Operation of a silicon quantum processor unit cell above one kelvin.

Quantum computers are expected to outperform conventional computers in several important applications, from molecular simulation to search algorithms, once they can be scaled up to large numbers-typically millions-of quantum bits (qubits)1-3. For most solid-state qubit technologies-for example, those using superconducting circuits or semiconductor spins-scaling poses a considerable challenge because every additional qubit increases the heat generated, whereas the cooling power of dilution refrigerators is severely limited at their operating temperature (less than 100 millikelvin)4-6. Here we demonstrate the operation of a scalable silicon quantum processor unit cell comprising two qubits confined to quantum dots at about 1.5 kelvin. We achieve this by isolating the quantum dots from the electron reservoir, and then initializing and reading the qubits solely via tunnelling of electrons between the two quantum dots7-9. We coherently control the qubits using electrically driven spin resonance10,11 in isotopically enriched silicon12 28Si, attaining single-qubit gate fidelities of 98.6 per cent and a coherence time of 2 microseconds during 'hot' operation, comparable to those of spin qubits in natural silicon at millikelvin temperatures13-16. Furthermore, we show that the unit cell can be operated at magnetic fields as low as 0.1 tesla, corresponding to a qubit control frequency of 3.5 gigahertz, where the qubit energy is well below the thermal energy. The unit cell constitutes the core building block of a full-scale silicon quantum computer and satisfies layout constraints required by error-correction architectures8,17. Our work indicates that a spin-based quantum computer could be operated at increased temperatures in a simple pumped 4He system (which provides cooling power orders of magnitude higher than that of dilution refrigerators), thus potentially enabling the integration of classical control electronics with the qubit array18,19.

Fidelity benchmarks for two-qubit gates in silicon.

Universal quantum computation will require qubit technology based on a scalable platform1, together with quantum error correction protocols that place strict limits on the maximum infidelities for one- and two-qubit gate operations2,3. Although various qubit systems have shown high fidelities at the one-qubit level4-10, the only solid-state qubits manufactured using standard lithographic techniques that have demonstrated two-qubit fidelities near the fault-tolerance threshold6 have been in superconductor systems. Silicon-based quantum dot qubits are also amenable to large-scale fabrication and can achieve high single-qubit gate fidelities (exceeding 99.9 per cent) using isotopically enriched silicon11,12. Two-qubit gates have now been demonstrated in a number of systems13-15, but as yet an accurate assessment of their fidelities using Clifford-based randomized benchmarking, which uses sequences of randomly chosen gates to measure the error, has not been achieved. Here, for qubits encoded on the electron spin states of gate-defined quantum dots, we demonstrate Bell state tomography with fidelities ranging from 80 to 89 per cent, and two-qubit randomized benchmarking with an average Clifford gate fidelity of 94.7 per cent and an average controlled-rotation fidelity of 98 per cent. These fidelities are found to be limited by the relatively long gate times used here compared with the decoherence times of the qubits. Silicon qubit designs employing fast gate operations with high Rabi frequencies16,17, together with advanced pulsing techniques18, should therefore enable much higher fidelities in the near future.

Effects of radial stress on piezoelectric ceramic tubes and transducers.

Static analysis is performed for fiber windings to quantitatively control the radial stress at the outer radius of the piezoelectric ceramic tube. The radial stress is verified both experimentally and theoretically, and the dependence of the resonant and material properties of the piezoelectric ceramic tubes on the radial stress is clarified. The resonance frequencies and dielectric loss remain relatively stable, but the relative permittivity and the short circuit elastic constant decrease with the radial stress. The variations of the increased bandwidth and decreased electromechanical coupling coefficient (k31), piezoelectric constant (d31 and g31), and mechanical quality factor (Qm) are associated with the height-to-radius ratio. The properties of three cylindrical transducers applied with various radial stress show similar change tendencies, and a difference of 0.34 MPa radial stress results in a variation of approximately 13 in the bandwidth, 14 in Qm, 15 in k31, d31, and g31, and 16 in the amplitude of the first pulse. These results suggest that the consistency of the radial stress is essential, and it should be relatively small. These findings guide the design and preparation of the enhanced transducer.

