transurethral plasmakinetic enucleation in our department from december 2021 to january 2023 were retrospectively analyzed. RESULTS: All 5 patients successfully completed the operation, aged 69－80 years (73.2±4.32),PSA level was 8.07～42.90ng/ml (22.81±13.97), prostate volume was 321.05－534.26g (388.34±84.26), enucleation time was 120－240 min (174±61.48), Gland processing time 40－120 min（63±32.71). There were 1 case of perforation of prostate capsule and severe hematuria，3 cases of blood transfusion. 2 cases of transient urinary incontinence were improved after 2 weeks and 4 months postoperative respectively. International Prostate Symptom Score (IPSS),and quality of life score (QoL) and Maximum urine flow rate(Qmax) were significantly improved compared with preoperative parameters. CONCLUSION: It is safe and effective to treat GPH with plasma enucleation through urethra with skilled plasma enucleation technique.

Tunable Superconducting Coupling of Quantum Dots via Andreev Bound States in Semiconductor-Superconductor Nanowires.

Semiconductor quantum dots have proven to be a useful platform for quantum simulation in the solid state. However, implementing a superconducting coupling between quantum dots mediated by a Cooper pair has so far suffered from limited tunability and strong suppression. This has limited applications such as Cooper pair splitting and quantum dot simulation of topological Kitaev chains. In this Letter, we propose how to mediate tunable effective couplings via Andreev bound states in a semiconductor-superconductor nanowire connecting two quantum dots. We show that in this way it is possible to individually control both the coupling mediated by Cooper pairs and by single electrons by changing the properties of the Andreev bound states with easily accessible experimental parameters. In addition, the problem of coupling suppression is greatly mitigated. We also propose how to experimentally extract the coupling strengths from resonant current in a three-terminal junction. Our proposal will enable future experiments that have not been possible so far.

Silencing of Gasdermin D by siRNA-Loaded PEI-Chol Lipopolymers Potently Relieves Acute Gouty Arthritis through Inhibiting Pyroptosis.

Gasdermin D (GSDMD) plays a causal role in NOD-like receptor protein 3 (NLRP3) inflammasome-mediated pyroptosis eruption, which has been regarded as a potential therapeutic target for pyroptosis-related diseases including acute gouty arthritis. In the present study, the synthesized PEI-Chol (cholesterol grafted polyethylenimine) was assembled with GSDMD small interfering RNA (siRNA) to form PEI-Chol/siGSDMD polyplexes, which provided high transfection efficiency for siRNA-mediated GSDMD knockdown. Then we evaluated the effect of GSDMD siRNA-loaded PEI-Chol on inflammatory cascades in bone-marrow-derived macrophages (BMDMs) and acute gouty arthritis animal models under MSU exposure. When accompanied by pyroptosis blockade and decreased release of interleukin-1 beta (IL-1ß), NLRP3 inflammasome activation was also suppressed by GSDMD knockdown in vivo and in vitro. Moreover, in MSU-induced acute gouty arthritis mice, blocking GSDMD with siRNA significantly improved ankle swelling and inflammatory infiltration observed in histopathological analysis. Furthermore, investigation using a mouse air pouch model verified the effect of siGSDMD-loaded PEI-Chol on pyroptosis of recruited macrophages and related signaling pathways in response to MSU. These novel findings exhibited that GSDMD knockdown relieved acute gouty arthritis through inhibiting pyroptosis, providing a possible therapeutic approach for MSU-induced acute gouty arthritis molecular therapy using PEI-Chol as a nucleic acid delivery carrier.

Optical planar and ridge waveguides formed in Er3+-doped germanate glass by ion implantation and precise diamond blade dicing.

In this work, we report on the preparation and characterization of the planar and ridge optical waveguides in the Er3+-doped germanate glass by combining hydrogen ion implantation and precise diamond blade dicing. The nuclear energy loss and the implantation depth were calculated by the SRIM 2013 software. The refractive index profile was obtained by the reflectivity calculation method. The dark-mode spectrum and the near-field intensity distribution were measured by the prism coupling system and end-face coupling technique, respectively. This work has important reference significance for the development of Er3+-doped germanate glass active devices in the optical communication field.

SYNE1-QK1 SNPs, G × G and G × E interactions on the risk of hyperlipidaemia.

