1.Calculating the lead equivalent for common radiation protection shielding materials
Dachuan TANG ; Taoyi JIANG ; Daoxin TANG
China Occupational Medicine 2025;52(3):318-323
Objective To determine the fitting parameters for the Archer equation (using shielding transmission factor as variables and shielding material thickness as functions) and quadratic equation with one unknown (using lead equivalent as variables and shielding material thickness as functions) for common radiation protection shielding materials, enabling calculation of lead equivalent or required shielding material thickness. Methods The shielding transmission factor of red brick, lime-sand brick, barium sulfate protective coating, lead glass, and standard lead sheets was measured under narrow-beam X-ray exposure, with tube voltages ranging from 70 to 150 kV. The data of standard lead sheet was used as the reference for lead equivalent. Related parameters were fitted according to the Archer equation recommended by the National Council on Radiation Protection and Measurements Report No. 147 and quadratic equation with one unknown relating lead equivalence to shielding materials thickness. Results The coefficients of determination for the quadratic equation with one unknown of red brick, lime-sand brick, barium sulfate coating, lead glass exceeded 0.999 3. Under 120 kV X-rays, 1 and 2 mmPb were equivalent to 101.02 and 171.09 mm red brick, 121.21 and 204.43 mm lime-sand brick, 10.63 and 24.27 mm barium sulfate coating, and 4.21 and 9.39 mm lead glass. Conclusion The Archer equation and quadratic equation with one unknown from 120 kV or higher tube voltage conditions derived in this study can be applied to calculate lead equivalent or required thickness of shielding materials under both primary and scattered radiation, without linear extrapolation. They provide a basis for radiation shielding design in radiation diagnosis and treatment facilities and for occupational radiation hazard assessments.
2.The Value of Ultrasonic Grey Scale Intensity Quantitative Analysis in Identifying the Properties of Pleural Effusion
Acta Medicinae Universitatis Scientiae et Technologiae Huazhong 2024;53(5):647-652
Objective To research the clinical value of ultrasonic grey scale intensity in identifying the properties of pleural effusion.Methods A prospective study approach was used to collect data from patients who underwent puncture drainage due to clinical needs.We enrolled 120 patients for whom we performed routine ultrasonography and measured the ultrasonic grey scale intensity(echo intensity.EI)value.According to the clinical test results,pleural effusion was divided into exudate fluid,leakage fluid,malignant pleural effusion and benign pleural effusion.The subject operating characteristic curve(ROC curve)of the ultrasound intensity EI value was drawn,and the area under the curve and the optimal cut-off value was calculated.Results Of the 120 pleural effusions,there were 90 exudates[mean intensity EI value:(-46.55±6.35)],30 leaks[mean intensity EI value:(-55.51±5.30)],62 malignant pleural effusions[mean intensity EI value:(-47.24±5.37)],and 58 benign pleural effusions[mean intensity EI value:(-50.46±7.92)].The mean EI value of the exudate group was significantly higher than that of the leakage group(P<0.05),and that of the benign pleural effusion group was lower than that of the malignant pleural effusion group(P<0.05).ROC curve analysis revealed that the EI value had high accuracy in distinguishing exudate from lea-king fluid(the area under the curve is 0.856),and the optimal cut-off value was-50.95,with a sensitivity of 80.0%and speci-ficity of 83.3%.The area under the curve of the EI+TP+LDH value for distinguishing benign and malignant pleural effusion was 0.736,and the optimal cut-off was 89.10,with a sensitivity of 98.4%and a specificity of 46.6%.Conclusion The quanti-tative EI value of ultrasonic grey scale intensity has high diagnostic value in distinguishing pleural effusion from exudate or leak-age.The EI+TP+LDH value has a moderate ability to identify benign and malignant pleural effusion.
