Enhancement of Quantum Heat Engine by Encircling a Liouvillian Exceptional Point.

Quantum heat engines are expected to outperform the classical counterparts due to quantum coherences involved. Here we experimentally execute a single-ion quantum heat engine and demonstrate, for the first time, the dynamics and the enhanced performance of the heat engine originating from the Liouvillian exceptional points (LEPs). In addition to the topological effects related to LEPs, we focus on thermodynamic effects, which can be understood by the Landau-Zener-Stückelberg process under decoherence. We witness a positive net work from the quantum heat engine if the heat engine cycle dynamically encircles a LEP. Further investigation reveals that a larger net work is done when the system is operated closer to the LEP. We attribute the enhanced performance of the quantum heat engine to the Landau-Zener-Stückelberg process, enabled by the eigenenergy landscape in the vicinity of the LEP, and the exceptional point-induced topological transition. Therefore, our results open new possibilities toward LEP-enabled control of quantum heat engines and of thermodynamic processes in open quantum systems.

Dynamical control of quantum heat engines using exceptional points.

A quantum thermal machine is an open quantum system coupled to hot and cold thermal baths. Thus, its dynamics can be well understood using the concepts and tools from non-Hermitian quantum systems. A hallmark of non-Hermiticity is the existence of exceptional points where the eigenvalues of a non-Hermitian Hamiltonian or a Liouvillian superoperator and their associated eigenvectors coalesce. Here, we report the experimental realization of a single-ion heat engine and demonstrate the effect of Liouvillian exceptional points on the dynamics and the performance of a quantum heat engine. Our experiments have revealed that operating the engine in the exact- and broken-phases, separated by a Liouvillian exceptional point, respectively during the isochoric heating and cooling strokes of an Otto cycle produces more work and output power and achieves higher efficiency than executing the Otto cycle completely in the exact phase where the system has an oscillatory dynamics and higher coherence. This result opens interesting possibilities for the control of quantum heat engines and will be of interest to other research areas that are concerned with the role of coherence and exceptional points in quantum processes and in work extraction by thermal machines.

The effect of neuropilin-1 silencing on the transforming growth factor-ß1-mediated epithelial-mesenchymal transition of colon cancer SW480 cells and its effect on the proliferation and migration of colon cancer cells.

This study aimed to investigate the effect of neuropilin-1 (NRP-1) silencing on epithelial-mesenchymal transformation (EMT) mediated by transforming growth factor-ß1 (TGF-ß1) and on the proliferation and migration of colon cancer SW480 cells. After transfection of small interfering ribonucleic acid (siRNA)-NRP-1 into colon cancer SW480 cells, the messenger RNA (mRNA) and protein expression levels of NRP-1 were detected using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot. Four EMT models were induced using 0, 2, 5, and 10 ng/mL TGF-ß1, respectively. Cell proliferation was detected using Cell Counting Kit-8, and the protein levels of EMT markers E-cadherin and vimentin were detected using Western blot. EMT was induced in the transfected SW480 cells using TGF-ß1, after which four groups were created: a negative control group (siRNA-Ncontrol), a transfection group (siRNA-NRP-1), an induction group (TGF-ß1), and a transfection + induction group (siRNA-NRP-1+TGF-ß1). Western blot was then used to detect the expression of E-cadherin and vimentin, and cell proliferation and migration were detected using cell counting kit-8 (CCK-8) and scratch assay. After transfection with siRNA-NRP-1, the mRNA and protein expression levels of SW480 cells were significantly decreased (P<0.05). After 48 hours of induction with 10 ng/mL TGF-ß1, cell proliferation was obvious, E-cadherin expression decreased, and vimentin expression significantly increased (P<0.05), indicating that EMT had been successfully induced compared with the induction group, the transfection + induction group had significantly increased E-cadherin expression after corresponding treatments (including transfection and induction alone) (P<0.05), and the proliferation and migration of colon cancer cells decreased (P<0.05). In conclusion: silencing, NRP-1 in colon cancer SW480 cells can partially reverse TGF-ß1-mediated EMT, reduce the proliferation activity of colon cancer cells, and slow their migration ability. Therefore, NRP-1 may become a new target for the treatment of colon cancer.

[Early warning of low maternal unconjugated estriol level by prenatal screening for fetus with X-linked ichthyosis].

