Search

An ideal packets pipeline operation scheme was used to set up the path-oriented capacity analytical model in single user multi-channel network. Then, through analyzing the essence of resource competition in multi-channel net- works, the resource constraint model of node contention domain was constructed. Furthermore, the network capacity analytical model in multi-user multi-channel network was set up based on mathematical programming. The centralized and distributed computing methods and applications are studied. The model can describe the path capacity, the network capacity, and the contention relation of the flows in multi-hop multi-channel network. The model is simple, and it can di- rect the network deployment and the design of network protocols.

The content of sugar is an important quality index for pears. However, the traditional sugar measurement methods are time-consuming and destructive. In the present study, the authors measured the sugar content of pears using visible and near infrared diffuse reflection spectroscopy. The pretreatment methods of multiplicative scatter correction (MSC), baseline correction, standard normal variate (SNV) transformation, and moving average algorithms were used on the original absorbance spectrum. Results indicate that the absorbance spectra after pretreatment are better than the original absorbance spectra for prediction. Partial least squares (PLS) regression was also used on the original absorbance spectrum and the absorbance spectrum after moving average and baseline correction. It follows that the forecast accuracy of the absorbance spectra after moving average is higher than that of the original absorbance spectra. The models gave good predictions of the sugar content of pears, with corresponding r values of 0.990 8, and standard errors of predictions of 0.019 0.

Objective: To investigate the feasibility of bone marrow mesenchymal stem cells(MSC)with the acellular dermal matrix(ADM) biological patch for the treatment of external anal sphincter injury on the animal models., Methods: Thirty Wistar rats with sphincter injury were randomly divided into three groups. Group A underwent end to end sphincteric repair directly, group B underwent end to end repair and then covered by ADM patch, and group C underwent end to end repair and then covered by ADM which was previously seeded with MSC. After six weeks, the whole ring specimens including anal canal and lower rectum were removed. The hematoxylin and eosin stain and Masson trichrome stain were performed to observe the change of histomorphology., Results: Two weeks later, the majority of rat models presented with moist anus and crissum with loose stools, which indicated that the model was established successfully. Six weeks after repair, in group A and B, the suffusion of fibrous connective tissue and the infiltration of inflammatory cells were observed at the repair site of sphincter. And lots of collagen fiber which was stained into blue deposited dispersedly at the site of repair with no obvious proliferation of capillaries. However, in group C, the blue collagenous fiber which deposited at the sphincter injury site was less than that in groups A and B. Muscle fibers were observed to be stained into red distributed dispersedly at the repair site of sphincter in group C., Conclusions: Transplantation of ADM biological patch rich in bone MSC can partly improve the regeneration of rat injured anal sphincter and lessen the formation of cicatrix.

Objective: To explore the feasibility and functional outcome of antiperistaltic cecoproctostomy in colorectal reconstruction., Methods: Fifty-six patients who underwent antiperistaltic cecoproctostomy were retrospectively studied. Indications for antiperistaltic cecoproctostomy included slow transit constipation(n=44), synchronous colon cancer or colonic polyps(n=5), acute obstructing left colon carcinoma(n=4), and adult megacolon(n=3)., Results: Short-term postoperative complications included wound infections(n=5), 3 lymphatic leakages(n=3), and inflammatory small bowel obstruction(n=1). One month after antiperistaltic cecoproctostomy, the median frequency of daily bowel movement was 4.0(range, 2-6). After a median follow-up of 4 years(range, 1 month to 7 years), the median daily bowel frequency was 2.5(range, 0.5-4.0). Five patients suffered from long-term postoperative complications including small bowel obstruction(n=3), incision hernia(n=1), and mild cecal dilatation(n=1). The mean Wexner incontinence score was 4.2±1.1., Conclusion: Antiperistaltic cecoproctostomy is safe and effective for colorectal reconstruction.

Objectives: To investigate the mechanical properties of bilateral atlantoaxial trans-articular screws and atlas laminar hooks instrumentation with finite element method., Methods: There was a volunteer with age of 28 years old, body height 172 cm, body weight of 60 kg and without cervical deformity by X rays. The ligamentous, nonlinear, three-dimensional finite element models of normal upper cervical spine (C0-3) was developed and validated. The destabilized model with bilateral atlantoaxial trans-articular screws and atlas laminar hooks was evaluated for quasistatic loading., Results: The finite element model of upper cervical spine consists of 229,047 nodes and 152,475 elements, and correlated well with experimental data for all load cases and could be used for experiment. The finite model with bilateral atlantoaxial trans-articular screws and atlas-laminar hooks predicted that the maximum Von Mises Stress was in the region in which screws penetrated the atlantoaxial articular facet. The novel instrumentation resulted in sufficient stability., Conclusion: The bilateral atlantoaxial trans-articular screws and atlas laminar hooks instrumentation is useful and effective for atlantoaxial arthrodesis.