AIM:To investigate the features of crush thoracic trauma in Sichuan earthquake victims using chest digital radiography(CDR).METHODS:We retrospectively reviewed 772 CDR of 417 females and 355 males who had suffered cru...AIM:To investigate the features of crush thoracic trauma in Sichuan earthquake victims using chest digital radiography(CDR).METHODS:We retrospectively reviewed 772 CDR of 417 females and 355 males who had suffered crush thoracic trauma in the Sichuan earthquake.Patient age ranged from 0.5 to 103 years.CDR was performed between May 12,2008 and June 7,2008.We looked for injury to the thoracic cage,pulmonary parenchyma and the pleura.obtained in 349 patients,the remaining 423 patients underwent only AP CDR.Thoracic cage fractures,pulmonary contusion and pleural injuries were noted in 331(42.9%;95% CI:39.4%-46.4%),67 and 135 patients,respectively.Of the 256 patients with rib fractures,the mean number of fractured ribs per patient was 3.Rib fractures were mostly distributed from the 3rd through to the 8th ribs and the vast majority involved posterior and lateral locations along the rib.Rib fractures had a significant positive association with non-rib thoracic fractures,pulmonary contusion and pleural injuries(P < 0.001).The number of rib fractures and pulmonary contusions were significant factors associated with patient death.CONCLUSION:Earthquake-related crush thoracic trauma has the potential for multiple fractures.The high number of fractured ribs and pulmonary contusions were significant factors which needed appropriate medical treatment.展开更多
Hydrostatic pulmonary edema is as an abnormal in-crease in extravascular water secondary to elevatedpressure in the pulmonary circulation, due to conges-tive heart failure or intravascular volume overload.Diagnosis of...Hydrostatic pulmonary edema is as an abnormal in-crease in extravascular water secondary to elevatedpressure in the pulmonary circulation, due to conges-tive heart failure or intravascular volume overload.Diagnosis of hydrostatic pulmonary edema is usuallybased on clinical signs associated to conventional ra-diography findings. Interpretation of radiologic signsof cardiogenic pulmonary edema are often question-able and subject. For a bedside prompt evaluation,lung ultrasound(LUS) may assess pulmonary conges-tion through the evaluation of vertical reverberationartifacts, known as B-lines. These artifacts are relatedto multiple minimal acoustic interfaces between smallwater-rich structures and alveolar air, as it happens incase of thickened interlobular septa due to increase of extravascular lung water. The number, diffusion and in-tensity of B lines correlates with both the radiologic andinvasive estimate of extravascular lung water. The inte-gration of conventional chest radiograph with LUS canbe very helpful to obtain the correct diagnosis. Com-puted tomography(CT) is of limited use in the work upof cardiogenic pulmonary edema, due to its high cost,little use in the emergencies and radiation exposure.However, a deep knowledge of CT signs of pulmonaryedema is crucial when other similar pulmonary condi-tions may occasionally be in the differential diagnosis.展开更多
BACKGROUND This study was designed to investigate the clinical outcomes of enhanced recovery after surgery(ERAS)in the perioperative period in elderly patients with nonsmall cell lung cancer(NSCLC).AIM To investigate ...BACKGROUND This study was designed to investigate the clinical outcomes of enhanced recovery after surgery(ERAS)in the perioperative period in elderly patients with nonsmall cell lung cancer(NSCLC).AIM To investigate the potential enhancement of video-assisted thoracic surgery(VATS)in postoperative recovery in elderly patients with NSCLC.METHODS We retrospectively analysed the clinical data of 85 elderly NSCLC patients who underwent ERAS(the ERAS group)and 327 elderly NSCLC patients who received routine care(the control group)after VATS at the Department of Thoracic Surgery of Peking University Shenzhen Hospital between May 2015 and April 2017.After propensity score matching of baseline data,we analysed the postoperative stay,total hospital expenses,postoperative 48-h pain score,and postoperative complication rate for the 2 groups of patients who underwent lobectomy or sublobar resection.RESULTS After propensity score matching,ERAS significantly reduced the postoperative hospital stay(6.96±4.16 vs 8.48±4.18 d,P=0.001)and total hospital expenses(48875.27±18437.5 vs 55497.64±21168.63 CNY,P=0.014)and improved the satisfaction score(79.8±7.55 vs 77.35±7.72,P=0.029)relative to those for routine care.No significant between-group difference was observed in postoperative 48-h pain score(4.68±1.69 vs 5.28±2.1,P=0.090)or postoperative complication rate(21.2%vs 27.1%,P=0.371).Subgroup analysis showed that ERAS significantly reduced the postoperative hospital stay and total hospital expenses and increased the satisfaction score of patients who underwent lobectomy but not of patients who underwent sublobar resection.CONCLUSION ERAS effectively reduced the postoperative hospital stay and total hospital expenses and improved the satisfaction score in the perioperative period for elderly NSCLC patients who underwent lobectomy but not for patients who underwent sublobar resection.展开更多
Research has shown that chest radiography images of patients with different diseases, such as pneumonia, COVID-19, SARS, pneumothorax, etc., all exhibit some form of abnormality. Several deep learning techniques can b...Research has shown that chest radiography images of patients with different diseases, such as pneumonia, COVID-19, SARS, pneumothorax, etc., all exhibit some form of abnormality. Several deep learning techniques can be used to identify each of these anomalies in the chest x-ray images. Convolutional neural networks (CNNs) have shown great success in the fields of image recognition and image classification since there are numerous large-scale annotated image datasets available. The classification of medical images, particularly radiographic images, remains one of the biggest hurdles in medical diagnosis because of the restricted availability of annotated medical images. However, such difficulty can be solved by utilizing several deep learning strategies, including data augmentation and transfer learning. The aim was to build a model that would detect abnormalities in chest x-ray images with the highest probability. To do that, different models were built with different features. While making a CNN model, one of the main tasks is to tune the model by changing the hyperparameters and layers so that the model gives out good training and testing results. In our case, three different models were built, and finally, the last one gave out the best-predicted results. From that last model, we got 98% training accuracy, 84% validation, and 81% testing accuracy. The reason behind the final model giving out the best evaluation scores is that it was a well-fitted model. There was no overfitting or underfitting issues. Our aim with this project was to make a tool using the CNN model in R language, which will help detect abnormalities in radiography images. The tool will be able to detect diseases such as Pneumonia, Covid-19, Effusions, Infiltration, Pneumothorax, and others. Because of its high accuracy, this research chose to use supervised multi-class classification techniques as well as Convolutional Neural Networks (CNNs) to classify different chest x-ray images. CNNs are extremely efficient and successful at reducing the number of parameters while maintaining the quality of the primary model. CNNs are also trained to recognize the edges of various objects in any batch of images. CNNs automatically discover the relevant aspects in labeled data and learn the distinguishing features for each class by themselves.展开更多
