Swept-source endoscopic optical coherence tomography real-time imaging system based on GPU acceleration for axial megahertz high-speed scanning.

OBJECTIVE: In order to solve the problem of image real-time processing and correction for high-speed endoscopic swept-source optical coherence tomography (SS-OCT), we highly optimize a computer-unified device architecture-based platform and use a field-programmable gate array to summarize the application experience. MATERIALS AND METHODS: We use the Half-Sync/Half-Asyn mode to optimize memory in order to build a high-throughput data thread pool for CPU. We use asynchronous streaming architecture to multiplex multiple threads at high speed to accelerate data processing. At the same time, we design a rotary scanning position information encoding feedback module to suppress image drift, which can realize 25ns logic-timing sequence synchronization control through FPGA 40MHz clock. RESULTS: The maximum complete attainable axial-scan-processing rate (including memory transfer and display of B-scan frames) is 3.52 MHz for a 16-bit pixel depth and A-scans/s of 1024 pixels. To our knowledge, this is the fastest processing rate reported to date with a single-chip graphical processing unit for SS-OCT. Finally, the established high-speed SS-OCT is used to image mouse esophagus and human fingers, and the output images are stable. When the image size is 1024 × 1024 pixels, the real-time imaging rate is 200 frames per second. CONCLUSIONS: This paper develops a real-time image processing and reconstruction technology suitable for high-throughput SS-OCT systems, which can have high-density operation and efficient parallelism, while suppressing high-speed image drift. It lays the foundation for the non-destructive, in vivo, non-staining, fast and convenient early tumor diagnosis of high-speed endoscopic SS-OCT.

[Security analysis of implanting drug-eluting stents for unprotected left main coronary artery disease patients with chronic kidney disease].

OBJECTIVE: To study the clinical characteristics and prognosis of unprotected left main (ULM) coronary artery disease patients with chronic kidney disease after drug-eluting stents (DES) implantation. METHODS: 267 ULM coronary artery disease patients who has implanted DES were included in the study from January 2005 to March 2010. Patients were divided into two groups according to their estimated glomerular filtration rate (eGFR): eGFR <60 ml·min(-1)·1.73 m(-2) (77 patients), and eGFR≥ 60 ml·min(-1)·1.73 m(-2) (190 patients) . The clinical parameters and prognosis of ULM patients treated with DES in different eGFR groups were retrospectively compared. RESULTS: In higher eGFR group, left ventricular ejection fraction (LVEF) and morbidity of coronary ostial lesions were higher than the other group. Cerebrovascular diseases (13.0% vs 5.3%), chronic total occlusion (CTO, 28.6% vs 12.1%), hypertension (70.1% vs 53.2%) were more common in lower eGFR patients(all P<0.05). Total mortality and cardiac mortality were higher in eGFR<60 ml·min(-1)·1.73 m(-2) group (P=0.016, 0.006, respectively). Low eGFR level was an independent risk factor after adjusting multiple factors. CONCLUSION: For the ULM disease patients with reduction in kidney function (eGFR<60 ml·min(-1)·1.73 m(-2)), DES should be selected with a careful study considering its increasing risk of death. Chronic renal insufficiency is a risk factor and may predict poor prognosis for patients with ULM after DES implantation.

Estrogen alone or in combination with parathyroid hormone can decrease vertebral MEF2 and sclerostin expression and increase vertebral bone mass in ovariectomized rats.

UNLABELLED: The study is about the regulatory effects of estrogen and parathyroid hormone (PTH) on sclerostin, a protein that inhibits the Wnt/ß-catenin pathway. The results indicate that estrogen may down-regulate sclerostin expression and that estrogen displays synergistic action with PTH. These results provide a new perspective on the relationship between estrogen and bone. PURPOSE: To investigate whether estrogen can down-regulate SOST and MEF2 (myocyte enhancer factor 2) expression and whether co-treatment with estrogen and PTH has a stronger effect on suppressing SOST than PTH applied alone in ovariectomized rats. METHODS: Forty-three-month-old virgin female Sprague-Dawley (SD) rats were ovariectomized and divided into four groups (n = 10). Another ten age-matched rats received sham operations as controls. After allowing 8 weeks for the development of vertebral osteopenia, the rats were administered the drug intervention. For this intervention, the estrogen group was subcutaneously injected with 17ß-estradiol at 25 µg/kg body weight, the PTH group was injected with 80 µg/kg synthetic human PTH (1-34), and the co-treatment group was concurrently treated with PTH and estrogen at the above dosage. The OVX group and sham group were treated with vehicle. The drug treatment was conducted for 12 weeks. After the lumbar spine bone mineral density (BMD) was measured, the rats were sacrificed, and the lumbar spine and blood were collected for qPCR, Western blot, immunohistochemistry and other tests. RESULTS: Estrogen can down-regulate MEF2 and sclerostin expression, and co-treatment with estrogen and PTH has a stronger effect on suppressing MEF2 and SOST mRNA than PTH alone. The co-treatment group displayed slightly higher bone mass and biomechanical properties than the PTH group, but the differences were not significant. CONCLUSIONS: Estrogen appears to be a regulator of sclerostin, and the effect may involve suppressing MEF2s. Combined treatment with PTH and estrogen is not more beneficial for vertebral bone mass and strength than treatment with PTH alone in ovariectomized rats.

