High-efficiency all-optical switching based on broadband coherent perfect absorption in an atom-cavity system.

We propose an ultrahigh-efficiency and broadband all-optical switching scheme based on coherent perfect absorption (CPA) in linear and nonlinear excitation regimes in a cavity quantum electrodynamics (CQED) system. Two separate atomic transitions are excited simultaneously by two signal fields coupled from two ends of an optical cavity under the collective strong coupling condition. Three polariton eigenstates are produced which can be tuned freely by varying system parameters. The output field intensities of multiple channels are zero when the CPA criterion is satisfied. However, destructive quantum interference can be induced by a free-space weak control laser when it is tuned to be resonant to the polariton state. As a consequence, the CQED system acts as a coherent perfect light absorber/transmitter as the control field is turned on/off the polariton resonances. In particular, the proposed scheme may be used to realize broadband multi-throw all-optical switching in the nonlinear excitation regime. The proposed scheme is useful for constructing all-optical routing, all-optical communication networks and various all-optical logic elements.

Macroscopic entanglement between ferrimagnetic magnons and atoms via crossed optical cavities.

We consider a two-dimensional opto-magnomechanical (OMM) system including two optical cavity modes, a magnon mode, a phonon mode, and a collection of two-level atoms. We show how the stationary entanglement between two-level atoms and magnons can be achieved. The presence of two optical cavities leads the atom-magnon entanglement to be achieved in a wide parameter regime. Furthermore, it is shown that one optical cavity can get entangled with magnons, phonons, and the other optical cavity. The entanglement is robust against thermal noise. The work may find applications in building hybrid quantum networks and quantum information processing.

High-efficiency entanglement of microwave fields in cavity opto-magnomechanical systems.

We demonstrate a scheme to realize high-efficiency entanglement of two microwave fields in a dual opto-magnomechanical system. The magnon mode simultaneously couples with the microwave cavity mode and phonon mode via magnetic dipole interaction and magnetostrictive interaction, respectively. Meanwhile, the phonon mode couples with the optical cavity mode via radiation pressure. Each magnon mode and optical cavity mode adopts a strong red detuning driving field to activate the beam splitter interaction. Therefore, the entangled state generated by the injected two-mode squeezed light in optical cavities can be eventually transferred into two microwave cavities. A stationary entanglement E a 1 a 2 =0.54 is obtained when the input two-mode squeezed optical field has a squeezing parameter r = 1. The entanglement E a 1 a 2 increases as the squeezing parameter r increases, and it shows the flexible tunability of the system. Meanwhile, the entanglement survives up to an environmental temperature about 385 mK, which shows high robustness of the scheme. The proposed scheme provides a new mechanism to generate entangled microwave fields via magnons, which enables the degree of the prepared microwave entanglement to a more massive scale. Our result is useful for applications which require high entanglement of microwave fields like quantum radar, quantum navigation, quantum teleportation, quantum wireless fidelity (Wi-Fi) network, etc.

A numerical simulation method of natural fragment formation and injury to human thorax.

OBJECTIVE: Fragment injury is a type of blast injury that is becoming more and more common in military campaigns and terrorist attacks. Numerical simulation methods investigating the formation of natural fragments and injuries to biological targets are expected to be developed. METHODS: A cylindrical warhead model was established and the formation process of natural fragments was simulated using the approach of tied nodes with failure through the explicit finite element (FE) software of LS-DYNA. The interaction between the detonation product and the warhead shell was simulated using the fluid-structure interaction algorithm. A method to simulate the injury of natural fragments to a biological target was presented by transforming Lagrange elements into smooth particle hydrodynamics (SPH) particles after the natural fragments were successfully formed. A computational model of the human thorax was established to simulate the injury induced by natural fragments by the node-to-surface contact algorithm with erosion. RESULTS: The discontinuous velocities of the warhead shell at different locations resulted in the formation of natural fragments with different sizes. The velocities of natural fragments increased rapidly at the initial stage and slowly after the warhead shell fractured. The initial velocities of natural fragments at the central part of the warhead shell were the largest, whereas those at both ends of the warhead shell were the smallest. The natural fragments resulted in bullet holes that were of the same shape as that of the fragments but slightly larger in size than the fragments in the human thorax after they penetrated through. Stress waves propagated in the ribs and enhanced the injury to soft tissues; additionally, ballistic pressure waves ahead of the natural fragments were also an injury factor to the soft tissues. CONCLUSION: The proposed method is effective in simulating the formation of natural fragments and their injury to biological targets. Moreover, this method will be beneficial for simulating the combined injuries of natural fragments and shock waves to biological targets.