BACKGROUND Postoperative pain management and cognitive function preservation are crucial for patients undergoing thoracoscopic surgery for lung cancer(LC).This is achieved using either a thoracic paravertebral block(T...BACKGROUND Postoperative pain management and cognitive function preservation are crucial for patients undergoing thoracoscopic surgery for lung cancer(LC).This is achieved using either a thoracic paravertebral block(TPVB)or sufentanil(SUF)-based multimodal analgesia.However,the efficacy and impact of their combined use on postoperative pain and postoperative cognitive dysfunction(POCD)remain unclear.AIM To explore the analgesic effect and the influence on POCD of TPVB combined with SUF-based multimodal analgesia in patients undergoing thoracoscopic radical resection for LC to help optimize postoperative pain management and improve patient outcomes.METHODS This retrospective analysis included 107 patients undergoing thoracoscopic radical resection for LC at The Affiliated Cancer Hospital of Zhengzhou University and Henan Cancer Hospital between May 2021 and January 2023.Patients receiving SUF-based multimodal analgesia(n=50)and patients receiving TPVB+SUF-based multimodal analgesia(n=57)were assigned to the control group and TPVB group,respectively.We compared the Ramsay Sedation Scale and visual analog scale(VAS)scores at rest and with cough between the two groups at 2,12,and 24 h after surgery.Serum levels of epinephrine(E),angio-tensin Ⅱ(Ang Ⅱ),norepinephrine(NE),superoxide dismutase(SOD),vascular endothelial growth factor(VEGF),transforming growth factor-β1(TGF-β1),tumor necrosis factor-α(TNF-α),and S-100 calcium-binding proteinβ(S-100β)were measured before and 24 h after surgery.The Mini-Mental State Examination(MMSE)was administered 1 day before surgery and at 3 and 5 days after surgery,and the occurrence of POCD was monitored for 5 days after surgery.Adverse reactions were also recorded.RESULTS There were no significant time point,between-group,and interaction effects in Ramsay sedation scores between the two groups(P>0.05).Significantly,there were notable time point effects,between-group differences,and interaction effects observed in VAS scores both at rest and with cough(P<0.05).The VAS scores at rest and with cough at 12 and 24 h after surgery were lower than those at 2 h after surgery and gradually decreased as postoperative time increased(P<0.05).The TPVB group had lower VAS scores than the control group at 2,12,and 24 h after surgery(P<0.05).The MMSE scores at postoperative days 1 and 3 were markedly higher in the TPVB group than in the control group(P<0.05).The incidence of POCD was significantly lower in the TPVB group than in the control group within 5 days after surgery(P<0.05).Both groups had elevated serum E,Ang Ⅱ,and NE and decreased serum SOD levels at 24 h after surgery compared with the preoperative levels,with better indices in the TPVB group(P<0.05).Marked elevations in serum levels of VEGF,TGF-β1,TNF-α,and S-100β were observed in both groups at 24 h after surgery,with lower levels in the TPVB group than in the control group(P<0.05).CONCLUSION TPVB combined with SUF-based multimodal analgesia further relieves pain in patients undergoing thoracoscopic radical surgery for LC,enhances analgesic effects,reduces postoperative stress response,and inhibits postoperative increases in serum VEGF,TGF-β1,TNF-α,and S-100β levels.This scheme also reduced POCD and had a high safety profile.展开更多
Aortic dissection is the deadliest disease of the cardiovascular system.Type B aortic dissection accounts for 30%-60%of aortic dissections and is mainly treated by endovascular repair of thoracic endovascular aneurysm...Aortic dissection is the deadliest disease of the cardiovascular system.Type B aortic dissection accounts for 30%-60%of aortic dissections and is mainly treated by endovascular repair of thoracic endovascular aneurysm repair(TEVAR).However,patients are prone to various complications after surgery,with central nervous system injury being the most common,which seriously affects their prognosis and increases the risk of disability and death.Therefore,exploring the risk factors of central nervous system injury after TEVAR can provide a basis for its prevention and control.AIM To investigate the risk factors for central nervous system injury after the repair of a thoracic endovascular aneurysm with type B aortic dissection.METHODS We enrolled 306 patients with type B aortic dissection who underwent TEVAR at our hospital between December 2019 and October 2022.The patients were categorized into injury(n=159)and non-injury(n=147)groups based on central nervous system injury following surgery.The risk factors for central nervous system injury after TEVAR for type B aortic dissection were screened by comparing the two groups.Multivariate logistic regression analysis was performed.RESULTS The Association between age,history of hypertension,blood pH value,surgery,mechanical ventilation,intensive care unit stay,postoperative recovery times on the first day after surgery,and arterial partial pressure of oxygen on the first day after surgery differed substantially(P<0.05).Multivariate logistic regression analysis indicated that age,surgery time,history of hypertension,duration of mechanical ventilation,and intensive care unit stay were independent risk factors for central nervous system injury after TEVAR of type B aortic dissection(P<0.05).CONCLUSION For high-risk patients with central nervous system injury after TEVAR of type B aortic dissection,early intervention measures should be implemented to lower the risk of neurological discomfort following surgery in high-risk patients with central nervous system injury after TEVAR for type B aortic dissection.展开更多
Directional solidification of Al-15% (mass fraction) Cu alloy was investigated by in situ and real time radiography which was performed by Shanghai synchrotron radiation facility (SSRF). The imaging results reveal...Directional solidification of Al-15% (mass fraction) Cu alloy was investigated by in situ and real time radiography which was performed by Shanghai synchrotron radiation facility (SSRF). The imaging results reveal that columnar to equiaxed transition (CET) is provoked by external thermal disturbance. The detaching and floating of fragments of dendrite arms are the prelude of the transition when the solute boundary layer in front of the solid-liquid interface is thin. And the dendrite triangular tip is the fracture sensitive zone. When the conditions are suitable, new dendrites can sprout and grow up. This kind of dendrite has no obvious stem and is named anaxial columnar dendrites.展开更多
