Practical Security of High-Dimensional Quantum Key Distribution with Intensity Modulator Extinction.

Quantum key distribution (QKD) has attracted much attention due to its unconditional security. High-dimensional quantum key distribution (HD-QKD) is a brand-new type of QKD protocol that has many excellent advantages. Nonetheless, practical imperfections in realistic devices that are not considered in the theoretical security proof may have an impact on the practical security of realistic HD-QKD systems. In this paper, we research the influence of a realistic intensity modulator on the practical security of HD-QKD systems with the decoy-state method and finite-key effects. We demonstrate that there is a certain impact in the secret key rate and the transmission distance when taking practical factors into security analysis.

Analysis of transcriptome sequencing of sciatic nerves in Sprague-Dawley rats of different ages.

An aging-induced decrease in Schwann cell viability can affect regeneration following peripheral nerve injury in mammals. It is therefore necessary to investigate possible age-related changes in gene expression that may affect the biological function of peripheral nerves. Ten 1-week-old and ten 12-month-old healthy male Sprague-Dawley rats were divided into young (1 week old) and adult (12 months old) groups according to their ages. mRNA expression in the sciatic nerve was compared between young and adult rats using next-generation sequencing (NGS) and bioinformatics (n = 4/group). The 18 groups of differentially expressed mRNA (DEmRNAs) were also tested by quantitative reverse transcription polymerase chain reaction (n = 6/group). Results revealed that (1) compared with young rats, adult rats had 3608 groups of DEmRNAs. Of these, 2684 were groups of upregulated genes, and 924 were groups of downregulated genes. Their functions mainly involved cell viability, proliferation, differentiation, regeneration, and myelination. (2) The gene with the most obvious increase of all DEmRNAs in adult rats was Thrsp (log2FC = 9.01, P < 0.05), and the gene with the most obvious reduction was Col2a1 (log2FC = -8.89, P < 0.05). (3) Gene Ontology analysis showed that DEmRNAs were mainly concentrated in oligosaccharide binding, nucleotide-binding oligomerization domain containing one signaling pathway, and peptide-transporting ATPase activity. (4) Analysis using the Kyoto Encyclopedia of Genes and Genomes showed that, with increased age, DEmRNAs were mainly enriched in steroid biosynthesis, Staphylococcus aureus infection, and graft-versus-host disease. (5) Spearman's correlation coefficient method for evaluating NGS accuracy showed that the NGS results and quantitative reverse transcription polymerase chain reaction results were positively correlated (rs = 0.74, P < 0.05). These findings confirm a difference in sciatic nerve gene expression between adult and young rats, suggesting that, in peripheral nerves, cells and the microenvironment change with age, thus influencing the function and repair of peripheral nerves.

Various changes in cryopreserved acellular nerve allografts at -80°C.

The experimental design evaluated histological, mechanical, and biological properties of allogeneic decellularized nerves after cryopreservation in a multi-angle, multi-directional manner to provide evidence for long-term preservation. Acellular nerve allografts from human and rats were cryopreserved in a cryoprotectant (10% fetal bovine serum, 10% dimethyl sulfoxide, and 5% sucrose in RPMI1640 medium) at -80°C for 1 year, followed by thawing at 40°C or 37°C for 8 minutes. The breaking force of acellular nerve allografts was measured using a tensile test. Cell survival was determined using L-929 cell suspensions. Acellular nerve allografts were transplanted into a rat model with loss of a 15-mm segment of the left sciatic nerve. Immunohistochemistry staining was used to measure neurofilament 200 expression. Hematoxylin-eosin staining was utilized to detect relative muscle area in gastrocnemius muscle. Electron microscopy was applied to observe changes in allograft ultrastructure. There was no obvious change in morphological appearance or ultrastructure, breaking force, or cytotoxicity of human acellular nerve allografts after cryopreservation at -80°C. Moreover, there was no remarkable change in neurofilament 200 expression, myelin sheath thickness, or muscle atrophy when fresh or cryopreserved rat acellular nerve allografts were applied to repair nerve injury in rats. These results suggest that cryopreservation can greatly extend the storage duration of acellular nerve tissue allografts without concomitant alteration of the physiochemical and biological properties of the engineered tissue to be used for transplantation.