3.The preoperative design optimization and clinical application of the anterolateral thigh flap
Shusen CHANG ; Wenhu JIN ; Zairong WEI ; Dachuan XU ; Bo WANG ; Guangfeng SUN ; Xiujun TANG ; Kaiyu NIE ; Xueqin ZENG ; Dali WANG
Chinese Journal of Microsurgery 2017;40(2):118-122
Objective To prospectively summary the piercing-out position,direction,length and piercing-in position of perforator,and investigate the feasibility of preoperative design and optimization of the anterolateral thigh flap and its clinical application.Methods All 58 cases of anterolateral thigh flaps were designed and taken from the lateral thigh area from January,2014 to January,2016.Portable Doppler ultrasound was used before an operation to detect the piercing-out position (point P) of perforators.The direction and length (lower subcutaneous segment of perforators) of perforators after leaving piercing-out position were observed during the operation.And the piercing-in positions (point P') on superficial fascia and the dermis were observed.Based on this,we added line B (anterior superior spine-lateral femoral epicondyle) and line C (anterior superior spine-the middle point of superior border of patella) in the lateral and anterior side of original ilium-patella line in the thigh (line A),respectively.Results All perforators found in 58 cases before and during the operations were located on line A or between line A and line B.No perforators were found between line A and line C.Perforators walked toward the anterior medial side after leaving the muscle membrane.The perforator vascular subcutaneous segment (distance between point P and point P') was (2.02±0.23) cm.There was rectus muscle branch in the descending branch of lateral femoral circumflex artery,while no rectus muscle cutaneous branch was seen.20 cases were designed by one-line method,12 cases were designed by two-line method,while 26 cases were designed by three-line method.Conclusion Advanced three-line method is beneficial to detect of the perforators on the anterior thigh lateral region and to reduce the intraoperative injury perforator vessels at the puncture point.Clinical application of the anterior lateral thigh flap is simple and reliable.
5.Anatomy of the superficial epigastric artery perforator flap in rats
Dong FANG ; Haishuang LIN ; Feng YU ; Sifang ZHANG ; Maochao DING ; Huairui CUI ; Maolin TANG ; Dachuan XU
Acta Anatomica Sinica 2014;(4):531-535
Objective To investigate the anatomy of the superficial epigastric artery perforator flap , and to provide anatomical basis for harvesting flap .Methods Of 27 SD rats, 7 were used for gross anatomy observation and anatomic characteristics and 20 rats for lead oxide-gelatin injection followed by computer picture processing , measurements and the related parameters recording .Results The superficial epigastric artery originated from femoral artery , and gave off its first branch when passed through the superficial fascia .The trunk branched into a lateral perforator and a medial perforator , which anastomosed with thoracodorsal artery and lateral thoracic artery , respectively .The average external diameter of superficial epigastric artery was (0.46 ±0.02)mm at its starting point,and(0.46 ±0.02)mm at the superficial fascia level . The nutritive area of superficial epigastric artery was (18.37 ±3.67) cm2 .The anastomosed area with thoracodorsal artery and lateral thoracic artery was(5.34 ±0.86)cm and(6.28 ±0.29)cm, respectively, away from the horizontal line through axillary,and (4.38 ±0.38)cm and(2.04 ±0.33)cm, respectively, away from the ventral median line.Conclusion The position and external diameter of superficial epigastric artery are constant , and the superficial epigastric artery perforator flap is a ideal flap model for research on free flap transplantation , flap supercharging , and hemodynamics .
6.Current research of neuroprotective effect of chitosan
Chinese Journal of Experimental Ophthalmology 2014;32(3):281-284
Many events can cause the irreversible damage of optical nerve.Conventional treatment of visual nerve damage is medicine therapy.However,each drug shows its advantages and disadvantages.Chitosan is a polysaccharide with positive charge and good biocompatibility,and it prosses the antioxidant,antiapoptosis and antineuritic effects,so it is thought to play a neuroprotective role for multiple causative neuropathies.The progress in neuroprotective mechanism of chitosan was reviewed in this paper.
