Modulation of an activity response with associative and nonassociative fear in the rat: A lighting differential influences the form of defensive behavior evoked after fear conditioning     

Godsil BP  Blackmore MA  Fanselow MS 《Learning & behavior》2005,33(4):454-463

Rats confronted with the onset of a light gradient display a transient increase in locomotion called theactivity response (AR) and a dark preference (Godsil & Fanselow, 2004). These experiments demonstrate that the magnitude of the AR can be blunted with Pavlovian fear-conditioning procedures via associative and nonassociative fear. Although manifested in decreased locomotion, the blunted AR effect was not due to increased freezing or immobility behaviors. Instead, rats displayed reduced rearing and an increase in a class of behaviors calledstationary activity. These results suggest that the lighting differential supplied by the cue influences the topography of defensive behavior and reduces the expression of freezing. This procedure provides a means by which to examine learned and unlearned defensive responses to the same stimulus.  相似文献   

Stability of pedalling mechanics during a prolonged cycling exercise performed at different cadences     

Sarre G  Lepers R  van Hoecke J 《Journal of sports sciences》2005,23(7):693-701

The aim of this study was to analyse the effect of pedalling rate on the pattern of mechanical torque application and on neuromuscular fatigue during prolonged cycling exercise. Eleven well-trained individuals performed three 1-h pedalling sessions, at 50 rev.min-1, 110 rev.min-1 and a freely chosen cadence, at an intensity corresponding to 65% of their maximal aerobic power. The mechanical torque applied on the right pedal was recorded for 30 s every 5 min while pedalling. Contractile and neural properties of the quadriceps and hamstring muscles were analysed before and immediately after each of the three pedalling sessions. The post-exercise reduction in knee extensors maximal voluntary contraction was significant (P<0.01) irrespective of the cadence, but no difference was found between cadences. The use of a particular cadence did not lead to preferentially central or peripheral fatigue. An increase in cadence resulted in greater positive and negative work generated during pedalling. The mechanical pattern was not altered during the exercise, whatever the selected cadence. The present study demonstrates that despite the occurrence of neuromuscular fatigue, trained individuals maintained a stable pedalling pattern throughout an endurance cycling exercise for cadences ranging from 50 to 110 rev.min-1.  相似文献   

High throughput fabrication of disposable nanofluidic lab-on-chip devices for single molecule studies     

Jeroen A. van Kan  Ce Zhang  Piravi Perumal Malar  Johan R. C. van der Maarel 《Biomicrofluidics》2012,6(3)

An easy method is introduced allowing fast polydimethylsiloxane (PDMS) replication of nanofluidic lab-on-chip devices using accurately fabricated molds featuring cross-sections down to 60 nm. A high quality master is obtained through proton beam writing and UV lithography. This master can be used more than 200 times to replicate nanofluidic devices capable of handling single DNA molecules. This method allows to fabricate nanofluidic devices through simple PDMS casting. The extensions of YOYO-1 stained bacteriophage T4 and λ−DNA inside these nanochannels have been investigated using fluorescence microscopy and follow the scaling prediction of a large, locally coiled polymer chain confined in nanochannels.  相似文献   

Is the occurrence of the sticking region the result of diminishing potentiation in bench press?     

Tillaar Rv  Saeterbakken AH  Ettema G 《Journal of sports sciences》2012,30(6):591-599

In this study we investigated if the occurrence of the sticking region was a result of diminishing potentiation (coinciding delayed muscle activation) or the result of a mechanically poor region in which the muscles can produce less force. A regular one-repetition maximum (1RM) free-weight bench press was compared with isometric bench presses performed at 12 different positions. A lower force at the sticking region compared to the other regions in the isometric bench presses would confirm the mechanically-poor-position hypothesis. Twelve resistance-trained males (age 21.7 ± 1.3 years, mass 78 ± 5.8 kg, height 1.81 ± 0.05 m) were tested in 1RM and in isometric contractions in bench press in 12 different positions, indicated by the vertical distance between barbell and sternum, covering the whole range of motion during the concentric phase. Barbell kinematics and muscle activity were registered. In both types of executions a region of lower force output was observed, which supports the mechanically-poor-position hypothesis. Electromyographic activity of four muscles showed the same pattern in the isometric and 1RM attempts. It was concluded that diminishing effect potentiation could not explain the existence of the sticking region.  相似文献   

Study of C-Reactive Protein and Myocardial Infarction in the Indian Population     

Kavita Shalia  Sudha Savant  Vijaya A. Haldankar  Tulip Nandu  Poonam Pawar  Siddhi Divekar  V. K. Shah  Purvi Bhatt 《Indian journal of clinical biochemistry : IJCB》2012,27(1):74-82

