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排序方式: 共有191条查询结果,搜索用时 15 毫秒
1.
目的分析ELISA和NAT平行的血液筛查模式对降低经输血感染病原体风险的有效性。方法收集常州市2016—2019年270215例无偿献血者血液标本,采用两次ELISA并行检测HBsAg、抗HCV、抗HIV和抗TP。268264例ELISA双阴性标本采用6人份混样(pool)NAT进行HBV DNA、HCV RNA和HIV RNA的检测,核酸阳性的pool进行拆分单检。结果270215例无偿献血者HBsAg、抗HCV、抗HIV和抗TP的阳性率分别为2.58‰(697例)、1.49‰(402例)、0.23‰(61例)和3.06‰(827例)。268264例酶免阴性无偿献血者HBV DNA、HCV RNA和HIV RNA阳性率分别为0.86‰(230例)、0.01‰(3例)和0.01‰(2例)。结论ELISA与NAT两种检测方法能相互补充,极大降低了输血感染病原体的残余风险,保障输血安全。NAT能进一步缩短血液传染性病毒的检测“窗口期”,检出隐匿性病毒。 相似文献
2.
浅谈新时期医院窗口的文明建设 总被引:9,自引:0,他引:9
医疗保险制度的建立和卫生监督执法等配套改革措施的出台,表明我国卫生改革已迈入一个全新的发展时期。医院的窗口服务面临一些新情况,新问题:病人方便就医的意识逐渐增强;求医过程中,病人自我保护意识增强;居民对健康的理解不再局限于没有疾病,阶段性的身心健康检查和体整需要逐渐增大。 相似文献
3.
Jihao Fan Jun Li Yongbin Zhou Min-Hsiu Hsieh H. Vincent Poor 《Proceedings of the National Academy of Sciences of the United States of America》2022,119(24)
Entanglement-assisted concatenated quantum codes (EACQCs), constructed by concatenating two quantum codes, are proposed. These EACQCs show significant advantages over standard concatenated quantum codes (CQCs). First, we prove that, unlike standard CQCs, EACQCs can beat the nondegenerate Hamming bound for entanglement-assisted quantum error-correction codes (EAQECCs). Second, we construct families of EACQCs with parameters better than the best-known standard quantum error-correction codes (QECCs) and EAQECCs. Moreover, these EACQCs require very few Einstein–Podolsky–Rosen (EPR) pairs to begin with. Finally, it is shown that EACQCs make entanglement-assisted quantum communication possible, even if the ebits are noisy. Furthermore, EACQCs can outperform CQCs in entanglement fidelity over depolarizing channels if the ebits are less noisy than the qubits. We show that the error-probability threshold of EACQCs is larger than that of CQCs when the error rate of ebits is sufficiently lower than that of qubits. Specifically, we derive a high threshold of 47% when the error probability of the preshared entanglement is 1% to that of qubits.Quantum error-correction codes (QECCs) are necessary to realize quantum communications and to make fault-tolerant quantum computers (1, 2). The stabilizer formalism provides a useful way to construct QECCs from classical codes, but certain orthogonality constraints are required (3). The entanglement-assisted (EA) QECC (EAQECC) (4–6) generalizes the stabilizer code. By presharing some entangled states between the sender (Alice) and the receiver (Bob), EAQECCs can be constructed from any classical linear codes without the orthogonality constraints. Therefore, the construction could be greatly simplified. As an important physical resource, entanglement can boost the classical information capacity of quantum channels (7–12). Recently, it has been shown that EAQECCs can violate the nondegenerate quantum Hamming bound (13) or the quantum Singleton bound (14).Compared to standard QECCs, EAQECCs must establish some amount of entanglement before transmission. This preshared entanglement is the price to be paid for enhanced communication capability. In a sense, we need to consider the net transmission of EAQECCs—i.e., the number of qubits transmitted minus that of ebits preshared. Further, it is difficult to preserve too many noiseless ebits in EAQECCs at present. Thus, we have to use as few ebits as possible to conduct the communication—e.g., one or two ebits are preferable (15–18). In addition, EAQECCs with positive net transmission and little entanglement can lead to catalytic quantum codes (4, 6), which are applicable to fault-tolerant quantum computation (FTQC). In ref. 4, a table of best-known EAQECCs of length up to 10 was established through computer search or algebraic methods. Several EAQECCs in ref. 4 have larger minimum distances than the best-known standard QECCs of the same length and net transmission. However, for larger