Background 900 MHz radiofrequency radiation (RF) is a commonly used frequency in modern wireless communication devices, and its potential health effects have drawn much attention, especially its impact on bone metabolism, which has not been fully clarified. Objective To investigate the effects of 900 MHz RF on the bone tissue and osteoblast senescence of mice, as well as the dose-effect relationship. Methods In vivo, 3-month-old female C57BL/6 mice were divided into five groups (n=10): sham exposure, low-dose RF (50 μW·cm⁻²), medium-dose RF (150 μW·cm⁻²), high-dose RF (450 μW·cm⁻²), and D-galactose positive control (D-gal). Treatments were administered for 4 h per day for 28 d. Bone mineral density (BMD) and microstructure, including bone volume (BV), tissue volume (TV), bone volume fraction (BV/TV), trabecular number (Tb.N), trabecular separation (Tb.Sp), and trabecular thickness (Tb.Th), were assessed by Micro-CT; bone morphology was examined after hematoxylin and eosin (HE) staining; osteoprotegerin (OPG) and receptor activator of nuclear factor kappa-κΒ ligand (RANKL) expression was detected by immunohistochemistry; serum OPG, tartrate-resistant acid phosphatase 5b (TRACP-5b), plasminogen activator inhibitor-1 (PAI-1), interleukin-6 (IL-6), and C-X-C motif chemokine ligand 15 (CXCL15) levels were measured by enzyme-linked immunosorbent assay (ELISA); mRNA expression of Tp53, Cdkn1a, and Cdkn2a in bone tissue was analyzed by reverse transcription polymerase chain reaction (RT-PCR). In vitro, MC3T3-E1 pre-osteoblasts were grouped into sham, low-dose RF (50 μW·cm⁻²), medium-dose RF (150 μW·cm⁻²), high-dose RF (450 μW·cm⁻²), and H₂O₂ control, groups, and were exposed for 4 h per day for 5 d. Cell morphology was observed by microscopy; viability was tested by cell counting kit-8 (CCK-8); senescence was evaluated by senescence-associated β-galactosidase (SA-β-gal) staining; P53 and P21 protein expression was detected by Western blot; Tp53 and Cdkn1a mRNA levels were measured by RT-PCR. Results In vivo, RF at each dose significantly reduced the BMD of the mice's femurs and the bone microstructure parameters, such as BV/TV, Tb.N, and Tb.Th (P<0.05). Among them, Tb.Sp only increased in the 150 μW·cm⁻² RF group (P<0.05), with a looser bone network; fewer, sparser trabeculae and increased marrow fat were observed after HE staining; down-regulated OPG and up-regulated RANKL expression levels were observed by immunohistochemistry; the ELISA test revealed that the serum OPG levels in the 150 μW·cm⁻² RF group and the 450 μW·cm⁻² RF group of mice were significantly decreased (P<0.05), while the indicator in the 50 μW·cm⁻² RF group showed a decreasing trend but the difference was not statistically significant (P>0.05), TRACP-5b rose, and PAI-1, IL-6, and CXCL15 levels increased (P<0.05); the RT-PCR results showed thatTp53, Cdkn1a, and Cdkn2a mRNA expression was upregulated (P<0.05). In vitro, radiofrequency radiation induced cell flattening, reduced viability (P<0.05), increased SA-β-gal-positive cells (P<0.05), and upregulated P53, P21, Tp53, and Cdkn1a expression (P<0.05). Conclusion 900 MHz RF disrupts bone metabolism in mice by inhibiting bone formation, promoting resorption, and inducing osteoblast senescence, accelerating bone aging. The 150 μW·cm⁻² RF dose exhibits the most pronounced effect, reflecting a nonlinear “window effect,” highlighting potential health risks.

