Mammography imaging is one of the most demanding imaging modalities from the point of view of the bal- ance between image quality (the visibility of small size and/or low contrast structures) and dose (screening of many asymptomatic people). Therefore, since the introduction of the first dedicated mammographic units, many efforts have been directed to seek the best possible image quality while minimizing patient dose. The performance of auto- matic exposure control (AEC) is the manifestation of this demand. The theory of AEC includes exposure detection and optimization and also involves some accomplished methodology. This review presents the development and present situa- tion of spectrum optimization, detector evolution, and the way how to accomplish and evaluate AEC methods.
Humans ; Mammography ; methods ; Phantoms, Imaging ; Radiation Dosage ; Radiographic Image Interpretation, Computer-Assisted

Objective To approach the design and clinical application of large anterolateral thigh flap and its effect in wound repair.Methods The flaps were designed according to the anatomical features of perforating branches in the anterolateral thigh flaps.When a flap was chipped,a thick branch or a terminal branch of original vessel was reserved,another suitable perforating branch was selected in the proximal or distal end of the flap,and then the two vessels were anastomosed to enlarge the range of blood supply.If the vessel pedicle of a flap was a musculocutaneous perforating branch,the perforating branch of anastomosis was cut at out-point of muscle.If the vessel pedicle of a flap was a intermusclar branch or a direct skin artery,the perforating branch of anastomosis was cut widely.From May 2006 to May 2012,the technique was applied in 28 patients with large skin defect of limbs.The diameters of perforating branches obtained at out-point of muscles were measured during surgery.The survival of flaps was observed after surgery and complications in donor sites were checked during follow-ups.Results There were 18 flaps whose vessel pedicle were musculocutaneous perforating branches.The branches were cut at outpoint of muscles.The diameters of these vessels were measured during surgery.They ranged from 1.3 mm to 1.8 mm with an average of 1.45 mm.All of the vessels could be anastomosed.All 28 flaps survived.All flaps survived.The areas of the flaps ranged from 22 cm × 15 cm to 42 cm × 14 cm.Artery crisis happened in 2 flaps whose vessel pedicle were musculocutaneous perforating branches.The second look operation found that the areas of artery anastomosis of perforating branches and vessel pedicles were compressed by hematoma and thrombus formed.The 2 flaps survived after the hematoma was cleared away and the vessels were reanastomosed.There were no infections.Both the donor and recipient site healed by first intention with no necrosis of flap margin.All 28 patients were followed up by 4-13 months with an average of 8 months.There were no apparent collapse deformities,muscle necrosis,declines of muscle strength and muscle hernia in the donor sites.The appearance of flaps was flat,the color was close to normal and the quality was fine.Conclusion It is a safe and effective method to repair wound surface by large anaterolateral thigh flap obtained by the modus operandi of perforating branch anastomosis.

Purpose　The aim is to obtain the cDNA sequence of encoding extramembrane human FL gene with high level expression in E.coli. Methods　The primers were designed based on the known FL cDNA sequence. The total RNA was isolated from fetal liver cells , and then RT-PCR was performed. The fragment was cloned into pUC-18T vector, and further sequenced by automatic sequence analyzer. The gene was inserted into GST fusion expression vector between BamH Ⅰ and EcoR Ⅰ sites. The recombinant plasmid was transformed into E.coli strain DH5 α and induced with 1mmol/L IPTG.Results　The 546bp DNA fragment was amplified by RT-PCR method from fetal liver cells and its sequence was identical to the published sequence encoding human FL. The expressed fusion protein, with molecular weight of about 22kD, was about 10% of the total bacteria protein by SDS-PAGE and densitometry analysis.Conclusion　cDNA was cloned successfully. This study provided a basis for the further fundamental research and clinical application of FL.

Objective To investigate the correlation between acute physiology and chronic health evaluation Ⅱ (APACHEⅡ) scores and delirium probability of senile severe pneumonia patients undergoing invasive mechanical ventilation (MV).Methods A retrospective study was conducted. Eighty-nine senile severe pneumonia patients undergoing invasive MV admitted to intensive care unit (ICU) of Hunan Provincial People's Hospital from January 2015 to March 2017 were enrolled. APACHE Ⅱ scores were collected 24 hours before invasive MV. Consciousness assessment method-ICU (CAM-ICU) was used to diagnose delirium, and the patients were divided into delirium group and non-delirium group. The first delirium occurrence time, duration of MV and the length of ICU stay were recorded. The patients were divided into ≤15, 16-20, 21-25, 26-30, 31-35, 36-40 groups according to APACHEⅡ score, and the incidence of delirium in all groups were observed. The linear regression and Pearson correlation were used to analyze the correlation between APACHE Ⅱ scores and delirium probability. Receiver operating characteristic (ROC) curve was plotted to analyze the predictive effect of APACHEⅡ score on delirium.Results Eighty-nine patients were enrolled in the final analysis, of which 35 had delirium, and 54 had no delirium, with delirium incidence of 39.33%, and the first delirium occurrence time of (1.85±1.30) days. The duration of MV and the length of ICU stay of delirium group were significantly higher than those of non-delirium group [duration of MV (days): 9.43±4.77 vs. 6.08±3.30, length of ICU stay (days): 14.60±6.59 vs. 9.69±4.61, bothP < 0.01]. The APACHE Ⅱ score in delirium group was significantly higher than that in non-delirium group (29.89±5.45 vs. 21.48±4.76,P < 0.01). With the increase in APACHE Ⅱ scores, the delirium incidence was gradually increased. Correlation analysis showed that there was a negative correlation between APACHE Ⅱ scores and first delirium occurrence time (r = -0.411,P = 0.014), and a significant linear positive correlation between APACHE Ⅱ scores and delirium incidence in all patients was found (r = 0.982, P = 0.000), which indicated the higher APACHE Ⅱ scores, the higher delirium incidences and the earlier first delirium occurrence time was. ROC curve analysis showed that the area under ROC curve (AUC) of APACHE Ⅱ scores on predicting delirium occurrence was 0.877, when the cut-off value of APACHE Ⅱ score was over 27, the sensitivity was 92.59%, the specificity was 71.43%, the positive predictive value was 83.33%, and the negative predictive value was 86.21%.Conclusions With the increase in APACHE Ⅱ score, the incidence of delirium was increased gradually in senile severe pneumonia patients receiving invasive MV. APACHE Ⅱ score played an important clinical value in evaluating the delirium probability of these patients