BACKGROUND Immune checkpoint inhibitors(ICIs)are therapeutic agents for advanced and metastatic non-small cell lung cancer(NSCLC)with high clinical antitumor efficacy.However,immune-related adverse events occur in 20%...BACKGROUND Immune checkpoint inhibitors(ICIs)are therapeutic agents for advanced and metastatic non-small cell lung cancer(NSCLC)with high clinical antitumor efficacy.However,immune-related adverse events occur in 20%of these patients and often requiring treatment with immunosuppressive agents,such as corticosteroids.Consequently,this may increase the risk of patients to opportunistic infections.Pneumocystis jirovecii pneumonia(PJP),a rare but serious opportunistic infection typically observed in patients with human immunodeficiency virus,can also occur in cancer patients undergoing long-term glucocorticoid treatment.CASE SUMMARY We report a case of a 56-year-old male with squamous NSCLC treated with triplimab combined with paclitaxel,carboplatin,and radical thoracic radiation therapy.Following this regimen,he developed acute kidney injury(AKI)with elevated creatinine levels.After concurrent radical chemoradiotherapy ended,he developed a grade 3 immune-related AKI.High-dose corticosteroids were administered to treat AKI,and renal function gradually recovered.Corticosteroids were reduced to a dose of 10 mg prednisone equivalent daily eight weeks later;however,he developed severe pneumonia with spontaneous pneumothorax.Next-generation sequencing of the bronchoscopic lavage revealed PJP co-infection with herpes simplex virus 1 and cytomegalovirus.The inflammation was more severe in areas exposed to radiation.Piperacillin-tazobactam,acyclovir,sulfamethoxazole,and trimethoprim were used to control the infection.The patient recovered,and immunotherapy was terminated.CONCLUSION PJP is rare but can occur in patients with ICI adverse events and should be differentiated from tumor progression or immune-related adverse events.Thoracic radiation may increase risk,necessitating careful monitoring and prevention.展开更多
Thoracic diseases pose significant risks to an individual's chest health and are among the most perilous medical diseases. They can impact either one or both lungs, which leads to a severe impairment of a person’...Thoracic diseases pose significant risks to an individual's chest health and are among the most perilous medical diseases. They can impact either one or both lungs, which leads to a severe impairment of a person’s ability to breathe normally. Some notable examples of such diseases encompass pneumonia, lung cancer, coronavirus disease 2019 (COVID-19), tuberculosis, and chronic obstructive pulmonary disease (COPD). Consequently, early and precise detection of these diseases is paramount during the diagnostic process. Traditionally, the primary methods employed for the detection involve the use of X-ray imaging or computed tomography (CT) scans. Nevertheless, due to the scarcity of proficient radiologists and the inherent similarities between these diseases, the accuracy of detection can be compromised, leading to imprecise or erroneous results. To address this challenge, scientists have turned to computer-based solutions, aiming for swift and accurate diagnoses. The primary objective of this study is to develop two machine learning models, utilizing single-task and multi-task learning frameworks, to enhance classification accuracy. Within the multi-task learning architecture, two principal approaches exist soft parameter sharing and hard parameter sharing. Consequently, this research adopts a multi-task deep learning approach that leverages CNNs to achieve improved classification performance for the specified tasks. These tasks, focusing on pneumonia and COVID-19, are processed and learned simultaneously within a multi-task model. To assess the effectiveness of the trained model, it is rigorously validated using three different real-world datasets for training and testing.展开更多
Thoracic epidural anesthesia(TEA)has been the gold standard of perioperative analgesia in various abdominal and thoracic surgeries.However,misplaced or displaced catheters,along with other factors such as technical ch...Thoracic epidural anesthesia(TEA)has been the gold standard of perioperative analgesia in various abdominal and thoracic surgeries.However,misplaced or displaced catheters,along with other factors such as technical challenges,equipment failure,and anatomic variation,lead to a high incidence of unsatisfactory analgesia.This article aims to assess the different sources of TEA failure and strategies to validate the location of thoracic epidural catheters.A literature search of PubMed,Medline,Science Direct,and Google Scholar was done.The search results were limited to randomized controlled trials.Literature suggests techniques such as electrophysiological stimulation,epidural waveform monitoring,and x-ray epidurography for identifying thoracic epidural placement,but there is no one particular superior confirmation method;clinicians are advised to select techniques that are practical and suitable for their patients and practice environment to maximize success.展开更多
Objective:This study aims to investigate the impact of combining general anesthesia with bronchial intubation and thoracic paravertebral nerve block during surgery for patients with tuberculous pyothorax.Methods:Eight...Objective:This study aims to investigate the impact of combining general anesthesia with bronchial intubation and thoracic paravertebral nerve block during surgery for patients with tuberculous pyothorax.Methods:Eighty patients diagnosed with tuberculous pyothorax,admitted to the hospital between January 2023 and September 2023,were randomly selected for this study.The patients were divided into control and study groups using a numerical table method.The control group underwent general anesthesia with bronchial intubation,while the study group received general anesthesia with bronchial intubation in conjunction with thoracic paravertebral nerve block.Subsequently,the patients were monitored to assess mean arterial pressure,heart rate variations,and adverse reactions to anesthesia.Results:The study group exhibited significantly lower mean arterial pressure and heart rate levels during the post-surgical incision,immediate end of surgery,and immediate extubation periods compared to the control group(P<0.05).Furthermore,the Ricker and Ramsay scores in the study group were significantly lower than those in the control group(P<0.05).Conclusion:The combined use of general anesthesia via bronchial intubation and thoracic paravertebral nerve block has been found to stabilize mean arterial pressure and heart rate while providing effective sedation for surgical treatment in patients with tuberculous septic thorax.展开更多
An OPG (orthopantmography) is an extra-oral radiographic imaging method which provides a panoramic or wide view of both jaws and teeth on a single image. Digital OPG images provide high contrast with more details o...An OPG (orthopantmography) is an extra-oral radiographic imaging method which provides a panoramic or wide view of both jaws and teeth on a single image. Digital OPG images provide high contrast with more details of the dentitions. The research main objective was to produce sophisticated and effective criteria that can be used by any radiographer with sound knowledge to identify common errors of digital OPG images and to increase the concern of high frequency of errors to minimize them to give an optimum image quality. The study was designed as retrospective cross sectional study. Hundred digital OPG images are evaluated by three qualified radiographers who had dental radiography experience and four student radiographers. Paired t-test was used to see the difference between the responses of radiographers and student radiographers. Kruskal-Wallis Test was used to see difference between each evaluator. Possible errors of OPG were divided into four main categories (identification, artifact, anatomical coverage and patient positioning). Each main category consists of sub-categories. Values of subcategories were given according to their importance to get the total of 100% for each main category. The results showed that there is no significant difference between radiographers and student radiographers’ responses and also between each evaluator. Hence it shows that the criteria were an easy understandable and user-friendly tool. And results showed the frequent error category was loss of anatomical coverage and frequent error was absence of positioning the tongue against the palate.展开更多
