[en] Based on the recommended level density formula of the Fermi gas model, considering the modification at low excitation energies, a level density formula is proposed. From the experimental data of mean neutron resonance spacing D-exp and cumulative number of levels No(E) for 264 nuclei, a set of suitable parameters is determined. With these parameters the calculated values agree very well with the experimental data. (author). 4 refs, 1 tab

[en] Based on the recommended level density formula of the Fermi gas model and considering the modifications at low excitation energy, a synthesis level density formula is proposed. From the mean neutron resonance spacing D-bar_exp for 248 nuclei and the cumulative numbers of levels for 529 nuclei, a set of parameters is determined

[en] Objective: To analyze the risk factors inducing the rupture of multiple intracranial aneurysms. Methods: Between July 2007 and July 2011, a total of 134 patients with 294 aneurysms were admitted to the hospital. Of the 294 aneurysms, 50 were ruptured and 244 were unruptured. Every patient had two or more aneurysms. Univariate and multivariate logistic regression analysis methods were used to analyze the risk factors, including age, gender, site and size, for multiple intracranial aneurysms. Results: The 134 patients were divided into three groups according to patient's age, including <4.5 group, (45-6.5) group and > 65 group. The rupture incidence of aneurysm in the (4.5-65) group was highest in the three groups. The difference was significant (P=0.001). Of 35 patients with anterior communicating arterial aneurysms, 13 (37.1%) were ruptured, accounting for 26% of all ruptured aneurysms, and the rupture rate of anterior communicating arterial aneurysms was significantly higher than that of the aneurysms located at other sites (P= 0.001). Of all 294 aneurysms, 88.1% were <5 mm, 58.2% were <3 mm. Of the ruptured aneurysms, 680-/o were <5 mm. Conclusion: This study indicates that the rupture of multiple intracranial aneurysm is closely related to the patient's age, the size and location of aneurysm. Therefore, patient's age, the size and location of aneurysm should be taken into consideration when to make the therapeutic plan. In multiple intracranial aneurysms, the anterior communicating arterial aneurysm is most prone to bleeding. (authors)

[en] Acute ischemic stroke is a common disease serevely threatening the public health. The main management involves intravenous thrombolysis, intra-arterial thrombolysis and mechanical embolectomy. Recently, endovascular mechanical embolectomy is attracted more attention because it provides a good outcome for patients either ineligible not responsible for IV thrombolytic therapy. The article reviews the relative aspects with summerization in this field. (authors)

[en] The author introduces the means of using cesium-137 measurements to investigate soil erosion and sediment and the method of collecting and making radioactive soil samples. An actual example of collecting soil samples in the area of the Caohai lake in Guizhou is also given

[en] Objective: To strengthen the management of the rational use of antibiotics after interventional procedure through a full-scale retrospective investigation about the perioperative preventive use of antibiotics in different periods. Methods: By using retrospective investigation method, the clinical data about the perioperative use of antibiotics in 3546 patients, who were treated with interventional management during the period from Jan. 2007 to Dec. 2011 in authors' hospital, were statistically analyzed. Based on the way of preventive use of antibiotics, the patients were divided into two groups. Patients in group A (n = 2508) routinely received antibiotics, i.e. intravenous dropping of second-generation cephalosporins or clindamycin antibiotics for 2∼3 days after interventional management, including endovascular procedure (n = 1362) and non-vascular procedure (n = 1146). Patients in group A (n = 1038) did not receive any antibiotic after the interventional management, including endovascular procedure (n = 680) and non-vascular procedure (n = 358). The results were analyzed and compared between the two groups. Results: The infection rates of group A and group B were 0.44% and 0.39% respectively. The infection rates after endovascular procedure in group A and group B were 0.29% and 0.15% respectively, while the infection rates after non-vascular procedure in group A and group B were 0.61% and 0.84% respectively. The differences in postoperative infection rate between the two groups were not statistically significant (P > 0.05). No statistically significant difference in the mean hospitalization days existed between the two groups (P > 0.05). Conclusion: For patients in good general condition, it is not necessary to preventively use antibiotics after a time-selective interventional procedure. (authors)