[Two cases of Wolfram syndrome].

Two adolescents with T1DM participated in the Shanghai Children and Adolescent DM Eye study (SCADE) 2017-2018. The previous T1DM history of the 2 children were 12 years and 4 years respectively. The history of optic atrophy were 8 years and 4 years respectively. The ophthalmic examination showed that there were slight posterior capsule cataract and atrophy of optic atrophy in both patients. Optical Coherance Tomographic examination showed that the choroidal thickness of the inferior inner ring of the optic nerve and RNFL layer thickness decreased markedly, perfusion density and vascular density of the optic disc area and macular decreased markedly, electrophysiological examination showed that amplitude decreased markedly, and visual field examination showed binocular extinction or tubular vision field. Now the 2 adolescents were in closely followed-up. We suggest that children with T1DM whose best corrected visual acuity decreased recently to 0.6 or lower, in addition to routine ophthalmic examination, choroidal thickness, retinal nerve fiber layer thickness, retinal blood flow, ERG and visual field examination are recommended to distinguish wolfram syndrome from T1DM. Genetic sequencing examination of WFS-1 is also recommended if possible.

A two-qubit logic gate in silicon.

Quantum computation requires qubits that can be coupled in a scalable manner, together with universal and high-fidelity one- and two-qubit logic gates. Many physical realizations of qubits exist, including single photons, trapped ions, superconducting circuits, single defects or atoms in diamond and silicon, and semiconductor quantum dots, with single-qubit fidelities that exceed the stringent thresholds required for fault-tolerant quantum computing. Despite this, high-fidelity two-qubit gates in the solid state that can be manufactured using standard lithographic techniques have so far been limited to superconducting qubits, owing to the difficulties of coupling qubits and dephasing in semiconductor systems. Here we present a two-qubit logic gate, which uses single spins in isotopically enriched silicon and is realized by performing single- and two-qubit operations in a quantum dot system using the exchange interaction, as envisaged in the Loss-DiVincenzo proposal. We realize CNOT gates via controlled-phase operations combined with single-qubit operations. Direct gate-voltage control provides single-qubit addressability, together with a switchable exchange interaction that is used in the two-qubit controlled-phase gate. By independently reading out both qubits, we measure clear anticorrelations in the two-spin probabilities of the CNOT gate.

[Auxiliary pathological diagnosis algorithm based on color moments for frozen-section of thyroid cancer].

Objective: To develop a color-moment based model for frozen-section diagnosis of thyroid lesions, and to evaluate the model's value in the frozen-section diagnosis of thyroid cancer. Methods: In this study, 550 frozen thyroid pathological slides, including malignant and non-malignant cases, were collected from Taizhou Central Hospital (Taizhou University Hospital), China, between June 2018 and January 2020. The 550 digitalized frozen-section slides of thyroid were divided into training set (190 slides), validation set (48 slides), test set A (60 slides) and test set B (252 slides). The tumor regions on the slides of malignant cases in the training and validation sets were labeled by pathologists. The labeling information was then used to train the thyroid frozen-section diagnosis models based on the voting method and those based on the color moment. Finally, the performance of two pathological slide diagnosis models was evaluated using the test set A and test set B, respectively. Result: The classification accuracy of the thyroid frozen-section diagnosis model based on the voting method was 90.0% and 83.7%, using test sets A and B, respectively, while that based on color moments was 91.6% and 90.9%, respectively. For actual frozen-section diagnosis of thyroid cancer, the model developed in this study had higher accuracy and stability. Conclusion: This study proposes a color-moment based frozen-section diagnosis model, which is more accurate than other classification models for frozen-section diagnoses of thyroid cancer.