Cube-corner autocollimator with expanded measurement range.

A cube-corner is employed as a photoelectric autocollimator's reflector to extend the angle measurement range and the corresponding algorithms are deduced. Experimental investigations reveal that the measurement range is extended from 1.2° to 12° without enlarging the objective lens's aperture. The accuracy is better than 35" when the deflection is less than 8°.

Characteristics and potentials of stem cells derived from human degenerated nucleus pulposus: potential for regeneration of the intervertebral disc.

BACKGROUND: Eliminating the symptoms during treatment of intervertebral disc degeneration (IVDD) is only a temporary solution that does not cure the underlying cause. A biological method to treat this disorder may be possible by the newly discovered nucleus pulposus derived stem cells (NPDCs). However, the uncertain characteristics and potential of NPDCs calls for a comprehensive study. METHODS: In the present study, nucleus pulposus samples were obtained from 5 patients with IVDD undergoing discectomy procedure and NPDCs were harvested using fluorescence activated cell sorting (FACS) by the co-expression of GD2+ and Tie2+. After in vitro expansion, the properties of NPDCs were compared with those of bone marrow mesenchyme stem cells (BMSCs) from the same subjects. RESULTS: NPDCs performed similar properties in cell colony-forming ability, cell proliferation rate, cell cycle and stem cell gene expression similar to those of BMSCs. In addition, NPDCs could be differentiated into osteoblasts, adipocytes, and chondrocytes, and are found to be superior in chondrogenesis but inferior in adipocyte differentiation. CONCLUSIONS: NPDCs derived from the degenerated intervertebral disc still keep the regeneration ability similar to BMSCs. Besides, the superior capacity in chondrogenesis may provide a promising cell candidate for cell-based regenerative medicine and tissue engineering in IVDD.

Generation of fully pluripotent female murine-induced pluripotent stem cells.

The high quality of induced pluripotent stem cells (iPSCs) has been determined to be high-grade chimeras that are competent for germline transmission, and viable mice can be generated through tetraploid complementation. Most of the high-quality iPSCs described to date have been male. Female iPSCs, especially fully pluripotent female iPSCs, are also essential for clinical applications and scientific research. Here, we show, for the first time, that a gender-mixed induction strategy could lead to a skewed sex ratio of iPSCs. After reprogramming, 50%, 70%, and 90% female initiating mouse embryonic fibroblasts at different male ratios resulted in 14.1 ± 6.8% (P < 0.05), 31.8 ± 5.4% (P < 0.05), and 80.1 ± 2.8% (P < 0.05) female iPSCs, respectively. Furthermore, these female iPSCs had pluripotent properties typical of embryonic stem cells. Importantly, these fully pluripotent female iPSCs could generate viable mice by tetraploid complementation. These findings indicate that high-quality female iPSCs could be derived effectively, and suggest that clinical application of female iPSCs is feasible.

Growing trend of China's contribution to the field of spine: a 10-year survey of the literature.

