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91.
Hypereutectic Al-Si alloys are attractive materials in the fields of electronic packaging and aerospace. A Bi2O3-ZnO-B2O3 system lead-free brazing filler glass was employed to braze hypereutectic Al-50Si alloys in air. The hypereutectic Al-50Si alloys were pre-oxidized and the low-temperature glass powder was flake-shaped in the brazing process. The effects of brazing temperature and time on joints microstructure evolution, resulting mechanical strength, and air tightness were systematically investigated. The results indicated that the maximum shear strength of the joint was 34.49 MPa and leakage rate was 1.0 × 10−10 Pa m3/s at a temperature of 495 °C for 30 min. Crystalline phases, including Bi24B2O39 and Bi2O3, were generated in the glass joint. The formation of a diffusion transition layer with a thickness of 3 μm, including elements of Al, Si, Zn, Bi, Na, and B, was the key to form an effective joint. The elements of Al, Si, and Bi had a short diffusion distance while the elements of Zn, Na, and B diffused in a long way under brazing condition. 相似文献
92.
目的 研究振幅整合脑电图联合感觉门控电位P50 对重症脑血管病患者预后结局的评估价值。
方法 选取2017 年5 月—2019 年5 月郴州市第一人民医院诊治的重症脑血管病患者62 例。根据患者预后情
况将其分成病死组(14 例)和预后良好组(48 例),比较两组患者振幅整合脑电图、P50 结果;分析振幅整
合脑电图、P50 与格拉斯哥预后评分表(GOS)评分的相关性;评估振幅整合脑电图、P50 单独与联合检测
对患者的预后价值。结果 两组振幅整合脑电图分级比较,差异有统计学意义(P <0.05)。病死组P50 较预
后良好组高(P <0.05)。预后良好组GOS 评分较病死组高(P <0.05)。振幅整合脑电图、P50 与GOS 评分呈
负相关(r s =-0.629 和-0.703,均P <0.05)。联合检测对患者预后的价值高于振幅整合脑电图、P50单独检测
(P <0.05)。结论 P50 联合振幅整合脑电图检测对重症脑血管病患者具有较高的预后评估价值。 相似文献
93.
This article describes a digital technique that combines intraoral digital scans with a 3-dimensional facial scan to predict the outcome of prosthodontic treatment of anterior teeth at the treatment planning phase. This approach may increase patient acceptance of the definitive treatment, as the altered facial appearance is visualized with definitive prosthodontic restorations, thereby improving communication before treatment begins. 相似文献
94.
Kyung Chul Oh Changjoo Jeon Ji-Man Park June-Sung Shim 《The Journal of prosthetic dentistry》2019,121(1):17-21
This article describes a workflow based on a top-down approach to provide a fixed-type immediate interim restoration after placing a single implant using a digitally driven surgical guide and a matrix-positioning device. A characteristic of the technique is that both the surgical guide and the matrix-positioning device are fabricated from a single diagnostic virtual trial restoration designed on computer-aided design (CAD) software. This workflow may shorten the time required for chairside placement of an interim restoration and enhance esthetics when rehabilitating anterior teeth. 相似文献
95.
Introduction
Intracerebral hemorrhage (ICH) is a major clinical concern with anticoagulation therapy. The effect of a new oral direct FXa inhibitor, edoxaban, was determined in a rat model of ICH and compared with a direct thrombin inhibitor, melagatran, and heparin.Methods
To induce ICH, 0.1 U collagenase type VII was injected into the striatum of male Wistar rats under anesthesia with thiopental or halothane. Immediately after ICH induction, edoxaban, melagatran, or heparin were infused intravenously. Five hours after ICH induction, the brain was removed and ICH size was measured. To estimate the margin of safety, antithrombotic effects were evaluated in a rat venous thrombosis model.Results
Edoxaban at 6 mg/kg/h significantly increased ICH volume (1.8-fold) and prolonged prothrombin time (PT) 2.8-fold compared to the vehicle group. No deaths were observed with edoxaban. Melagatran at 1 mg/kg/h increased ICH volume at 1 mg/kg/h (2.8-fold) with 6.1-fold PT prolongation. At 3 mg/kg/h, all rats died due to severe ICH (3.9-fold). Heparin at both 100 and 500 U/kg/h significantly increased ICH. At 500 U/kg/h, 5 out of 8 rats died. The doses required for 50% inhibition of thrombosis of edoxaban, melagatran, and heparin were 0.045 mg/kg/h, 0.14 mg/kg/h, and 55 U/kg/h, respectively. The safety margins between antithrombotic and ICH exacerbation effects of these anticoagulants were 133, 7.1, and 1.8, respectively.Conclusion
The safety margin of edoxaban was wider than that of melagatran or heparin. These results suggest that edoxaban may be preferable from the perspective of ICH exacerbation risk. 相似文献96.
97.
Gary Greenstein John Cavallaro Dennis Tarnow 《Journal of the American Dental Association (1939)》2013,144(4):362-368
BackgroundIncreased stress (force) on prostheses induces strain (deformation) in the peri-implant bone. Elevated stress and strain could result in the failure of implants that support prostheses. However, the survival rate of implants supporting prostheses under increased stress is high. Either the bone is stronger than expected or it adapts to increased stress. Concepts regarding bone’s adaptive capacity continue to evolve and are the focus of this literature review.Types of Studies ReviewedThe authors searched the literature to find studies that addressed the bone’s capacity to adjust to increased stress and strain. They assessed experimental and clinical trials in which investigators monitored healing after placement of dental implants.ResultsThe data indicate that forces greater than the bone’s adaptive ability can induce loss of osseointegration, as well as osseous resorption. In contrast, it is possible that increased stress on prostheses initiates a reparative process, thereby facilitating retention of implants experiencing increased stress. Numerous lines of evidence support the concept that bone can modify itself to withstand increased mechanical forces.Practical ImplicationsThe authors provide an explanation for the high success rate of prostheses and implants in bone that are exposed to increased stress and strain. 相似文献
98.
99.
High‐risk neuroblastomas harbor abundant myeloid cells that suppress antitumor immunity and support tumor growth. Macrophages lacking the inhibitory NF‐κB p50 subunit adopt a pro‐inflammatory phenotype. We now report that murine 9464D neuroblastoma cells, which express high levels of exogenous MYCN, grow slower in syngeneic p50(f/f);Lys‐Cre mice that lack p50 in macrophages and neutrophils, compared with p50(f/f) littermates. Tumors in p50(f/f);Lys‐Cre mice possess increased numbers of total and activated CD4+ and CD8+ T cells, and depletion of both of these T‐cell populations accelerates tumor growth. Anti‐PD‐1 T‐cell checkpoint blockade, or DNA methyltransferase and histone deacetylase inhibition, further slows tumor growth. In addition, adoptive transfer of immature myeloid cells lacking NF‐κB p50 (p50‐IMC), generated either from the bone marrow of p50−/− mice or via nucleofection of a p50 sgRNA:Cas9 complex into wild‐type hematopoietic progenitors, also slowed growth of MHC‐matched 9464D tumors but not of MHC‐mismatched Neuro2A tumors. These findings further validate the utility of targeting myeloid NF‐κB p50 as a strategy for cancer therapy and demonstrate activity of p50‐IMC generated by gene editing of syngeneic marrow cells, a cell product relevant to clinical translation. 相似文献
100.
Anna F. Tyson Laura P. Boschini Michelle M. Kiser Jonathan C. Samuel Steven N. Mjuweni Bruce A. Cairns Anthony G. Charles 《Burns : journal of the International Society for Burn Injuries》2013