Autonomic dysfunction as an independent risk factor for uncontrolled inflammation in chronic rhinosinusitis following functional endoscopic sinus surgery.

BACKGROUND: Chronic rhinosinusitis (CRS) is a multi-factorial disorder that causes systemic symptoms beyond rhinologic symptoms alone. A possible association between autonomic nervous system (ANS) dysfunction and CRS has been identified; however, few studies have confirmed this observation. In this study, we prospectively measured changes in ANS dysfunction symptoms following functional endoscopic sinus surgery (FESS) and explored the impact of ANS dysfunction on surgical outcomes of CRS. METHODOLOGY: Patients diagnosed with CRS who consented to surgical intervention were included prospectively. All patients completed the Sino-nasal Outcome Test-22 (SNOT-22) and the 31-item Composite Autonomic Symptom Score (COMPASS 31) questionnaires before the operation and during the follow-up period. Clinical demographic data, Lund-Mackay, and modified Lund-Kennedy scores were recorded and measured. RESULTS: A total of 102 patients were enrolled. The median SNOT-22 and COMPASS 31 scores significantly improved following FESS from 43.0 to 14.0 and 21.0 to 11.2 (all P less than 0.001), respectively. FESS led to a significant reduction in the prevalence of various ANS dysfunction symptoms. In multivariate analyses, revision surgeries (odds ratio [OR] 5.012, 95% confidence interval [CI] 1.52416.489; P=0.008), CRS with nasal polyps (OR 4.071, 95% CI 1.454-11.40; P=0.008), and higher Pre-FESS COMPASS 31 scores (OR 1.043, 95% CI 1.003-1.084; P=0.036) were independent risk factors for uncontrolled inflammation following FESS. CONCLUSIONS: ANS dysfunction symptoms are prevalent in CRS and higher preoperative COMPASS 31 scores correspond with poor surgical outcomes. Following FESS, the majority of ANS dysfunction symptoms can be alleviated. Further investigations are required to explore the possible mechanism of how ANS is involved in the pathogenesis of CRS.

Delayed-type hypersensitivity reactions induced by proton pump inhibitors: A clinical and in vitro T-cell reactivity study.

BACKGROUND: Proton pump inhibitors (PPIs) have been known to induce type I hypersensitivity reactions. However, severe delayed-type hypersensitivity reactions (DHR) induced by PPI, such as Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), or drug rash with eosinophilia and systemic symptoms (DRESS), are rarely reported. We conducted a study of a large series of PPI-related DHR, followed up their tolerability to alternative anti-ulcer agents, and investigated the T-cell reactivity to PPI in PPI-related DHR patients. METHODS: We retrospectively analyzed patients with PPI-related DHR from multiple medical centers in Taiwan during the study period January 2003 to April 2016. We analyzed the causative PPI, clinical manifestations, organ involvement, treatment, and complications. We also followed up the potential risk of cross-hypersensitivity or tolerability to other PPI after their hypersensitivity episodes. Drug lymphocyte activation test (LAT) was conducted by measuring granulysin and interferon-γ to confirm the causalities. RESULTS: There were 69 cases of PPI-related DHR, including SJS/TEN (n=27) and DRESS (n=10). The LAT by measuring granulysin showed a sensitivity of 59.3% and specificity of 96.4%. Esomeprazole was the most commonly involved in PPI-related DHR (51%). Thirteen patients allergic to one kind of PPI could tolerate other structurally different PPI without cross-hypersensitivity reactions, whereas three patients developed cross-hypersensitivity reactions to alternative structurally similar PPI. The cross-reactivity to structurally similar PPI was also observed in LAT assay. CONCLUSIONS: PPIs have the potential to induce life-threatening DHR. In patients when PPI is necessary for treatment, switching to structurally different alternatives should be considered.

Periorbital erythema and swelling as a presenting sign of lupus erythematosus in tertiary referral centers and literature review.

