Enhancing the performance of mode-pairing quantum key distribution by wavelength division multiplexing.

Mode-pairing quantum key distribution (MP-QKD) holds great promise for the practical implementation of QKD in the near future. It combines the security advantages of measurement device independence while still being capable of breaking the Pirandola-Laurenza-Ottaviani-Banchi bound without the need for highly demanding phase-locking and phase-tracking technologies for deployment. In this work, we explore optimization strategies for MP-QKD in a wavelength-division multiplexing scenario. The simulation results reveal that incorporation of multiple wavelengths not only leads to a direct increase in key rate but also enhances the pairing efficiency by employing our novel pairing strategies among different wavelengths. As a result, our work provides a new avenue for the future application and development of MP-QKD.

Novel Tu translation elongation factor, mitochondrial (TUFM) homozygous variant in a consanguineous family with premature ovarian insufficiency.

Premature ovarian insufficiency (POI) is a clinical syndrome of ovarian dysfunction characterized by cessation of menstruation occurring before the age of 40 years. The genetic causes of idiopathic POI remain unclear. Here we recruited a POI patient from a consanguineous family to screen for potential pathogenic variants associated with POI. Genetic variants of the pedigree were screened using whole-exome sequencing analysis and validated through direct Sanger sequencing. A homozygous variant in TUFM (c.524G>C: p.Gly175Ala) was identified in this family. TUFM (Tu translation elongation factor, mitochondrial) is a nuclear-encoded mitochondrial protein translation elongation factor that plays a critical role in maintaining normal mitochondrial function. The variant position was highly conserved among species and predicted to be disease causing. Our in vitro functional studies demonstrated that this variant causes decreased TUFM protein expression, leading to mitochondrial dysfunction and impaired autophagy activation. Moreover, we found that mice with targeted Tufm variant recapitulated the phenotypes of human POI. Thus, this is the first report of a homozygous pathogenic TUFM variant in POI. Our findings highlighted the essential role of mitochondrial genes in folliculogenesis and ovarian function maintenance.

Boosting the performance of loss-tolerant measurement-device-independent quantum key distribution.

Measurement-device-independent quantum key distribution can remove all possible detector side channels, and is robust against state preparation flaws when further combined with the loss-tolerant method. However, the secure key rate in this scenario is relatively low, thus hindering its practical application. Here, we first present a four-intensity decoy-state protocol where the signal intensity is modulated only in Z basis for key generation while the decoy intensities are modulated in both Z and X bases for parameter estimation. Moreover, we adopt collective constraint and joint-study strategy in statistical fluctuation analysis. We have also experimentally demonstrated this protocol and the result indicates high performance and good security for practical applications.

Elevated cell-free mitochondria DNA level of patients with premature ovarian insufficiency.

BACKGROUND: Premature ovarian insufficiency (POI) patients present with a chronic inflammatory state. Cell-free mitochondria DNA (cf-mtDNA) has been explored as a reliable biomarker for estimating the inflammation-related disorders, however, the cf-mtDNA levels in POI patients have never been measured. Therefore, in the presenting study, we aimed to evaluate the levels of cf-mtDNA in plasma and follicular fluid (FF) of POI patients and to determine a potential role of cf-mtDNA in predicting the disease progress and pregnancy outcomes. METHODS: We collected plasma and FF samples from POI patients, biochemical POI (bPOI) patients and control women. Quantitative real-time PCR was used to measure the ratio of mitochondrial genome to nuclear genome of cf-DNAs extracted from the plasma and FF samples. RESULTS: The plasma cf-mtDNA levels, including COX3, CYB, ND1 and mtDNA79, were significantly higher in overt POI patients than those in bPOI patients or control women. The plasma cf-mtDNA levels were weakly correlated with ovarian reserve, and could not be improved by regular hormone replacement therapy. The levels of cf-mtDNA in FF, rather than those in plasma, exhibited the potential to predict the pregnancy outcomes, although they were comparable among overt POI, bPOI and control groups. CONCLUSIONS: The increased plasma cf-mtDNA levels in overt POI patients indicated its role in the progress of POI and the FF cf-mtDNA content may hold the value in predicting pregnancy outcomes of POI patients.

