Intensity-modulated radiation therapy is widely used in the treatment of tumor,and the dose distribution highly conforms to tumor target area in three-dimension.However,the factors such as complex beam,data error,algorithm error and machine error may cause large dose deviation in intensity-modulated radiation therapy,which may lead to unnecessary radiation accident.Therefore,standing on the patients' safety point of view,dose verification is usually performed before executing the treatment plan in order to ensure the safe implementation of the treatment plan and to avoid un-planned irradiation dose.Currently,there are many tools and methods of dose verification in clinic,including point dose verification tools like finger-shaped ionization chamber and thermoluminescence dosimeter;two-dimensional dose verification tools like Mapcheck,MatriXX and films;three-dimensional dose verification tools like ArcCHECK,Delta4 and the third-party software.These common clinical dose verification methods are reviewed in this paper.

Objective To investigate the effects of 860MHz microwave on the formation and extinction of context conditioned fear in mice. Methods The mice were exposed to 860MHz continuous microwave ( power density were 380 μW/cm2 or 550 μW/cm2, respectively) for 30 min or 2 h, which then were divided in to 5 groups.Each group consisted of 15 animals. Footshocks were used to induce context conditioned fear by 75 voltages. The frequency and time of freezing after irradiation were investigated. Results When 24 h after foot shocking, the values of freezing time: control group was 2.31 ±4. 17 , two groups of the microwave irradiation 2 h were 3.93 ±6.99 and 2.47 ± 3.34, the Nemenyi test results (P = 0.004): control group was 32.63333, while two groups of the microwave irradiation 2 h were 52.46667 and 39.76667; and the values of freezing frequency: control group was 0.73 ± 1.16 , two groups of the microwave irradiation 2 h were 0.86 ± 1.41 and 1.07 ± 1.16, the Nemenyi test results of (P=0. 014): control group was 33. 26667, while two groups of the microwave irradiation 2 h were 50. 76667 and 40.90000. Conclusion The mice receiving relatively longer period of microwave irradiation showed more stable memory of the context conditioned fear.

Objective To quantize the synergistic force in movement of upper limbs between shoulders and elbows. Methods The trans-verse forces of elbows and shoulders during movement were recorded in a healthy adult with an upper-limb-force-measuring plate form which comprised of 2 three-dimensional force sensors, respectively. Then he performed shoulder abduction/adduction and elbow extension/flexion at 100%, 75%, 50%and 25%of the maximum contraction force, respectively. The ratio of the active action force and the joint action force (named assessment index) was used to assess the synergistic degree of the forearm and the upper arm. Results In the shoulder abduc-tion motion, the assessment index decreased as the strength of active action decreased, meant interference of joint action increased. Howev-er, it was almost stable in the shoulder adduction, increased in the elbow extensionas, and was irregular in the elbow flexion, as the active ac-tion strength decreased, respectively. Conclusion It may be more difficult to control upper arm than the forearm.

Objective To investigate the biophysical properties of mechanosensitive(MS) channels in cultured dorsal root ganglion neurons of neonatal rats. Methods MS channels current of cultured dorsal root ganglion neurons of neonatal rats were recorded using cell-attached and inside-out patch-clamp technique.The biophysical properties such as pressure response relationship,current voltage relationship,channel kinetics and ion selectivity were analyzed.Membrane stretch was achieved by the application of negative pressure(suction) to a patch-clamp electrode. Results One type of MS non-selective cation ion channels in the membrane patches tested in cultured dorsal root ganglion neurons of neonatal rats were recorded. Those channels were activated rapidly when suction was applied, and kept active during sustained application of negative pressure and quickly turned off when the suction was released.The MS channels exhibited a nearly linear current voltage relationship in the balance solution.The outward chord conductance was (96.2?3.6)pS (mV is between +40 mV and +60 mV) and the inward slope conductance was (62.5?0.4)pS (mV is between -60 mV and 0 mV). This kind of channels appeared to be outward rectifier.The average reversal potential was (-2.3?0.8)mV.The channel kinetics analysis indicated that suction could significantly increase the duration of short-openings and long-openings and decrease that of long-closings,with no effects on short-closings. Conclusion The results of this study could serve as a reference to the understanding of electric activity of DRG neurons.

Objective To investigate the characteristics of spontaneous discharges of hippocampal pyramidal cells (PC) in rats in age and memory groups with the help of nonlinear theory. Methods Rats were randomly divided into age group and memory group. Age group included aged group (16-19 months) and young group (3-4 months) whereas memory group included good memory and poor memory groups in adult. Extracellular single cell recording was performed in vivo . Results No characteristics of the rhythm of spontaneous discharges of hippocampal pyramidal cells in distribution figure of interspike interval(ISI) were found, but the loss of complexity(C) and low percentage of favored patterns(PF) were found in age and poor memory groups. Conclusion The ISI complexity and the PF of the hippocampal pyramidal cells are correlated to age and memory, suggesting that the analysis of the complexity and favored patterns may be helpful for the discovery of the characteristics of the information coding in spontaneous discharges of hippocampal pyramidal cells.