Background Cutaneous lupus erythematosus (CLE) includes a broad range of dermatologic manifestations. Periorbital involvement, however, is a relatively rare clinical presentation of CLE. Objectives This clinical study aimed to investigate the characteristics of this unique presentation of CLE in tertiary medical centers. Methods We enrolled patients with periorbital erythema and swelling as the presenting sign of lupus erythematosus, from January 2003 to November 2017, using the data of 553 pathologically proven CLE cases from the registration database of the Chang Gung Memorial Hospitals in Taiwan. Results We enrolled a total of 25 patients. The mean age was 46.7 years and 68% of the patients were female. Most of the patients (84.0%) presented with unilateral involvement, with the left orbit involved in 15 patients (60%); the upper eyelid was the most frequently involved (72%). Mean duration between the onset of clinical manifestations and the diagnosis of CLE was approximately 59 weeks. Nineteen patients had been previously misdiagnosed. All patients had features compatible with CLE on histopathological examination. In contrast, laboratory analysis of the autoimmune profile often revealed negative results, including those for antinuclear antibodies (25%). Notably, anti-SSA/SSB (45.5%) showed the highest positive rate. During follow-up, six patients developed systemic lupus erythematosus (SLE) and two patients developed Sjögren syndrome. Conclusions The diagnosis of CLE presenting as periorbital erythema and swelling is often delayed because of clinical mimicry and the high proportion of negative results on autoantibody tests. Increased clinical suspicion and prompt histopathological examination are crucial for early diagnosis. Moreover, one-fourth of the patients ultimately developed SLE, which highlights the importance of clinical awareness.

[Human umbilical cord mesenchymal stem cell transplantation for the treatment of two noncontinuous segments spinal cord compression injury in rabbits].

Objective: In order to explore the effects of human umbilical cord mesenchymal stem cells (UCMSC) transplantation on the treatment of two noncontinuous segments spinal cord compression injury and to investigate whether repeated intravenous injection UCMSC was more beneficial for the recovery of spinal cord function. Methods: A total of 30 adult rabbits were randomly divided into three groups: control group (received PBS), single injection group, repeated injection group with 3 days intervals. A noncontinuous two segments SCI model was established by using the 2F Fogarty balloon catheter. Rabbits were infused with either a single total dose or three divided doses of 2×10(6) UCMSC (3 intervals) at first day post-decompreesion. Behavioral scores, somatosensory evoked potentials (SSEP) and histopathological were used to evaluate therapeutic effects. The rates of stem cell homing were studied by immunofluorescence test and the apoptosis of the spinal cord was evaluated by TUNEL test. Results: Behavior alanalyses showed that the rabbits in the UCMSC injection groups showed better motor performance than those in the control group (P<0.01), and the motor performance in the repeated transplantation group was better than that in the single transplantation group (P<0.01). The SSEP latencies were (22.53±0.75) ms, (24.52±0.45) ms and (26.31±0.69) ms in the repeated injection group, single injection group and control group (all P<0.01), respectively. Treatment with UCMSC increased ventral horn motor neurons preservation and decreased the number of TUNEL-positive cells compared with control group (P<0.01). The rates of stem cell homing in the repeated injection group was significantly higher than that in single injection group (P<0.01). Conclusion: Transplantation of UCMSC after spinal cord compression injury of two noncontinuous segments can promote functional recovery through enhancement anti-apoptotic and neuroprotective effects, and the recovery was more pronounced in the rabbits repeatedly injected at 3-day intervals.

The GGDEF-domain protein GdpX1 attenuates motility, exopolysaccharide production and virulence in Xanthomonas oryzae pv. oryzae.