Photoswitchable Enantioselective and Helix-Sense Controlled Living Polymerization.

A pair of enantiomeric photoswitchable PdII catalysts, alkyne-PdII /LR-azo and alkyne-PdII /LS-azo , were prepared via the coordination of alkyne-PdII and azobenzene-modified phosphine ligands LR-azo and LS-azo . Owing to the cis-trans photoisomerization of the azobenzene moiety, alkyne-PdII /LR-azo and alkyne-PdII /LS-azo exhibited different polymerization activities, helix-sense selectivities, and enantioselectivities during the polymerization of isocyanide monomers under irradiation of different wavelength lights. Furthermore, the achiral isocyanide monomer A-1 could be polymerized efficiently using alkyne-PdII /LR-azo under dark condition in a living/controlled manner. Further, it generated single right-handed helical poly-A-1m (LR-azo ), confirmed by the circular dichroism spectra and atomic force microscopy images. However, the polymerization of A-1 almost could not be initiated under 420 nm light in identical conditions of dark condition. Moreover, the photoswitchable catalyst alkyne-PdII /LR-azo exhibited high enantioselectivity for the polymerization of the racemates of L-1 and D-1, respectively. D-1 was polymerized preferentially under dark condition with a D-1/L-1 rate ratio of 70, yielding single right-handed polyisocyanides. Additionally, reversible enantioselectivity was observed under 420 nm light using alkyne-PdII /LR-azo , and the calculated polymerization rate ratio of L-1/D-1 was 57 because of the isomerization of the azobenzene moiety of the catalyst. Furthermore, alkyne-PdII /LS-azo showed opposite enantioselectivity and helix-sense selectivity during the polymerization of the racemates of L-1 and D-1.

Measurement-device-independent quantum key distribution with insecure sources.

Measurement-device-independent quantum key distribution (MDI-QKD) can remove all detection side channels but still makes additional assumptions on sources that can be compromised through uncharacterized side channels in practice. Here, we combine a recently proposed reference technique to prove the security of MDI-QKD against possible source imperfections and/or side channels. This requires some reference states and an upper bound on the parameter that describes the quality of the sources. With this formalism we investigate the asymptotic performance of single-photon sources, and the results show that the side channels have a great impact on the key rates.

Effect of gelatin content and oral processing ability on vitamin C release in gummy jelly.

In order to investigate the factors affecting the release of vitamin C (VC) in gummy jelly during oral processing, four levels of gelatin (3%, 6%, 9% and 12%) were selected and a bionic chewing robot was employed in chewing experiments. Textural profile analysis showed the hardness of gummy jelly increased from 91.7 N to 198.8 N when the gelatin content was raised from 3 to 12%. Single factor chewing experiment showed that the release of VC was positively correlated with chewing frequency (Fchew) and chewing strain (STchew), while negatively correlated with gelatin content, chewing speed (SPchew) and volume of saliva (Vsaliva). Orthogonal chewing experiment showed that the priority of the factors affected the release of VC was following: STchew > Fchew > SPchew > Vsaliva. Multivariate linear regression analysis proposed a model to predict the amount of VC released and the goodness-of-fit of the model was 95.7%. The amount of VC released was the highest under the combination of Fchew 12 times, STchew 100%, Vsaliva 2 ml and SPchew 40 times/min. The optimal amount of gelatin addition was 6%. This study provided an effective reference for the formula design and chewing mode optimization of gummy jelly.

Experimental three-state measurement-device-independent quantum key distribution with uncharacterized sources.

Measurement-device-independent quantum key distribution (MDI-QKD) removes all detector side-channel attacks and guarantees a promising way for remote secret keys sharing. Several proof-of-principal experiments have been demonstrated to show its security and practicality. However, these practical implementations demand mostly, for example, perfect state preparation or completely characterized sources to ensure security, which are difficult to realize with prior art. Here, we investigate a three-state MDI-QKD using uncharacterized sources, with the simple requirement that the encoding state is bidimensional, which eliminates security threats from both the source flaws and detection loopholes. As a demonstration, a proof-of-principal experiment over 170 km transmission distance based on Faraday-Michelson interferometers is achieved, representing, to the best of our knowledge, the longest transmission distance recorded under the same security level.