PURPOSE: China, as a rapidly developing country with the largest population including over 50,000 orthopaedic surgeons, has an increasing importance in the field of spine. However, the quantity and quality of research production in the field of spine in the major regions of China-Mainland China, Taiwan, and Hong Kong is unclear. This study aimed to investigate the contribution of China to the field of spine. METHODS: Articles published in the 5 major spine journals originating from Mainland China, Taiwan and Hong Kong in 2004-2013 were retrieved from the database of Web of Science. The number of articles, impact factors, citations, article type, city, institution, funding source and conflict of interest were analyzed. RESULTS: There were 1006 publications in the 5 spine journals between 2004 and 2013 from China, including 706 from Mainland China, 210 from Taiwan, and 90 from Hong Kong. The time trend of the number of articles from these three regions showed a significant increase of 8.74-fold (from 23 to 201) between 2004 and 2013 (p = 0.000). From 2006, the number of publications from Mainland China exceeded Taiwan and Hong Kong. Mainland China had the highest total impact factors (1686.54) and total citations (4214), followed by Taiwan (498.93; 2009) and Hong Kong (222.89; 1311). Hong Kong had the highest mean impact factor (2.48) and mean citations (14.46), followed by Mainland China (2.40; 10.26) and Taiwan (2.38; 10.14). The journal Spine published the largest number of articles (470), followed by European Spine Journal (268). CONCLUSIONS: Chinese contributions to the field of spine have a significant increase during the past 10 years, particularly from Mainland China. Hong Kong had the highest quality research output in terms of mean impact factor and mean citation per article.

Melatonin improves the reprogramming efficiency of murine-induced pluripotent stem cells using a secondary inducible system.

This study focused on the effect of melatonin on reprogramming with specific regard to the generation of induced pluripotent stem cells (iPSCs). Here, a secondary inducible system, which is more accurate and suitable for studying the involvement of chemicals in reprogramming efficiency, was used to evaluate the effect of melatonin on mouse iPSC generation. Secondary fibroblasts collected from all-iPSC mice through tetraploid complementation were cultured in induction medium supplemented with melatonin at different concentrations (0, 10(-6), 10(-7), 10(-8), 10(-9), or 10(-10 )m) or with vitamin C (50 µg/mL) as a positive control. Compared with untreated group (0.22 ± 0.04% efficiency), 10(-8) (0.81 ± 0.04%), and 10(-9 )m (0.83 ± 0.08%) melatonin supplementation significantly improved reprogramming efficiency (P < 0.05). Moreover, we verified that the iPSCs induced by melatonin treatment (MiPSCs) had the same characteristics as typical embryonic stem cells (ESCs), including expression of the pluripotency markers Oct4, Sox2, and Nanog, the ability to form teratomas and all three germ layers of the embryo, as well as produce chimeric mice with contribution to the germ line. Interestingly, only the melatonin receptor MT2 was detected in secondary fibroblasts, while MiPSCs and ESCs expressed MT1 and MT2 receptors. Furthermore, during the early stage of reprogramming, expression of the apoptosis-related genes p53 and p21 was lower in the group treated with 10(-9) m melatonin compared with the untreated controls. In conclusion, melatonin supplementation enhances the efficiency of murine iPSC generation. These beneficial effects may be associated with inhibition of the p53-mediated apoptotic pathway.

[O-arm real-time guidance in cervical pedicle screw fixation].

OBJECTIVE: To explore the technical aspects of the accuracy of cervical pedicle screw placement with O-arm guidance. METHODS: The clinical data of 21 patients who underwent cervical pedicle screw fixation by O-arm real-time guidance from December 2015 to January 2020 were analyzed retrospectively. There were 15 males and 6 females, aged from 29 to 76 years old with an average of (45.3±11.5) years. The postoperative CT scan was utilized to evaluate the placement of the pedicle screw and classified according to the Gertzbein and Robbins classification. RESULTS: A total of 132 pedicle screws were implanted in 21 patients, 116 at C3-C6 and 16 at C1 and C2. According to Gertzbein & Robbins classification, the overall breach rates were found to be 11.36% (15/132) with 73.33% (11 screws) Grade B, 26.67% (4 screws) Grade C, and no Grade D or E screw breaches. There were no pedicle screw placement related complications at final follow-up. CONCLUSION: The application of O-arm real-time guidance technology can make cervical pedicle screw placement reliable. High accuracy and better intra-operative control can increase surgeon's confidence in using cervical pedicle instrumentation. Considering the high-risk nature of anatomical area around cervical pedicle and the possibility of catastrophic complications, the spine surgeon should have sufficient surgical skills, experience, ensures stringent verification of the system, and never relies solely on the navigation system.