Objective: To analyze the characteristic of prenatal serological screening in fetus with X-linked ichthyosis (XLI), and to explore the relationship between unconjugated estriol (uE3) levels and XLI. Methods: A total of 56 fetuses with Xp22.31 microdeletion indicated by prenatal diagnosis and 70 fetuses diagnosed with trisomy 21 and 26 fetuses with trisomy 18 in Henan Provincial People's Hospital and Affiliated Hospital of Weifang Medical College from September 2016 to June 2021 were collected. The multiples of median (MoM) values of uE3, alpha-fetoprotein (AFP), and human chorionic gonadotropin (hCG) during the second trimester of pregnancy were retrospectively analyzed. Prenatal diagnosis was made by amniotic fluid karyotype analysis and genome copy number variant analysis, parent genetic verification and pathogenicity analysis were performed, and maternal and infant outcomes were followed up. Results: Of 56 pregnant women with fetal Xp22.31 microdeletion, 43 underwent serological screening during the second trimester of pregnancy, of which 42 were abnormal (39 male fetuses and 3 female fetuses). The median uE3 MoM value of 39 male fetuses [0.06 (0.00-0.21)] was lower than the normal value and significantly lower than that of fetuses with trisomy 21 [0.71 (0.26-1.27)] and fetuses with trisomy 18 [0.36 (0.15-0.84)], the difference was statistically significant (Z=99.96, P<0.001). While the MoM values of AFP and hCG were all within the normal range. Among the 56 fetuses carrying Xp22.31 microdeletion, 45 were male fetuses and 11 were female fetuses, and the deletion fragments all involved STS gene. Eighty-nine percent (50/56) were inherited from mother (49 cases) or father (1 case), and 11% (6/56) were de novo mutations. Follow-up showed 48 live births (38 males and 10 females) and 8 chose to terminate pregnancy (7 males and 1 female). Among the 38 male newborns, 37 presented with scaly skin changes from 1 to 3 months of age, and one had no clinical manifestations until 4 months after birth. Ten female newborns had no obvious clinical manifestations. Conclusions: The decrease levels of uE3 MoM on maternal serological screening is closely related to the higher risk of XLI in male fetuses. For pregnant women with low uE3 in serological screening or with family history of ichthyosis, in addition to chromosomal karyotype analysis, joint detection of genomic copy number variant analysis should be recommended.

Experimental Verification of Dissipation-Time Uncertainty Relation.

Dissipation is vital to any cyclic process in realistic systems. Recent research focus on nonequilibrium processes in stochastic systems has revealed a fundamental trade-off, called dissipation-time uncertainty relation, that entropy production rate associated with dissipation bounds the evolution pace of physical processes [Phys. Rev. Lett. 125, 120604 (2020)PRLTAO0031-900710.1103/PhysRevLett.125.120604]. Following the dissipative two-level model exemplified in the same Letter, we experimentally verify this fundamental trade-off in a single trapped ultracold ^{40}Ca^{+} ion using elaborately designed dissipative channels, along with a postprocessing method developed in the data analysis, to build the effective nonequilibrium stochastic evolutions for the energy transfer between two heat baths mediated by a qubit. Since the dissipation-time uncertainty relation imposes a constraint on the quantum speed regarding entropy flux, our observation provides the first experimental evidence confirming such a speed restriction from thermodynamics on quantum operations due to dissipation, which helps us further understand the role of thermodynamical characteristics played in quantum information processing.

Single-Atom Verification of the Noise-Resilient and Fast Characteristics of Universal Nonadiabatic Noncyclic Geometric Quantum Gates.

Quantum gates induced by geometric phases are intrinsically robust against noise due to the global properties of their evolution paths. Compared to conventional nonadiabatic geometric quantum computation, the recently proposed nonadiabatic noncyclic geometric quantum computation (NNGQC) works in a faster fashion while still remaining the robust feature of the geometric operations. Here, we experimentally implement the NNGQC in a single trapped ultracold ^{40}Ca^{+} ion to verify the noise-resilient and fast feature. By performing unitary operations under imperfect conditions, we witness the advantages of the NNGQC with measured fidelities by quantum process tomography in comparison to other two quantum gates by conventional nonadiabatic geometric quantum computation and by straightforward dynamical evolution. Our results provide the first evidence confirming the possibility of accelerated quantum information processing with limited systematic errors even in an imperfect situation.

[Effect of RNA interference targeting neuropilin-2 gene on proliferation and apoptosis of colon cancer cell line HCT-8].