Objective To evaluate the safety and clinical efficacy of stent implantation using a rapid artificial cardiac pacing technique on ostial lesions of left anterior descending artery (LAD).Methods From Jun 2008 to Nov 2010,38 patients with ostial lesions of LAD were recruited and randomly divided into two groups:patients with stent implantation using a rapid artificial cardiac pacing technique (pacing group,n =19 ) and patients with direct stent implantation (no-pacing group,n =19 ).Post-stenting examination was performed.Patients were followed-up for 9 months and coronary angiography was reviewed.The immediate success rate,major adverse cardiac events including death,reinfarction and target vessel revascularization,late lumen loss,sent thmmbosisin,rent-restenosis were compared between these two groups.Results There were no significant differences in the baseline values,disease characteristics and instant response to surgery between pacing and no-pacing groups(P ＞ 0.05 ).The time cost for stent placement was significantly shorter in the pacing group than that in the no-pacing group ( [ 16.5 ± 0.5 ] s vs.[46.6 ± 1.4 ] s,t =88.256,P =0.004 ).After surgery,there was no acute or subacute thrombosis,in-stent restenosis or occlusion for patients in the pacing group.In the no-pacing group,one patient developed acute thrombosis.The symptoms disappeared after thrombus aspiration and balloon dilatation by emergency percutaneous coronary intervention.Patients were followed up for 270 -275 days,and patients in the pacing group received post-stenting coronary angiography 9 months after stent implantation using a rapid artificial cardiac pacing technique,and no in-stent re-stenosis was found.During this period,nobody had adverse events such as death,myocardial infarction or target lesion revascularization,while five cases with in-stent restenosis (50％ -60％ )were found in the no-pacing group,without further target lesion reconstruction due to symptomless.Conclusion Compared with previous positioning technique,stent implantation using a rapid artificial cardiac pacing technique on treatment of ostial lesions of LAD is safer,and more effective.It is a favorable method for accurate positioning of bracket and can improve the prognosis,reduce the occurrence of acute thrombosis and in-stent restenosis.

Objective To compare the efficacy of thrombus aspiration catheter combined with intracoronary tirofiban and nitroglycerol injection through the aspiration catheter versus the guiding catheter during primary percutaneous coronary intervention (PCI) in patients with acute ST-segment elevation myocardial infarction (STEMI).Methods Thirty-four patients with STEMI undergoing primary PCI and receiving thrombus aspiration catheter combined with intracoronary tirofiban and nitroglyeerol injection through the aspiration catheter were enrolled as the aspiration group (n =34),and those who had similar coronary angiography results and basic characteristics but receiving thrombus aspiration catheter combined with intracoronary tirofiban and nitroglycerol injection through the guiding catheter were served as the guiding group ( n =33 ).The outcomes of the two groups were observed and compared.Results There was no significant change of blood pressure between before and after injection in the aspiration group ( P ＞ 0.05 ),but the change of blood pressure was significant after injection compared with before injection in the guiding group ( P ＜ 0.01 ).The cTn-I,BNP,peak-value of CK-MB,peak-time of CK-MB,TIMI grade 3 flow,slow-reflow in IRA after PCI in the aspiration group were superior to those in the guiding group ( t =3.92,P ＜ 0.01 ;t =4.70,P ＜ 0.01 ; t =3.39,P ＜ 0.01 ; t =7.17,P ＜0.01 ; x2 =3.877,P ＜ 0.05 ; x2 =3.876,P ＜ 0.05 ).LVEF,LVEDd and LVESd after 1 month in the aspiration group were superior to those in the guiding group (t =5.99,P ＜ 0.01 ;t =4.53,P ＜ 0.01 ;t =8.12,P ＜ 0.01 ),but no significant differences of LVEF,LVEDd,LVESd were found after 1 week resolution of sum of ST-segment elevation and the MACE rates after PCI were found between the two group ( P ＞ 0.05 ).Conclusion Application of thrombus aspiration catheter combined with intracoronary tirofiban injection through the aspiration catheter is more effective than through the guiding catheter in patients with Acute ST-segment elevation myocardial infarction,which could decrease slow-reflow phenomenon and improve re-perfusion and left ventricular function with better clinical outcomes.