[en] Objective: To observe the effect of dl-3n-butylphthalide (NBP) on the expression of vascular endothelial growth factor (VEGF) in the rat model with focal cerebral ischemia-reperfusion injury and to discuss its impact on the therapeutic time window for cerebral ischemia-reperfusion injury. Methods: Seventy-two SD rats were randomly and equally divided into three groups with 24 rats in each group: sham operation (SO) group, ischemia-reperfusion (I-R) group and NBP group; and each group was again randomly and equally subdivided into three subgroups: 2-hour, 3-hour and 4-hour reperfusion subgroup according to the reperfusion time after ischemia. By using modified suture embolus method the focal cerebral ischemia-reperfusion model was established. The experimental models were kept under close observation for the extent of cerebral infarction and the neurological deficit. The expressions of VEGF in the brain tissues were determined with immunohistochemical method. The results were statistically analyzed and compared among different groups. Results: As the ischemia time went on, the extent of cerebral infarction and the neurological deficit after reperfusion increased. The severity of cerebral infarction and the neurological deficit in NBP group was significantly lower than that in I-R group, the difference between the two groups was significant (P<0.05). The extent of cerebral infarction and the neurological deficit of ischemia observed in the 4-hour subgroup of NBP group was quite similar to that observed in the 2-hour subgroup of I-R group, the difference was not significant (P>0.05). Along with the increased ischemia time the expressions of VEGF in brain tissues in both NBP group and I-R group were significantly decreased (P<0.01). The expression level of VEGF in NBP group was significantly higher than those in both I-R group and SO group (P<0.01). Conclusion: The dl-3n-butylphthalide has a protective effect on focal cerebral ischemia-reperfusion injury. Its mechanism may be associated with VEGF expression level. The use of dl-3n-butylphthalide can prolong the therapeutic time window of reperfusion. (authors)

[en] Objective: To clarify whether early use of high-dose human albumin can reduce the permeability of blood-brain barrier (BBB) damaged by delayed thrombolysis or not, and, in tun, reduce the vasogenic brain edema. Methods: A total of 138 male SD rats weighing 320-380 grams were randomly divided into 4 groups: sham operation group (n=3), control group (n=45), albumin group (n=45) and albumin+rt-PA group (n=45). According to the reperfusion time after the onset of middle cerebral artery occlusion (MCAO), each group, except sham operation group, was divided into three subgroups of 2 h, 3 h and 4 h with 15 rats in each subgroup. Rats in albumin group and albumin+rt-PA group received an intravenous infusion of 20% human albumin (2.5 g/kg) 2 hours after the onset of MCAO, and rats in albumin+rt-PA group received an intravenous infusion of rt-PA (10 mg/kg) at all points of reperfusion time via the rat's femoral vein immediately after the reperfusion. All rats were sacrificed 24 hours after MCAO, the infarct volume of the brain was determined with TTC dye method, the leakage extent of BBB was quantitatively estimated by using Evans blue method, and the matrix metalloproteinase-9 (MMP-9) expression was assessed with immunohistochemistry technique. Results: Early intervention with the use of high-dose human albumin could significantly improve the neurological score at 24 h. In MCAO 3 h albumin group, MCAO 4 h albumin group and MCAO 3 h albumin+rt-PA group, neurological score was significantly better than that in the control group (P<0.05). The neurological score was improved more remarkably in albumin+rt-PA group of MCAO 4 h than in the control group, although the difference was of no statistical significance (P>0.05). The volume of the infarct tissue was also significantly smaller in all the treated groups with high-dose human albumin groups (P<0.05) when compared with the control group. The infarct volume of the MCAO 4 h in albumin group and albumin+rt-PA group was reduced by 23% and by 17.3%, respectively. Cerebral hemorrhage transformation occurred in two rats of MCAO 4 h control group, in one rat of MCAO 4 h albumin group and in one rat of MCAO 4 h albumin+rt-PA group. Evans blue leakage at the corresponding reperfusion time points in albumin group and albumin+rt-PA group was significantly decreased when compared with that in the control group (P<0.05). Compared with the control group, the expression of MMP-9 at the infarct margin was significantly decreased in the albumin group and albumin+rt-PA group. Conclusion: The results of this study indicate that early use of high-dose human albumin can reduce can reduce the permeability of the blood-brain barrier damaged by delayed thrombolysis and can reduce the infarct volume as well in the experimental rats. (authors)

