Objective To simulate the dynamic procedure of bullet damage to the three-dimensional(3D) finite element(FE) model of mandible from different angle with computer-aided engineering.Methods A mandible was scanned by thin-layer CT,and then CT images were analyzed and managed with Dicom standard and Mimics software.At the same time,a simulation of the 3D FE model penetrated by a 7.62-mm bullet was carried out through LS-DYNA software from different angle.Results A 3D FE model of human mandible was established with highly-identical geometric size,and the dynamic process of bullet damage to the model was successfully simulated.The results of this work indicated that the exit wounds in model tended to be larger than the entrances resulting from the same shot.Conclusion Thin-layer CT and Dicom standard can improve the efficiency of establishment of a more precise 3D FE model of mandible.The procedure of bullet damage to the mandible can be simulated by the finite element.

Objective To investigate the feasibility of achieving consistent image quality with dose reduction technology in lumber spine MSCT examination with Z-axis automatic tube current modulation (ATCM). Methods Forty-eight patients diagnosed as lumber intervertebral disc protrution scanned twice by MSCT before and after interventional operations with the same coverage from third lumbar vertebra to first sacral vertebra. The first scan (FM) was with fixed tube current of 320 mAs. The follow-up scan was with ATCM with noise index (NI) of 12.0 HU. At the levels of L3-4, L4-5 and 15-S1, image quality, image noise and radiation dose were measured and analyzed. Image quality and radiation dose were compared by paired t-test and the image noise was compared by ANOVA test. Results The dosage of the ATCM had a 31.3% reduction compared with FM, the average DLP was(187.9±66.4)mGy·cm and(273.4±45.4) mGy·cm respectively, where t = 8.205, P < 0.05. The average noise and their deviations for the FM group were (9.8±2.4) HU,(9.9±2.4) HU, and (11.5±3.2) HU at level of L3-4, L4-5, 15-S1, respectively. With ATCM, the average noise was(12.0±0.8) HU, (11.7±0.6) HU, and (11.7±1.4) HU, respectively. There was statistical difference between the two groups (F = 23.31, P < 0.05). The image quality scores for the FM group were (4.7±0.3), (4.5±0.2), (4.5±0.2) and showed no statistical difference to ATCM group (4.6±0.3), (4.5±0.2), (4.5±0.2) at level of L3-4, L4-5, L5-S1, respectively, where t = 1.000, P > 0.050 Conclusion ATCM technique with the noise index setting at 12.0 HU can achieved a 31.3% dose reduction while keep the consistent image quality for lumbar spine MSCT study.

OBJECTIVE: To screen the anti-tumor fraction of ethanol extracts from Thymus quinquecostatus Celak and investigate its anti-tumor effect on human leukemia cell line. METHODS: Ethyl acetate, n-butanol and acetone fractions were separated from the ethanol extracts of wild Thymus quinquecostatus Celak. Growth inhibiting effects of these extracts on human leukemia cell lines K562 and HL-60 were determined by live cell counting and cell growth curve analysis. The possible anti-tumor mechanism was studied by morphological analysis with norcantharidin as a positive control. RESULTS: Ethyl acetate fraction could significantly inhibit the proliferations of K562 and HL-60 cells, and the inhibiting effect depended on the concentration of ethyl acetate fraction. Ethyl acetate fraction could induce apoptosis of K562 and HL-60 cells. The n-butanol and acetone fractions had no significant inhibiting effect on K562 and HL-60 cells. CONCLUSION: Ethyl acetate fraction is the major anti-tumor fraction in ethanol extracts from Thymus quinquecostatus Celak.

Objective To evaluate diagnostic value of CT coronal scan to foreign body in bronchus of children.Methods 30 cases appearances of CT coronal scan to foreign body in bronchus of children were analysed.The appearances between CT coronal scan and axial scan,X-ray examination of chest were contrasted in some cases.Results Foreign body in bronchus or granuloma around part of foreign body were shown clearly by CT coronal scan in 30 cases,28 cases obstructive emphysema,13 cases obstructive pneumonia and 3 cases obstructive atelectasis were also shown clearly.Another,CT coronal scan showed the double margin sign of 16 cases diaphragm and 11 cases mediastinum.Conclusion CT coronal scan could show direct and indirect signs of the most foreign body in bronchus of children and it may be acte as primary examintion.