AIMS: Cyclic di-GMP (c-di-GMP), a ubiquitous bacterial second messenger that is synthesized by diguanylate cyclase (DGC) with the GGDEF-domain, regulates diverse virulence phenotypes in pathogenic bacteria. Although 11 genes encoding GGDEF-domain proteins have been shown in the genome of Xanthomonas oryzae pv. oryzae (Xoo) strain PXO99(A) , the causal pathogen of bacterial blight of rice, however, little is known about their roles in the c-di-GMP regulation of virulence in the pathogen. GdpX1, one of the GGDEF-domain proteins in Xoo was investigated in this study to reveal its regulatory function of bacterial virulence expression through genetic analysis. METHODS AND RESULTS: GdpX1 was functionally characterized in virulence expression through deletion and overexpression analysis. Bioinformatics analysis revealed the GGDEF-domain in GdpX1 was well conserved, indicating it is a putative DGC. Deletion of gdpX1 resulted in significant increases in virulence, exopolysaccharide (EPS) production and flagellar motility. In contrast, overexpression of gdpX1 dramatically reduced these virulence phenotypes. qRT-PCR analysis showed genes related to the type III secretion system (T3SS), EPS synthesis, and flagellar motility, were up-regulated in ∆gdpX1 and down-regulated in the gdpX1-overexpressed strains. In addition, overexpression of gdpX1 promoted biofilm formation and xylanase activity. CONCLUSION: GdpX1 is the first GGDEF-domain protein functionally characterized in Xoo, which functions as a negative regulator of bacterial virulence via suppression of virulence-related gene transcription. SIGNIFICANCE AND IMPACT OF THE STUDY: Identification and functional characterization of GdpX1 provided additional insights into molecular mechanisms of c-di-GMP regulation of bacterial virulence expression.

The microRNA expression profile in porcine skeletal muscle is changed by constant heat stress.

Heat stress has profound effects on animal performance and muscle function, and microRNAs (miRNAs) play a critical role in muscle development and stress responses. To characterize the changes in miRNAs in skeletal muscle responding to heat stress, the miRNA expression profiles of longissimus dorsi muscles of pigs raised under constant heat stress (30 °C; n = 8) or control temperature (22 °C; n = 8) for 21 days were analyzed by Illumina deep sequencing. A total of 58 differentially expressed miRNAs were identified with 30 down-regulated and 28 up-regulated, and 63 differentially expressed target genes were predicted by miRNA-mRNA joint analysis. GO and KEGG analyses showed that the genes regulated by differentially expressed miRNAs were enriched in glucose metabolism, cytoskeletal structure and function and stress response. Real-time PCR showed that the mRNA levels of PDK4, HSP90 and DES were significantly increased, whereas those of SCD and LDHA significantly decreased by heat exposure. The protein levels of CALM1, DES and HIF1α were also significantly increased by constant heat. These results demonstrated that the change in miRNA expression in porcine longissimus dorsi muscle underlies the changes in muscle structure and metabolism in porcine skeletal muscle affected by constant heat stress.

Effects and mechanism of Tripterygium wilfordii on chronic glomerulo nephritis.

The objective of this study was to investigate the clinical effects of Tripterygium wilfordii on chronic glomerulo nephritis (CGN) and its mechanisms. Eighty-two cases of CGN treated in our hospital were randomly divided into observation and control groups. The control group was treated with conventional western medicine, and the observation group was treated with conventional western medicine and orally-administered T. wilfordii pills for three courses of treatment, each consisting of 4 weeks. Changes in serum reatinine, blood urea nitrogen, blood total cholesterol, blood albumin, and 24-h urine protein were observed. The levels of peripheral tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were determined with enzyme-linked immunosorbent assay. The curative effects of both groups were evaluated respectively. Both groups had significantly improved serum creatinine, blood urea nitrogen, blood total cholesterol, blood albumin, and 24-h urine protein (P < 0.05), and the observation group exhibited a more significant improvement (P < 0.05). TNF-α and IL-6 levels in both groups obviously decreased (P < 0.05), and the observation group exhibited remarkable changes (P < 0.05). After treatment, the total efficiency of the observation group was 90.24%, which was significantly higher than the 73.17% of the control group (P < 0.05). In conclusion, T. wilfordii can significantly improve kidney function and clinical symptoms in CGN patients, and the mechanism is possibly related to its inhibition of the secretion of TNF-α and IL-6.