Eggshell translucency in late-phase laying hens and its effect on egg quality and physiological indicators.

Eggshell translucency severely affects external egg quality, and variations in the eggshell or eggshell membrane are considered the structural basis of the trait. Research has shown that 1.85% additional mixed fatty acids in the diet would greatly decrease the occurrence of eggshell translucency. Only a few studies have examined the phenotypic regularity of eggshell translucency with the increasing age of hens. Therefore, two strains, 1139 Rhode Island Red-White (RIR-White) and 836 Dwarf Layer-White (DWL-White), were used, and from each strain, 30 hens each that consecutively laid translucent or opaque eggs at 67 wks of age were selected. Subsequently, eggshell translucency, internal quality and external quality of eggs, and total cholesterol, albumin, calcium binding protein and other physiological indicators related to lipid, lipoprotein, and calcium metabolisms at the 75th, 79th, and 83rd wks of age in the late phase of the laying cycle were determined. Results: (1) In terms of flocks, for both strains, the translucency scores of the translucent groups were significantly higher than those of the opaque groups (P < 0.05); in terms of individuals, 81.1% RIR-White and 82.8% DWL-White hens consecutively laid eggs of the same or similar translucency, indicating the stability of the trait with increasing hen age; (2) In RIR-White, the eggshell strength of the translucent group at 75 weeks was significantly higher than that of the opaque group (P < 0.05); in DWL-White, the eggshell membrane thickness of the translucent group at the 75th and 83rd weeks was significantly lower than that of the opaque group (P < 0.05); (3) Compared to the opaque groups, the translucent groups had lower total cholesterol content in both RIR-White and DWL-White, lower albumin content in DWL-White at the 79th weeks (P < 0.05), and higher calcium-binding protein (CALB1) in RIR-White at the 83rd weeks (P < 0.05). In summary, this study illustrates the stability of eggshell translucency in late-phase laying hens and provides a reference of physiological indicators for exploring the formation of translucent eggs.

[Research progress of risk factors of adjacent segment degeneration after anterior cervical discectomy and fusion].

Anterior cervical discectomy and fusion (ACDF) has achieved good clinical results since it was used in clinic, and is considered as the gold standard for the treatment of cervical spondylosis. However, more and more attention has been paid to adjacent segment degeneration(ASDeg) after fusion, and the debate about its pathogenesis is mainly focused on the bio-machanical stress changes of adjacent segments caused by fusion and the result of the natural aging process. The occurrence of ASDeg after fusion seriously affect the med-and long-term outcome of surgery, and some patients even need secondary surgery. In order to reduce or even avoid the occurrence of ASDeg, many new techniques have emerged in clinic, such as artificial disc replacement with preservation of motor segments, emerging cell transplantation technology and so on, but the clinical effect still needs to be confirmed by a large number of studies. Therefore, finding the risk factors of ASDeg after fusion is of great significance for fusion surgery on the clinical work. At present, there is still no unified overview of the research on the risk factors of ASDeg. This article will review the research progress and corresponding countermeasures of the risk factors of ASDeg after ACDF, in order to guide the clinical application.

Efficacy and safety of long-term transcutaneous electroacupuncture versus sham transcutaneous electroacupuncture for delayed gastric emptying after distal gastrectomy: study protocol for a randomized, patient-assessor blinded, controlled trial.

BACKGROUND: Delayed gastric emptying (DGE) after distal gastrectomy impacts patients' nutritional status and quality of life. The current treatments of DGE seem unsatisfactory or need invasive interventions. It is unknown whether transcutaneous electroacupuncture (TEA) is effective in treating DGE. METHODS: A total of 90 eligible participants who underwent distal gastrectomy will be randomly allocated to either the TEA group (n = 60) or the sham transcutaneous electroacupuncture (sham-TEA) group (n = 30). Each participant will receive TEA on the bilateral acupoints of Zusanli (ST36) and Neiguan (PC6) for 4 weeks. The primary outcomes will be the residual rates of radioactivity in the stomach by gastric scintigraphy and total response rates. The secondary outcomes will be endoscopic features, autonomic function, nutritional and psychological status, serum examination, and quality of life (QoL). The adverse events will also be reported. The patients will be followed up 1 year after the treatment. DISCUSSION: The findings of this randomized trial will provide high-quality evidence regarding the efficacy and safety of long-term TEA for treating DGE after distal gastrectomy. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2000033965. Registered on 20 June 2020.