Objective To evaluate the clinical application value of multi-slice helical CT volumetric (VH) scanning in lumber spine. Methods One thousand of patients with back and leg pain who underwent CT examinations were selected as subjects. We simulated the traditional protocol of single-slice(SS) discrete scanning for L3/4, L4/5, and LS/S1 intervertebral discs. The VH scanning mode was performed with 120 kV, 210 mAs,pitch of 1.5 and coverage of 97. 5 mm. The simulated SS scanning mode was performed with 120 kV, 240 mAs and coverage of 45.0 mm. The diagnostic outcomes and the radiation doses were compared between the two scanning modes. Two groups doctors observed ten terms, including the osseous spinal stenosis,narrowed intervertebral space and so on in two scanning modes respectively. Then consistency analysis of the data was carried out. Results The VH scanning mode showed far more features than the SS mode. The detection rates of the VH mode in the osseous spinal stenosis, narrowed intervertebral space,herniated nucleus pulposus, narrowed lateral recess, vertebral lesion, hypertrophy of L5 transverse process,abnormal direction of facet, facet degeneration, lumbar spondyloschisis, and paraspinal soft tissue were 11.8% (n =118), 38. 5% (n =385), 9. 3% (n =93), 46. 8% (n =468), 31.4% (n =314), 5.7% (n =57), 25.4% (n = 254), 49. 7% (n = 497), 9.9% (n = 99), and 0. 6% (n = 6) respectively, while the detection rates of the SS mode in ten terms were 5.6% (n = 56), 0, 0. 6% (n = 6), 27. 9% (n = 279),22.4% (n =224), 1.2% (n = 12), 16.7% (n = 167), 37.2% (n =372), 0.5% (n =5), and 0.2%(n = 2) respectively. The difference between the two groups had statistically significance (average P <0.05), except the paraspinal soft tissue abnormal (P > 0.05). The detection rates of the VH mode were higher than the SS mode in the osseous spinal stenosis, narrowed intervertebral space, herniated nucleus pulposus, lumbar spondyloschisis, being 6.2% (n = 62) , 38. 5% (n = 385) , 8.7% (n = 87), and 9.4%(n =94), respectively. In addition, VH mode only partially showed the articular facets, narrowed lateral recess, hypertrophy of L.5 transverse process, and paraspinal soft tissue. We could not acquire the imaging slices paralleling to intervertebral discs in SS mode in 467 patients (46.7%) with lumbosacral angle greater than 35°. The radiation dose of VH mode (164.9 mGy/em) was slightly higher than SS mode (147.0 mGy/cm) Conclusion MSCT VH scanning mode can significantly improve the diagnostic rate of lumbar spine diseases compared with SS mode, and was not restricted by the lumbosacral angle with slightly increasing radiation dosage.

OBJECTIVETo investigate the influences of recasting on the mechanical properties of Au-Pt ceramic alloy.

METHODSAu-Pt ceramic alloy samples were prepared and recast for 3 times without adding any new Au-Pt ceramic alloy. The tensile strength, 0.2% yield strength, percentage of elongation, flexural strength, flexural modulus and Vickers hardness of each specimen were measured.

RESULTSBeing cast for different times, the Au-Pt ceramic alloy showed no significant differences on their tensile strength, 0.2% yield strength, percentage of elongation, flexural strength or Vickers hardness. The flexural modulus of the Au-Pt alloys being cast for 2 or 3 times was significantly higher than that of the alloys being cast for 1 time (P < 0.05). CONCLUSION Au-Pt ceramic alloy can be recast for 3 times at least, without any decrease in the mechanical properties.

Alloys ; Ceramics ; Dental Alloys ; Gold Alloys ; Hardness ; Materials Testing ; Metal Ceramic Alloys ; Tensile Strength

OBJECTIVE: To study the effect of hyperventilat ion on brain tissue oxygen pressure (P(ti)O(2)), brain tissue carbon dio xide pressure (P(ti)O(2)), pH value and intracranial pressure (ICP) dur ing intracranial hypertension in pigs. METHODS: Autologous arterial blood (5.5 mlplus minus0.5 ml) was injected into the left frontal lobe by micropump to establish the model of intr acerebral hematoma in pigs. After blood injection, the animals were hyperventila ted for 15 minutes to decrease the pressure of carbon dioxide in arterial blood (P(a)CO(2)) to 27.35 mm Hgplus minus11.97 mm Hg (1 mm Hg=0.133 kPa). The mean arterial pressure (MAP), intracranial pressure (ICP), cerebral perfusion pressure (CPP), P(ti)O(2), (P(ti)CO(2)), pH value and [HCO(3)(-)] were continuously monitored and the blood gas was analyzed. RESULTS: After hyperventilation, the ICP significantly decr eased (P<0.01), the CPP significantly increased (P<0.05), while the P(ti)O(2) greatly decreased to t he ischemic level (8.20 mm Hgplus minus2.50 mm Hg) (P<0.01), the P(ti)CO(2) decreased (P<0.01) and the pH value increased (P<0.01). At the same time, bl ood gas analysis showed that the P(a)CO(2) greatly decreased and the pH valu e increased. CONCLUSIONS: Hyperventilation can decrease the ICP and the P(ti)O(2) significantly. Therefore, hyperventilation should be avoided earl y after brain injury. The P(ti)O(2) monitoring will be helpful for detec ting cerebral ischemia early.