Routine chest radiography is not a requirement in post-surgery cardiac bypass patients.However,the safety of abandoning routine chest radiographs in critically ill patients remains uncertain.Surgery in an asymptomatic...Routine chest radiography is not a requirement in post-surgery cardiac bypass patients.However,the safety of abandoning routine chest radiographs in critically ill patients remains uncertain.Surgery in an asymptomatic coronavirus disease 2019(COVID-19)patient presents additional challenges in postoperative management.Chest radiography remains a valuable tool for assessment of all patients,even a stable one.Management of surgical patients as an emergency in an asymptomatic COVID-19 case remains a surgeon’s dilemma.展开更多
AIM: To compare the reported injuries on initial assessment of the chest X-ray (CXR) in thoracic trauma patients to a second read performed by a dedicated trauma radiologist. METHODS: By retrospective analysis of a pr...AIM: To compare the reported injuries on initial assessment of the chest X-ray (CXR) in thoracic trauma patients to a second read performed by a dedicated trauma radiologist. METHODS: By retrospective analysis of a prospective database, 712 patients with an injury to the chest admitted to the University Medical Center Utrecht were studied. All patients with a CXR were included in the study. Every CXR was re-evaluated by a trauma radiologist, who was blinded for the initial results. The findings of the trauma radiologist regarding rib fractures, pneumothoraces, hemothoraces and lung contusions were compared with the initial reports from the trauma team, derived from the original patient files. RESULTS: A total of 516 patients with both thorax trauma and an initial CXR were included in the study. After re-evaluation of the initial CXR significantly more lung contusions (53.3% vs 34.1%, P < 0.001), hemothoraces (17.8% vs 11.0%, P < 0.001) and pneumothoraces (34.4% vs 26.4%, P < 0.001) were detected.During initial assessment significantly more rib fractures were reported (69.8% vs 62.3%, P < 0.001). CONCLUSION: During the initial assessment of a CXR from trauma patients in the emergency department, a significant number of treatment-dictating injuries are missed. More awareness for these specific injuries is needed.展开更多
Fast neutron radiography(FNR) is an effective non-destructive testing technique.Due to the scattering effect and low detection efficiency,the detection limit of FNR under certain conditions cannot be determined.In ord...Fast neutron radiography(FNR) is an effective non-destructive testing technique.Due to the scattering effect and low detection efficiency,the detection limit of FNR under certain conditions cannot be determined.In order to obtain the minimum detectable thickness by FNR,we studied the contrast sensitivity of FNR lead samples,both theoretically and experimentally.We then clarified the relationship between pixel value and irradiation time,and sample materials and thickness.Our experiment,using a4-cm-thick lead sample,verified our theoretical expression of FNR contrast sensitivity.展开更多
Video-assisted thoracic surgery (VATS) has developed very rapidly in these two decades, and has replaced conven-tional open thoracotomy as a standard procedure for some simple thoracic operations as well as an option ...Video-assisted thoracic surgery (VATS) has developed very rapidly in these two decades, and has replaced conven-tional open thoracotomy as a standard procedure for some simple thoracic operations as well as an option or a complementary procedure for some other more complex operations. In this paper we will review its development history, the present status and the future perspectives.展开更多
AIM: To determine the diagnostic accuracy and radiation dose of conventional radiography and multidetector computed tomography(MDCT) in suspected scaphoid fractures.METHODS: One hundred twenty-four consecutive patient...AIM: To determine the diagnostic accuracy and radiation dose of conventional radiography and multidetector computed tomography(MDCT) in suspected scaphoid fractures.METHODS: One hundred twenty-four consecutive patients were enrolled in our study who had suffered from a wrist trauma and showed typical clinical symptoms suspicious of an acute scaphoid fracture. All patients had initially undergone conventional radiography. Subsequent MDCT was performed within 10 d because of persisting clinical symptoms. Using the MDCT data as the reference standard, a fourfold table was used to classify the test results. The effective dose and impaired energy were assessed in order to compare the radiation burden of the two techniques. The Wilcoxon test was performed to compare the two diagnostic modalities.RESULTS: Conventional radiography showed 34 acute fractures of the scaphoid in 124 patients(42.2%). Subsequent MDCT revealed a total of 42 scaphoid fractures. The sensitivity of conventional radiography for scaphoid fracture detection was 42.8% and its specificity was 80% resulting in an overall accuracy of 59.6%. Conventional radiography was significantly inferior to MDCT(P < 0.01) concerning scaphoidfracture detection. The mean effective dose of MDCT was 0.1 m Sv compared to 0.002 m Sv of conventional radiography.CONCLUSION: Conventional radiography is insufficient for accurate scaphoid fracture detection. Regarding the almost negligible effective dose, MDCT should serve as the first imaging modality in wrist trauma.展开更多
Owing to the immobility of traditional reactors and spallation neutron sources,the demand for compact thermal neutron radiography(CTNR)based on accelerator neutron sources has rapidly increased in industrial applicati...Owing to the immobility of traditional reactors and spallation neutron sources,the demand for compact thermal neutron radiography(CTNR)based on accelerator neutron sources has rapidly increased in industrial applications.Recently,thermal neutron radiography experiments based on a D-T neutron generator performed by Hefei Institutes of Physical Science indicated a significant resolution deviation between the experimental results and the values calculated using the traditional resolution model.The experimental result was up to 23%lower than the calculated result,which hinders the achievement of the design goal of a compact neutron radiography system.A GEANT4 Monte Carlo code was developed to simulate the CTNR process,aiming to identify the key factors leading to resolution deviation.The effects of a low collimation ratio and high-energy neutrons were analyzed based on the neutron beam environment of the CTNR system.The results showed that the deviation was primarily caused by geometric distortion at low collimation ratios and radiation noise induced by highenergy neutrons.Additionally,the theoretical model was modified by considering the imaging position and radiation noise factors.The modified theoretical model was in good agreement with the experimental results,and the maximum deviation was reduced to 4.22%.This can be useful for the high-precision design of CTNR systems.展开更多
