以线性参数模型和信息分解方法评价QT变异性对心率变异性的响应

自主神经系统(ANS)的平衡对于规避与心脏相关的疾病风险具有重要意义。本课题运用频域的线性参数模型和非线性信息分解方法,分析QT变异性(QTV)对于心率变异性(HRV)的响应,揭示心脏自主神经的调节状态。使用来自THEW数据库的Holter数据,选用其中的正常组(Normal,n=186)和高心律失常和心源性猝死风险组(ESRD,n=41)进行对比。提取昼夜安静态各5 min RR间期(RRI)和相对应的QT间期(QTI)序列,计算频域参数QTV与HRV相关的百分占比(LR)和信息分解的RRI对于QTI的可预测性(PI),并结合RRI序列的时域、频域和符号动力学分析,探讨QTV对于HRV的响应在两组人群中可能的差异和发生机制。对于LR和PI,Normal组均表现出显著的昼夜差异,而ESRD组则均不存在,反映出ESRD组ANS交互作用的缺失。两组间同时段同指标对比时,低频段LR无显著差异,而在高频段,Normal组的LR值均显著小于同时段ESRD组的LR值(白天:18.36%±17.38% vs 39.37%±23.80%, P<0.05;夜晚: 28.63%±18.77% vs 42.31%±21.97%, P<0.05);Normal组夜晚的PI显著大于ESRD组夜晚的PI(0.310±0.155 vs 0.236±0.131, P<0.05),而在白天无显著差异。研究表明,线性参数模型和基于信息分解的非线性预测对自主神经活动的敏感性不同;高心律失常和心源性猝死风险人群中HRV对QTV的调控呈复杂度降低的特点。     

慢性乙肝患者血清HBV-DNA和HBeAg定量的相关性分析

目的：研究慢性乙型肝炎病毒（chronic HBV,CHB）患者血清HBV-DNA含量与e抗原定量的相关性。方法：实时荧光定量PCR（FQ-PCR）和化学发光法（CLIA）分别测定1084例CHB患者血清HBV-DNA、HBeAg含量。结果：1084例HBV患者中HBeAg阳性组和阴性组HBV-DNA检出率分别为74.2%和23.8%,平均含量分别为（4.9±1.9）log10（copies/ml）和（3.9±1.0）log10（copies/ml）;HBV-DNA和HBeAg之间的kap-pa系数为0.49;HBV-DNA定量和HBeAg定量之间相关系数（r）为0.659,HBeAg阳性组HBV-DNA定量和HBeAg定量之间r为0.664;不同载量HBV-DNA组,HBeAg量相差显著,HBV-DNA载量高,HBeAg量也高。结论：HBeAg阳性模式的HBV-DNA阳性率及含量进一步证实了HBeAg确实是反映HBV复制活跃的一个可靠指标,但这并不意味HBeAg转阴病毒复制就停止,HBeAg阴性CHB患者血清中仍有部分患者存在乙肝病毒颗粒;HBV-DNA载量与HBeAg量之间有一定的相关性,但相关性一般;同时检测HBV-DNA和HBeAg量对乙肝患者HBV感染、复制、传染性的判断、治疗方案的选择和疗效判断有一定的指导意义。     

脂联素与非酒精性脂肪肝肝纤维化及胰岛素抵抗的关系

目的：研究脂联素水平与非酒精性脂肪肝（NAFLD）患者肝纤维化指标及胰岛素抵抗指数（IRI）的关系。方法：采用ELISA法检测NAFLD患者和正常对照组的脂联素水平及Ⅲ型前胶原（PCⅢ）、透明质酸（HA）、Ⅳ型胶原（CⅣ）、层黏蛋白（LN）水平,采用稳态模式胰岛素抵抗指数（HOMA IRI）评估胰岛素抵抗。结果：NAFLD组脂联素水平显著低于对照组,胰岛素抵抗指数与肝纤维化指标显著高于对照组（P〈0.05）,IRI与PCⅢ、PCⅣ、HA和LN呈显著正相关（P〈0.05）,脂联素水平与WHR、BMI、FBG、Tg、FINS、HOMA-IRI、PCⅢ、PCⅣ、HA和LN呈显著负相关（P〈0.01或〈0.05）。结论：NAFLD患者血清脂联素水平降低,脂联素的表达在NAFLD患者肝纤维化与胰岛素抵抗进程中可能起重要作用。     