A novel splice variant of the bovine GALNTL5 gene identified in Chinese Holstein bull testis tissue and its mRNA expression.

The polypeptide N-acetylgalactosaminyltransferase-like protein 5 (GALNTL5) is a newly identified protein that is specifically expressed in testis tissue and participates in spermatogenesis. In this study, we characterized a novel bovine GALNTL5 splice variant, designated as GALNTL5-AS, by using real-time polymerase chain reaction (RT-PCR) and clone sequencing methods. The novel GALNTL5 isoform was derived from the complete transcript, GALNTL5-complete, via alternative splicing (AS). The pattern of the splice variant was exon skipping. Bovine GALNTL5 transcripts were expressed in the testis, as demonstrated by RT-PCR. The expression levels of both transcripts were higher in adult testes than in calf testes (P < 0.05). In addition, prediction analysis showed that the GALNTL5-AS transcript only encoded 122 amino acids and lost its glycosyltransferase 1 and Gal/GalNAc-T motifs, which may result in a dysfunctional protein compared with the predominant transcript GALNTL5-complete. This study improves our understanding of the bovine GALNTL5 gene function during bull sperm formation.

Identification of CD14 transcript in blood polymorphonuclear neutrophil leukocytes and functional variation in Holsteins.

Polymorphonuclear neutrophil (PMN) leukocytes are primary phagocytic cells of the bovine mammary gland and a first line of defense against invading pathogens during bovine mastitis infection. Cluster of differentiation 14 (CD14) is mainly expressed in macrophages and neutrophils and acts as a co-receptor that binds bacterial lipopolysaccharide (LPS) and recruits PMNs to CD14-LPS complexes in mammary epithelial cells. In this study, we identified a novel splice variant in PMNs, named CD14-SV, characterized by a deleted region from c.143-579 nt compared to the CD14 reference mRNA sequence. Moreover, a single nucleotide polymorphism (c.523 A>G) in exon 2 of CD14 was identified and found to modify the secondary structure and hydrophilicity of the CD14 protein. Association analysis also showed that the milk somatic cell score, an indicator of mastitis, of cows with the GG genotype was lower than that of cows with the AA and AG genotypes. Our findings suggest that the expression of CD14 in bovine blood PMNs is regulated by alternative splicing, and that CD14-SV is a candidate functional marker that may influence mastitis-resistance in dairy cows.

Stevens-Johnson syndrome and toxic epidermal necrolysis in patients with malignancies.

BACKGROUND: Malignancy is known to be associated with an increased mortality rate in patients with Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). However, risk factors contributing to the poor prognosis of patients with SJS/TEN with malignancies remain undefined. OBJECTIVES: To explore the potential involvement of malignancy and its related factors contributing to the poor outcome of SJS/TEN, in a retrospective study. METHODS: In total 517 patients with SJS/TEN were enrolled. Forty-seven who sustained various types of malignancies were analysed for numerous malignancy-related factors, including cancer types, clinical stages and chemotherapies given or not before the onset of SJS/TEN. RESULTS: We found that the mortality rate of patients with SJS/TEN with malignancies was higher than that of patients without malignancies (32%, 15/47 vs. 8·5%, 40/470, respectively) (P < 0·001). The use of phenytoin was significantly higher in the malignancy group. The presence of hepatocellular carcinoma (80%, four of five; P < 0·001; odds ratio 43) and colorectal cancer (67%, two of three; P = 0·022; odds ratio 21·5) significantly increased the death rate of patients with SJS/TEN, whereas lung cancer and urothelial carcinoma did not. Patients who had received ongoing or recent chemotherapy showed higher mortality than those without chemotherapy (P = 0·022; odds ratio 4·95). Furthermore, among the 47 patients with SJS/TEN with malignancies, lower serum albumin, haemoglobin and platelet count were detected in the deceased patients than in the surviving patients before the onset of SJS/TEN. CONCLUSIONS: Our results suggest that several factors related to malignancies, such as specific cancer types, chemotherapy and malnutrition, may contribute to poor prognosis in patients with malignancies developing SJS/TEN.