280-km experimental demonstration of a quantum digital signature with one decoy state.

A quantum digital signature (QDS) guarantees the unforgeability, nonrepudiation, and transferability of signature messages with information-theoretic security, and hence has attracted much attention recently. However, most previous implementations of QDS showed relatively low signature rates and/or short transmission distance. In this Letter, we report a proof-of-principle phase-encoding QDS demonstration using only one decoy state. First, such a method avoids the modulation of the vacuum state, thus reducing experimental complexity and random number consumption. Moreover, incorporated with low-loss asymmetric Mach-Zehnder interferometers and a real-time polarization calibration technique, we have successfully achieved a higher signature rate, e.g., 0.98 bit/s at 103 km, and to date, a record-breaking, to the best of our knowledge, transmission distance of over 280-km installed fibers. Our work represents a significant step towards real-world applications of QDS.

Long non-coding RNA TUG1 and its molecular mechanisms in polycystic ovary syndrome.

Polycystic ovary syndrome (PCOS) causes anovulatory infertility in women of reproductive age, but etiopathogenesis of PCOS remains undetermined. Taurine up-regulated 1 (TUG1), an evolutionarily conserved long non-coding RNA, performs various biological functions; however, the role of TUG1 in PCOS remains unclear. Herein, TUG1 expression was assayed in granulosa cells (GCs) of 100 patients with PCOS and 100 control participants. Receiver operating characteristic (ROC) curve analysis was conducted to determine the diagnostic value of TUG1 in PCOS. TUG1 expression was also silenced in KGN cells to explore the role of TUG1 in cellular proliferation, apoptosis, cell-cycle progression, autophagy, and steroidogenesis. We found that TUG1 levels were dramatically increased in the PCOS group compared with those of the control group; this increased expression was related to a rising antral follicle count (R = 0.209, P < 0.001 versus control). The ROC curve indicated a significant separation between PCOS group and the control group (AUC: 0.702; 95% CI: 0.630-0.773; P < 0.001). TUG1 showed a predominantly nuclear localization in human GCs. TUG1 knockdown reduced cellular proliferation, and promoted MAPKs pathway-dependent apoptosis and P21-dependent autophagy, but may not affect cell-cycle progression. TUG1 knockdown increased aromatase expression and oestradiol biosynthesis. Our results indicate that increased TUG1 expression in PCOS GCs may contribute to excessive follicular activation and growth, and may disrupt the selection of dominant follicle. Our study shows that TUG1 can be used as a diagnostic biomarker for PCOS.

Synthesis and molecular docking studies of novel pyrimidine derivatives as potential antibacterial agents.

The present work describes the in vitro antibacterial evaluation of some new pyrimidine derivatives. Twenty-two target compounds were designed, synthesized and preliminarily explored for their antimicrobial activities. The antimicrobial assay revealed that some target compounds exhibited significantly inhibitory efficiencies toward bacteria and fungal including drug-resistant pathogens. Compound 7c presented the most potent inhibitory activities against Gram-positive bacteria (e.g., Staphylococcus aureus 4220), Gram-negative bacteria (e.g., Escherichia coli 1924) and the fungus Candida albicans 7535, with an MIC of 2.4 µmol/L. Compound 7c was also the most potent, with MICs of 2.4 or 4.8 µmol/L against four multidrug-resistant, Gram-positive bacterial strains. The toxicity evaluation of the compounds 7c, 10a, 19d and 26b was assessed in human normal liver cells (L02 cells). Molecular docking simulation and analysis suggested that compound 7c has a good interaction with the active cavities of dihydrofolate reductase (DHFR). In vitro enzyme study implied that compound 7c also displayed DHFR inhibition.

Down-regulation of long non-coding RNA MALAT1 inhibits granulosa cell proliferation in endometriosis by up-regulating P21 via activation of the ERK/MAPK pathway.

