A discrete time feedback control system model based on a multi-router network has been presented. The model can be described by a set of recurrence equations. The numerical examples about the bifurcation of average and instantaneous queue size along with the variety of RED control parameter are shown. The simulate experiments about those of the RED control parameters are also presented. All of these results show that instability in TCP-Reno traffic under RED can be induced by the inherent nonlinear behavior of the network.

Objective To discuss the diagnosis and surgical treatment of solid pseudopapillary tumor (SPTP) of the pancreatic head.Methods From January 2008 to August 2013,the clinicopathological data of 12 patients who were diagnosed and surgically treated in our hospital for this condition were analyzed retrospectively.Results There were 11 women and 1 man,the mean age was 28.7 years,with a range from 11 to 43.The mean diameter of the tumor was 7.5 cm(2 ～ 15 cm),6 of 12 of these tumors were more than 10 cm.Seven patients underwent pancreaticoduodenectomy,2 duodenum-preserving pancreatic head resection,2 local resection of tumor,1 palliative resection,1 pancreaticoduodenectomy combined with resection of part of the portal vein.All the diagnoses were confirmed by postoperative histopathology.In a follow-up which ranged from 3 to 65 months,all the patients were alive with no evidence of disease recurrence.Conclusions Most of the SPTPs of the pancreatic head were huge.The diagnosis was difficult.Complete tumor resection is the best treatment.

Objective To explore the expressions of matrix metalloproteinases-1(MMP-1) and tissue inhibitor of metalloproteinase-1(TIMP-1) in sternomastoid muscle and explore the pathogenesis of sternomastoid muscle fibrosis in congenital fibra muscular torticollis in children.Methods The hyperplastic state of collagen fiber were determine by Masson collagen stainning method and muscular torticollis and fibra torticollis was differed,obtained 22 cases of the fibra torticollis group.Immunohistochemical method was used to determine the expression of MMP-1 and TIMP-1 in sternomastoid muscle of fibra torticollis and compared them with 6 cases of control group.Results By the immunohistochemical method,the expression of MMP-1 in the experiment group significantly decreased than that in control group(P0.05).Conclusion In congenital fibra torticollis,the sternomastoid muscle fibrosis is related to the decrease of MMP-1.

Animals ; Central Nervous System Diseases ; drug therapy ; Drug Design ; Drugs, Chinese Herbal ; Humans ; Inflammation ; drug therapy

Objective To identify whether the branches of cervical nerve roots joined into the accessory nerve trunk or not.Methods In 10 adult cadavers (7 males and 3 females, including 20 laterals of brachial plexus nerves), we observe source of cervical plexus branches to the accessory nerve anatomically.In 10 clinical cases of males with brachial plexus nerve injures, in the supraclavicular approach of brachial plexus exploration, the part of the supraclavicular cutaneous nerve for histological specimen were cut off;in the posterior approach, electrical stimulation of the trunk and branches of cervical plexus were performed to observed istaltrapezius muscle contraction.After accessory nerve transfer, the residual terminal accessory nerve and branch of cervical plexus were taked for histological specimens;and observed and judged of each nerve sample by acetylcholinesterase (AchE) immunohistochemical staining.Results In 10 of 20 lateral cases, cervical plexus communicating branches were derived from the fourth cervical nerve root.The intraoperative electrical stimulation of the accessory nerve trunk, 10 cases of distal trapezius muscle were significantly shrink;electrical stimulation of the cervical plexus branch, 2 cases after stimulation of the mild distal trapezius contraction, the remaining 8 cases without trapezius muscle contraction.10 cases of supraclavicular nerve staining for AchE were negative, 10 cases of accessory nerve terminal branches of AchE staining were mixed,10 cases of branch AchE cervical plexus to the accessory nerve staining were negative.Conclusion The branches of the fourth cervical nerve root constantly joins into the accessory nerve, participating in the trapezius muscle inner vation, the fibers of the branches are sensorial fibers.

The study evaluates the lipolysis rate and extent of type Ⅲ lipid formulations using testosterone undecanoate as a model drug after digestion with in vitro lipolysis model, and studies the digestive regularity with optical microscope and electrical conductivity. The results showed that for testosterone undecanoate type Ⅲ lipid formulations with castor oil as oil phase and Transcutol HP as latent solvent, the lipolysis rate and extent were increased with the increase of oil phase proportion and were decreased with excessive proportion of surfactant, in which can see liquid crystal phase during lipolysis process. The lipolysis rate of type ⅢB lipid preparations with different surfactant were ordered as Labrasol > Tween 80 > Cremophor EL, but the rate of type ⅢA is different in quick digestion phase and slow digestion phase. The lipolysis extent of type Ⅲ lipid formulations with different surfactant were ordered as Cremophor EL > Tween 80 > Labrasol. These may be related to the digestive effect of pancreatic lipase on different surfactants. This study implied that the lipolysis rate and extent of type Ⅲ lipid formulations are greatly influenced by the proportion of oil phase and surfactant, and the surfactant structure. These factors will affect the in vivo digestion and should be taken into account when screening type Ⅲ lipid formulations.

