高频宽增益小信号放大器的设计及在医用超声功率计中的应用

介绍供医用超声功率计用的两种高频、宽增益的小信号放大器，并比较了它们彼此的优缺点。     

UF-100型全自动尿液沉渣检测仪测定参考范围调查

目的　确定UF - 10 0型全自动尿液沉渣检测仪检测健康人尿沉渣检测的参考值范围。方法　用UF - 10 0型全自动尿液沉渣检测仪随机检测 5 2 0例健康人不离心尿液标本 ,对尿液沉渣进行分析。结果　尿液中红细胞 (RBC)、白细胞 (WBC)、上皮细胞 (EC)、管型 (CAST)各年龄组之间检测值经 F 检验 ,差异无显著意义 (P >0 .0 5 ) ,但男、女性别之间差异有显著意义 (P <0 .0 5 )。结论　尿液RBC、WBC、EC的多少与年龄无关 ,但与性别有关。健康人参考值的确立 ,为尿液常规检验定量标准化和临床应用提供了依据     

老年男性2型糖尿病患者目标范围内时间与长期血糖变异性的关系研究

背景 目标范围内时间(TIR)作为血糖管理的新指标,与短期血糖波动相关,是否与长期血糖变异性相关尚不清楚。目的 探讨老年男性2型糖尿病患者TIR与长期随访期间糖化血红蛋白(HbA_1c)变异系数、HbA_1c变异性评分(HVS)的关系。方法 选取2007年1月至2011年1月在解放军总医院第二医学中心住院行动态血糖监测(CGM)的老年男性2型糖尿病患者200例,根据患者基线TIR水平,将其分为TIR≥85%组(n=141)和TIR<85%组(n=59)。对受试者随访观察(12.5±1.1)年,比较两组长期随访期间HbA_1c变异系数和HVS。采用Pearson相关、多元线性回归分析TIR与HbA_1c变异系数、HVS的关系。结果 TIR<85%组患者的长期HbA_1c变异系数[(9.7±3.8)%比(8.2±4.5)%,P=0.028)]、HVS[(48.7±20.4)分比(32.5±20.8)分,P<0.001)]均明显高于TIR≥85%组。Pearson相关分析结果...     

Sequence Analysis of the Washington/1964 Strain of Human Parainfluenza Virus Type 1 (HPIV1) and Recovery and Characterization of Wild-Type Recombinant HPIV1 Produced by Reverse Genetics

A complete consensus sequence was determined for the genomic RNA of human parainfluenza virus type 1 (HPIV1) strain Washington/20993/1964 (HPIV1 WASH/64), a clinical isolate that previously was shown to be virulent in adults. The sequence exhibited a high degree of relatedness to both Sendai virus, a PIV1 virus recovered from mice, and human PIV3 (HPIV3) with regard to cis-acting regulatory regions and protein-coding sequences. This consensus sequence was used to generate a full-length antigenomic cDNA and to recover a recombinant wild-type HPIV1 (rHPIV1). Interestingly, the rHPIV1 could be rescued from full-length antigenomic rHPIV1 cDNA using HPIV3 support plasmids, HPIV1 support plasmids, or a mixture thereof. The replication of rHPIV1 in vitro and in the respiratory tract of hamsters was similar to that of its biologically derived parent virus. The similar biological properties of rHPIV1 and HPIV1 WASH/64 in vitro and in vivo, together with the previous demonstration of the virulence of this specific isolate in humans, authenticates the rHPIV1 sequence as that of a wild-type virus. This rHPIV1 can now be used to study the biological properties of HPIV1 and as a substrate to introduce attenuating mutations for the generation of live-attenuated HPIV1 vaccine candidates.An erratum to this article can be found at     

Systemic and mucosal antibody responses specific to SARS-CoV-2 during mild versus severe COVID-19

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颈椎内植入固定器生物力学性能测试系统的研究

在颈椎生物力学研究中,通过离体实验对颈椎内植入固定器的生物力学性能进行评价是国际上普遍采用并认可的方法.本研究利用多靶点三维运动跟踪系统和USB数据采集卡,以LabVIEW和Matlab为软件开发平台,构建了颈椎内植入固定器生物力学性能测试系统.测试参数包括三维运动角度范围(ROM)和压力载荷值.对颈椎模型的测试结果表明,本系统能有效地用于颈椎生物力学的离体实验测试.     