code lengths, the efficient construction of EAQECCs with better parameters than standard QECCs is still unknown.In classical coding theory, concatenated codes (CCs), originally proposed by Forney in the 1960s (19), provide a useful way of constructing long codes from short ones. CCs can achieve very large coding gains with reasonable encoding and decoding complexity (20). Moreover, CCs can have large minimum distances since the distances of the component codes are multiplied. As a result, CCs have been widely used in many digital communication systems—e.g., the NASA standard for the Voyager program (21) and the compact disc (20). Similarly, in QECCs, the concatenated quantum codes (CQCs), introduced by Knill and Laflamme in 1996 (22), are also effective for constructing good quantum codes. In particular, it has been shown that CQCs are of great importance in realizing FTQC (23–25).Moreover, there exists a specific phenomenon in QECCs, called “error degeneracy,” which distinguishes quantum codes from classical ones in essence. It is widely believed that degenerate codes can correct more quantum errors than nondegenerate ones. Indeed, there are some open problems concerning whether degenerate codes can violate the nondegenerate quantum Hamming bound (26) or can improve the quantum-channel capacity (27, 28). Many CQCs have been shown to be degenerate, even if the component codes are nondegenerate—e.g., Shor’s code and the CQC (23, 29). If we introduce extra entanglement to CQCs, it is possible to improve the error-degeneracy performance of CQCs.In this article, we generalize the idea of concatenation to EAQECCs and propose EACQCs. We show that EACQCs can beat the nondegenerate quantum Hamming bound, while standard CQCs cannot. Several families of degenerate EACQCs that can surpass the nondegenerate Hamming bound for EAQECCs are constructed. The same conclusion could be reached for asymmetric error models, in which the phase-flip errors (Z errors) happen more frequently than the bit-flip errors (X errors) (30, 31). Furthermore, we derive a number of EACQCs with better parameters than the best-known QECCs and EAQECCs. In particular, we see that many EACQCs have positive net transmission, and each of them consumes only one or two ebits. Thus, they give rise to catalytic EACQCs with little entanglement and better parameters than the best-known QECCs. Further, we show that the EACQC scheme makes EA quantum communication possible, even if the ebits are noisy. We compute the entanglement fidelity (EF) of the [[15,1,9;10]] EACQC by using Bowen’s [[3,1,3;2]] EAQECC (32) or the [[3,1,3;2]] EA repetition code (4, 6) as the inner code. The outer code is the standard [[5,1,3]] stabilizer code. We show that the [[15,1,9;10]] EACQC performs much better than the [[25,1,9]] CQC over depolarizing channels if the ebits suffer a lower error rate than the qubits. Moreover, we compute the error-probability threshold of EACQCs, and we show that EACQCs have much higher thresholds than CQCs when the error rate of ebits is sufficiently lower than that of qubits. 相似文献
4.
5.
《中国现代医生》2020,58(17):141-143
目的评价不同CT窗技术及后处理技术对肺栓塞的诊断价值。方法回顾性分析2018年9月~2020年1月在我院行CTPA确诊的45例肺栓塞患者的资料,分别应用常规纵膈窗及常用调节窗、常规纵膈窗+调节窗观察肺栓塞的位置(段以上、段及段以下)及阳性血管数,以纵膈窗联合调节窗检出的肺栓塞作为金标准。比较最大密度投影(MIP)、多平面重组(MPR)和容积重建(VR)三种后处理技术对不同位置的肺动脉显示率,组间比较采用χ~2检验。结果段及段以下肺栓塞,单独使用调节窗的漏诊率低于单独使用纵膈窗,分别为3.3%、12.5%,差异有统计学意义(P0.05)。段以上肺栓塞,单独应用常用调节窗、纵膈窗漏诊率分别为4.5%、13.6%,组间比较差异无统计学意义(P0.05)。MPR对段及段以下肺动脉栓塞的显示率优于MIP及VR影像,差异具有统计学意义(P0.05)。结论在阅读CTPA图像中,单纯使用常规纵膈窗或常用调节窗都可漏掉部分栓塞,特别是较小血管的栓塞,临床工作中,应常规使用纵膈窗+常用调节窗宽、MPR重建技术减少肺栓塞的漏诊。 相似文献
6.
流行病学研究发现大气污染对人群健康已造成一定影响[1]。但以往学者多关注大气污染对成人死亡率和呼吸道疾病发病率的影响,而与不良妊娠结局关系的研究近期才得以重视。不良妊娠结局指正常妊娠以外所有的病理妊娠及分娩期并发症,包括早产、胎膜早破、自然流产、低出生体重、出生缺陷和新生儿窒息等孕产妇及围产儿的不良结局。本文将对大气主要污染物大气颗粒物(PM)、氮氧化物(NOX)、二氧化硫(SO2)、一氧化碳(CO)和臭氧(O3)与不良妊娠结局的低出生体重、早产、出生缺陷、流产、死产和婴儿期死亡之间关系进行综述。 相似文献
7.