STUDY QUESTION: Is there a specific mechanism underlying the association between lung adenocarcinoma transcript 1 (MALAT1) and endometriosis-related infertility? SUMMARY ANSWER: The down-regulation of MALAT1 in endometriosis granulosa cells (GCs) may have an adverse effect on the growth and development of oocytes by inhibiting GC proliferation, due to cell cycle-dependent mechanisms that enhance P21 expression through activation of the extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) pathway. WHAT IS KNOWN ALREADY: The association between endometriosis and infertility is well supported throughout the literature, and endometriosis per se and its surgical treatment have an adverse effect on the ovarian reserve and on oocyte development. MALAT1, one of the most extensively expressed and evolutionarily conserved transcripts, has been implicated to play a role in human development and many diseases. However, little is known about the role of MALAT1 long non-coding RNA (lncRNA) in endometriosis and its associated infertility. STUDY DESIGN, SIZE, DURATION: We measured MALAT1 lncRNA expression levels in GCs from 52 endometriosis patients and 52 controls. Also, MALAT1 was knocked down in a human GC tumor-derived cell line, KGN, to investigate the role of MALAT1 and its molecular mechanism in cell proliferation. PARTICIPANTS/MATERIALS, SETTING, METHODS: GCs were collected from women with or without endometriosis undergoing IVF or ICSI treatment. All endometriosis patients were diagnosed by laparoscopy or laparotomy, and control patients were limited to male factor or tubal disease and had a normal ovarian reserve. Quantitative real-time PCR (qRT-PCR) was used to measure the differential expression levels of MALAT1 lncRNA between endometriosis patients and controls. The receiver operating characteristic (ROC) curve was drawn to evaluate the diagnostic values of MALAT1 in endometriosis. In the KGN cell line, MALAT1 was knocked down with locked nucleic acid GapmeRs. Cell counting kit-8 assays, ethynyl-2-deoxyuridine assays and flow cytometry were used to study the role of MALAT1 in cell proliferation and cell-cycle progression, and western blotting was performed to detect the potential underlying mechanism. MAIN RESULTS AND THE ROLE OF CHANCE: We first found that MALAT1 lncRNA was significantly down-regulated in endometriosis GCs and was associated with the antral follicle count (R = 0.376, P < 0.001 versus control). In addition, MALAT1 lncRNA levels were significantly lower in the GCs of infertile women with advanced stages of endometriosis (P = 0.01 versus control). The ROC curves illustrated strong separation between all the endometriosis patients and the control group (AUC: 0.705; 95% CI: 0.606-0.804; P < 0.001), Stage I-II and control group (AUC: 0.651; 95% CI: 0.536-0.767; P = 0.016), and Stage III-IV and control group (AUC: 0.827; 95% CI: 0.718-0.936; P < 0.001). MALAT1 lncRNA was primarily localized in the nuclei of GCs. We found a negative correlation between MALAT1 lncRNA and P21 mRNA in the GCs from patients (R = -0.628; P < 0.001). MALAT1 knockdown in KGN cells inhibited cell proliferation and cell-cycle progression. In addition, MALAT1 knockdown induced an increase in both the mRNA and protein levels of P21, and of P53, phosphorylated ERK1/2 (p-ERK1/2) and phosphorylated c-Jun N-terminal protein kinase (p-JNK) protein levels, as well as causing a decrease in cyclin dependent kinase 2 (CDK2), cyclin D1 and p-P38 MAPK protein levels. Furthermore, inhibition of the ERK/MAPK pathway with U0126, the up-regulation of p-ERK1/2, P21 and P53, and the down-regulation of CDK2 and cyclin D1 by the knockdown of MALAT1 were all attenuated by MALAT1 knockdown. Therefore, MALAT1 may regulate GC proliferation through P21/P53-dependent control of the cell cycle, and the ERK/MAPK pathway participates in this process. LARGE SCALE DATA: None. LIMITATIONS, REASONS FOR CAUTION: The hormonal treatment used in IVF and surgical removal of endometriotic lesions may have altered MALAT1 expression in GCs. The ovarian granulosa-like tumor cell line, KGN, was used for further functional and mechanistic studies due to the difficulties in obtaining human GCs in sizable amounts and maintaining primary cultures. WIDER IMPLICATIONS OF THE FINDINGS: Our finding represents the first example of an lncRNA-based mechanism in endometriosis GCs. Women with endometriosis show altered MALAT1 expression levels in GCs that may impair fertility by regulating the function of GCs. Therefore, analysis of MALAT1 and its molecular mechanisms of action provide new insights into the pathogenesis of endometriosis and its associated infertility. STUDY FUNDING/COMPETING INTEREST(s): This work was supported by the National Natural Science Foundation of China (grant number: 81671524) and the National key research and development program of China (grant number: 2017YFC1001100). The authors declare there is no conflict of interest.