To analyse the association of high sensitivity C-reactive (hsCRP) protein levels and −717A/G single nucleotide polymorphism of CRP with acute myocardial infarction (AMI) in the Indian population. Study population included 100 MI cases wherein 32 patients had experienced previous MI (MI-Group-1), 68 MI cases were recruited at presentation (MI-Group-2) and equal number of age and gender matched healthy individuals. hsCRP levels were determined by ELISA and genotyping of −717A/G was carried out by polymerase chain reaction-based restriction digestion method. The −717A/G genotypes did not influence hsCRP level and their distribution did not differ between groups. However, in the present study hsCRP demonstrated significant correlation with BMI in controls of both the genders and with triglycerides in females of AMI at presentation who otherwise are with low risk profile. Identifying traditional risk factors associated with inflammation may help in controlling the acute event.  相似文献   

A Comparative Study of Bone Scan Findings and Serum Levels of Tumor Marker CA15-3 in Patients with Breast Carcinoma     

Meera S. Ghadge  Purva P. Naik  Bijaynath P. Tiwari  Ruprekha M. Hegde  Tanaji J. Matale 《Indian journal of clinical biochemistry : IJCB》2012,27(1):97-99

Breast cancer is one of the most frequent malignancies in the world. Available staging procedures to detect breast cancer are bone scan, chest X-ray, liver ultrasonography, computerized tomography, estimation of tumor markers like carbohydrate antigen (CA15-3) and carcino embryonic antigen. These procedures are expensive and may not be required in all cases. Out of 70 patients studied, 55 had normal CA15-3 and 15 had elevated levels of Ca15-3. Eight (14.5%) of the 55 patients with normal CA15-3 had abnormal bone scan. Fifteen patients had CA15-3 levels above the normal range and among these 9 (60%) had abnormal bone scan. While prime facie it would appear that a high level of CA15-3 correlate with abnormal bone scan, it is also true that the numbers are small at present and conclusions about the validity of CA15-3 as marker of bone metastasis may be premature.  相似文献   

Current status and development of percutaneous coronary intervention in China     

Yong Huo 《Journal of Zhejiang University. Science. B》2010,11(8):631-633

##正##Dr.Gruntzig et al.(1979) successfully completed the world's first percutaneous coronary intervention (PCI),a percutaneous transluminal coronary  相似文献   

Mathematical models of canine right and left atria cardiomyocytes     

Ling Xia  Ying-lan Gong  Xiu-wei Zhu  Yu Zhang  Qi Sun  Heng-gui Zhang 《Journal of Zhejiang University. Science. B》2010,11(6):402-416

The aim of this study is to build two mathematical models of canine ionic currents specific to right atria and left atria.The canine left atria mathematical model was firstly modified from the Ramirez-Nattel-Courtemanche(RNC) model using the recently available experimental data of ionic currents and was further developed based on our own experimental data.A model of right atria was then built by considering the differences between right atria and left atria.The two developed models well reproduced the exper...  相似文献   

Neurochip based on light-addressable potentiometric sensor with wavelet transform de-noising     

Qing-jun Liu  Wei-wei Ye  Hui Yu  Ning Hu  Li-ping Du  Ping Wang 《Journal of Zhejiang University. Science. B》2010,11(5):323-331

Neurochip based on light-addressable potentiometric sensor(LAPS),whose sensing elements are excitable cells,can monitor electrophysiological properties of cultured neuron networks with cellular signals well analyzed.Here we report a kind of neurochip with rat pheochromocytoma(PC12) cells hybrid with LAPS and a method of de-noising signals based on wavelet transform.Cells were cultured on LAPS for several days to form networks,and we then used LAPS system to detect the extracellular potentials with signals d...  相似文献   

Congenital atresia of the left main coronary artery in an infant     

Su Ye Sohn  Gi Young Jang  Byung Min Choi 《Journal of Zhejiang University. Science. B》2010,11(7):539-541

Congenital atresia of the left main coronary artery is a rare occurrence, and surgical revascularizationbypass graft is required. We here report a rare case of congenital coronary anomaly in an infant. A 10-month-old male infant was admitted to the hospital with heart failure symptoms. Echocardiographic examinations revealed mitral valve regurgitation and ischemic changes of the anterolateral papillary muscle and chordae. Coronary angiography showed atresia of the left main coronary artery with a severe hypoplastic left anterior descending artery and a circumflex coronary artery. Unfortunately, sudden cardiac arrest occurred after catheterization and the infant did not recover despite of immediate cardiopulmonary resuscitation. Further studies are needed to find a newer diagnostic method to detect coronary anomaly in an infant, and coronary angiography, if necessary, has to be performed very carefully.  相似文献