This study aimed to assess the relationship of 3 spectrin repeat containing nuclear envelope protein 1 (SYNE1) and 4 KH domain containing RNA binding (QK1) single nucleotide polymorphisms (SNPs), their haplotypes, gene-gene (G × G), gene-environment (G × E) interactions and hypercholesterolaemia (HCH) and hypertriglyceridaemia (HTG) in the Chinese Maonan minority. The genetic make-up of the SYNE1-QK1 SNPs in 1932 unrelated subjects (normal, 641; HCH, 649; and HTG, 642) was obtained by next-generation sequencing technologies. The genotypic frequencies of following SNPs were suggestively distinctive between the control and HCH groups (rs2623963, rs7745725, rs9459317, rs16897566), or between the control and HTG groups (rs2623963, rs1358317, rs7745725, rs1923608, rs16897566 SNPs; P < .05, respectively). Multiple-locus linkage disequilibrium analysis indicated that the identified SNPs were not inherited independently. Several haplotypes and gene-gene interaction haplotypes among the detected SNPs may be related with an increased morbidity of HCH (C-G-A, C-G-G and C-G-G-T-C-A-T) and HTG (C-G-G, G-T-G-C, C-G-G-G-T-G-C and C-G-G-T-C-A-T), whereas others may be related with an decreased risk of HCH (G-A-A, G-C-A-T, C-A-A-T-C-A-T and G-A-A-G-C-A-T) and HTG (G-A-A, G-C-A-T, C-A-A-T-C-A-T and G-A-A-G-C-A-T). The association evaluation based on haplotypes and gene-gene interactions could improve the power of detecting the risk of dyslipidaemia than anyone of SNP alone. There was significant three-locus model involving SNP-SNP, haplotype-haplotype/environment and G × G interactions (P < .05-0.001) that were detected by GMDR in HCH and HTG groups. Different interactions between genetic and environmental factors would produce different redundancy or synergy effects on the morbidity of HCH and/or HTG.

The MC4R SNPs, their haplotypes and gene-environment interactions on the risk of obesity.

BACKGROUND: Little is known about the correlation between the melanocortin 4 receptor gene (MC4R) single nucleotide polymorphisms (SNPs) and the risk of obesity. This research sought to test the MC4R rs17782313, rs476828 and rs12970134 SNPs, their haplotypes and gene-environment interactions on the risk of obesity in the Maonan ethnic group, an isolated minority in China. METHODS: A case-control study comprised of 1836 participants (obesity group, 858; and control group, 978) was conducted. Genotypes of the three SNPs were determined by the next-generation sequencing (NGS) technology. RESULTS: The genotypic frequencies of the three SNPs were different between the obesity and control groups (P <  0.05 for all). The minor allelic frequency of the MC4R rs17782313C, rs476828C and rs12970134A was higher in obesity than in control groups (13.8% vs. 8.3%, P <  0.001, 17.1% vs. 10.9%, P <  0.001; and 15.5% vs. 11.5%, P <  0.001; respectively). Additionally, the dominant model of rs17782313 and rs476828 SNPs revealed an increased morbidity function on the risk of obesity (P <  0.05). A correlation between SNP-environment and the risk of obesity was also observed. The rs17782313C-rs476828C-rs12970134A haplotype was associated with high risk of obesity (OR = 1.796, 95% CI = 1.447-2.229), whereas the rs17782313T-rs476828T-rs12970134G and rs17782313T-rs476828T-rs12970134A haplotypes were associated with low risk of obesity (OR = 0.699, 95% CI = 0.586-0.834 and OR = 0.620, 95% CI = 0.416-0.925; respectively). The interactions between haplotype and waist circumference on the risk of obesity were also noted. CONCLUSIONS: We discovered that the MC4R rs17782313, rs476828 and rs12970134 SNPs and their haplotypes were associated with the risk of obesity in the Chinese Maonan population.

Proposal for Measuring the Parity Anomaly in a Topological Superconductor Ring.

A topological superconductor ring is uniquely characterized by a switch in the ground state fermion number parity upon insertion of one superconducting flux quantum-a direct consequence of the topological "parity anomaly." Despite the many other tantalizing signatures and applications of topological superconductors, this fundamental, defining property remains to be observed experimentally. Here we propose definitive detection of the fermion parity switch from the charging energy, temperature, and tunnel barrier dependence of the flux periodicity of two-terminal conductance of a floating superconductor ring. We extend the Ambegaokar-Eckern-Schön formalism for superconductors with a Coulomb charging energy to establish new explicit relationships between thermodynamic and transport properties of such a ring and the topological invariant of the superconductor. Crucially, we show that the topological contribution to the conductance oscillations can be isolated from Aharonov-Bohm oscillations of nontopological origin by their different dependence on the charging energy or barrier transparency.