Practical quantum digital signature with a gigahertz BB84 quantum key distribution system: erratum.

In this erratum the formulas (6) and (8) of Opt. Lett.44, 139 (2019) OPLEDP0146-959210.1364/OL.44.000139 have been updated.

Practical quantum digital signature with a gigahertz BB84 quantum key distribution system.

Quantum digital signature (QDS) can guarantee message integrity and non-repudiation with information-theoretical security, and it has attracted more attention recently. Since proposed by Andersson et al. [Phys. Rev. A93, 032325 (2016)PLRAAN1050-294710.1103/PhysRevA.93.032325], a quantum digital signature protocol using an insecure channel has been realized with several different quantum key distribution (QKD) systems. Here we report an experimental QDS based on a BB84 QKD system. An asymmetric Faraday-Sagnac-Michelson interferometer structure has been designed in our system, which is intrinsically stable against channel disturbance. The innovatory structure supports the system to work at high speed and, in practice, the repetition rate is in gigahertz. A 0.044 bit/s signature rate has been attained with a 25 dB channel loss composed of a 25 km installed fiber with additional optical attenuation in a 10-10 security level. Thus, our QDS device is stable and highly efficient. This Letter provides a further step for the practical application of QDS.

Improved statistical fluctuation analysis for measurement-device-independent quantum key distribution with four-intensity decoy-state method.

Recently Zhang et al [ Phys. Rev. A95, 012333 (2017)] developed a new approach to estimate the failure probability for the decoy-state BB84 QKD system when taking finite-size key effect into account, which offers security comparable to Chernoff bound, while results in an improved key rate and transmission distance. Based on Zhang et al's work, now we extend this approach to the case of the measurement-device-independent quantum key distribution (MDI-QKD), and for the first time implement it onto the four-intensity decoy-state MDI-QKD system. Moreover, through utilizing joint constraints and collective error-estimation techniques, we can obviously increase the performance of practical MDI-QKD systems compared with either three- or four-intensity decoy-state MDI-QKD using Chernoff bound analysis, and achieve much higher level security compared with those applying Gaussian approximation analysis.

Proof-of-principle demonstration of parametric down-conversion source-based quantum key distribution over 40 dB channel loss.

Quantum key distribution (QKD) offers information-theoretic security verified by quantum mechanics to share keys between legitimate users. Most of the existing QKD systems employ active decoy states based on weak coherent sources (WCS). Meanwhile, parametric down-conversion (PDC) sources are seldom used due to several of their shortcomings. In the present work, to show the superiority of PDC sources, we have accomplished a proof-of-principle demonstration of a PDC source-based QKD with over 40 dB based on the one-way BB84 protocol. In this QKD system, a novel passive decoy-state scheme-secure to coherent attacks-is proposed, using several built-in decoy states for parameter estimation. This not only avoids intensity modulating errors, but also diminishes all possible information leakage from the intensity modulating process. The experimental results show a significantly enhanced performance compared with existing PDC source-based QKD systems. In addition, it exhibits some superiority even over active decoy-state QKD systems based on WCS.

[Purification of PTCDA by Vacuum Sublimation and Spectral Test and Analysis].