Objective To analyze the influence of segmental pedicle screws versus hybrid instrumentation on the correction results in adolescent idiopathic scoliosis patients undergoing posterior selective thoracic fusion. Metho...Objective To analyze the influence of segmental pedicle screws versus hybrid instrumentation on the correction results in adolescent idiopathic scoliosis patients undergoing posterior selective thoracic fusion. Methods By reviewing the medical records and roentgenograms of adolescent idiopathic scoliosis patients who underwent selective thoracic fusion from February 2000 to January 2007 in our hospital, the patients were divided into 2 groups according to different instrumentation fashions: Group A was hook-screw-rod (hybrid) internal fixation type, Group B was screw-rod (all pedicle screws) internal fixation type, and the screws were used in every segment on the concave side of the thoracic curve. The parameters of the scoliosis were measured and the correction results were analyzed. Results Totally, 48 patients (7 males, 41 females) were included, with an average age of 14.4 years old and a mean follow-up time of 12.3 months. Thirty and 18 patients were assigned to group A and group B, respectively. The mean preoperative coronal Cobb angles of the thoracic curve were 48.8° and 47.4°, respectively. After surgery, they were corrected to 13.7° and 6.8°, respectively. At final follow-up, they were 17.0° and 9.5°, with an average correction rate of 64.6% and 79.0%, respectively, and the correction rate of group B was significantly higher than that of group A (P=0.003). The mean preoperative coronal Cobb angles of the lumbar curve were 32.6° and 35.2°, respectively. After surgery, they were corrected to 8.6° and 8.3°, respectively. At final follow-up, they were 10.3° and 11.1°, with an average correction rate of 66.8% and 69.9%, respectively, and the correction rate of group B was significantly higher than that of group A (P=0.003). The correction loss of the thoracic curve and lumbar curve in the 2 groups were 3.1° and 1.8°, 2.4° and 2.4°, respectively. No significant difference was noted (both P〉0.05). The decompensation rate at final follow-up in these 2 groups were 4% (1/25) and 7.1% (1/14) respectively, with no significant difference (P〉0.05).展开更多
The results of the previous studies seem to show the crustaceans can secrete growth hormone,which regulate their growth.However,more evidences are needed to determine it.So the following research was conducted.The ext...The results of the previous studies seem to show the crustaceans can secrete growth hormone,which regulate their growth.However,more evidences are needed to determine it.So the following research was conducted.The extract of thoracic ganglia (TGE) of adult Macrobrachium rosenbergii was applied to a Sephadex G-50 column,the resulting second peak was further isolated by HPLC,and 9 fractions were obtained.Among the fractions only the second fraction significantly increased the protein synthesis of the abdomen muscle of the juvenile M.rosenbergii that was injected TGE.The increasing effects were related to the protein concentration of the injecting fractions.The molecular weight of the substance in the second fraction isolated by HPLC was below 3.4?kDa.The results indicate that the thoracic ganglia of M.rosenbergii could secrete a peptide hormone,which stimulates the muscle protein synthesis of prawn,and the hormone might be the growth hormone of the prawn.展开更多
基金Supported by National Nature Sciences Foundation of China,No.30970820 and 30870688Science Foundation for Distinguished Young Scholars of Sichuan Province,No. 2010JQ0039
文摘AIM:To investigate the features of crush thoracic trauma in Sichuan earthquake victims using chest digital radiography(CDR).METHODS:We retrospectively reviewed 772 CDR of 417 females and 355 males who had suffered crush thoracic trauma in the Sichuan earthquake.Patient age ranged from 0.5 to 103 years.CDR was performed between May 12,2008 and June 7,2008.We looked for injury to the thoracic cage,pulmonary parenchyma and the pleura.obtained in 349 patients,the remaining 423 patients underwent only AP CDR.Thoracic cage fractures,pulmonary contusion and pleural injuries were noted in 331(42.9%;95% CI:39.4%-46.4%),67 and 135 patients,respectively.Of the 256 patients with rib fractures,the mean number of fractured ribs per patient was 3.Rib fractures were mostly distributed from the 3rd through to the 8th ribs and the vast majority involved posterior and lateral locations along the rib.Rib fractures had a significant positive association with non-rib thoracic fractures,pulmonary contusion and pleural injuries(P < 0.001).The number of rib fractures and pulmonary contusions were significant factors associated with patient death.CONCLUSION:Earthquake-related crush thoracic trauma has the potential for multiple fractures.The high number of fractured ribs and pulmonary contusions were significant factors which needed appropriate medical treatment.
文摘Hydrostatic pulmonary edema is as an abnormal in-crease in extravascular water secondary to elevatedpressure in the pulmonary circulation, due to conges-tive heart failure or intravascular volume overload.Diagnosis of hydrostatic pulmonary edema is usuallybased on clinical signs associated to conventional ra-diography findings. Interpretation of radiologic signsof cardiogenic pulmonary edema are often question-able and subject. For a bedside prompt evaluation,lung ultrasound(LUS) may assess pulmonary conges-tion through the evaluation of vertical reverberationartifacts, known as B-lines. These artifacts are relatedto multiple minimal acoustic interfaces between smallwater-rich structures and alveolar air, as it happens incase of thickened interlobular septa due to increase of extravascular lung water. The number, diffusion and in-tensity of B lines correlates with both the radiologic andinvasive estimate of extravascular lung water. The inte-gration of conventional chest radiograph with LUS canbe very helpful to obtain the correct diagnosis. Com-puted tomography(CT) is of limited use in the work upof cardiogenic pulmonary edema, due to its high cost,little use in the emergencies and radiation exposure.However, a deep knowledge of CT signs of pulmonaryedema is crucial when other similar pulmonary condi-tions may occasionally be in the differential diagnosis.
基金Supported by the Scientific Research Foundation of Peking University Shenzhen Hospital,No.KYQD2021096the National Natural Science Foundation of China,No.81972829Precision Medicine Research Program of Tsinghua University,No.2022ZLA006.
文摘BACKGROUND This study was designed to investigate the clinical outcomes of enhanced recovery after surgery(ERAS)in the perioperative period in elderly patients with nonsmall cell lung cancer(NSCLC).AIM To investigate the potential enhancement of video-assisted thoracic surgery(VATS)in postoperative recovery in elderly patients with NSCLC.METHODS We retrospectively analysed the clinical data of 85 elderly NSCLC patients who underwent ERAS(the ERAS group)and 327 elderly NSCLC patients who received routine care(the control group)after VATS at the Department of Thoracic Surgery of Peking University Shenzhen Hospital between May 2015 and April 2017.After propensity score matching of baseline data,we analysed the postoperative stay,total hospital expenses,postoperative 48-h pain score,and postoperative complication rate for the 2 groups of patients who underwent lobectomy or sublobar resection.RESULTS After propensity score matching,ERAS significantly reduced the postoperative hospital stay(6.96±4.16 vs 8.48±4.18 d,P=0.001)and total hospital expenses(48875.27±18437.5 vs 55497.64±21168.63 CNY,P=0.014)and improved the satisfaction score(79.8±7.55 vs 77.35±7.72,P=0.029)relative to those for routine care.No significant between-group difference was observed in postoperative 48-h pain score(4.68±1.69 vs 5.28±2.1,P=0.090)or postoperative complication rate(21.2%vs 27.1%,P=0.371).Subgroup analysis showed that ERAS significantly reduced the postoperative hospital stay and total hospital expenses and increased the satisfaction score of patients who underwent lobectomy but not of patients who underwent sublobar resection.CONCLUSION ERAS effectively reduced the postoperative hospital stay and total hospital expenses and improved the satisfaction score in the perioperative period for elderly NSCLC patients who underwent lobectomy but not for patients who underwent sublobar resection.