Objective: To investigate the effects of down-regulation of expression of neuropilin-2 (NRP-2) by RNA interference (RNAi) technique on proliferation and apoptosis of HCT-8 colon cancer cells. Methods: NRP2-siRNA and negative control (NControl)-siRNA were transferred into HCT-8 colon cancer cells by liposomes (lip2000) as transfection group and negative control group, and phosphate buffered solution (PBS) was added as blank control group. Quantitative reverse transcription PCR (RT-qPCR) and Western blot were used to detect the transfection effect. The proliferation of cells in the three groups was examined by cell counting kit (CCK) assay, colony-forming unit assay and Ki-67 protein staining assay, respectively. Moreover, the apoptosis of cells in the three groups was determined by acridine orange/propranidine iodide (AO/PI) staining method. Results: The results of RT-qPCR and Western blot showed that the relative expression of NRP-2 mRNA and the content of NRP-2 protein in the transfer group decreased (0.46±0.05 vs 0.99±0.05 and 1.00±0.06; 1.04±0.06 vs 1.73±0.09 and 1.65±0.11) (all P<0.05). The results of CCK-8 demonstrated that the optical density of transfection group was significantly lower than that of the negative control group and the blank control group(24 h: 0.53±0.04 vs 0.82±0.07 and 0.87±0.07; 48 h: 0.54±0.05 vs 1.00±0.09 and 1.17±0.05; 72 h: 0.75±0.05 vs 1.31±0.13 and 1.50±0.03; 96 h:1.05±0.04 vs 1.46±0.09 and 1.86±0.06) (all P<0.05). The results of colony-forming unit assay indicated that the proliferation ability of the cells in the transfer group was significantly lower than that in the other two groups (134.67±8.74 vs 245.33±19.14 and 300.33±14.01, P<0.05). The results of Ki-67 protein staining assay showed that compared with the negative control group and blank control group, the expression of Ki-67 protein was significantly decreased in the transfection group (5.93±0.22 vs 8.36±0.09 and 8.70±0.21, P<0.05). The results of AO/PI assay revealed that the ratio of apoptotic cells to living cells in the transfer group was significantly higher than that in the other two groups (0.43±0.07 vs 0.14±0.04 and 0.11±0.04, P<0.05). Conclusion: The proliferation ability of HCT-8 colon cancer cells decreases, and the apoptosis ability increases by decreasing the expression of NRP-2.

[Measuring and analyzing of otoacoustic emission tests of a family with genetic progressive sensorineural hearing loss].

OBJECTIVE: To study the diagnostic significance of otoacoustic emission in patients with genetic progressive sensorineural hearing loss. METHOD: To analyse the cochlear function pure tone audiometry Transient Evoked Otoacoustic Emission (TEOAE) and distortion Products Otoacoustic Emission (DPOAE) were measured in 54 members of a six-generation family with genetic progressive sensorineural hearing loss (108 cases) and 50 normal people. RESULT: The family was autosomal dominant heritage. In the group with pure tone thresholds more than 20 dB HL, the amplitudes of TEOAE descended or disappeared in 84% cases and the amplitudes of DPOAE declined or vanished in 82% cases. In the group with normal pure tone thresholds, the amplitudes of TEOAE descended in 75% cases and the amplitudes at one of the frequencies of DPOAE dropped or disappeared in 64% cases. But the incidence of TEOAE and DPOAE in normal people was 100%. CONCLUSION: OAE had important significance in the diagnosis of genetic hearing loss at early stage.

Multidrug resistance-associated protein (MRP) mediated transport of daunomycin and leukotriene C4 (LTC4) in isolated plasma membrane vesicles.

Studies have been carried out to examine in vitro drug transport in plasma membrane vesicles isolated from HL60/ADR cells that overexpress MRP. The results demonstrate that glutathione (GSH) enhances transport of daunomycin. A greater increase in transport activity occurs when the reaction is carried out in the presence of both GSH and sodium chloride. Sodium chloride alone has no effect on daunomycin transport. It has also been observed that GSH in the presence of sodium chloride induces a major increase in the transport level of LTC4. Thus far, no metal ion other than sodium chloride has been found to be active in the drug transport system. Kinetic analysis reveals that GSH in the presence of sodium chloride greatly reduces Km and increases Vmax, for daunomycin. Additional studies show that ATPase activity in isolated plasma membrane from HL60/ADR cells is greatly enhanced in the presence of both GSH and sodium chloride. These results suggest the possibility that GSH and sodium chloride stimulate MRP-mediated transport as a result of increased ATPase activity.

Role of EAC1q4 in C1a transfer reaction (C1aTR) and further information on the nature of the EAC1q4 site.

The complement intermediates EAC1, EAC4, and EAC1q4 were prepared with guinea pig, porcine, as well as human complement. EAC4 and EAC1q4 were made from EC4 and EAC14 respectively. The C1a transfer reaction (C1aTR), the second step of Borsos' C1a fixation and transfer test, was carried out with various combinations of these intermediates. It was found that the EAC1q4, instead of the EAC4, was the C1a acceptor, and the C1rs subcomponents rather than the whole C1 molecule should have to transfer in the C1aTR. The EAC41 derived from EC4 generated no EAC1q4 in EDTA medium as the EAC14 did. This presented evidence for the joining of C4 to A in the EAC1q4 site.