Bounds in the Sensitivity of BioMEMS Devices for Cell Detection

This paper presents an ongoing effort to characterize performance and reliability of micro electromechanical systems used for biomedical diagnostics (BioMEMS). In order to study the interactions of human osteosarcoma (HOS) cells with BioMEMS devices, cultures were performed on silicon (Si) surfaces as well as silicon surfaces coated with 50 nm of titanium (Ti). Cell spreading on the surfaces was observed over time for up to 2 hours. It was seen that titanium coated silicon surfaces have the potential to provide a better interface for BioMEMS devices, due to enhanced adherence and spreading of the cells on these surfaces. Atomic force microscope (AFM) cantilevers were used as cell detection sensors. These cantilevers were coated with 50nm of titanium metal to provide a cell friendly surface. Theoretical models were then developed for the prediction of the vibrational responses of the AFM cantilevers before and after cell attachment. The models were used to relate the experimentally observed changes in frequency to the number of cells that are attached on the cantilever. The bounds in the possible frequency changes were determined within a theoretical framework. From experimentally calculated values for the mass of cells, random number simulations were carried out to determine the probability of cell attachment as a function of the change in resonance frequency of the cantilever sensor. The implications of the results are then discussed for the future reliability modeling of the sensor.     

Sensitivity to mechanical stimuli and the role of general sensory and perceptual processes in heartbeat detection

Sensitivity to heartbeat sensations is commonly assessed using tasks that require individuals to judge the simultaneity of heartbeats and tones. In two experiments, we investigated the suitability of this paradigm for examining cardioception. In the first experiment, participants judged the simultaneity of near–threshold vibrations and suprathreshold tones. Precision in judging vibration–tone simultaneity was directly related to the detectability of the mechanical stimuli, thereby supporting use of the simultaneity paradigm to assess heartbeat detection. In the second experiment, we examined the influences of sensitivity to mechanical stimuli and the ability to make intermodality simultaneity judgments on the precision of heartbeat detection. We measured participants' vibrotactile thresholds, precision in judging light–tone simultaneity, and precision in judging heartbeat–tone simultaneity. The ability to judge the simultaneity of lights and tones accounted for 24.3% of the variance in precision of heartbeat detection, and mechanical sensitivity accounted for a further 8.5%.     

Number of cortisol time-points and dexamethasone suppression test sensitivity for major depression

Failure to suppress cortisol secretion after administration of dexamethasone has been reported to be a diagnostic marker for major depression and to have prognostic implications when repeated after antidepressant treatment. The pulsatile pattern of cortisol secretion suggested to us that increasing the number of post-dexamethasone cortisol determinations might significantly increase the sensitivity of the dexamethasone suppression test (DST) for major depression. With a conventional two-point DST (1600 h and midnight), 5% of 20 normal volunteers, 8% of 13 inpatients with non-major depressions, and 31% of 65 inpatients with primary major depression failed to suppress. With six post-dexamethasone points (0800 h, 1200 h, 1600 h, 2000 h, 2200 h, midnight), the respective percentages were 10, 15 and 44%. The additional points increased the sensitivity from 31 to 44%, mostly by identifying more major depressives with a "late escape" pattern. If a clinician is using the DST to establish a marker for major depression that can be repeated to monitor response to treatment and the likelihood of relapse, then perhaps the increased sensitivity of the six-point DST would be helpful, despite a modest decrease in specificity from 94 to 88%.     

影响柴油低温流动改进剂作用的因素

考察了柴油对流动改进剂的感受性与柴油正构烷烃含量、正构烷烃分布等因素的关系。流动改进剂的作用与正构烷烃含量有最佳匹配点。柴油中正构烷烃的平均碳数减少,冷滤点越低。柴油中正构烷烃的分布与流动改进剂的熔点匹配时,改进剂的效果最好。由此进一步分析了柴油流动改进剂的作用机理。     

糖尿病对白内障超声乳化术后角膜知觉改变的影响

目的 探讨糖尿病对白内障超声乳化吸除术后角膜知觉改变的影响。方法 选择行白内障超声乳化吸除手术的糖尿病患者42例（42只眼）,不伴有糖尿病的患者46例（46只眼）,分别观察白内障超声乳化手术前、术后1天、术后1周、术后1个月、术后3个月、术后6个月的角膜知觉。结果 与术前相比,糖尿病白内障患者角膜知觉在术后1天、术后1周、术后1个月、术后3个月明显降低,差异有显著性,术后6个月接近术前水平;不伴糖尿病的白内障患者角膜知觉在术后1天、术后1周、术后1个月降低,差异有显著性,术后3个月接近术前水平。两组患者术前角膜知觉比较,差异有显著性;术后角膜知觉最大降幅比较,差异有显著性。结论 糖尿病可降低患者的角膜知觉,增大白内障手术后角膜知觉的降幅,延长角膜知觉的恢复时间。     