Coupled-resonator-induced transparency with a squeezed vacuum.

We present the first experimental observation of quantum fluctuation spectra in two coupled optical cavities with an injected squeezed vacuum light. The quadrature components of the reflected squeezed vacuum spectra are measured by phase-sensitive homodyne detector. The experimental results demonstrate coupled-resonator-induced transparency in the quantum regime, in which the electromagnetically-induced-transparency-like characteristic of the absorption and dispersion properties of the coupled optical cavities determines the line shape of the reflected quantum noise spectra.

Effect of natural garlic essential oil on chickens with artificially infected Eimeria tenella.

Chicken coccidiosis is a kind of parasitic protozoosis caused by Eimeria parasitizing in the chicken intestinal epithelial cells. Eimeria tenella is considered as a significantly virulent and harmful parasite. At present, drug resistance remains a major problem and a large number of drug residues have been found to be produced in the treatment of the disease. Hence, novel strategies are needed to avoid the harmful effects caused by the generation of various chemical drug residues to the human body and also reduce the economic loss caused by coccidiosis to the chicken industry. In this study, natural garlic essential oil was used to control Eimeria tenella infection. The anticoccidial index (ACI) was calculated according to the clinical symptoms, body weight gain, oocyst excretion and cecal lesions. The immune organ index and serum biochemical indexes were measured to verify the possible anticoccidial effects. The results showed that: compared with the infected group, continuous feeding of different doses of natural garlic essential oil could significantly reduce the clinical symptoms, cecal lesions, the number of oocysts, but increase the weight of sick chickens, and effectively improve the intestinal functions. Moreover, compared with diclazuril control group, 0.06 mL/L garlic essential oil exhibited similar anticoccidial index. The content of immune organ index, serum biochemical index IgM, IgG and IgA in 0.06 mL/L garlic essential oil group was the highest, which indicated that garlic essential oil had a significant tendency to improve the immune function of the chickens. This study also showed that the natural garlic essential oil exhibited the same beneficial effects as that of diclazuril on chicken coccidiosis, and the anti-coccidiosis index of 0.06 mL/L garlic essential oil was favorable. Thus based on the above evidences and its relatively low cost, garlic essential oil can be potentially be used as an efficient anti parasitic drug.

Stromal cell-derived factor-1α promotes recruitment and differentiation of nucleus pulposus-derived stem cells.