The organic semiconductor 3, 4, 9, 10 perylenetetracarboxylic dianhydride (PTCDA) with the purity of 97.5% was purified by sublimation to 99.9%. The high-purity PTCDA material was measured by mass spectra, infrared spectrum and X-ray photoelectron spectroscopy (XPS). Detailed analysis revealed its molecular structure, the forming of chemical bond, the vibration modes of atoms in equilibrium lattice position, electronic configuration and the shift of binding energy of atoms. Based on the infrared spectrum analysis, the molecular structure of PTCDA is consisting of perylene core group with five C rings and two anhydrides located at both ends of perylene core, which is mainly bonded with covalent bond. The stretching vibration of C atoms in the crystal lattice dominates in their equilibrium positions. The PTCDA molecules have a large number of π electrons which can move freely; the intermolecular delocalized π bond overlap determines the conductivity of PTCDA. Based on XPS analysis, it can be found that there exist two kinds of C atoms with different binding energy: 285.3 and 288.7 eV, respectively, corresponding to the C atoms in the perylene ring and anhydride. In addition, there are two kinds of O atoms, i. e. C==0 and C--O--C, whose bonding energy is 531.3 and 533.1 eV, respectively.

Total date rate of multi-wavelength 2R regenerators for time-interleaved RZ-OOK signals.

Multi-wavelength regeneration free of inter-channel crosstalk is desirable for wavelength division multiplexing (WDM) systems, especially from the cost-effectiveness point of view. This paper presents the design rules of time-interleaved multi-wavelength 2R regeneration systems based on data-pump four wave mixing (FWM) effect, and several key factors, such as FWM bandwidth, wavelength assignment, and duty cycle, are comprehensively taken into account. The total data rate of time-interleaved WDM regeneration systems along with polarization multiplexing or bidirectional transmission are discussed, which are mainly determined by temporal overlap, spectral broadening and FWM bandwidth. As two examples, an eight-wavelength unidirectional regenerator using polarization multiplexing is designed by optimizing the fiber birefringence, and a six-wavelength bidirectional regenerator is demonstrated by experiment. Each is expected to have a total data rate of about 200 Gb/s for the optical RZ-OOK signals, and the wavelength number is increased at the expense of spectral efficiency.

Novel method for identifying the heaviest QED atom.

QED atoms are composed of unstructured and point-like lepton pairs bound together by the electromagnetic force. The smallest and heaviest QED atom is formed by a τ+τ- pair. Currently, the only known atoms of this type are the e+e- and µ+e- atoms, which were discovered 64 years ago and remain the sole examples found thus far. We demonstrate that the Jτ (τ+τ- atom with JPC=1--) atom signal can be observed with a significance larger than 5σ including both statistical and systematic uncertainties, via. the process e+e-→X+Y-Ɇ (X,Y=e,µ,π,K, or ρ, and Ɇ is the missing energy due to unobserved neutrinos) with 1.5ab-1 data taken around the τ pair production threshold. The τ lepton mass can be measured with a precision of 1 keV with the same data sample. This is within one year's running time of the proposed super tau-charm facility in China or super charm-tau factory in Russia.

Resveratrol prevents age-related heart impairment through inhibiting the Notch/NF-κB pathway.

Resveratrol (RSV) is a natural polyphenol compound found in various plants that has been shown to have potential benefits for preventing aging and supporting cardiovascular health. However, the specific signal pathway by which RSV protects the aging heart is not yet well understood. This study aimed to explore the protective effects of RSV against age-related heart injury and investigate the underlying mechanisms using a D-galactose-induced aging model. The results of the study indicated that RSV provided protection against age-related heart impairment in mice. This was evidenced by the reduction of cardiac histopathological changes as well as the attenuation of apoptosis. RSV-induced cardioprotection was linked to a significant increase in antioxidant activity and mitochondrial transmembrane potential, as well as a reduction in oxidative damage. Additionally, RSV inhibited the production of pro-inflammatory cytokines such as interleukin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α). Furthermore, the expression of toll-like receptor 4 (TLR4), nuclear factor kappa-B p65 (NF-κB p65), and notch 1 protein were inhibited by RSV, indicating that inhibiting the Notch/NF-κB pathway played a critical role in RSV-triggered heart protection in aging mice. Moreover, further data on intestinal function demonstrated that RSV significantly increased short-chain fatty acids (SCFAs) in intestinal contents and reduced the pH value in the feces of aging mice. RSV alleviated aging-induced cardiac dysfunction through the suppression of oxidative stress and inflammation via the Notch/NF-κB pathway in heart tissue. Furthermore, this therapeutic effect was found to be associated with its protective roles in the intestine.