文摘Research has shown that chest radiography images of patients with different diseases, such as pneumonia, COVID-19, SARS, pneumothorax, etc., all exhibit some form of abnormality. Several deep learning techniques can be used to identify each of these anomalies in the chest x-ray images. Convolutional neural networks (CNNs) have shown great success in the fields of image recognition and image classification since there are numerous large-scale annotated image datasets available. The classification of medical images, particularly radiographic images, remains one of the biggest hurdles in medical diagnosis because of the restricted availability of annotated medical images. However, such difficulty can be solved by utilizing several deep learning strategies, including data augmentation and transfer learning. The aim was to build a model that would detect abnormalities in chest x-ray images with the highest probability. To do that, different models were built with different features. While making a CNN model, one of the main tasks is to tune the model by changing the hyperparameters and layers so that the model gives out good training and testing results. In our case, three different models were built, and finally, the last one gave out the best-predicted results. From that last model, we got 98% training accuracy, 84% validation, and 81% testing accuracy. The reason behind the final model giving out the best evaluation scores is that it was a well-fitted model. There was no overfitting or underfitting issues. Our aim with this project was to make a tool using the CNN model in R language, which will help detect abnormalities in radiography images. The tool will be able to detect diseases such as Pneumonia, Covid-19, Effusions, Infiltration, Pneumothorax, and others. Because of its high accuracy, this research chose to use supervised multi-class classification techniques as well as Convolutional Neural Networks (CNNs) to classify different chest x-ray images. CNNs are extremely efficient and successful at reducing the number of parameters while maintaining the quality of the primary model. CNNs are also trained to recognize the edges of various objects in any batch of images. CNNs automatically discover the relevant aspects in labeled data and learn the distinguishing features for each class by themselves.
文摘BACKGROUND Postoperative pain management and cognitive function preservation are crucial for patients undergoing thoracoscopic surgery for lung cancer(LC).This is achieved using either a thoracic paravertebral block(TPVB)or sufentanil(SUF)-based multimodal analgesia.However,the efficacy and impact of their combined use on postoperative pain and postoperative cognitive dysfunction(POCD)remain unclear.AIM To explore the analgesic effect and the influence on POCD of TPVB combined with SUF-based multimodal analgesia in patients undergoing thoracoscopic radical resection for LC to help optimize postoperative pain management and improve patient outcomes.METHODS This retrospective analysis included 107 patients undergoing thoracoscopic radical resection for LC at The Affiliated Cancer Hospital of Zhengzhou University and Henan Cancer Hospital between May 2021 and January 2023.Patients receiving SUF-based multimodal analgesia(n=50)and patients receiving TPVB+SUF-based multimodal analgesia(n=57)were assigned to the control group and TPVB group,respectively.We compared the Ramsay Sedation Scale and visual analog scale(VAS)scores at rest and with cough between the two groups at 2,12,and 24 h after surgery.Serum levels of epinephrine(E),angio-tensin Ⅱ(Ang Ⅱ),norepinephrine(NE),superoxide dismutase(SOD),vascular endothelial growth factor(VEGF),transforming growth factor-β1(TGF-β1),tumor necrosis factor-α(TNF-α),and S-100 calcium-binding proteinβ(S-100β)were measured before and 24 h after surgery.The Mini-Mental State Examination(MMSE)was administered 1 day before surgery and at 3 and 5 days after surgery,and the occurrence of POCD was monitored for 5 days after surgery.Adverse reactions were also recorded.RESULTS There were no significant time point,between-group,and interaction effects in Ramsay sedation scores between the two groups(P>0.05).Significantly,there were notable time point effects,between-group differences,and interaction effects observed in VAS scores both at rest and with cough(P<0.05).The VAS scores at rest and with cough at 12 and 24 h after surgery were lower than those at 2 h after surgery and gradually decreased as postoperative time increased(P<0.05).The TPVB group had lower VAS scores than the control group at 2,12,and 24 h after surgery(P<0.05).The MMSE scores at postoperative days 1 and 3 were markedly higher in the TPVB group than in the control group(P<0.05).The incidence of POCD was significantly lower in the TPVB group than in the control group within 5 days after surgery(P<0.05).Both groups had elevated serum E,Ang Ⅱ,and NE and decreased serum SOD levels at 24 h after surgery compared with the preoperative levels,with better indices in the TPVB group(P<0.05).Marked elevations in serum levels of VEGF,TGF-β1,TNF-α,and S-100β were observed in both groups at 24 h after surgery,with lower levels in the TPVB group than in the control group(P<0.05).CONCLUSION TPVB combined with SUF-based multimodal analgesia further relieves pain in patients undergoing thoracoscopic radical surgery for LC,enhances analgesic effects,reduces postoperative stress response,and inhibits postoperative increases in serum VEGF,TGF-β1,TNF-α,and S-100β levels.This scheme also reduced POCD and had a high safety profile.
文摘Aortic dissection is the deadliest disease of the cardiovascular system.Type B aortic dissection accounts for 30%-60%of aortic dissections and is mainly treated by endovascular repair of thoracic endovascular aneurysm repair(TEVAR).However,patients are prone to various complications after surgery,with central nervous system injury being the most common,which seriously affects their prognosis and increases the risk of disability and death.Therefore,exploring the risk factors of central nervous system injury after TEVAR can provide a basis for its prevention and control.AIM To investigate the risk factors for central nervous system injury after the repair of a thoracic endovascular aneurysm with type B aortic dissection.METHODS We enrolled 306 patients with type B aortic dissection who underwent TEVAR at our hospital between December 2019 and October 2022.The patients were categorized into injury(n=159)and non-injury(n=147)groups based on central nervous system injury following surgery.The risk factors for central nervous system injury after TEVAR for type B aortic dissection were screened by comparing the two groups.Multivariate logistic regression analysis was performed.RESULTS The Association between age,history of hypertension,blood pH value,surgery,mechanical ventilation,intensive care unit stay,postoperative recovery times on the first day after surgery,and arterial partial pressure of oxygen on the first day after surgery differed substantially(P<0.05).Multivariate logistic regression analysis indicated that age,surgery time,history of hypertension,duration of mechanical ventilation,and intensive care unit stay were independent risk factors for central nervous system injury after TEVAR of type B aortic dissection(P<0.05).CONCLUSION For high-risk patients with central nervous system injury after TEVAR of type B aortic dissection,early intervention measures should be implemented to lower the risk of neurological discomfort following surgery in high-risk patients with central nervous system injury after TEVAR for type B aortic dissection.
基金Project(51001074)supported by the National Natural Science Foundation of ChinaProject(12ZR1414500)supported by Shanghai Municipal Natural Science Fund of ChinaProject(2012CB619505)supported by the National Basic Research Program of China
文摘Directional solidification of Al-15% (mass fraction) Cu alloy was investigated by in situ and real time radiography which was performed by Shanghai synchrotron radiation facility (SSRF). The imaging results reveal that columnar to equiaxed transition (CET) is provoked by external thermal disturbance. The detaching and floating of fragments of dendrite arms are the prelude of the transition when the solute boundary layer in front of the solid-liquid interface is thin. And the dendrite triangular tip is the fracture sensitive zone. When the conditions are suitable, new dendrites can sprout and grow up. This kind of dendrite has no obvious stem and is named anaxial columnar dendrites.
基金Supported by Shandong Natural Science Foundation,No.ZR2021QH034China Postdoctoral Science Foundation,No.2023M731305.