Ground simulation of the G-excess illusion.

Objective. To observe the subjects' perception of orientation following certain head movements or change of simulator cab attitude in hypergravity (HG), and assess the feasibility of simulating G-excess illusion on the ground by a centrifuge-like Spatial Disorientation (SD) simulator. Method. 1.6 G force field was generated by planetary rotation of the simulator. Perception of orientation of the cab were collected from twelve male pilots' report following their heads pitch movements in pitch plane or cab attitude changes in roll plane under 1.6 G. Result. While making a pitch-up head movement, the pilots experienced a 63.8 degrees +/- 48.3 degrees pitch-up attitude change of the cab in pitch plane, and when the cab was tilted left 20 degrees, pilots experienced a tilt-left perception of 48.6 degrees +/- 39.4 degrees in roll plane. Conclusion. Although there's strong Coriolis effects onboard the SD simulator under 1.6 G, most pilots experienced the G-excess illusion. It demonstrated that it was feasible to use the centrifuge-like device to generate this kind of illusion on the ground.

[5-HT3 receptors in amygdala mediate neuroimmunomodulation in rats].

The present study was to explore the possible immunomodulatory role of 5-HT3 receptors in the amygdala in rats. Concanovalin A (Con A)- and lipopolysaccharide (LPS)-stimulated splenocyte proliferation response (SPR), production of IL-2, activity of natural killer (NK) cells and serum cortisol were measured by 3H-TdR incorporating method, MTT method and RIA, respectively. The Con A- and LPS-stimulated SPR was enhanced in a dose-dependent manner by 5-HT3 receptor antagonist granisetron (GNT) (0.1-0.4 mg/kg, i.p.). SPR was also enhanced by intracerebroventricular (icv) administration of 1-phenylbiguanide (PBG, 10 micrograms/d). Con A-stimulated SPR and production of IL-2 were increased either by bilateral or by unilateral central amygdala (CeA) microinfusion of PBG (0.5 microgram/side), but LPS-induced SPR and NK cell activity were not affected. On the contrary, the LPS-induced SPR was increased by either bilateral or unilateral basomedial amygdala (BmA) microinfusion of PBG (0.5 microgram/side). The plasma cortisol level was significantly raised by CeA or BmA PBG microinfusion, but the effect induced by PBG intra-CeA was greater than that induced by PBG intra-BmA (P < 0.01). The effects of icv PBG and intra-amygdala infusion were antagonized by granisetron. Asymmetrical modulation of immune reactivity by 5-HT3 receptors in CeA or BmA was not observed in these experiments. It is suggested that 5-HT3 receptors within the amygdala may modulate rat mitogen-stimulated SPR in different manners.

[Bacterial genetic diversity in soils and their correlation with vegetation].

Soil is an important epicenter of biodiversity. Human activity has threatened such biodiversity through vegetation shift. As the major type of microbes, bacteria have played key roles in material cycling. Since simple morphological characters and the failure of the major portion of bacteria in surviving artificial cultivation have hindered bacterial diversity from analyses using traditional taxonomic approaches, bacterial diversity and its correlation with vegetation is less understood. In order to detour cultivation, tag serial sequencing strategy was developed in this study, in which a 26 base pair highly variable region has been chosen from 16S ribosomal RNA gene as variant-representing tags, ligated into serials and sequenced. Molecular bacterial diversity in soils has been determined using tag types, tag frequencies and diversity index as parameters. The correlation of bacterial diversity with vegetation has been explored as well. Bacterial diversity and differentiation correlate highly with contents of organic matter and nitrogen of soils and further vegetation.