An access-sequence control scheme to enhance random-accessperformance of embedded DRAM's

An embedded DRAM enables a high data-transfer rate since it provides an on-chip wide-bus interconnection. However, the net data-transfer rate is reduced by page misses because of the inherently large row-access time of DRAM's. We previously proposed a multibank DRAM macro based on a micromodule architecture to overcome this problem. The pipelined access of the DRAM macro is especially useful for regular access in graphics applications. In this paper, we propose an access-sequence control scheme which enhances the random-access performance of embedded DRAMs. Access ID numbers, an access queue register, and a write-data buffer combined with the multibank DRAM enable out-of-sequence access which reduces the page-miss penalty during random access. In the case of four successive accesses, the estimated total access time was, respectively, reduced by up to 38 and 32% for one and two page misses, and for five successive accesses with one or two page misses, it was, respectively, reduced by up to 44 and 45%     

Spinal needle navigation by tracked ultrasound snapshots

Purpose: Ultrasound (US) guidance in facet joint injections has been reported previously as an alternative to imaging modalities with ionizing radiation. However, this technique has not been adopted in the clinical routine, due to difficulties in the visualization of the target joint in US and simultaneous manipulation of the needle. Methods: We propose a technique to increase targeting accuracy and efficiency in facet joint injections. This is achieved by electromagnetically tracking the positions of the US transducer and the needle, and recording tracked US snapshots (TUSS). The needle is navigated using the acquired US snapshots. Results: In cadaveric lamb model, the success rate of facet joint injections by five orthopedic surgery residents significantly increased from 44.4% with freehand US guidance to 93.3% with TUSS guidance. Needle insertion time significantly decreased from 47.9 ± 34.2?s to 36.1 ± 28.7?s (mean ± SD). In a synthetic human spine model, a success rate of 96.7% was achieved with TUSS. The targeting accuracy of the presented system in a gel phantom was 1.03 ± 0.48?mm (mean ± SD). Conclusion: Needle guidance with TUSS improves the success rate and time efficiency in spinal facet joint injections. This technique readily translates also to other spinal needle placement applications.     

高强度管线钢及其焊管的性能研究

目前X80级管线钢管已在大口径输送管线中得到应用,使得对进一步提高管线钢强度(X100—X120级)的需求也更迫切了。使用高强度管线钢目的是拟通过提高管道的输送压力来提高其输送效率和降低铺设管线费用。为将这两点期望变为现实,高强度管线钢管及其焊接热影响区(HAZ)应具备良好的低温韧性和现场焊接(环焊)性能,所以,必须综合应用合理的合金成分设计,超纯净冶炼,控轧、控冷(TMCP)等工艺,改善焊接热影响区工艺等多方面的技术和措施,以得到同时具备高强度、良好的低温韧性和现场焊接性能的管线钢。     

Alpha-melanocyte-stimulating hormone blocks invasion of reconstituted basement membrane (Matrigel) by murine B16 melanoma cells

We have examined the effect of alpha-melanocyte-stimulating hormone (alpha-MSH) on invasive ability of murine melanoma cell lines with different metastatic potential in a Matrigel invasion assay. alpha-MSH potently blocked the invasion of B16-BL6 cells with highly metastatic potential in a concentration-dependent manner, whereas it was less effective in inhibiting the invasion of weakly metastatic B16-F1 cells. Pretreatment of B16-BL6 cells with alpha-MSH resulted in a decrease of the adhesiveness to fibronectin and laminin substrates in a time-dependent fashion. As assessed by zymographic analysis, alpha-MSH partially inhibited the production of matrix metalloproteinase (MMP)-2 and -9 from both cell lines to a similar degree without affecting the degradative activity of these MMPs. alpha-MSH was more potent in inhibiting the migration of B16-BL6 cells towards both fibronectin- and laminin-coated substrates than that of B16-F1 cells. The growth and morphology of B16-BL6 cells were not changed after a 7-day incubation with alpha-MSH. The number of lung tumor colonies markedly decreased when B16-BL6 cells were coinjected intravenously with 10(-6) M alpha-MSH. However, alpha-MSH had no effect on the experimental lung metastases by B16-F1 cells. These results suggest that alpha-MSH suppressed the invasive and metastatic properties of B16 melanoma cells, and the degree of inhibition was associated with metastatic potential of B16 melanoma cells.     

Histological comparison of early wound healing following dense hydroxyapatite granule grafting and barrier placement in surgically-created bone defects neighboring implants

The purpose of this study was to examine early wound healing following grafting of dense hydroxyapatite granules (HA granules) and barrier placement in surgically-created bone defects surrounding implants. Eight healthy adult dogs with an average weight of 15 kg were used in this study. Thirty-two bone defects measuring 4 mm x 4 mm were removed with a surgical bur to form continuous bucco-lingual bone defects and 32 implants (16 titanium [Ti]) and 16 hydroxyapatite-coated [HA]) were then placed into the defects. Four implant groups were created: 1) grafting HA; 2) covering with an expanded polytetrafluoroethylene (ePTFE) membrane; 3) grafting HA and covering with ePTFE membrane; and 4) control (no treatment). Animals were sacrificed 28 days after surgery. Histological sections revealed large amounts of newly-formed bone in all bone defects surrounding the implants treated with ePTFE membranes alone. Fibrous encapsulation of HA granules was observed in the defects of the HA granules grafting group. In the group with grafting of HA granules and covering with ePTFE membranes, small amounts of bone tissue were observed among HA granules, but most HA granules were surrounded with fibrous tissue. Bone defects were completely filled with connective tissue in the control group. There were no differences in the histological findings between Ti and HA-coated implants in all cases. Histomorphometric data disclosed that the presence of HA granules in the bone defects significantly arrested bone formation. Our study suggests that the grafting of dense HA into bone defects surrounding implants will result in fibrous healing during the early healing stage.     

A modular architecture for a 6.4-Gbyte/s, 8-Mb DRAM-integratedmedia chip

A modular architecture for a DRAM-integrated, multimedia chip with a data transfer rate of 6 to 12 Gbyte/s is proposed. The architecture offers the design flexibility in terms of both DRAM capacity and the logic-memory interface for use in a wide variety of applications. A DRAM macro built from cascadable DRAM bank modules having a 256-kb memory capacity and 128-b I/Os provides flexibility and reconfigurability of DRAM capacity and a high data transfer rate with an area of 6.4 mm² /Mb. A data transfer circuit (called the “reconfigurable data I/O attachment”), which is attached to the I/O lines of the DRAM macro, provides a flexible logic-memory interface by changing the data-transfer routes between the DRAM macro and logic circuits in real time. A 6.4-Gbyte/s test chip (called the “media chip”) for three-dimensional computer graphics was fabricated to test the proposed design methodology. It integrates an 8-Mb DRAM and four pixel processors on an 8.35×14.6-mm chip by using a 0.4-μm CMOS design rule