BACKGROUND: Intervertebral disc (IVD) degeneration is a condition characterized by a reduction in the water and extracellular matrix content of the nucleus pulposus (NP) and is considered as one of the dominating contributing factors to low back pain. Recent evidence suggests that stromal cell-derived factor 1α (SDF-1α) and its receptor C-X-C chemokine receptor type 4 (CXCR4) direct the migration of stem cells associated with injury repair in different musculoskeletal tissues. AIM: To investigate the effects of SDF-1α on recruitment and chondrogenic differentiation of nucleus pulposus-derived stem cells (NPSCs). METHODS: We performed real-time RT-PCR and enzyme-linked immunosorbent assay to examine the expression of SDF-1α in nucleus pulposus cells after treatment with pro-inflammatory cytokines in vitro. An animal model of IVD degeneration was established using annular fibrosus puncture in rat coccygeal discs. Tissue samples were collected from normal control and degeneration groups. Differences in the expression of SDF-1α between the normal and degenerative IVDs were analyzed by immunohistochemistry. The migration capacity of NPSCs induced by SDF-1α was evaluated using wound healing and transwell migration assays. To determine the effect of SDF-1α on chondrogenic differentiation of NPSCs, we conducted cell micromass culture and examined the expression levels of Sox-9, aggrecan, and collagen II. Moreover, the roles of SDF-1/CXCR4 axis in the migration and chondrogenesis differentiation of NPSCs were analyzed by immunofluorescence, immunoblotting, and real-time RT-PCR. RESULTS: SDF-1α was significantly upregulated in the native IVD cells cultured in vitro with pro-inflammatory cytokines, such as interleukin-1ß and tumor necrosis factor-α, mimicking the degenerative settings. Immunohistochemical staining showed that the level of SDF-1α was also significantly higher in the degenerative group than in the normal group. SDF-1α enhanced the migration capacity of NPSCs in a dose-dependent manner. In addition, SDF-1α induced chondrogenic differentiation of NPSCs, as evidenced by the increased expression of chondrogenic markers using histological and immunoblotting analyses. Real-time RT-PCR, immunoblotting, and immunofluorescence showed that SDF-1α not only increased CXCR4 expression but also stimulated translocation of CXCR4 from the cytoplasm to membrane, accompanied by cytoskeletal rearrangement. Furthermore, blocking CXCR4 with AMD3100 effectively suppressed the SDF-1α-induced migration and differentiation capacities of NPSCs. CONCLUSION: These findings demonstrate that SDF-1α has the potential to enhance recruitment and chondrogenic differentiation of NPSCs via SDF-1/CXCR4 chemotaxis signals that contribute to IVD regeneration.

Value of somatosensory evoked potentials in diagnosis, surgical monitoring and prognosis of cervical spondylotic myelopathy.

BACKGROUND: The value of somatosensory evoked potentials (SEPs) in the diagnosis and prognosis of cervical spondylotic myelopathy, as well as the usefulness of monitoring intraoperative potentials in terms of safety and predictive factors were investigated. METHODS: Each of the 76 myelopathic patients underwent surgical intervention. According to the wave configurations of the SEPs, the cases were categorised into four groups: Type I, II, III and IV. The clinical myelopathy disability was classified and the severity of neurological deficits was scored. Clinical function after surgery was evaluated. Preoperative potentials and intraoperative monitoring were categorized. The correlations between .evoked potentials detection, monitoring, myelopathy disability and surgical outcome in the different groups were discussed. RESULTS: According to the configurations of the SEPs, there were 27 patients (36%) of Type I, 30 patients (39%) of Type II, 8 patients (11%) of Type III, and 11 patients (14%) of Type IV. The categorised evoked potentials were shown to be significantly associated with the clinical representation of myelopathy (P<0.01) and the recovery rate from identifiable SEPs waves (groups A, B and C) was significantly higher than unidentifiable waves (group D, P<0.01). A deterioration of SEPs was detected in 23 cases (30%), whereas there was no change in 40 cases (53%) and improvements in 13 cases (17%). A significant difference in recovery rates could be observed in various monitoring groups within the short-term follow-up period, while there were no obvious differences in the long-term follow-up groups. CONCLUSIONS: SEP technique is a valuable and practical tool for the diagnosis, monitoring and prognosis of myelopathy. Classified evoked potentials are well correlated with cervical spondylotic myelopathy disability, and unidentifiable SEPs waves in patients are indicative of a relatively poor outcome. In addition, intraoperative monitoring of SEPs plays an important role in protecting neural structures during cervical spine surgery.

Transcutaneous electroacupuncture alleviates postoperative ileus after gastrectomy: A randomized clinical trial.

