Search

With the introduction of computer technology, network attacks have become more frequent. Some illegal elements may intrude into computers through network attacks to tamper with messages, spread viruses and other destructive behaviors, causing great damage to personal sensitive information, industrial control networks, transaction systems, etc. . For this, this design proposes an improved intrusion detection method based on feature selection and integrated model. The NSL-KDD training data set is used to evaluate the proposed model. First, balance the data categories through the SMOTE-ENN method, and then use feature selection technology and PCA feature extraction technology to reduce the number of irrelevant features and improve the classification accuracy. Finally, using CART as the base classifier, Bagging technology is used to establish an integrated model and an intrusion detection system. Experimental results show that the CART-based Bagging method provides better accuracy, lower false alarm rate and faster model training speed, and the system can detect intrusion attacks with similar attributes and has a certain degree of adaptability.

This paper analysed the rhinoscope's clinical value in microsurgical treatment of intracranial aneurysms. Application of the rhinoscope in 87 patients, only 2 patients had ruptured during operation. However, 11 cases had ruptured in 94 cases without using rhinoscope, P0.05, they had a significant difference. By DSA follow-up review, 82 cases of used rhinoscope only 2 cases had remained the aneurysm neck, but 9 cases had the aneurysm neck in 77 cases which had not used the rhinoscope in the microsurgical treatment, P0.05, they also had significant difference. The application of rhinoscope in microsurgical treatment of intracranial aneurysms intraoperative, can reduce the risk of the intraoperative aneurysm rupture. It can achieve better clinical effect.

We performed a prospective study to evaluate the intraoperative value of indocyanine green (ICG) video angiography in anterior circulation aneurysms. From January 2007 to April 2008, 42 patients with anterior circulation aneurysms who were to undergo aneurysm clipping were enrolled in the study. Intraoperative ICG video angiography was performed using a fluorescence microscope. After the operation, three-dimensional CT angiography (CTA), digital substraction angiography (DSA) and magnetic resonance angiography (MRA) were used to evaluate the use of intraoperative ICG video angiography. Of the 42 patients, on ICG video angiography after initial clip placement, neck remnants of the aneurysm were found in two patients, inadvertent clipping of branching vessels in one patient, and inadvertent clipping of perforating vessels in two patients. ICG video angiography after adjustment of the clip position showed a perfect residual elimination with no abnormal findings. Post-operative DSA, CTA and MRA results corresponded to the intraoperative ICG video angiography findings. Therefore, ICG video angiography is an important tool to monitor residual aneurysm, parent artery stenosis or perforating artery occlusion during intracranial aneurysm clipping.

Metabolite concentrations in normal adult brains and in gliomas were quantitatively analyzed by in vivo proton magnetic resonance spectroscopy (MRS) using the fully relaxed water signal as an internal standard. Between January 1998 and October 2001, 28 healthy volunteers and 18 patients with gliomas were examined by in vivo proton MRS. Single-voxel spectra were acquired using the point-resolved spectroscopic (PRESS) pulse sequence with a 1.5 T scanner (TR/TE/Ave = 3000 ms/30 ms/64). The calculated concentrations of N-acetyl-aspartate (NAA), creatine (Cre), choline (Cho), and water(H(2)O) in the normal hemispheric white matter were 23.59 +/- 2.62 mM (mean +/- SD), 13.06 +/- 1.8 mM, 4.28 +/- 0.8 mM, and 47280.96 +/- 5414.85 mM, respectively. The metabolite concentrations were not necessarily uniform in different parts of the brain. The concentrations of NAA and Cre decreased in all gliomas (p < 0.001). The NAA/Cho and NAA/H(2)O ratios can distinguish the normal brain from gliomas and low-grade from high-grade astrocytoma (p < 0.001). The concentration of taurine (Tau) in medulloblastomas was 29.64 +/- 5.76 mM. This is the first quantitative analysis of Tau in medulloblastoma in vivo and confirms earlier in vitro findings.

Objective and importance Intracranial giant optic nerve gliomas, usually presumed as optic chiasmatic gliomas, are much less common. The architectural tumor form of optic nerve glioma without neurofibromatosis type 1 is usually the expansile-intraneural pattern. The exophytic optic nerve gliomas without neurofibromatosis type 1 are relatively uncommon. Surgical decompression for intracranial optic gliomas frequently leads to clinical improvement, but obvious improvement of vision is rare. We report a case that demonstrated significant recovery of visual function after removal of the intracranial giant optic nerve glioma, revealing exophytic growth. Clinical presentation A 13-year-old boy presented with visual impairment in both eyes. Magnetic resonance images (MRI) disclosed a 6 cm diameter mass in the suprasellar area. On heavily T2-reversed MRIs, it was obvious that the intracranial portion of right optic nerve was enlarged, and optic tracts were shifted to the left by the tumor. The relationship of the tumor to the chiasma could not be affirmed on MRIs. Intervention A right frontotemporal craniotomy for decompression of the optic apparatus was performed. After the majority of the tumor was resected, it became clear that the tumor originated in the right optic nerve. The tumor exophytically grew and dislocated the optic chiasma and optic tracts. Significant improvement of visual functions began from the first week after surgery and continued gradually thereafter. The histological diagnosis was pilocytic astrocytoma. A follow-up MRI taken 4 years after surgery showed no regrowth of the residual tumor. Conclusion Giant exophytic gliomas without neurofibromatosis type 1 may arise from the intracranial portion of an isolated optic nerve. Direct visualization of optic component by heavily T2-reversed MRI could more precisely delineate the relationship of the intracranial optic nerve glioma to the optic apparatus. Surgery may be indicated in giant exophytic intracranial optic nerve gliomas and preoperative postulated optic chiasmatic gliomas. Microsurgical resection can induce postoperative visual improvement without regrowth of the residual tumor.