The phrenic nerve as a motor nerve donor for facial reanimation with the free latissimus dorsi muscle.

Free functional muscle transfer for acquired facial paralysis most often involves two stages. In this report, we describe single-stage free muscle transfer using the phrenic nerve as the donor motor nerve. Six patients with unilateral facial paralysis underwent single-stage facial reanimation using a free latissimus dorsi muscle with the ipsilateral phrenic nerve as the donor nerve. These cases were retrospectively studied to review technique and to determine outcomes including time to muscle reinnervation, patient satisfaction, smile symmetry, and complications. The mean age was 33 years. Five patients had complete unilateral facial paralysis and one had incomplete. There was no flap loss. The transferred muscle demonstrated active contraction in all patients at a mean of 14 weeks postoperatively (range, 12 to 16 weeks). Good dynamic symmetry was achieved by 6 to 9 months in all patients. All patients underwent rehabilitation including nerve reeducation. No clinically significant pulmonary morbidity was observed after the unilateral transection of the phrenic nerve. Using the phrenic nerve in free muscle transfer for facial paralysis allows a single-stage procedure with no requirement for nerve grafting and a rapid reinnervation time, shortening the time required for restoring facial animation.

[The anatomic features of supratrochlear artery].

OBJECTIVE: To explore the anatomical features of supratrochlear artery which is related to the blood supply of paramedian frontal flap in nasal reconstruction. METHODS: 10 adult head specimens (20 sides) were used for observation of the course, layer and anastomosis of the supratrochlear artery. The horizontal line of supraorbital rim and the frontal middle line were used as X and Y axis to locate the position of supratrochlear artery. RESULTS: Supratrochlear artery is directed medially and upward after it gets out from orbit. Some arteries (9/20) have one sharp bend at the beginning. The frontal muscle penetration point of the artery is (15.2 +/- 2.6) mm above the X axis and (12. 1 +/- 1 .4) nun lateral to the Y axis. The artery goes subcutaneously after muscle penetration point. It goes more superficially and is anastomosed to the supraorbital artery and frontal branches of the superficial temporal artery at the same side, and also the contra-lateral supratrochlear artery. CONCLUSION: The pedicle of the paramedian frontal flap should not be too narrow. The dissection of the pedicle should not be too near to the artery, so as to protect the bend at the beginning. The flap elevation must be performed beneath the frontal muscle, when it is 2-3 cm above the supraorbital rim.

Repair of extended peripheral nerve lesions in rhesus monkeys using acellular allogenic nerve grafts implanted with autologous mesenchymal stem cells.

Despite intensive efforts in the field of peripheral nerve injury and regeneration, it remains difficult in humans to achieve full functional recovery following extended peripheral nerve lesions. Optimizing repair of peripheral nerve injuries has been hindered by the lack of viable and reliable biologic or artificial nerve conduits for bridging extended gaps. In this study, we utilized chemically extracted acellular allogenic nerve segments implanted with autologous non-hematopoietic mesenchymal stem cells (MSCs) to repair a 40 mm defect in the rhesus monkey ulnar nerve. We found that severely damaged ulnar nerves were structurally and functionally repaired within 6 months following placement of the MSC seeded allografts in all animals studied (6 of 6, 100%). Furthermore, recovery with the MSC seeded allografts was similar to that observed with Schwann cell seeded allografts and autologous nerve grafts. The findings presented here are the first demonstration of the successful use of autologous MSCs, expanded in culture and implanted in a biological conduit, to repair a peripheral nerve gap in primates. Given the difficulty in isolating and purifying sufficient quantities of Schwann cells for peripheral nerve regeneration, the use of MSCs to seed acellular allogenic nerve grafts may prove to be a novel and promising therapeutic approach for repairing severe peripheral nerve injuries in humans.