Objective To observe the safety and efficiency of DIVER thrombus aspiration catheter application during percutaneous coronary intervention(PCI) in patients with acute myocardial infarction(AMI)and to evaluate its impacts on the myocardial reperfusion,cardiac function and in-stent restenosis after 9months.Methods A total of 86 cases of ST-segment elevation patients of AMI treated with PCI and confirmed complete occlusion lesion by angiography from November 2008 to December 2010 were randomly divided into two groups:aspiration group(n =43)with DIVER thrombus aspiration cathetcrs were used,and non-aspiration group (n =43).ST-segment recovery within two hours,TIMI grade,the in-hospital adverse major cardiac events,the levels of Pro-BNP,coronary function determined by ultrasound heartbeat graph and the results of coronary angiography after PCI for 9 months were compared between two groups.Results There was significant difference on ST-segment recovery within two hours between these two groups[95.35％(41/43)vs 79.02％(34/43),x2 =11.862,P =0.0006].The incidence of TIMI 3 grade flow was significantly higher,the incidence of TIMI 2(slow flow)and TIMI 0-1(no-reflow)grade flow were much lower in aspiration group than those in non-aspiration group immediately after PCI[TIMI 3:93.02％(40/43) vs 81.40％(35/43),x2 =6.06,P =0.0335 ; TIMI 2:6.98％(3/43) vs 13.95 ％(6/43),x2 =3.12,P =0.0495 ; TIMI 0-1:0 vs 6.98 ％(3/43),x2 =5.29,P =0.0352].There was no difference on LVEF[(0.420±0.054) ％ vs(0.408±0.052)％,t =1.0496,P =0.766and LVEDD(56.5±4.5)mm vs(57.6±4.4)mm,t =1.0419,P =0.7832]between these two groups one day after PCL LVEF was significandy higher in aspiration group than that in non-aspiration group one and nine months after PCI[(0.452±0.050) ％ vs(0.432±0.049) ％,t =3.3957,P =0.0482 ;(0.469±0.053) ％ vs (0.413±0.052)％,t =4.9457,P =0.0336].LVEDD was significantly smaller in aspiration group than that in non-aspiration group one and nine months after PCI[(49.6±5.1) mm vs(53.4±4.6) mm,t =3.4548,P =0.0473 ;(46.5±4.4) mm vs(50.2±4.8) mm,t =3.7260,P =0.0421].There were no cardiovascular events (angina,myocardial infarction,heart failure,cardiac death)in both groups during 9 months follow-up.The coronary angiography results showed that the occurrence rate of in-stent restenosis in aspiration group was significantly lower than that in non-aspiration group(2.33％ vs 6.98％,x2 =4.4351,P =0.0463).Conclusion The application of DIVER thrombus aspiration catheters during PCI in all patients with AMI was safe and effective,it can improve the myocardial tissue perfusion and the post-operative cardiac function and can lower the occurrence rate of in-stent restenosis.

ObjectiveTo explore the determinants of average length of stay of three county hospitals and eleven countryside hospitals of Xinjiang province.MethodsRelative data of the county and the countryside hospitals from 2009 to 2010 were collected,and descriptive analysis and rank sum test were employed to explore the determinants of average length of stay.ResultsThe average length of stay of the county hospital was longer than the countryside hospital,the average length of stay had significant differences between the gender,age,and the disease classfication.ConclusionThe average length of stay of the county hospitals and countryside hospitals had difference significantly.

OBJECTIVE To make a further understanding of the imaging findings of the carotid artery pseudoaneurysm (CAPA) in head and neck and to explore the clinical value of imaging in diagnosis of it, especially the angiographic diagnosis. METHODS The clinical and imaging data of 36 patients with CAPA were analyzed retrospectively. The imaging appearances in all of the patients were observed by two experienced radiologists together and formed a consensus interpretation. RESULTS Imaging examination can establish definitive diagnosis in all cases. The parent arteries included the common carotid artery (2 case), common carotid artery bifurcation (18 cases), internal carotid artery (10 cases) and external carotid artery (2 cases). The imaging features of the CAPA were:the contrast media retained in the aneuysm in all cases;the aneuysm lumen with turbulent flow in 18 cases;the"jetting sign"at the leak of the parent artery in 14 cases;increase of bifurcation angles of internal and external carotid arteries in 24 cases. CONCLUSION Imaging examination is the most valuable examination method in diagnosis of CAPA, and it can not only make definitive diagnosis, but also play an important role in selection of therapeutic planning.

Objective To investigate the manifestation of HCC on superparamagnetic iron oxide(SPIO)-enhanced MRI in rats and clarify its pathologic basis in hope of the application of SPIO-enhanced MRI in estimation of histological grading in HCC.Methods HCC was induced chronically with 1 ml of 2% DEN solution once a day in 80 rats for 14 weeks,and another 10 rats served as normal controls.All rats received dynamic MR examinations on week 16,18,20,21,22,23,24,25.MR imaging was performed before and after SPIO injection using SE-T1WI,FMPSPGR-T1WI,GRE-T2WI,FSE-PDWI,FSE-T2WI, and the relative parameters were obtained.Rats were killed as soon as MRI finished.The tumors were observed grossly and the parts matched with the lesions on MRI were cut into pieces,stained with HE and PerIs,for pathologic examination.Results Kupffer cell number in HCCs was significantly smaller than that in normal liver tissues(P