Association between the XKR6 rs7819412 SNP and serum lipid levels and the risk of coronary artery disease and ischemic stroke.

BACKGROUND: The present study aimed to expound the association between the XK related 6 gene (XKR6) rs7819412 single nucleotide polymorphism (SNP) and serum lipid profiles and the risk of coronary artery disease (CAD) and ischemic stroke. METHODS: The genetic makeup of the XKR6 rs7819412 SNP in 1783 unrelated participants (controls, 643; CAD, 588 and ischemic stroke, 552) of Han Chinese was obtained by the Snapshot technology. RESULTS: The genotypic frequencies of the SNP were disparate between CAD (GG, 81.0%; GA/AA, 19.0%) or ischemic stroke (GG, 81.2%; GA/AA, 18.8%) patients and healthy controls (GG, 85.7%, GA/AA, 14.3%; P < 0.05 vs. CAD or ischemic stroke; respectively). The A allele frequency was also diverse between CAD (10.1%) or ischemic stroke (10.0%) and control groups (7.5%; P < 0.05 vs. CAD or ischemic stroke; respectively). The GA/AA genotypes and A allele were associated with high risk of CAD and ischemic stroke (CAD: P = 0.026 for GA/AA vs. GG, P = 0.024 for A vs. G; Ischemic stroke: P = 0.029 for GA/AA vs. GG, P = 0.036 for A vs. G). The GA/AA genotypes were also associated with increased serum triglyceride (TG) concentration in CAD and total cholesterol (TC) concentration in ischemic stroke patients. CONCLUSIONS: These data revealed that the XKR6 rs7819412 A allele was related to increased serum TG levels in CAD, TC levels in ischemic stroke patients and high risk of CAD and ischemic stroke.

Potential molecular mechanism of ACE gene at different time points in STEMI patients based on genome-wide microarray dataset.

BACKGROUND: This study aimed to investigate the angiotensin converting enzyme (ACE) co-expression genes and their pathways involved in ST-segment elevation myocardial infarction (STEMI) at different time points. METHODS: The array data set of GSE59867 was examined for the ACE co-expression genes in peripheral blood samples from 111 patients with STEMI at four time points (admission, discharge, and 1 and 6 months after MI). Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, Gene Ontology (GO) annotation and protein-protein interaction (PPI) of the co-expression genes were determined using online analytical tools. The Cytoscape software was used to create modules and hub genes. RESULTS: The number of biological processes (BP), cellular components (CC) and molecular functions (MF) was 43, 22 and 24 at admission; 18, 19 and 11 at discharge; 30, 37 and 21 at 1 month after MI; and 12, 19 and 14 at 6 months after MI; respectively. There were 6 BP, 8 CC and 4 MF enriched at every time point. The co-expression genes were substantially enriched in 12, 5, 6 and 14 KEGG pathways at the four time points, respectively, but no KEGG pathway was found to be common in all time points. We identified 132 intersectional co-expression genes (90 positive and 42 negative) from the four time points and 17 BP, 13 CC, 11 MF and 7 KEGG pathways were enriched. In addition, the PPI network contained 129 nodes and 570 edges, and only 1 module was identified to be significantly enriched in just 1 BP (chromatin-mediated maintenance of transcription). CONCLUSIONS: The results of the present study showed that the ACE co-expression genes and their pathways involved in STEMI were significantly different at four different time points. These findings may be helpful for further understanding the functions and roles of ACE in different stages of STEMI, and providing reference for the treatment of STEMI.

Marchantin M Induces Apoptosis of Prostate Cancer Cells Through Endoplasmic Reticulum Stress.

