Test Verification and Design of the Bicycle Frame Parameters

Research on design of bicycles is concentrated on mechanism and auto appearance design, however few on matches between the bike and the rider. Since unreasonable human-bike relationship leads to both riders＇ worn-out joints and muscle injuries, the design of bicycles should focus on the matching. In order to find the best position of human-bike system, simulation experiments on riding comfort under different riding postures are done with the lifemode software employed to facilitate the cycling process as well as to obtain the best position and the size function of it. With BP neural network and GA, analyzing simulation data, conducting regression analysis of parameters on different heights and bike frames, the equation of best position of human-bike system is gained at last. In addition, after selecting testers, customized bikes based on testers＇ height dimensions are produced according to the size function. By analyzing and comparing the experimental data that are collected from testers when riding common bicycles and customized bicycles, it is concluded that customized bicycles are four times even six times as comfortable as common ones. The equation of best position of human-bike system is applied to improve bikes＇ function, and the new direction on future design of bicycle frame parameters is presented.

In vivo auditory nerve stimulation with visible light

Background:Infrared laser stimulation has been proposed as an innovative method to elicit an auditory nerve response.Most studies have focused on usi ng long-wavelength infrared(>980 nm)pulsod lasers with high water absoption cofficients.This paper sought to assts8 whether a short-wavelength laser(465 nm)with an absorption cofficient as low as 103 cm^(-1) would activate the auditory nerve and studied its potential mechanism.Method:Optical compound action potentials(OCAPs)were recorded when synchronous triger laser pulses st imulate the cochlea before and after deafening,varying the pulse durations(from 8001us to 36001us)and the amount of radiant enengy(fom 18.05 mJ/cm^(2) to 107.91 mJ/cm^(2)).A thermal infrared imager was applied to monitor the tempenature change of the guinea pig cochlea.Results:The results showed that pulsed laser stimulation at 465 nm could invoke OCAPs and had a similar waveform compared to the acoustical compound action potentials.The amplitude of OCAPs had a poaitive correlation with the in-creasi ng laser peak power,while the latency of OCAPs showed a negative correlation.The imager data showed that the temperature in thecochlea rose quickly by about 0.3℃ right after stimulating the cochlea and decreased quickly back to the initial temperature as the stimulation ended.Con-clusions:This paper demonstrates that 465-nm laser st imulation can successfully induce OCAPs outside the cochlea,and that the amplitude and latency of the invoked OCAPs are highly affected by laser peak power.This paper proposes that a photothermal efect might be the main mechanism for the auditory nerve response induced by short-wavelength laser stimulation.

Photoacoustic effect invokes auditory response in infrared neuron stimulation

Infrared neuron stimulation is regarded as an innovative approach for stimulating cochleae in animals while the exact mechanism still remains unknown.In this paper,we studied compound action potentials of guinea pig cochleae with chronic or acute deafness.We recorded optical compound action potentials and analyzed stretched cochlear preparations by fiuorescence microscopy.Photoacoustic signals were measured by hydrophone and microphone,respectively.In our experiment,we observed a switch response effect in vitro and in vivo experiments.Therefore,we proposed photoacoustic effect could invoke auditory response in infrared neuron stimulation.

A photoacoustic imaging system with variable gain at different depths

We established a photoacoustic imaging(PAI)system that can provide variable gain at different depths.The PAI system consists of a pulsed laser with an optical parametric oscillator working at a 728 nmwavelength and an imaging-acquisition-and-processing unit with an ultrasound transducer.Avoltage-controlled attenuator was used to realize variable gain at different depths when acquiring PAI signals.The proof-of-concept imaging results for variable gain at different depths were achieved using specic phantoms.Both resolution and optical contrast obtained through the results of variable gain for a targeted depth range are better than those of constant gain for all depths.To further testify the function,we imaged the sagittal section of the body of in vivo nude mice.In addition,we imaged an absorption sample embedded in a chicken breast tissue,reaching a maximum imaging depth of
4.6 cm.The results obtained using the proposed method showed better resolution and contrast than when using 50 dB gain for all depths.The depth range resolution was
1 mm,and the maximum imaging depth of our system reached
4.6 cm.Furthermore,blood vessels can be revealed and targeted depth range can be selected in nude mice imaging.

Pyoderma Gangrenosum as the Initial Manifestation of Small Cell Lung Cancer with Dermatomyositis

To the Editor：A 54-year-old man developed painful ulcers on the neck one month ago,followed by periorbital edema.The ulcers then spread to his trunk,back,and upper arms.He had muscle weakness,mild muscle soreness with activity,and dysphagia for foods for the past three weeks.He was diagnosed as drug eruption in a local hospital and received irregular corticosteroids therapy for two weeks.Thereafter,the ulcers started to heal.He had a 40 years＆#39; history of smoking.The patient was emaciation,and physical examination revealed heliotrope sign,poikiloderma involving the face,＆quot;V＆quot; sign of the chest,and the upper arm,nail fold telangiectasia,and large well-defined ulcers on the abdomen,back,and upper arms,there was no Gottron sign [Figure 1].It was hard for him to raise his arms and squat.The triceps and quadriceps were tender to palpation.Investigation revealed elevated levels of antinuclear antibodies （1：40;normal range,〈1：40）,creatin kinase （382 U/L;normal range,56-244 U/L）,lactic dehydrogenase （254 U/L;normal range,109-245 U/L）,white blood cell （19.71 x 109/L,normal range,3.5-9.5 ＆#215; 109/L）,erythrocyte sedimentation rate （78 mm/h;normal range,0-15 mm/h）,C-reactive protein （117.52 mg/L;normal range,〈8 mg/L）,neurospecific enolase （25.03 ng/ml;normal range,0-16.30 ng/ml）,and electromyography showed muscle damage.Chest computed tomography plain and enhanced scan suggested possible malignant tumor in left upper lobe [Figure 1].The biopsy of axillary lymph node showed ＆quot;small cell lung cancer＆quot;.Histopathology of ulcer edge revealed ulceration of the epidermis with a dense neutrophils infiltration.There was no organisms or vasculitis [Figure 1].