7.Application of chitosan and its derivatives in nerve tissue engineering
Chinese Journal of Experimental Ophthalmology 2014;32(8):752-755
Chitosan (CS) is known as a polysaccharide with positive charge and good biocompatibility.Researches showed that CS possesses the advantages of nontoxicity,biodegradability,plasticity and good biocompatibility,and therefore it can be used to repair of neural injury and serve as a biological carrier scaffold in engineered nerve tissue.Recently,the research is performed for the modification of CS structure or mix the CS with different materials to prepare the multiple compound and biological vector to offer three-dimensional scaffold and environment for the reconstruction of defective neural tissue and culture of neural stem cells.In addition,CS engineered biological materials are confirmed to possess the better performance,more diverse functions and more dominant effect on the regeneration of neural tissue,so it is predicted a more extensive application prospect in neural repair and regeneration.The basic properties and biological functions of CS,and its application in neural tissue engineering are reviewed.
8.Role of interferon alpha in the management of severe acute pancreatitis.
Yaoqing TANG ; Dachuan QI ; Jun WU ; Enqiang MAO ; Jun JI ; Tianquan HAN ; Shendao ZHANG
Chinese Journal of Surgery 2002;40(2):146-149
OBJECTIVETo investigate the efficacy of IFN-alpha on severe acute pancreatitis (SAP) of IFN-alpha.
METHODSA SAP model was developed in adult male rats by retrograde injection of 5% sodium taurocholate in the pancreatic duct. Serum amylase was measured by the blue-starch method and serum cytokines were determined by ELISA.
RESULTSCompared with to the control group, less pancreatic injury and lower amylase level were observed treat in the rats with IFN-alpha. In contrast, the concentration of IL-10 was higher.
CONCLUSIONIFN-alpha has significant curative effect on SAP.
Animals ; Disease Models, Animal ; Immunologic Factors ; therapeutic use ; Interferon-alpha ; therapeutic use ; Interleukin-10 ; metabolism ; Kidney ; metabolism ; Male ; Pancreatitis, Acute Necrotizing ; drug therapy ; metabolism ; pathology ; Rats ; Rats, Sprague-Dawley ; Tumor Necrosis Factor-alpha ; metabolism
9.The zonal pattern of extrinsic blood supply to the brachial plexus and its clinical significance
Tianhong PENG ; Maolin TANG ; Dachuan XU
Chinese Journal of Orthopaedics 1999;0(07):-
Objective To explore the arterial origin and the artery distribution to the brachial plexus and its clinical significance. Methods 1)To observe the zonal pattern of arteries supplying brachial plexus in three fresh cadavers by means of modified lead-oxide and gelatin infusion and radiologic development. 2)To observe the arterial origin and distribution under microscope in 10 cadavers embalmed which were injected with red latex from the common carotid artery. Results The brachial plexus was supplied by branches of the subclavian-axillary axis (SAA), and these branches anastomose each other, according to their distribution feature, the supplied neural structures were divided into three zones. The first zone including the nerve roots from intervertebral foramina to the trunks and this region of the brachial plexus were supplied by the vertebral artery and the deep cervical artery. The second zone including the divisions and the main region of the cords of the brachial plexus were supplied by direct branches of the subclavian artery or by branches originating from the dorsal scapular artery. The dorsal scapular artery was usually thick and contributed to blood supply of a large region. There were 2.7 (1-5) direct branches of the subcalvian artery on the average which have relatively smaller diameter. The third zone including the distal portion of the cords and the terminal branches of the brachial plexus were supplied by direct branches of the axillary artery. The mean number of these branches was 3.4 (1-6). Conclusion The brachial plexus has plenty of vascular supply which can be divided into three zones. Every vasa nervorum tends to divide into a distal branch and a proximal branch shortly after they enter the brachial plexus. The branches from vasa nervorum communicates without changing their diameter which is called "real connection", and the blood supplied from the three zones can compensate each other, which provide a rich longitudinal blood supply to the brachial plexus. This study provides an anatomical basis for vascularized brachial plexus replacement.

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