Clearance of Theiler's virus infection depends on the ability to generate a CD8+ T cell response against a single immunodominant viral peptide

Theiler's murine encephalomyelitis virus (TMEV) induces a chronic demyelinating disease in the central nervous system of susceptible mice. Resistance to persistent TMEV infection maps to he D locus of the major histocompatibility complex suggesting a prominent role of antiviral CTL in the protective immune response. Introduction of the D(b) gene into the FVB strain confers resistance to this otherwise susceptible mouse line. Infection of the FVB/D(b) mouse with TMEV provides a model where antiviral resistance is determined by a response elicited by a single class I molecule. Resistant mice of the H-2(b) haplotype mount a vigorous H-2D(b)-restricted immunodominant response to the VP2 capsid protein. To investigate the extent of the contribution of the immunodominant T cell population in resistance to TMEV, FVB/D(b) mice were depleted of VP2-specific CD8(+) T cells by peptide treatment prior to virus infection. Peptide-treated mice were not able to clear the virus and developed extensive demyelination. These findings demonstrate that the D(b)-restricted CD8(+) T cells specific for a single viral peptide can confer resistance to TMEV infection. Our ability to manipulate this cellular response provides a model for investigating the mechanisms mediating protection against virus infection by CD8(+) T cells.     

Effects of massage on delayed-onset muscle soreness, swelling, and recovery of muscle function

Context: Delayed-onset muscle soreness (DOMS) describes muscle pain and tenderness that typically develop several hours postexercise and consist of predominantly eccentric muscle actions, especially if the exercise is unfamiliar. Although DOMS is likely a symptom of eccentric-exercise–induced muscle damage, it does not necessarily reflect muscle damage. Some prophylactic or therapeutic modalities may be effective only for alleviating DOMS, whereas others may enhance recovery of muscle function without affecting DOMS.Objective: To test the hypothesis that massage applied after eccentric exercise would effectively alleviate DOMS without affecting muscle function.Design: We used an arm-to-arm comparison model with 2 independent variables (control and massage) and 6 dependent variables (maximal isometric and isokinetic voluntary strength, range of motion, upper arm circumference, plasma creatine kinase activity, and muscle soreness). A 2-way repeated-measures analysis of variance and paired t tests were used to examine differences in changes of the dependent variable over time (before, immediately and 30 minutes after exercise, and 1, 2, 3, 4, 7, 10, and 14 days postexercise) between control and massage conditions.Setting: University laboratory.Patients or Other Participants: Ten healthy subjects (5 men and 5 women) with no history of upper arm injury and no experience in resistance training.Intervention(s): Subjects performed 10 sets of 6 maximal isokinetic (90°·s⁻¹) eccentric actions of the elbow flexors with each arm on a dynamometer, separated by 2 weeks. One arm received 10 minutes of massage 3 hours after eccentric exercise; the contralateral arm received no treatment.Main Outcome Measure(s): Maximal voluntary isometric and isokinetic elbow flexor strength, range of motion, upper arm circumference, plasma creatine kinase activity, and muscle soreness.Results: Delayed-onset muscle soreness was significantly less for the massage condition for peak soreness in extending the elbow joint and palpating the brachioradialis muscle (P < .05). Soreness while flexing the elbow joint (P = .07) and palpating the brachialis muscle (P = .06) was also less with massage. Massage treatment had significant effects on plasma creatine kinase activity, with a significantly lower peak value at 4 days postexercise (P < .05), and upper arm circumference, with a significantly smaller increase than the control at 3 and 4 days postexercise (P < .05). However, no significant effects of massage on recovery of muscle strength and ROM were evident.Conclusions: Massage was effective in alleviating DOMS by approximately 30% and reducing swelling, but it had no effects on muscle function.     

Varied biologic functions of c-reactive protein

Our investigations of human C-reactive protein (CRP) and CRP transgenic mice have produced novel data that firmly establish this protein as an important host defense molecule. For example, we have learned that depending on the disease model, the beneficial effect of CRP can be direct, depend on the protein's ability to engage complement and Fcγreceptors, or rely on its ability to bridge innate and adaptive immunity. In addition, the degree of protection correlates with acute phase expression, but more important, also with the amount of CRP expressed constitutively. Furthermore, differences in baseline levels of CRP among healthy individuals and among patients can be attributed to a CRP gene polymorphism. In this article, we discuss these and other observations we have made during the last 5 yr and summarize our ongoing studies and future plans related to CRP biology.