ABSTRACT
The integration of quantum key distribution (QKD) and classical optical communication has attracted widespread attention. In this Letter, we experimentally demonstrate a real-time co-propagation of 1 Tbps for 10 classical channels with one discrete-variable QKD channel in the weakly coupled few-mode fiber (FMF). Based on the selection of optimal device parameters and wavelength assignment of classical channels, as well as the optimization of equipment performance, a secure key rate of as high as 2.7 kbps of coexistence transmission of QKD and classical optical communication can be achieved using a 100.96 km weakly coupled FMF. Therefore, this study is a step toward realizing long-distance quantum-classical coexistence transmission.
ABSTRACT
Through analysis of near-field beam profiles, we propose a method using Shannon entropy to assess the development of small-scale self-focusing during laser propagation and amplification in high-power laser systems. In this method, the entropy curve that corresponds to increasing B integral displays an evident turning point at which small-scale self-focusing starts to rapidly develop. In contrast to classical methods using contrast, modulation, or power spectral density, the proposed method provides the B integral criterion more clearly and objectively. This approach is an optimization method that can be utilized in the design and operation of high-power laser systems.
ABSTRACT
BACKGROUND: Published data indicate that thyroid stimulating hormone receptor (TSHR) activities are associated with osteoporosis in some patients. AIM: This study aimed to elucidate whether a given polymorphism of the TSHR gene is associated with osteoporosis. MATERIALS AND METHODS: One hundred and fifty subjects with osteoporosis were recruited in this study. The diagnosis of osteoporosis was performed with quantitative ultrasound system. The TSHR gene polymorphism was examined by polymerase chain reaction-restriction fragment length polymorphism. RESULTS: The results showed a nucleotide substitution in the first position of codon 36 of the TSHR gene. The nucleotide substitution was from G to C, leading to a (36)D â (36)H change (D36H) in the predicted amino acid sequence of the receptor. The change did not show significance between healthy subjects and patients with osteoporosis (P > 0.05). On the other hand, we identified another single nucleotide polymorphism that is a C-to-G substitution at codon 727 (GAC to GAG); its frequency was significantly higher in patients with osteoporosis than that in healthy subjects. Using logistic regression analysis, significant correlation was revealed between the genotype D727E and the serum levels of TSH, or the quantitative ultrasound value of the calcaneal bone. CONCLUSIONS: The present study suggests that the genotype D727E of the TSHR, but not the genotype D36H, may be a genetic risk factor for osteoporosis.
ABSTRACT
OBJECTIVE: To investigate the expression of survivin and COX-2 in giant cell tumor of bone (GCT) and explore the prognostic factors for GCT. METHODS: The expressions of survivin and COX-2 in 39 GCT tissues of three Jaffe grades and 4 normal bone tissues were detected by immunohistochemical staining, and the data were analyzed in relation to the clinicopathological features of the patients. RESULTS: The expressions of survivin and COX-2 were significantly higher in the GCT tissues than in normal bone tissues (P<0.01). A positive correlation was found between survivin and COX-2 expressions and the pathological grade (P<0.01), but their expressions were not correlated to the patients' gender, age or surgical approaches (P>0.05). An obviously lowered recurrence rate was observed in patients with resection of the bone segment compromised by the tumor and subsequent bone grafting. Survivin and COX-2 were not independent risk factors of the prognosis of GCT. CONCLUSION: Survivin and COX-2 expressions may participate in the pathogenesis and development of GCT, but is not indicative of the prognosis.