AIM: To investigate the efficacy and safety of transcutaneous electroacupuncture (TEA) to alleviate postoperative ileus (POI) after gastrectomy. METHODS: From April 2014 to February 2017, 63 gastric cancer patients were recruited from the Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China. After gastrectomy, the patients were randomly allocated to the TEA (n = 33) or control (n = 30) group. The patients in the TEA group received 1 h TEA on Neiguan (ST36) and Zusanli (PC6) twice daily in the morning and afternoon until they passed flatus. The main outcomes were hours to the first flatus or bowel movement, time to nasogastric tube removal, time to liquid and semi-liquid diet, and hospital stay. The secondary outcomes included postoperative symptom assessment and complications. RESULTS: Time to first flatus in the TEA group was significantly shorter than in the control group (73.19 ± 15.61 vs 82.82 ± 20.25 h, P = 0.038), especially for open gastrectomy (76.53 ± 14.29 vs 87.23 ± 20.75 h, P = 0.048). Bowel sounds on day 2 in the TEA group were significantly greater than in the control group (2.30 ± 2.61/min vs 1.05 ± 1.26/min, P = 0.017). Time to nasogastric tube removal in the TEA group was earlier than in the control group (4.22 ± 1.01 vs 4.97 ± 1.67 d, P = 0.049), as well as the time to liquid diet (5.0 ± 1.34 vs 5.83 ± 2.10 d, P = 0.039). Hospital stay in the TEA group was significantly shorter than in the control group (8.06 ± 1.75 vs 9.40 ± 3.09 d, P = 0.041). No significant differences in postoperative symptom assessment and complications were found between the groups. There was no severe adverse event related to TEA. CONCLUSION: TEA accelerated bowel movements and alleviated POI after open gastrectomy and shortened hospital stay.

[Experimental study of inhibition of safflower injection on mesenteric microvascular motion in rabbits DI].

OBJECTIVE: To dynamically observe the effect of Safflower Injection (SI) on mesenteric microvascular motion in vivo in rabbits, and to explore the effect of nitric oxide (NO) in the process to further investigate the action mechanism of activating blood to remove stasis of SI. METHODS: Twenty healthy male albino rabbits were intraperitoneally injected with urethane for basic anesthesia and injected with alpha-chloralose via ear marginal venous to maintain anesthesia, spontaneously ventilated via tracheotomy tube, with the in-step record of breath and blood pressure. The vasomotion was induced by noradrenaline (NA) in vivo, then the changes of vasomotion after injecting SI and N(G)-monomethyl-L-arginine (L-NMMA, a NO synthase inhibitor) were measured respectively on a TV monitor using a TV camera mounted on the microscope, and the influence of L-NMMA on effect of SI was also observed. RESULTS: L-NMMA injection alone can inhibit the NA induced vasomotion in vasoconstriction state, while SI injection alone can inhibit it in vaso-dilation state. SI could abolish the effect of L-NMMA on vasomotion but L-NMMA did not influence the effect of SI on vasomotion. CONCLUSION SI can inhibit vasomotion in vaso-dilation status, but its mechanism is not mediated by endogenous NO.

* Coculture with Partial Digestion Notochordal Cell-Rich Nucleus Pulposus Tissue Activates Degenerative Human Nucleus Pulposus Cells.

Recent studies suggested that notochordal cells (NCs) and NC-conditioned medium (NCCM) can stimulate cell viability and matrix production of nucleus pulposus cells (NPCs). However, the potential of notochordal cell-rich nucleus pulposus (NRNP) incorporating the native environment of the intervertebral disc (IVD) has not been evaluated. The objective of this study was to develop an optimal NRNP model and test whether it can allow a significant level of NPC activation in vitro. Rabbit NRNP explants were divided into three groups according to different digestion time: digestion NRNP of 8 h, partial digestion NRNP of 2 h, and natural NRNP. Cell viability and NC phenotype were compared between these groups after 14 days of incubation. The products of the selected partial digestion NRNP group were then cocultured with human degenerated NPCs for 14 days. NPC viability, cell proliferation and senescence, the production of glycosaminoglycan (GAG) found in extracellular matrix, and NP matrix production by NPCs were assessed. The results showed that coculturing with partial digestion NRNP significantly improved the cell proliferation, cell senescence, and disc matrix gene expression of NPCs compared with those in the monoculture group. In addition, GAG/DNA ratio in the coculture group increased significantly, while the level of collagen II protein remained unchanged. In this study, we demonstrated that partial digestion NRNP may show a promising potential for NPC regeneration in IVD tissue engineering.