As a new type of carbon nanomaterials, fluorescent carbon dots (fluorescent CDs) have many advantages when compared with the traditional fluorescent probes. They are photoluminescence stable and resistance to photo bleaching. Moreover, they are excellent in biocompatibility, low-toxic and easy to modify. All these above make them a promising optical image material as a probe in optical image. This article reviews structure, the common carbon sources, the preparation methods, and the light-emitting principles of the carbon dots. We also introduce the research progress of fluorescent carbon dots in biomedicine, and the problems need to be resolved in the study of fluorescent CDs.

Objective To compare the quality and radiation doses of coronary artery angiography under the natural heart rate condition between Flash spiral heart mode and prospective electrocardiogramtriggering sequence mode using dual-source,in order to choose personalized low doses of coronary artery scanning mode.Methods Sixty patients who underwent coronary angiography(CTA)on a 128-slice,dualsource CT scanner were divided into 2 group i.e,group A(27cases)and group B(33 cases).Flash spiral heart scan mode was employed for group A.Inclusion criteria included:heart rate<65 bpm.regular sinus rhythm,heart rate fluctuation less than ±5 bpm.Date acquisition was set at 60% of the R-R interval.Prospective electrocardiogram-triggering sequence scan mode(SAS)was performod for group B.Inclusion criteria included:(1)heart rate≥65 bpm,(2)arrhythmias,premature beat,fibrillation atrial.Exclusion criteria included:bad holding breath.Date acquisition(1)At low heart rate(≤75 bpm),date acquisition was set at 60%-80%of the R-R interval.(2)At high heart rate(>75 bpm),date acquisition was set at 30%-50%of the R-R interval. (3)At the arrhythmias,premature beat,fibrillation atrial,date acquisition was set at 20%-90%of the R-R interval.In both gronps,patients with a BMI≥25.0kg/m2 were examined with a tube voltage of 120 kV.while the other patients with a BMI<25.0 kg/m2 were examined with a tube voltage of 100 kV.The BMl was(24.6±1.0)kg/m2 in group A,while that was (24.6±0.9)kg/m2 in group B.In both groups,all images were transferred to the workstation for further processing and analysis.The imaging quality of coronary artery segments and the radiation dose were compared with t test.Results A total of 336 coronary artery segments were evaluated in group A and 412 segments were evaluated in group B.The imaging quality of coronary artery segments were scored.Excellent or good was achieved in 98.2%(330 of 336)artery segments in group A,and that was 98.1%(404 of 412)in group B.There was no statistical difference in imaging quality between the two groups(t=0.513,P=0.608).The average effective dose was(0.74±0.29)mSv in group A,whereas that was(3.67±1.37)mSv in group B.There was a significant difference between the two groups(t=-10.858,P=0.000).Conclusions The personalized low doses coronary artery scanning mode can substantially reduce radiation damage while preserving good imaging quality.

Objective To study the image quality and radiation dose in dual-source CT cerebral angiography with prospective ECG-triggered sequence mode (step-and-shoot,SAS).Methods A total of forty-three patients with clinically suspected cerebral vascular disease underwent cerebral CT angiography with prospective ECG-triggering (step-and-shoot,SAS).Data acquisition was at 60％ R-R interval of the ECG presentation mode.The post-processing included maximum intensity projection (MIP),multiplanar reformation (MPR) and volume rendering (VR).The CTA image quality,radiation dose and rates of excellent images were evaluated.Results The CTA image quality score was 4.72 ± 0.50 and 97.7％ (42/43) patients had excellent CTA images.The average effective dose of SAS-CTA was (0.22 ± 0.01 )mSv,which was lower by 76.31％ than that of DE-CTA.Conclusions Prospective ECG-triggering sequence could be used in cerebral angiography with a significant reduction in radiation dose and diagnostic image quality.

Objective To investigate the feasibility of low dose dual phase contrast-enhanced chest CT with iterative mod el reconstruction (IMR) technique.Methods Totally 130 patients with suspected pulmonary occupying lesions underwent dual phase contrast-enhanced chest CT,who were randomly assigned into 2 groups (group A and group B,each n=65).Patients in group A were scanned with 100 kV,DoseRight technique with dose right index 10,and images were reconstructed with the hybrid iterative reconstruction (iDose4).While patients in group B were scanned with 80 kV,DoseRight technique with dose right index 8,and images were reconstructed with iterative model reconstruction (IMR).The objective image quality,subjective image scores and the excellence rate of vascular visualization were compared in both pulmonary artery (PA) and bronchial artery (BA) phases.The radiation dose was also calculated.Results The effective dose was (3.30 ±0.89)mSv in group A and (1.27 ±0.19)mSv in group B.Compared to group A,the effective dose reduced 61.52％ in group B (P＜0.001).Lower image noise and greater CNR were obtained in group B compared to group A in both PA and BA phases (all P＜0.001).No significant difference was found in subjective image scores of lung and mediastinal setting and the excellence rate of vascular visualization in both groups (all P＞0.05).Conclusion Using IMR,dual phase contrast-enhanced chest CT allows for a radiation dose reduction up to 61.52％,meanwhile,ensures the image quality and meets the diagnostic requirements.