文摘BACKGROUND Immune checkpoint inhibitors(ICIs)are therapeutic agents for advanced and metastatic non-small cell lung cancer(NSCLC)with high clinical antitumor efficacy.However,immune-related adverse events occur in 20%of these patients and often requiring treatment with immunosuppressive agents,such as corticosteroids.Consequently,this may increase the risk of patients to opportunistic infections.Pneumocystis jirovecii pneumonia(PJP),a rare but serious opportunistic infection typically observed in patients with human immunodeficiency virus,can also occur in cancer patients undergoing long-term glucocorticoid treatment.CASE SUMMARY We report a case of a 56-year-old male with squamous NSCLC treated with triplimab combined with paclitaxel,carboplatin,and radical thoracic radiation therapy.Following this regimen,he developed acute kidney injury(AKI)with elevated creatinine levels.After concurrent radical chemoradiotherapy ended,he developed a grade 3 immune-related AKI.High-dose corticosteroids were administered to treat AKI,and renal function gradually recovered.Corticosteroids were reduced to a dose of 10 mg prednisone equivalent daily eight weeks later;however,he developed severe pneumonia with spontaneous pneumothorax.Next-generation sequencing of the bronchoscopic lavage revealed PJP co-infection with herpes simplex virus 1 and cytomegalovirus.The inflammation was more severe in areas exposed to radiation.Piperacillin-tazobactam,acyclovir,sulfamethoxazole,and trimethoprim were used to control the infection.The patient recovered,and immunotherapy was terminated.CONCLUSION PJP is rare but can occur in patients with ICI adverse events and should be differentiated from tumor progression or immune-related adverse events.Thoracic radiation may increase risk,necessitating careful monitoring and prevention.
文摘Thoracic diseases pose significant risks to an individual's chest health and are among the most perilous medical diseases. They can impact either one or both lungs, which leads to a severe impairment of a person’s ability to breathe normally. Some notable examples of such diseases encompass pneumonia, lung cancer, coronavirus disease 2019 (COVID-19), tuberculosis, and chronic obstructive pulmonary disease (COPD). Consequently, early and precise detection of these diseases is paramount during the diagnostic process. Traditionally, the primary methods employed for the detection involve the use of X-ray imaging or computed tomography (CT) scans. Nevertheless, due to the scarcity of proficient radiologists and the inherent similarities between these diseases, the accuracy of detection can be compromised, leading to imprecise or erroneous results. To address this challenge, scientists have turned to computer-based solutions, aiming for swift and accurate diagnoses. The primary objective of this study is to develop two machine learning models, utilizing single-task and multi-task learning frameworks, to enhance classification accuracy. Within the multi-task learning architecture, two principal approaches exist soft parameter sharing and hard parameter sharing. Consequently, this research adopts a multi-task deep learning approach that leverages CNNs to achieve improved classification performance for the specified tasks. These tasks, focusing on pneumonia and COVID-19, are processed and learned simultaneously within a multi-task model. To assess the effectiveness of the trained model, it is rigorously validated using three different real-world datasets for training and testing.
文摘Thoracic epidural anesthesia(TEA)has been the gold standard of perioperative analgesia in various abdominal and thoracic surgeries.However,misplaced or displaced catheters,along with other factors such as technical challenges,equipment failure,and anatomic variation,lead to a high incidence of unsatisfactory analgesia.This article aims to assess the different sources of TEA failure and strategies to validate the location of thoracic epidural catheters.A literature search of PubMed,Medline,Science Direct,and Google Scholar was done.The search results were limited to randomized controlled trials.Literature suggests techniques such as electrophysiological stimulation,epidural waveform monitoring,and x-ray epidurography for identifying thoracic epidural placement,but there is no one particular superior confirmation method;clinicians are advised to select techniques that are practical and suitable for their patients and practice environment to maximize success.
基金Research Project of the Xi’an Municipal Health Commission(No.2023yb40,Project leader:Duan Chunyu)。
文摘Objective:This study aims to investigate the impact of combining general anesthesia with bronchial intubation and thoracic paravertebral nerve block during surgery for patients with tuberculous pyothorax.Methods:Eighty patients diagnosed with tuberculous pyothorax,admitted to the hospital between January 2023 and September 2023,were randomly selected for this study.The patients were divided into control and study groups using a numerical table method.The control group underwent general anesthesia with bronchial intubation,while the study group received general anesthesia with bronchial intubation in conjunction with thoracic paravertebral nerve block.Subsequently,the patients were monitored to assess mean arterial pressure,heart rate variations,and adverse reactions to anesthesia.Results:The study group exhibited significantly lower mean arterial pressure and heart rate levels during the post-surgical incision,immediate end of surgery,and immediate extubation periods compared to the control group(P<0.05).Furthermore,the Ricker and Ramsay scores in the study group were significantly lower than those in the control group(P<0.05).Conclusion:The combined use of general anesthesia via bronchial intubation and thoracic paravertebral nerve block has been found to stabilize mean arterial pressure and heart rate while providing effective sedation for surgical treatment in patients with tuberculous septic thorax.
文摘An OPG (orthopantmography) is an extra-oral radiographic imaging method which provides a panoramic or wide view of both jaws and teeth on a single image. Digital OPG images provide high contrast with more details of the dentitions. The research main objective was to produce sophisticated and effective criteria that can be used by any radiographer with sound knowledge to identify common errors of digital OPG images and to increase the concern of high frequency of errors to minimize them to give an optimum image quality. The study was designed as retrospective cross sectional study. Hundred digital OPG images are evaluated by three qualified radiographers who had dental radiography experience and four student radiographers. Paired t-test was used to see the difference between the responses of radiographers and student radiographers. Kruskal-Wallis Test was used to see difference between each evaluator. Possible errors of OPG were divided into four main categories (identification, artifact, anatomical coverage and patient positioning). Each main category consists of sub-categories. Values of subcategories were given according to their importance to get the total of 100% for each main category. The results showed that there is no significant difference between radiographers and student radiographers’ responses and also between each evaluator. Hence it shows that the criteria were an easy understandable and user-friendly tool. And results showed the frequent error category was loss of anatomical coverage and frequent error was absence of positioning the tongue against the palate.
文摘Routine chest radiography is not a requirement in post-surgery cardiac bypass patients.However,the safety of abandoning routine chest radiographs in critically ill patients remains uncertain.Surgery in an asymptomatic coronavirus disease 2019(COVID-19)patient presents additional challenges in postoperative management.Chest radiography remains a valuable tool for assessment of all patients,even a stable one.Management of surgical patients as an emergency in an asymptomatic COVID-19 case remains a surgeon’s dilemma.