[en] Objective: To explore the effect of stent implantation on the hemodynamic characteristics of middle cerebral artery (MCA) aneurysm and analyze the effect of stent on hemodynamic factors such as wall shear stress. Methods: One patient with wide-neck MCA bifurcation aneurysm was analyzed before operation and during follow-up according to clinical images and using fluid dynamics software (ANSYS software) based on computational fluid dynamics (CFD) numerical simulation methods. The blood streamlines and wall shear stress were compared in both conditions. Results: There was significant change in morphology of arteries after stent implantation and the aneurysm was gone. The angle of vascular bifurcation became smaller from 196.4° to 92.5°. The aneurysm disappeared completely. The distribution of wall shear stress on the surface of aneurysm turned uniform after stent implantation. The region of high wall stress value near the neck of aneurysm was disappeared directly. Conclusion: Stent implantation can change the partial hemodynamics of aneurysm and parent artery. The numerical simulation of CFD can directly reflect the hemodynamic characteristics of aneurysm. (authors)

[en] Objective: To investigate the value of dynamic contrast-enhanced (DCE) -MRI based textural analysis in differentiating IDH mutated high-grade gliomas from IDH gene wild types. Methods: Twenty-nine patients with high grade gliomas collected from April 2016 to December 2019 in First People's Hospital of Changzhou were assessed retrospectively, including 10 patients with IDH mutation and 19 patients with IDH gene wild type. All patients underwent DCE, conventional plain and enhanced MR scanning. Omni Kinetics software was used to perform DCE-MRI data processing, volume transfer constant (K^trans), ratio constant of tracer refluxing from tissue to plasma (Kep), extravascular extracellular space per unit volume of tissue (Ve), blood plasma volume (Vp) and area under the gadolinium concentration-time curve (AUC) were obtained. Five commonly used textural features, including Energy, Entropy, Inertia, Correlation, and Invert Difference Moment (IDM), were generated based on gray-level co-occurrence matrices. The independent samples t test (normal distribution and equal variance) or Mann-Whitney rank sum test (abnormal distribution or unequal variance) was used to compare the differences in textural features of DCE-MRI parameters between IDH mutated group and IDH gene wild type group. Receiver operating characteristic (ROC) curves were used to evaluate the efficiency of textural features of DCE-MRI parameters in differentiating IDH mutated high-grade gliomas from IDH gene wild types for statistically significant textural features. Results: Entropy of K^trans and Ve for IDH mutated group were 5.368 ± 1.458 and 6.698 ± 1.081, respectively; while the corresponding values were 7.334 ± 1.385 and 8.213 ± 1.320 for IDH gene wild type group, respectively. The difference between the two groups was statistically significant (t values were -3.570, -3.113, P values were 0.001, 0.004, respectively). Inverse difference moment of K^trans and Ve for IDH mutated group were 0.567 ± 0.147 and 0.417 ± 0.106, respectively; while for IDH gene wild type group, the values were 0.393 ± 0.119 and 0.296 ± 0.101, respectively. The difference between the two groups was statistically significant (t values were 3.452, 3.014, P values were 0.002, 0.006, respectively). In all textural features, the area under the ROC curve of entropy of K^trans was the largest (0.874), and the sensitivity was the highest (100%), and the specificity of IDM of Ve was the highest (94.7%). Conclusion: Textural analysis of DCE-MRI can help to differentiate IDH mutated high-grade gliomas from IDH gene wild types. (authors)