Objective To treat hematospermia by ureteroscopy and investigate its application value for the treatment of hematospermia.Methods Nineteen patients with persistent hematospermia, TRUS,seminal vesicle MRI or CT were examined to exclude seminal vesicle tumor, tuberculosis, prostatic occupancy and preoperative prostatic fluid and drug sensitivity.Transurethral 4.5 - 6 F ureteroscopy entered through the microscopic seminal vesicle, wash of the old blood, reserved perfusion with Quinolones, and the lithoclasty on the seminal stones by holmium laser, resection of small polypi.Results The ureteroscopy was successful in 18 (95%) cases for bilateral seminal vesicle, wash and drug reserved perfusion, and one case was also successful seminal vesicle microscopy on the affected side; five cases with the seminal stones by olmium laser, three cases with small polypi by resection.The averse duration of the procedure was 35 10 -75) min.There were no compliocations during or after the operation.In 18 cases at 6 - 12 months follow-up the hematospermia and symptoms of hematospermia disappeared fully after 90 d.There was recurrence in one case which improved with anti-inflammaotry treatment.Conclusions Ureteroscopic treatment for persistent hematospermia by 4.5 - 6 F ureteroscopy through the seminal vesicle is effective and safe method and results in a micro-wound.

Objective To study the epidemiologic characteristics of trauma in the prehospital first-aid in megapolis. Methods The epidemiologic data of 10 654 traumatic patients,including treated by prehospital treatment and emergency treatment from January 2000 to January 2005,were analyzed.Results The proportion of male was 70.96%,adult patients(21～50 years old)79.23%,suburb 62.86%,downtown 37.14%.The patients whose ISS scores surpassed 16 accounted for 37.98%,which caused by traffic accident was 37.74%,by public order 24.39%,by industrial trauma 21.71%.The trauma in the limbs accounted for 67.51%,cephalic and cervical wounds accounted for 58.64%,multiple wounds 41.77%,thoracic and abdominal wounds 39.41%.Three hundred and sixty one were killed on the spot,which caused by traffic accident were 46.81%,by public order 28.81%,by industrial trauma 14.40%.Forty-two percent point six six patients died of multiple trauma,54.07% died of cephalic and cervical trauma,15.79% died of thoracic and abdominal wounds.Conclusion Suburban area gradually became the frequently-occurred areas of trauma in megapolis. The wounded were mainly young adults and had a tendency of juvenility.The majority of damaging and lethal factors were traffic accident,public order and industrial trauma.Some pertinet measures and professional first-aid models may improve the traumatic first-aid level.

Objective To explore the anatomic basis of the thinning of the free posterior tibial artery perforator flaps and the clinical effect of repairing wound on hand or foot due to trauma.Methods From November,2016 to December,2017,10 cases of lower extremity cadaver specimens perfused with red ralex were dissected,which were perfused through the amputated femoral artery.Five of them were left and the rest were right.All cases were males.The number,diameter,branches and distribution of the perforator was observed.From September,2012 to September,2017,there were 13 cases of clinical application,which were 5 cases of hand wound and 8 cases of foot wound.The size of the wound was 3.0 cm × 2.0 cm to 6.0 cm × 4.0 cm,and the flap area was 3.5 cm × 2.2 cm to 6.5 cm × 4.5 cm.The repairing procedure was suitable for the wound associated with tendon,bone,joint capsule exposure.Results The number of posterior tibial artery perforating branches that more than 0.50 mm in diameter was 4 to 6,and the mean diameter was (0.87±0.26) mm.The perforating branch penetrated into the fat layer and was divided into 3 layers of vascular network:deep fat vascular network,superficial fat vascular network and subdermal vascular network.The perforating branch was located according to the positional relationship from deep to shallow,and vessel diameter become smaller step by step.The perforating branch trunk gave off branches to the deep vascular network,and the superficial vascular network had the same origin or shared with the deep blood vessels.The subdermal vascular network issued from the superficial vascular network or directly from the perforating branch trunk.There was no or few communicating branch between the deep vascular network and superficial ones,besides the vessel pedicle.So trimming deep fat layer will not affect the blood supply of superficial vascular network and neither will affect the flap blood supply.Most of the deep fat tissue was trimmed in 13 cases.The superficial and subdermal fat vascular network was preserved,and the same to the trunk and branches of the pedicle.All the flaps survived.Of which,1 appeared arterial crisis on the 2nd day after operation,and relieved by the local injection of papaverine.There was 1 case of venous crisis on the 3rd day,and improved by stitches,local release of congestion.Followed-up time was ranged from 2 to 12 months.All flaps were soft with good blood supply and good appearance,and did not need a second thinning surgery.Flaps restored the protective feeling 6 months later.Conclusion The microdissection of perforator flap of posterior tibial artery provides a theoretical basis for the perforator flap thinning,and the thinning of perforator flap is a good method to repair the appearance and function of the wound after foot and hand injuries.