Serological comparison of antibodies to avian influenza viruses, subtypes H5N2, H6N1, H7N3 and H7N9 between poultry workers and non-poultry workers in Taiwan in 2012.

In Taiwan, avian influenza virus (AIV) subtypes H5N2, H6N1 and H7N3 have been identified in domestic poultry, and several strains of these subtypes have become endemic in poultry. To evaluate the potential of avian-to-human transmission due to occupational exposure, an exploratory analysis of AIV antibody status in poultry workers was conducted. We enrolled 670 poultry workers, including 335 live poultry vendors (LPVs), 335 poultry farmers (PFs), and 577 non-poultry workers (NPWs). Serum antibody titres against various subtypes of viruses were analysed and compared. The overall seropositivity rates in LPVs and PFs were 2·99% (10/335) and 1·79% (6/335), respectively, against H5N2; and 0·6% (2/335) and 1·19% (4/335), respectively, for H7N3 virus. Of NPWs, 0·35% (2/577) and 0·17% (1/577) were seropositive for H5N2 and H7N3, respectively. Geographical analysis revealed that poultry workers whose workplaces were near locations where H5N2 outbreaks in poultry have been reported face greater risks of being exposed to viruses that result in elevated H5N2 antibody titres. H6N1 antibodies were detected in only one PF, and no H7N9 antibodies were found in the study subjects. Subclinical infections caused by H5N2, H6N1 and H7N3 viruses were thus identified in poultry workers in Taiwan. Occupational exposure is associated with a high risk of AIV infection, and the seroprevalence of particular avian influenza strains in humans reflects the endemic strains in poultry in this region.

Interface control of bulk ferroelectric polarization.

The control of material interfaces at the atomic level has led to novel interfacial properties and functionalities. In particular, the study of polar discontinuities at interfaces between complex oxides lies at the frontier of modern condensed matter research. Here we employ a combination of experimental measurements and theoretical calculations to demonstrate the control of a bulk property, namely ferroelectric polarization, of a heteroepitaxial bilayer by precise atomic-scale interface engineering. More specifically, the control is achieved by exploiting the interfacial valence mismatch to influence the electrostatic potential step across the interface, which manifests itself as the biased-voltage in ferroelectric hysteresis loops and determines the ferroelectric state. A broad study of diverse systems comprising different ferroelectrics and conducting perovskite underlayers extends the generality of this phenomenon.

Inhibition of melanogenesis by ß-caryophyllene from lime mint essential oil in mouse B16 melanoma cells.

OBJECTIVE: Volatile essential oils of mint species are used for cosmetics and in skin care products. In this study, we evaluated the main chemical components of the lime mint and the anti-melanogenic properties of its main components. METHODS: The essential oil was analysed by gas chromatography-mass spectrometry (GC/MS). The anti-melanogenic effects of mint essential oil and ß-caryophyllene were investigated in B16F10 murine melanoma cells. RESULTS: The main components of lime mint essential oil were found to be D-limonene (41.10%), D-carvone (8.58%), δ-selinene (6.73%) and ß-caryophyllene (6.24%). The lime mint essential oil reduced melanin production in a dose-dependent manner in murine B16F10 cells. ß-Caryophyllene, one of the main compounds in lime mint essential oil, could reduce melanogenesis by down-regulating the expression of MITF, TRP-1, TRP-2 and tyrosinase, resulting in a decrease in melanin content decrease. CONCLUSION: These results reveal that lime mint essential oil and ß-caryophyllene are considered to be valuable as potential skin-whitening agents.