BACKGROUND Apoptosis is mediated by the endoplasmic reticulum (ER) stress pathway, mitochondrial pathway, and death receptor. Data herein suggested an inhibitory effect of marchantin M on tumor formation in nude mice as well as the impact on CHOP and GRP78 expression. MATERIAL AND METHODS The role of marchantin M on proliferation and apoptosis of DU145 cells were measured by MTT and flow cytometry, respectively. Western blot was applied to detect the expression of GRP78 and CHOP. The mice received abdominal injection at 1 time/2 d and 2 ml/time. Tumor volume was measured every 6 days. The mice were euthanatized 30 days after marchantin injection and tumor weight was measured. Cell apoptosis was determined by TUNEL. The expressions of CHOP and GRP78 were detected by immunohistochemistry. RESULTS Tumor size and weight in marchantin groups were significantly lower than in the control group (A, B) (P<0.05), and the inhibitory rate presented a dose-dependent increase. Compared with controls, the levels of CHOP and GRP78 expression elevated obviously following the treatment with marchantin (P<0.05). It showed statistically significant difference among groups C, D, E, with different levels of apoptosis indexes incremented in groups of marchantin H, M, L, compared with groups A and B (P<0.05). CONCLUSIONS Overall, this study shows that marchantin M circumvents the growth of prostate cancer PC-3 tumor and up-regulates expressions of CHOP and GRP78. Our data also indicate that marchantin M limits the proliferation and favors apoptosis of DU145 cells in a time- and dose-dependent manner.

[Early removal of the urethral catheter after transurethral plasma kinetic resection of the prostate in the treatment of BPH].

OBJECTIVE: To investigate the feasibility and effect of early removal of the urethral catheter after transurethral plasma kinetic resection of the prostate (PKRP) in the treatment of benign prostatic hyperplasia (BPH). METHODS: We equally randomized 128 BPH patients treated by PKRP to an experimental group and a control group, urethral catheters removed at 1 -2 days for the former and at 5 -7 days for the latter. We compared the relevant indexes and clinical effects between the two groups. RESULTS: The baseline data were not significantly different between the two groups. Compared with the controls, the experimental group showed a significantly shorter postoperative hospital stay ([6.8 +/- 1.9] d vs [3.7 +/- 1.5] d, P < 0.05) and lower infection rate (25.0% vs 10.9%, P < 0.05). All the patients were followed up for 3 -6 months postoperatively. At 3 months after surgery, both the experimental and the control groups showed remarkable improvement in the International Prostatic Symptoms Scores (4. 9 +/- 2. 2 vs 5. 3 +/- 2. 3), maximum urine flow rate ([21.5+/- 5.6 ] ml/s vs [19.1 +/-4.9 ] ml/s) , and residual urine ( [ 16.8+/- 10.3 ] ml vs [18.9 +/- 12.3 ] ml), but with no significant differences between the two (P > 0.05) , and no significant differences were observed in postoperative complications (P >0.05). CONCLUSION: Early removal of the urethral catheter after PKRP, with its advantages of shorter postoperative hospital stay, lower infection rate, and no influence on the long-term effect, deserves to be recommended as a routine method in the treatment of BPH.

[Single nucleotide polymorphisms and prostate cancer].

Prostate cancer is a common malignancy that affects men's health in the Western countries. Single nucleotide polymorphisms (SNPs), as the third generation of genetic markers, can influence the development, progression, and prognosis of prostate cancer. The same SNP may be related differently with prostate cancer among different races. This paper describes the relationship between SNPs and prostate cancer according to their related genes. SNPs can predict the risk of prostate cancer as well as the possible adverse reactions in its treatment, but at present they do have some limitations.

[Transurethral bipolar plasmakinetic enucleation and resection versus transurethral bipolar plasmakinetic resection of the prostate for BPH: a randomized controlled trial on the incidence of postoperative urinary incontinence].

OBJECTIVE: To compare the incidence rates of postoperative urinary incontinence between transurethral bipolar plasmakinetic enucleation and resection of the prostate (PKERP) and transurethral bipolar plasmakinetic resection of the prostate (PKRP), and provide evidence for the clinical application of PKERP. METHODS: Totally, 180 BPH patients were equally and randomly assigned to undergo PKERP and PKRP, respectively. We measured the urinary incontinence of the patients by pad test at 24 hours after extubation and every week after surgery for 4 weeks. Meanwhile, we recorded and compared the PSA level, prostate volume, Qmax, residual urine, IPSS, QOL, and the results of pad test between the two groups before and after surgery. RESULTS: The incidence rates of urinary incontinence in the PKERP and PKRP groups were 35.56% and 18.89% (P < 0.01) at 24 hours after extubation, 20.00% and 7.78% at 1 week after surgery (P < 0.05), and 3.33% and 2.22% at 2 weeks. There was no significant difference in the severity of urinary incontinence between the two groups at any time point (P > 0.05). No permanent urinary incontinence was observed in either group. CONCLUSION: Compared with PKRP, PKERP has a higher incidence rate of short-term urinary incontinence in the treatment of BPH, but not that of genuine incontinence, with similar severity and recovery time.