Organo‐Solubility Carbazole‐Containing Polyimides with Tunable Memory Characteristics Based on Different Dianhydride Moieties

A novel asymmetric carbazole‐based diamine (9‐((4′‐(9H‐carbazolyl)‐[1,1′‐biphenyl])methyl)‐3,6‐diaminocarbazole (BCDA‐CBZ)) is synthesized and characterized. Two aromatic conjugated polyimides (PI‐a and PI‐b) are prepared via a two‐step procedure using BCDA‐CBZ reacting with 2,2′,3,3′‐biphenyl‐tetracarboxylic dianhydride (i‐BPDA) and 2,2′‐bis(4′‐phenyl)‐4,4′,5,5′‐biphenyltetracarboxylic dianhydride (DPBPDA), respectively. The resulting PIs possess excellent organo‐solubility, are thermally stable, and have film‐formation ability. The Al/PI‐a/ITO exhibits a dynamic random access memory behavior, whereas the Al/PI‐b/ITO presents a rewritable type memory capability. The fabricated PI‐a device shows low turn‐on threshold voltages at ?1.47 and +2.85 V, and the switching voltages of PI‐b device are  ?2.07 (turn‐on) and +2.85 V (turn‐off). The electrical conduction behaviors are analyzed using theoretical models based on the experimental data. The molecular simulation by density functional theory calculations suggests that field‐induced charge‐transfer and the conformation change mechanism could be used to explain the memory characteristics.     

Reactions to online colorectal cancer risk estimates among a nationally representative sample of adults who have never been screened

Data on the public’s reactions to online tailored colorectal cancer (CRC) risk estimates are sparse. We assessed among 560 men and women aged 50–75 with no CRC screening history reactions to online tailored CRC estimated comparative risk (i.e., self vs. other their age and sex). Assessed were reactions to estimate (i.e., repeating back estimate, match between perceived comparative risk and estimate, accuracy and usefulness of estimate, emotional reactions), risk appraisals and screening intentions. 73% of the sample accurately repeated back their estimate; the match between perceived comparative risk and the estimate was lowest among those informed of being at higher risk. Higher estimates were viewed as less useful and evoked more negative emotions. Viewing the estimate as more useful and experiencing more negative emotions were related with higher risk appraisals and, in turn, screening intentions. These data indicate that adults at higher comparative risk resist accepting a higher risk status.     

Needle-tissue interactive mechanism and steering control in image-guided robot-assisted minimally invasive surgery: a review

Image-guided robot-assisted minimally invasive surgery is an important medicine procedure used for biopsy or local target therapy. In order to reach the target region not accessible using traditional techniques, long and thin flexible needles are inserted into the soft tissue which has large deformation and nonlinear characteristics. However, the detection results and therapeutic effect are directly influenced by the targeting accuracy of needle steering. For this reason, the needle-tissue interactive mechanism, path planning, and steering control are investigated in this review by searching literatures in the last 10 years, which results in a comprehensive overview of the existing techniques with the main accomplishments, limitations, and recommendations. Through comprehensive analyses, surgical simulation for insertion into multi-layer inhomogeneous tissue is verified as a primary and propositional aspect to be explored, which accurately predicts the nonlinear needle deflection and tissue deformation. Investigation of the path planning of flexible needles is recommended to an anatomical or a deformable environment which has characteristics of the tissue deformation. Nonholonomic modeling combined with duty-cycled spinning for needle steering, which tracks the tip position in real time and compensates for the deviation error, is recommended as a future research focus in the steering control in anatomical and deformable environments.

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Graphical abstract a Insertion force when the needle is inserted into soft tissue. b Needle deflection model when the needle is inserted into soft tissue [68]. c Path planning in anatomical environments [92]. d Duty-cycled spinning incorporated in nonholonomic needle steering [64]

     

The Trypanosoma brucei sphingolipid synthase, an essential enzyme and drug target