文摘AIM: To compare the reported injuries on initial assessment of the chest X-ray (CXR) in thoracic trauma patients to a second read performed by a dedicated trauma radiologist. METHODS: By retrospective analysis of a prospective database, 712 patients with an injury to the chest admitted to the University Medical Center Utrecht were studied. All patients with a CXR were included in the study. Every CXR was re-evaluated by a trauma radiologist, who was blinded for the initial results. The findings of the trauma radiologist regarding rib fractures, pneumothoraces, hemothoraces and lung contusions were compared with the initial reports from the trauma team, derived from the original patient files. RESULTS: A total of 516 patients with both thorax trauma and an initial CXR were included in the study. After re-evaluation of the initial CXR significantly more lung contusions (53.3% vs 34.1%, P < 0.001), hemothoraces (17.8% vs 11.0%, P < 0.001) and pneumothoraces (34.4% vs 26.4%, P < 0.001) were detected.During initial assessment significantly more rib fractures were reported (69.8% vs 62.3%, P < 0.001). CONCLUSION: During the initial assessment of a CXR from trauma patients in the emergency department, a significant number of treatment-dictating injuries are missed. More awareness for these specific injuries is needed.
文摘Fast neutron radiography(FNR) is an effective non-destructive testing technique.Due to the scattering effect and low detection efficiency,the detection limit of FNR under certain conditions cannot be determined.In order to obtain the minimum detectable thickness by FNR,we studied the contrast sensitivity of FNR lead samples,both theoretically and experimentally.We then clarified the relationship between pixel value and irradiation time,and sample materials and thickness.Our experiment,using a4-cm-thick lead sample,verified our theoretical expression of FNR contrast sensitivity.
文摘Video-assisted thoracic surgery (VATS) has developed very rapidly in these two decades, and has replaced conven-tional open thoracotomy as a standard procedure for some simple thoracic operations as well as an option or a complementary procedure for some other more complex operations. In this paper we will review its development history, the present status and the future perspectives.
文摘AIM: To determine the diagnostic accuracy and radiation dose of conventional radiography and multidetector computed tomography(MDCT) in suspected scaphoid fractures.METHODS: One hundred twenty-four consecutive patients were enrolled in our study who had suffered from a wrist trauma and showed typical clinical symptoms suspicious of an acute scaphoid fracture. All patients had initially undergone conventional radiography. Subsequent MDCT was performed within 10 d because of persisting clinical symptoms. Using the MDCT data as the reference standard, a fourfold table was used to classify the test results. The effective dose and impaired energy were assessed in order to compare the radiation burden of the two techniques. The Wilcoxon test was performed to compare the two diagnostic modalities.RESULTS: Conventional radiography showed 34 acute fractures of the scaphoid in 124 patients(42.2%). Subsequent MDCT revealed a total of 42 scaphoid fractures. The sensitivity of conventional radiography for scaphoid fracture detection was 42.8% and its specificity was 80% resulting in an overall accuracy of 59.6%. Conventional radiography was significantly inferior to MDCT(P < 0.01) concerning scaphoidfracture detection. The mean effective dose of MDCT was 0.1 m Sv compared to 0.002 m Sv of conventional radiography.CONCLUSION: Conventional radiography is insufficient for accurate scaphoid fracture detection. Regarding the almost negligible effective dose, MDCT should serve as the first imaging modality in wrist trauma.
基金supported by the Nuclear Energy Development Project of China (No.[2019]1342)the Presidential Foundation of HFIPS (No.YZJJ2022QN40)。
文摘Owing to the immobility of traditional reactors and spallation neutron sources,the demand for compact thermal neutron radiography(CTNR)based on accelerator neutron sources has rapidly increased in industrial applications.Recently,thermal neutron radiography experiments based on a D-T neutron generator performed by Hefei Institutes of Physical Science indicated a significant resolution deviation between the experimental results and the values calculated using the traditional resolution model.The experimental result was up to 23%lower than the calculated result,which hinders the achievement of the design goal of a compact neutron radiography system.A GEANT4 Monte Carlo code was developed to simulate the CTNR process,aiming to identify the key factors leading to resolution deviation.The effects of a low collimation ratio and high-energy neutrons were analyzed based on the neutron beam environment of the CTNR system.The results showed that the deviation was primarily caused by geometric distortion at low collimation ratios and radiation noise induced by highenergy neutrons.Additionally,the theoretical model was modified by considering the imaging position and radiation noise factors.The modified theoretical model was in good agreement with the experimental results,and the maximum deviation was reduced to 4.22%.This can be useful for the high-precision design of CTNR systems.
文摘Objective To analyze the influence of segmental pedicle screws versus hybrid instrumentation on the correction results in adolescent idiopathic scoliosis patients undergoing posterior selective thoracic fusion. Methods By reviewing the medical records and roentgenograms of adolescent idiopathic scoliosis patients who underwent selective thoracic fusion from February 2000 to January 2007 in our hospital, the patients were divided into 2 groups according to different instrumentation fashions: Group A was hook-screw-rod (hybrid) internal fixation type, Group B was screw-rod (all pedicle screws) internal fixation type, and the screws were used in every segment on the concave side of the thoracic curve. The parameters of the scoliosis were measured and the correction results were analyzed. Results Totally, 48 patients (7 males, 41 females) were included, with an average age of 14.4 years old and a mean follow-up time of 12.3 months. Thirty and 18 patients were assigned to group A and group B, respectively. The mean preoperative coronal Cobb angles of the thoracic curve were 48.8° and 47.4°, respectively. After surgery, they were corrected to 13.7° and 6.8°, respectively. At final follow-up, they were 17.0° and 9.5°, with an average correction rate of 64.6% and 79.0%, respectively, and the correction rate of group B was significantly higher than that of group A (P=0.003). The mean preoperative coronal Cobb angles of the lumbar curve were 32.6° and 35.2°, respectively. After surgery, they were corrected to 8.6° and 8.3°, respectively. At final follow-up, they were 10.3° and 11.1°, with an average correction rate of 66.8% and 69.9%, respectively, and the correction rate of group B was significantly higher than that of group A (P=0.003). The correction loss of the thoracic curve and lumbar curve in the 2 groups were 3.1° and 1.8°, 2.4° and 2.4°, respectively. No significant difference was noted (both P〉0.05). The decompensation rate at final follow-up in these 2 groups were 4% (1/25) and 7.1% (1/14) respectively, with no significant difference (P〉0.05).
文摘The results of the previous studies seem to show the crustaceans can secrete growth hormone,which regulate their growth.However,more evidences are needed to determine it.So the following research was conducted.The extract of thoracic ganglia (TGE) of adult Macrobrachium rosenbergii was applied to a Sephadex G-50 column,the resulting second peak was further isolated by HPLC,and 9 fractions were obtained.Among the fractions only the second fraction significantly increased the protein synthesis of the abdomen muscle of the juvenile M.rosenbergii that was injected TGE.The increasing effects were related to the protein concentration of the injecting fractions.The molecular weight of the substance in the second fraction isolated by HPLC was below 3.4?kDa.The results indicate that the thoracic ganglia of M.rosenbergii could secrete a peptide hormone,which stimulates the muscle protein synthesis of prawn,and the hormone might be the growth hormone of the prawn.