Objective To investigate the electrophysiological and morphological properties of the single ventral neuron in the medial geniculate body (MGBv) in rats. Methods The basic electrophysiological properties and action potentials at different levels of membrane potentials were recorded by whole cell patch clamp technique. Morphological properties of ventral neurons in the medial geniculate body were studied by biocytin staining. Results Nissl and biocytin stainings indicated that MGBv neurons were composed of oval shaped cell bodies, and the dendritic branches were tufted. In current clamp recordings, the resting membrane potential was (-54.92?10.85) mV, the input resistance (945.67?507.80) M?, the membrane capacitance (5.37?1.98) pF, and the time constant (2 109 87 ?2 496 01) ?s. Action potentials under different current inputs were various. Spontaneous discharge could be recorded by voltage clamp and current clamp. Conclusion MGBv dendritic trees are fairly dense with bushy tufted neurons and variety of action potentials under different current inputs in ventral neurons of the medial geniculate body. Spontaneous activities recorded by current clamp are similar to the action potential, which may be the spontaneous action potential due to the exceeding of membrane potential over liminal value.

In order to adapt to the education of the professional who work in thecurrent medical lab,we set up the course of'Experimental Technology of Medical Function'. It is a required subject for the professional with laboratory skill. This article explores the curriculum sys-tem,teaching contents,teaching methods and examination.

Objective To detect the change of discharge phase of guinea pig hippocampal CA1 pyramidal cells during visual discriminative task with an effective and convenient program we designed. Methods Five guinea pigs were performed by extracellular single unit recording in vivo when they were performing visual discriminative task. Discharge signals of individual pyramidal cells were extracted from different frequency signals by wavelet transform (WT), which made it feasible to calculate discharge phase of pyramidal cells in terms of time correlation between discharge and ? rhythm. Results The discharge phase of CA1 pyramidal cells in the 1 to 5s interval before visual discriminative task (172??1.8?) was obviously earlier than that in the 6 to 10s interval after visual discriminative task (189??3.7?) ( P0.01). Conclusion The program we designed is capable of detecting discharge phase of pyramidal cells. Regular shift of discharge phase of hippocampal CA1 pyramidal cells emerges before and after performing visual discriminative task.

Objective To investigate the role of cerebellar dentate-interpositus (D-I) nuclei during acquisition of classical eyeblink conditioning in guinea pigs. Methods A 500 ms tone conditioned stimulus (CS) was paired with a 100 ms corneal oxygen-puff unconditioned stimulus (US) in a delay paradigm. Guinea pigs were trained daily to acquire the classically conditioned eyeblink responses. Micorinjections of Muscimol into bilateral cerebellar D-I nuclei were performed during the 4-6 day of training session. A high-resolution potentiometer was used to detect the eyeblink responses. Results The conditioned response (CR) rates of Muscimol-injected group on session 4-6 were significantly lower than their rates on session 3 (P1=0.005,P2=0.004,P3=0.010); Their rates on session 7 and 8 were as the same level as those without microinjection on session 4 and 5 (P1=0.061,P2=0.669). However, there was no significant difference on their amplitude and peak latency of unconditioned responses (URs) during the entire course of training (P1=0.926,P2=0.939). Conclusion The cerebellar D-I nucleus is actively involved in the neural circuitry of motor learning, which is essential for both acquisition and performance of the classically conditioned eyeblink responses.

Objective To reconstruct 16?bit images of metal implants using the extended function of computed tomography ( CT) imaging, and to analyze the effect of the metal CT value on calculation of dose distribution by evaluation of metal CT values in different scanning conditions. Methods A stainless steel rod and a titanium rod were inserted in a phantom. The 12?and 16?bit images and CT value distribution of metal implants were obtained by scanning the phantom using 120 kV tube voltage and 230 mA tube current. The 16?bit images and CT value distribution of metal implants were obtained by scanning the phantom using fixed tube current ( 230 mA) with varied tube voltage ( 100, 120, and 140 kV) or fixed tube voltage ( 120 kV) with varied tube current ( 180, 230, and 280 mA) . In the Varian treatment planning system, a single?field plan and a parallel?opposed field plan were designed based on the CT images. The dose distribution was calculated and compared by the paired t test. Results The CT values of the stainless steel rod and the titanium rod were both 3 071 HU in 12?bit CT images. In 16?bit CT images;however, the CT value of the stainless steel rod was significantly larger than that of the titanium rod. There were no significant differences in CT value of 16?bit image and dose distribution in radiotherapy plan between three scanning conditions with different tube currents. Under three scanning conditions with different tube voltages, the maximum CT values were 13 568, 13 127, and 12 295 HU for the stainless steel rod and 8 420, 7 140, and 6 310 HU for the titanium rod, respectively. Conclusions High?density metal implants cannot be distinguished by 12?bit images, while the distribution of metal CT value can be obtained by 16?bit images. The dose distribution of metal implants based on 12?bit images is different from that based on 16?bit images. Changes in tube voltage cause substantial changes in the CT value for metal implants, leading to changes in dose distribution in radiotherapy. Variation of tube current within a certain range causes slight changes in metal CT value and dose distribution.