Sphingolipids are important components of eukaryotic membranes, particularly the plasma membrane, and are involved in a diverse array of signal transduction processes. In the Eukaryota the biosynthetic pathway for the formation of these lipid species is largely conserved. However, in contrast to mammals which produce sphingomyelin (SM), several pathogenic fungi and protozoa synthesize inositol phosphorylceramide (IPC) as the primary phosphosphingolipid. This process is catalyzed by the enzyme IPC synthase, a recognized target for anti-fungals encoded by the AUR1 gene in yeast. Recently, functional orthologues of the AUR1p have been identified in a group of insect vector-borne pathogenic protozoa, the Kinetoplastida, which are responsible for a range of so-called neglected diseases. Of these the Trypanosoma brucei species are the causative agents of human African trypanosomiasis in many of the most under-developed regions of Africa. The available treatments for these diseases are limited, of decreasing efficacy, and often demonstrate severe side-effects. Against this background the T. brucei sphingolipid synthase, an orthologue of the yeast AUR1p, may represent a promising target for novel anti-protozoals. Our studies identify an isoform of this protein as a novel bi-functional enzyme capable of catalyzing the synthesis of both IPC and SM, both known to be present in the parasite. Furthermore, the synthase is essential for parasite growth and can be inhibited by a known anti-fungal at low nanomolar levels in vitro. Most notably this drug demonstrates trypanocidal activity against cultured bloodstream form parasites. Thus, the T. brucei sphingolipid synthase represents a valid and promising drug target.     

Partial monosomy 13q (13q21.32--->qter) and partial trisomy 8p (8p1--->pter) presenting with anencephaly and increased nuchal translucency: array comparative genomic hybridization characterization

ObjectiveTo present array comparative genomic hybridization (aCGH) characterization of partial monosomy 13q (13q21.32→qter) and partial trisomy 8p (8p12→pter) presenting with anencephaly and increased nuchal translucency (NT).Case ReportA 34-year-old primigravid woman was referred to the hospital at 12 weeks of gestation for termination of the pregnancy because of major structural abnormalities of the fetus. Prenatal ultrasound revealed a malformed fetus with anencephaly and an increased NT thickness of 5 mm at 12 weeks of gestation. Cytogenetic analysis of the fetus revealed a derivative chromosome 13. The mother was subsequently found to carry a balanced reciprocal translocation between 8p12 and 13q21. Bacterial artificial chromosome-based aCGH using fetal DNA demonstrated partial trisomy 8p and partial monosomy 13q [arr cgh 8p23.3p12 (RP11-1150M5→RP11-1145H12)×3, 13q21.32q34 (RP11-326B4→RP11-450H16)×1]. Oligonucleotide-based aCGH showed a 36.7-Mb duplication of distal 8p and a 48.4-Mb deletion of distal 13q. The fetal karyotype was 46,XY,der(13) t(8;13)(p12;q21.32)mat. The maternal karyotype was 46,XX,t(8;13)(p12;q21.32).ConclusionThe 13q deletion syndrome can be associated with neural tube defects and increased NT in the first trimester. Prenatal sonographic detection of neural tube defects should alert chromosomal abnormalities and prompt cytogenetic investigation, which may lead to the identification of an unexpected parental translocation involving chromosomal segments associated with neural tube development.     

Use of an oxytocin antagonist in in vitro fertilization-embryo transfer for women with repeated implantation failure: a retrospective study

ObjectiveThis retrospective study aimed to investigate the use of an oxytocin antagonist in improving the pregnancy outcome of in vitro fertilization–embryo transfer (IVF–ET) in patients with repeated implantation failure (RIF).Materials and MethodsA total of 150 infertile couples with RIF undergoing IVF–ET were divided into three groups. Patients who did not receive atosiban were used as controls (Group 1; n = 80). Forty patients received a single bolus dose (6.75 mg, 0.9 mL/vial) of atosiban before ET (Group 2), and 30 patients received a bolus dose of 6.75 mg atosiban followed by infusion at 18 mg/hr for 3 hours immediately after ET (Group 3).ResultsA significantly higher implantation rate (30.21%) was noted in Group 2 compared with Groups 1 and 3 (11.8% and 15.9%, respectively; p = 0.0006). The clinical pregnancy rate of Group 2 (37.5%) was significantly higher than that of Groups 1 (12.5%) and 3 (20%) (p = 0.0057). The live birth rate was significantly higher in Group 2 (35%) than in Groups 1 and 3 (10% and 16.67%, respectively; p = 0.0031).ConclusionThese results suggest that IVF–ET using lower dosage of atosiban may improve pregnancy outcomes of patients with RIF.