Objective To explore the effect of mindfulness-based music therapy (MBMT) on sleep-wakefulness behavior in patients with acute stress disorder (ASD) coexisting sleep disorder with cerebral hemorrhage. Methods A total of 70 patients with cerebral hemorrhage and ASD coexisting sleep disorders were randomly divided into two groups (n=35 each group). The study group was treated with mindfulness and soothing music training on the basis of routine treatment for 28 consecutive days. The control group only received routine treatment. Polysomnography (PSG) was used to compare sleep-wake behavior before and after intervention. Results After the intervention, the numbers of awakenings, awakenings greater than 5 min, micro awakenings, NREM micro awakenings, micro awakenings in phase 1, micro awakenings in phase 2, and REM awakenings were decreased in both groups (P<0.05). The degree of reduction of those parameters were greater and the proportion of total sleep time to recording time was longer in the study group than in the control group (P<0.05). Conclusion Music therapy based on mindfulness can effectively improve the sleep-wakeful behavior of ASD patients with cerebral hemorrhage, change the sleep process, and improve their sleep quality.

Objective To explore the relationship between brain injury related symptom groups and acute stress disorder( ASD). Methods Totally 301 patients with brain injury hospitalized in the Affiliated Hospital of North China University of Technology from March 2017 to March 2018 were recruited. The pa-tients were assessed by Stanford Acute Stress Response Questionnaire ( SASRQ), Brain Trauma Subscale (BIS) and Pittsburgh Sleep Quality Index (PSQI). Results The prevalence of acute stress disorder pa-tients with brain injury was 46. 51% (140/301). The SASRQ score of all patients with brain injury was (70. 78±28. 00). Univariate analysis showed that there were significant differences in age (χ2= 4. 172,P=0. 041),personality type (χ2= 57. 281,P<0. 001),sleep quality ( χ2= 70. 785,P<0. 001),hospitalization frequency (χ2= 43. 547,P<0. 001),depression,obsessive-compulsive and hostile symptoms between pa-tients with and without ASD ( P<0. 05). The scores of depression and obsessive-compulsive symptoms were significantly correlated with SASRQ scores(P<0. 05). The scores of hostility symptoms were significantly cor-related with SASRQ scores except for patients who lost their temper uncontrollably ( r=0. 176-0. 698,P<0. 05). Personality ( OR=0. 243,95% CI=0. 142-0. 415),sleep disorders( OR=0. 072,95% CI=0. 029-0. 178),hospitalization times(OR=0. 129,95%CI=0. 054-0. 306),depressive symptoms( OR=1. 260,95% CI=1. 061-1. 497),obsessive-compulsive symptoms(OR=1. 419,95%CI=1. 239-1. 625) and hostile symp-toms(OR=1. 253,95%CI=1. 058-1. 482) were the influencing factors of ASD in patients with brain injury (P<0. 05). Conclusion The incidence of ASD is higher in patients with brain injury. Personality type,hos-pitalization,sleep quality,depressive symptoms,obsessive-compulsive symptoms and hostile symptoms are the influencing factors,which should be paid more attention.

Objective To evaluate the role of dynamic contrast-enhanced magnetic resonance imaging (MRI) in the diagnose of prostatic cancer and benign prostatic hyperplasia (BPH), and to determine the correlation between dynamic MRI findings with angiogenesis.Methods Thirty-two cases of prostatic cancer and 40 cases of BPH underwent dynamic contrast-enhanced MRI.All the patients in this study were diagnosed by histopathology.The results of dynamic contrast-enhanced MRI were evaluated by early-phase enhancement parameters and time-signal intensity curves (SI-T curves), and the curves were classified according to their shapes as type Ⅰ, which had steady enhancement; type Ⅱ, plateau of signal intensity; and type Ⅲ, washout of signal intensity.The pathologic specimens of region of interest (ROI) were obtained, and HE staining, immunohistochemical vascular endothelial growth factor (VEGF), and microvessel density (MVD) measurements were performed.The relationships among dynamic contrast-enhanced MRI features, VEGF, and MVD expression were analyzed.Results In the early-phase enhancement parameters of dynamic contrast-enhanced MRI, onset time,maximum signal intensity, and early-phase enhancement rate differed between prostatic cancer and BPH(P