Objective To explore the value of dynamic contrast-enhanced MRI (DCE-MRI)and diffusion tensor imaging(DTI)in grading of glioma.Methods 3.0T DCE-MRI and DTI scans were performed in 31 patients with glioma confirmed by pathology.Capacity volume transfer constant (Ktrans ),extravascular extracellular volume fraction (Ve ),exchange rate constant (Kep ),initial area under the gadolinium concentration-time curve (iAUC),and relative fractional anisotropy (rFA)were measured in the low grade glioma (LGG)and the high grade glioma (HGG).The correlation between parameters of DCE-MRI and rFA with microvessel denisity (MVD)and microvessel structure (MVS)were performed by Spearman rank correlation analysis.Results The MVD and MVS were positive correlation with the grading of glioma.Ktrans ,Kep ,Ve ,iAUC and rFA values of the LGG were (0.02±0.01)min-1 ,1.82 (0.18-8.54)min-1 ,0.05±0.03, 2.47±1.66 and 0.55±0.22,respectively.Ktrans ,Kep ,Ve ,iAUC and rFA values of the HGG were (0.1 1±0.02)min-1 ,1.31 (0.12-7.58)min-1 ,0.28±0.10,10.84 ±6.46 and 0.28 ±0.08,respectively.The differences of all parameters between the LGG and the HGG were statistically significant,except for Kep (P <0.05 ).Ktrans ,Ve and iAUC values were positive correlation with MVD and MVS (P <0.05),and rFA values were negative correlation with MVD and MVS (P <0.01).Conclusion The quantitative parameters of DCE-MRI and DTI have important values in grading of glioma and evaluating tumor angiogenesis and microvessel structure.

Objective To investigate the relationship between psychological quality and performance capacity of the crew in armored equipment so as to provide scientific evidence for the training of crew .Methods The psychological quality of 82 crew members of armored cavalry was tested and analyzed by neurobehavioral testers and questionnaires .Results and Conclusion The education level and age had no significant effect on the performance capacity among the armored crew . The test results of psychological quality parameters showed the same trend as the performance capacity of the crew , but their psychological health status had obvious effect on the performance capacity .The psychological quality of the crew had great influence on their performance capacity ,so we should pay attention to mental intervention ,enhance psychological protection ability of the crew , and improve their combat effectiveness continuously .

The characteristics of human body impact response and several impact test objects are analyzed.The strengths and weaknesses of different research methods applied to different human landing impact test objects are contrasted.The relevant experimental findings and evaluation criteria of domestic and international tests on human landing impact are analyzed.The results show that the selected human substitutes in several research tests have some flaws, so it is urgent to formulate regulations on the load characteristics, individual characteristics, the posture of the test object and the protection status, and it is recessary to study impact tolerance and protective methods of corresponding operating personnel for different transports.

To develop a standard defibrillation energy source which can output monophasic and biphasic de-fibrillation impulses and can display standard energy values. The storage capacitor was charged by single-end flyback transformator and discharged through the H bridge composed of insulated gate bipolar transistor (IGBT). Impulse voltage and current were collected by divider while discharging, and the energy value was calculated by STM32. The en-ergy value and waveform were displayed through the control module. The energy source could output both monophsic and biphasic waveforms, and the accuracy of displayed value was higher than ±2% or ±1 J. The standard defibrillation energy source can be used as standard device for defibrillator analyzer, and the metrological trace-ability system of defibrillation energy may come to be completed.

Objective To design a measuring system for operative gestures used for the crew in armored vehicles. Methods The MEMS sensor was used to collect gesture parameters of important parts of four crew members,such as the head, neck,trunk,arms,legs.The infrared tracking auxiliary measurement was used to calibrate the gesture parameters of arms of drivers.The wireless transceiver was used to transmit data to the control unit for preprocessing and then send the data to the collector for storage, before being transmitted to the back-end computers.A software system was used to process and display the body posture parameters.Results and Conclusion The system can mesure the operative gestures of the crew and provide means by which to analyze the kinematics for the crew in armored vehicles.