Objective To evaluate the diagnostic value of dermoscopy and reflectance confocal microscopy (RCM) alone or in combination for melanocytic nevus.Methods A total of 37 patients with clinically diagnosed melanocytic nevus were collected.Skin lesions were firstly examined by dermoscopy and RCM,then were resected to be subjected to histopathological examination for final diagnosis.The imaging features of melanocytic nevus were summarized.The sensitivity,specificity,positive predictive value,negative predictive value and accuracy of different skin imaging techniques were calculated,and the consistency was analyzed between skin imaging techniques and histopathological examination.Results Based on the dermoscopic and RCM findings,2 kinds of nevus cells with different morphological features were observed in the dermis of intradermal nevus.One kind of nevus cells was characterized by a nonfusional,highly-refractive round structure in the papillary dermis under RCM,and by a brown or light brown homogenous pattern under dermoscopy,which was observed in 5 skin lesions.The other kind of nevus cells appeared as irregular,highly-refractive cell clumps in the papillary dermis under RCM,and by a cobblestone or globular pattern under dermoscopy,which was observed in 31 skin lesions.For the diagnosis of melanocytic nevus,the sensitivity,specificity,accuracy,positive predictive value and negative predictive value of RCM combined with dermoscopy were 91.7％,87.5％,90.9％,97.1％ and 70％ respectively,those of RCM were 86.1％,75％,84％,93.9％ and 54.5％ respectively,and those of dermoscopy were 77.8％,87.5％,75％,96.3％ and 41.2％ respectively.All the diagnostic indices of RCM combined with dermoscopy were higher than those of RCM or dermoscopy alone,except that the specificity was equal to that of dermoscopy alone.RCM showed higher sensitivity,accuracy and negative predictive value,but lower specificity and positive predictive value compared with dermoscopy.There were no significant differences in the diagnostic yield in melanocytic nevus between RCM combined with dermoscopy or RCM alone and histopathological examination (x2 =0.25,0.57,P =0.63,0.45,Kappa value =0.72,0.53,respectively).However,a significant difference in the diagnostic yield in melanocytic nevus was observed between dermoscopy and histopathological examination (x2 =5.81,P =0.012).Conclusion RCM combined with dermoscopy shows higher diagnostic accuracy for melanocytic nevus compared with RCM or dermoscopy alone.

Objective To investigate the clinical features and the prognosis after surgical treatment for hilar cholangiocarcinoma (HCC).Methods The surgical therapy and follow-up result were retrospectively analyzed on 98 cases of hilar cholangiocarcinoma admitted into our hospital from January 1995 to January 2005.Differences between groups were evaluated using Chi-square analysis or Student t-test according to the data type.Survival rate was calculated with Kaplan-Meier method,and using the log-rank test.Results Among 98 patients,83 patients underwent surgical treatment (radical resection in 33,palliative resection in 16,and nonresectional internal or external bile duct drainage in 34),15 patients underwent conservative therapy.The 1-,3-,5-year survival rates were 79％,42％,and 17％ in the resection group and 88％,54％,and 24％ in the radical resection group,respectively.The 1-,3-year survival rates were 55％,and 9％ in palliative resection group,respectively,and none of the patient survived for over 5 years.There were significant differences in the survival rate among the radical resection group and the palliative resection group (log-rank test,P ＜ 0.001).Conclusions Radical resection improves the prognosis of hilar cholangiocarcinoma.

Objective To explore the value of 64-slice spiral CT angiography in diagnosis of pulmonary arteriovenous fistulas(PAVF).Methods 12 patients with suspect PAVF were performed by enhanced scan with 64-SliceCT.Two-dimensional and three-dimensional reformation were performed in all cases including coronal multiplanar reconstruction(MPR),maximum intensity projection(MIP),volume rendering(VR).Resnlts 12 cases were diagnosed as PAVF by 64-SliceCT angiography.Single PAVF in 7 cases,Multi-PAVF in 5cases.We found 20 lesions in 12 patients,Except direct multi-pulmonary arteriovenous fistulas in the area of near the heart in one case.Conclusion 64-slice spiral CT angiography is a useful and noninvasive means to identify PAVF and is also useful for therapeutic planning and postoperative follow-up.

Objective:To summarize our experience in diagnosis and treatment of Budd-Chiari syndrome(BCS) accompanied with hepatic nodules.Methods:The clinical data of 33 patients with BCS accompanied with hepatic nodules who were treated at Henan Provincial People's Hospital from January 2012 to December 2018 were retrospectively analysed. A total of 33 patients were enrolled, including 17 males and 16 females, with an average age of 51 years. Analyze the treatment and prognosis of different types of nodules.Results:Of 33 patients, 27 were diagnosed to have hepatocellular carcinoma and 6 benign proliferative nodules. Treatment of patients with hepatocellular carcinoma included, transcatheter arterial chemoembolization ( n=1) and hepatectomy ( n=26). The survival time of these patients with hepatocellular carcinoma ranged from 10.0 to 78.0 months (mean 37.8 months). For the remaining 6 patients with benign nodules, the nodules were multiple and no malignant changes were observed on follow-up. Conclusion:For patients with BCS associated with benign nodules, no specific treatment was required. Hepatocellular carcinoma assocated with BCS had good prognosis. An aggressive surgical resectional approach is recommended to treat and to relieve the hepatic outflow obstruction.