目的探讨FKBP52在反复体外受精种植失败患者种植窗期子宫内膜的表达情况。方法采用实时荧光定量聚合酶链式反应(RT-PCR)技术和免疫组织化学方法分别测定20例反复体外受精种植失败妇女(组1)种植窗期子宫内膜组织中FKBP52蛋白及其mRNA的表达,并与15例正常生育能力妇女卵泡晚期(组2)和种植窗期(组3)相比较。结果组1的FKBP52mRNA表达水平低于组2,组2低于组3,但差异均无统计学意义(P0.05)。FKBP52蛋白表达于腺上皮的胞核及胞浆,组1在腺上皮的胞核表达明显,组2在腺上皮的胞浆表达明显,组3在腺上皮的胞核及胞浆均有明显表达;组1和组2的FKBP52蛋白表达量分别为(2 125.9±1 729.9)和(1 360.2±853.7),并显著低于组3(8 319.1±5 873.8)(P0.05,P0.01)。结论 FKBP52蛋白在种植窗期的表达和定位异常可能是反复体外受精种植失败患者子宫内膜容受性的影响因素。 相似文献
8.
Diemah F. Alhekeir Rana A. Al-Sarhan Abdulmohsen F. Al Mashaan 《Saudi Dental Journal》2014,26(2):63-67
ObjectiveTo investigate the association of the failure of porcelain laminate veneers with factors related to the patient, material, and operator.MethodsThis clinical survey involved 29 patients (19 women and 10 men) and their dentists, including undergraduate and postgraduate dental students and dental interns. Two questionnaires were distributed to collect information from participants. All patients were clinically examined. Criteria for failure of the porcelain laminate veneers included color change, cracking, fracture, and/or debonding.ResultsA total of 205 porcelain laminate veneers were evaluated. All of the restorations were fabricated from IPS e.max Press and cemented with Variolink Veneer (Ivoclar Vivadent, Schaan, Principality of Liechtenstein) or RelyX veneer cement (3M ESPE, St. Paul, MN, USA). The preparations were generally located in enamel (58.6%), and most veneers had an overlapped design (89.7%). Ten patients (34.48%) showed veneer failure, most often in terms of color change (60%). Overall, 82.8% of patients were satisfied with their restorations.ConclusionInsufficient clinical skills or operator experience resulted in restoration failure in one-third of patients. 相似文献
9.
Xin Xia Yonghua Cai Xiaoli Zhu Yingying Zhu Le Shen Yalin Zhou Wenwen Diao Xingming Chen 《Interactive Cardiovascular and Thoracic Surgery》2021,33(6):899
Open in a separate windowOBJECTIVESThe aim of this study was to present surgical techniques and evaluate outcomes of a sternocleidomastoid muscle (SCM) myoperiosteal flap used for the reconstruction of tracheal or laryngotracheal defects after the radical resection of invasive thyroid carcinoma.METHODSA retrospective study was performed for patients at Peking Union Medical College Hospital from January 2008 to December 2018 of papillary thyroid carcinoma with tracheal or laryngotracheal invasion. Patients were enrolled only when they received window resection and reconstruction via an SCM myoperiosteal flap. The primary outcome was a stable airway, and the secondary outcome was survival.RESULTSA total of 15 invasive thyroid carcinoma patients were enrolled in this study. Laryngotracheal and tracheal reconstruction were performed in 11 and 4 patients respectively, with a median vertical defect of 3.5 cm (3.0, 4.5). A stable airway was achieved in 14 patients postoperatively. One patient experienced tracheal stenosis and received a second operation of tracheal sleeve resection and end-to-end anastomosis 105 days after the first operation. Tracheostomy was conducted in 5 out of 15 patients in whom the vertical defects were larger than 4 cm, and the tubes were extubated after a median time of 56 days (32, 84). The median observation time was 55 months (48, 86), and all 15 patients achieved a stable airway and showed no evidence of local recurrence at the end of follow-up.CONCLUSIONSFor thyroid carcinoma with tracheal or laryngotracheal invasions, window resection with the SCM myoperiosteal flap reconstruction presented positive results in terms of a stable airway as well as oncological outcomes. The SCM myoperiosteal flap can be an appropriate reconstruction strategy, especially when the defects reach the thyroid cartilage. 相似文献
10.
目的:探讨CT显示胃肠道及其病变的最适宜窗口。方法:随机选取50例行胃肠道充气螺旋CT检查者断面图像68帧,在四种不同窗宽窗位下,观察六个指标的显示情况。结果:第③窗(窗宽为180-280Hu,窗位为-20- 20Hu)时,直径约0.3-0.5cm细小结节或小血管断面,软组织内密度对比,脂肪与软组织对比的显示为优,气体与脂肪的对比、胃肠腔轮廓及软组织形态轮廓方面显示较好,可不同程度兼顾到所需观察的多种组织,较好显示胃肠道及其病变。结论:窗宽180-280Hu,窗位-20- 20Hu,是观察胃肠道的较适宜窗口。 相似文献