518例泌尿生殖支原体感染的分类及药敏结果

应用支原体药敏试剂盒检测出的 5 18例支原体感染病例中 ,溶脲脲原体 (Uu)培养阳性为 30 8例 ,占5 9 4% ;人型支原体 (Mh)阳性 2 1例 ,占 4 1% ;Uu合并Mh感染者 189例 ,占 36 5 %。对大环内脂类的红霉素 (ery thromycin,Ery)、罗红霉素 (roxithromycin ,Rox)、交沙霉素 (josamycin ,Jos)、阿齐霉素 (azithromycin ,Azi)、四环素类的强力霉素 (doxycycline ,Dox)、美满霉素 (mincon ,Min)、喹诺酮类的氧氟沙星 (ofloxacin ,of1)、环丙沙星 (cipofloxacin ,Cip)等 8种抗生素进行药敏检测 ,发现Uu与Mh感染者对抗生素的敏感性有差异 ,Uu对大环内脂类较为敏感 ,Mh对喹诺酮类较为敏感 ,Uu合并Mh感染者对多种抗生素表现出耐药性。     

Nerve Conduction Studies in Surgical Cubital Tunnel Syndrome Patients

Background: Electrodiagnostic studies (EDX) serve a prominent role in the diagnostic workup of cubital tunnel syndrome (CBTS), but their reported sensitivity varies widely. The goals of our study were to determine the sensitivity of EDX in a cohort of patients who responded well to surgical cubital tunnel release (CBTR), and whether the implementation of the Association of Neuromuscular and Electrodiagnostic Medicine (AANEM) criteria improves the sensitivity. Methods: We identified 118 elbows with clinical CBTS who had preoperative EDX and underwent CBTR. The EDX diagnoses were CBTS, ulnar neuropathy (UN), and normal ulnar nerves. We divided the 118 elbows into those that received above-elbow stimulation (XE group) and those that did not (non-XE group). We calculated the sensitivities for all groups and reinterpreted the results according to the AANEM guidelines. Results: Cubital tunnel release provided significant relief in 93.6% of the elbows. Based on the EDX reports, 11% patients had clear CBTS, 23% had UN, and 66% showed no UN. The sensitivities were 11.7% for CBTS and 34.2% for any UN. In the XE group, the sensitivity of the EDX reports for CBTS and UN climbed to 33.3% and 58.3%, respectively. When we calculated the across-elbow motor nerve conduction velocity, the sensitivity for CBTS and UN was 87.5% and 100%, respectively. The XE and non-XE groups showed no difference except for sex, bilaterality, concomitant carpal tunnel release, and obesity (P < .05). Conclusion: Implementing AANEM guidelines results in significant improvement in correlation of clinical and electrodiagnostic findings of CBTS.     

The peril and promise of sensitivity in eating disorders

Differential susceptibility, a reconceptualization of the diathesis-stress model of psychopathology, describes gene–environment interactions that reflect individual differences in responsiveness to environmental influences, both detrimental and beneficial. This model has been described metaphorically by the classification of orchids, which thrive under optimal care but wither under adverse conditions, and dandelions, which weather broad environmental circumstances but are less responsive to careful cultivation. Etiological research in the field of eating disorders has largely focused on the identification of specific behavioral phenotypes, temperamental traits, genotypes and neurobiological processes that confer risk. In this article, we propose that these putative vulnerability factors represent phenotypes and endophenotypes of a genetic predisposition towards environmental sensitivity. We assert that this sensitivity not only transmits eating disorder risk but also confers resilience, depending on the circumstances. In particular, we propose that differential susceptibility can be used as a framework to organize disparate temperamental and neurobiological findings and their complex interplay with various developmental, environmental and sociocultural influences to increase eating disorder risk and treatment responsiveness. Finally, we assert that viewed through the lens of differential susceptibility, sensitivity can be leveraged to refine our interventions and develop novel treatment and prevention strategies to support favorable outcomes for individuals with eating disorders.     

2017—2019年包头医学院第一附属医院细菌耐药性监测

目的 了解包头医学院第一附属医院2017—2019年临床分离菌的分布及对临床常见抗菌药物的耐药性。方法 收集2017年1月1日至2019年12月31日临床分离的非重复菌株,采用自动化仪器法、纸片扩散法和E-试验法进行药敏试验。 结果 3年我院临床分离非重复菌共4679株,其中革兰阳性菌1358株（32.9%）,革兰阴性菌3141株（67.1%）。金黄色葡萄球菌和凝固酶阴性葡萄球菌中甲氧西林耐药株（Methicillin-resistant Staphylococcus aureus,MRSA和Methicillin-coagulase negative staphylococcus,MRCNS）检出率分别为16.2%(96/592),56.5%(245/434）,未发现万古霉素、替考拉宁和利奈唑胺耐药葡萄球菌株。屎肠球菌对多数抗菌药物的耐药率高于粪肠球菌。 产ESBL的大肠埃希菌和克雷伯菌属细菌的检出率分别为48.2%（567/1177）和16.6%（140/841）,碳青霉烯耐药肠杆菌科细菌（Carbapenem resistant enterobacteriaceae bacteria,CRE）的检出率为0.8%（19/2411）。肠杆菌科细菌对碳青霉希类抗菌药物的耐药率仍然处于较低水平,总体低于0.8%（19/2411）。铜绿假单胞菌和嗜麦芽窄食单胞菌对常见抗菌药物的耐药率均较低,鲍曼不动杆菌对常用抗菌药物的耐药率较高,对环丙沙星和头孢他啶的耐药率均高于60.0%。结论 该院临床常见菌的耐药性仍然比较严峻,进行细菌耐药监测有助于及时了解本院耐药变迁情况,为临床合理使用抗菌药物提供依据。