OBJECTIVETo observe the effects of Tripterygium polyglycosides (TWP) on mucous immune function in rat models of arthritis induced respectively with collagen-II induced arthritis (CIA) & adjuvant arthritis (AA).

METHODSCIA and AA model rats were induced by immunization with collagen II emulsified with complete Freund's adjuvant and complete Freund's adjuvant respectively and treated with TWP. Rats' mucus, systemic immunological indexes (peripheral subsets of T cells), local inflammatory factors (IL-6, TNF-alpha, COX-2,and NF-kappaB, etc. ) were observed.

RESULTSIn CIA model group, CD4+ in Peyer's Patch (PP), peripheral CD4+ and CD8+ positive T cells all raised, while in the AA model group, CD4+ lowered and CD8+ raised on PP, with both subsets increased. Effects of TWP on T lymphocyte subsets in PP and blood of the two models were different. High leveled IL-6, TNF-alpha, COX-2 and NF-kappaB expression could be seen in both model groups, and these inflammatory media could be inhibited by TWP.

CONCLUSIONThere exist similarities and differences between the two models in aspects of mucus immune response and effect of TWP on them.

Animals ; Arthritis, Experimental ; chemically induced ; drug therapy ; immunology ; Collagen Type II ; Freund's Adjuvant ; Glycosides ; pharmacology ; Male ; Mucous Membrane ; immunology ; Rats ; Rats, Sprague-Dawley ; Tripterygium ; chemistry

Objective To explore the imaging features of brucellar spondylitis (BS).Methods The imaging data of 49 cases who were diagnosed as brucellar spondylitis by a positive standard tube agglutination titer test (≥1:100) and (or) the isolation of brucella species from blood or other tissue at our institution between September 2012 and October 2016 were retrospectively reviewed.X-ray,CT scan and MRI examination was performed in 49,28 and 42 cases,respectively,of which 19 cases underwent both CT scan and MRI examination.The imaging manifestations of the spine were analyzed.The x2 test or Fisher's exact test were applied to compare the imaging manifestations of the patients who underwent both CT scan and MRI examination.Results Of the 49 patients,34 patients (69.4％) had involvement of the lumbar vertebra.Forty-five patients (91.8％) had contiguous involvement at adjacent 2 vertebral bodies.There were 10 cases (20.4％) with bony spur or bone bridge,3 cases (6.1％) with spondylolisthesis and 3 cases (6.1％)with slightly kyphosis deformity.There were 8 cases (28.6％) showing bone destruction of more than half of the vertebral body and 6 cases (21.4％) with sequestra on CT.There were 14 cases (33.3％) with psoas abscesses,of which 2 (4.8％) had migrating abscess.Epidural abscesses with dural sac compression were found in 17 cases (40.5％) and 3 cases (7.1％) showed nerve roots compression.There were statistically significant differences in the detection of vertebral bone destruction,bone marrow edema,hyperosteogeny,intervertebral disc changes,abscess formation and sequestrum between CT and MRI (P＜0.05).Conclusion BS has characteristic imaging features.The presence of bone destruction,sequestrum,and migrating abscess should warrant the possibility of BS.

Objective To investigate the clinical value of eynovial membrane volume measurement by MRI in patients with hemophilic arthropathy receiving radionuclide synoviectomy. Methods Forty two patients,total 63 diseased joint,who hospitalized in the hemophilia diagnosis and treatment center of Henan Province People's Hospital were enrolled in the study after receiving both enhanced an non enhanded MRI, from May 2011 to January 2015.Sixteen patients(21 joints)were treated with 32P radionuclide synoviectomy (PRS)and followed up.The synovial membrane volume were evaluated by enhanced and non enhanded MRI before and after PRS. All data were analyzed by t test. Results The synovial membrane volume had no statistical difference by using the non enhanced(3 104.38±60.19)mm3and enhanced(2 995.19±59.14)mm3 MRI scans (t=-1.369, P=0.191). The synovial membrane volume post PRS (2 479.45 ± 46.48)mm3much lower than that before PRS (2 983.30 ± 42.87) mm3(t=7.831,P=0.000). The magnetic resonance enhanced range after PRS (0.92 ± 0.06) was significantly lower than that before treatment (1.17 ± 0.07) (t=2.108, P=0.048). Conclusion Synovial membrane volume and magnetic resonance enhanced range are important index to predict clinical efficacy of PRS.