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  • Author: Xu Zhou x
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Abstract

Let G be a graph, and let k, r be nonnegative integers with k ≥ 2. A k-factor of G is a spanning subgraph F of G such that dF(x) = k for each xV (G), where dF(x) denotes the degree of x in F. For SV (G), NG(S) = ∪xS NG(x). The binding number of G is defined by bind (G)=min{|NG(S)||S|:SV(G),NG(S)V(G)}. In this paper, we obtain a binding number and neighborhood condition for a graph to have a k-factor excluding a given r-factor. This result is an extension of the previous results.

Abstract

The electrohydrodynamic (EHD) flow induced by the corona discharge was experimentally investigated in an electrostatic precipitator (ESP). The ESP was a narrow horizontal Plexiglas box (1300 mm×60 mm×60 mm). The electrode set consisted of a single wire discharge electrode and two collecting aluminum plate electrodes. Particle Image Velocimetry (PIV) method was used to visualize the EHD flow characteristics inside the ESP seeded with fine oil droplets. The influence of applied voltage (from 8 kV to 10 kV) and primary gas flow (0.15 m/s, 0.2 m/s, 0.4 m/s) on the EHD flow transition was elucidated through experimental analysis. The formation and transition of typical EHD flows from onset to the fully developed were described and explained. Experimental results showed that the EHD flow patterns change depends on the gas velocity and applied voltage. EHD flow starts with flow streamlines near collecting plates bending towards the wire electrode, forming two void regions. An oscillating jet forming the downstream appeared and moved towards the wire electrode as voltage increased. For higher velocities (≥0.2 m/s), the EHD transition became near wire phenomenon with a jet-like flow structure near the wire, forming a void region behind the wire and expanding as voltage increased. Fully developed EHD secondary flow in the form of counter-rotating vortices appeared upstream with high applied voltage.

CD20 Expression in the Transplanted Kidney of Patients with Graft Loss and Transient Allograft Dysfunction

This study aimed to explore the relationship between the infiltration of CD20+ B cells and the survival time of a renal allograft and to investigate the role of infiltrated B cells in the rejection of the renal allograft. A total of 40 patients with renal allograft loss due to refractory rejection and 20 patients with transient renal allograft dysfunction were recruited. Renal biopsy was done and CD20 expression was detected by immunohistochemistry. In addition, the survival time of the renal allograft was also obtained. The relationships between the CD20 expression and the survival time of the renal allograft and graft loss due to rejection were analyzed. The associations of gender, age and clinicopathogical types with the CD20 expression were also investigated. The proportion of patients positive for CD20 in the transplanted kidney was higher in patients receiving nephrectomy of the allograft due to rejection than in those with transient allograft dysfunction. The diffuse infiltration of CD20+ B cells was considered as positive staining. In 40 samples from patients with graft loss, 19 had diffuse infiltration of CD20+ B cells (47.5%). In 19 patients positive for CD20, hyperacute rejection was found in 1 patient, acute rejection in 5 and chronic rejection in 13. Statistical analysis showed the CD20 expression was not associated with the age and gender of donors and recipients, regimen for immunosuppressive treatment, cold/warm ischemia time and secondary transplantation. CD20+ B cell infiltration predicts a poor prognosis of patients with kidney transplantation and is one of the risk factors of graft loss.

Abstract

Objective A diagnostic model was established to discriminate infectious diseases from non-infectious diseases.

Methods The clinical data of patients with fever of unknown origin (FUO) hospitalized in Xiangya Hospital Central South University, from January, 2006 to April, 2011 were retrospectively analyzed. Patients enrolled were divided into two groups. The first group was used to develop a diagnostic model: independent variables were recorded and considered in a logistic regression analysis to identify infectious and non-infectious diseases (αin = 0.05, αout = 0.10). The second group was used to evaluate the diagnostic model and make ROC analysis.

Results The diagnostic rate of 143 patients in the first group was 87.4%, the diagnosis included infectious disease (52.4%), connective tissue diseases (16.8%), neoplastic disease (16.1%) and miscellaneous (2.1%). The diagnostic rate of 168 patients in the second group was 88.4%, and the diagnosis was similar to the first group. Logistic regression analysis showed that decreased white blood cell count (WBC < 4.0×109/L), higher lactate dehydrogenase level (LDH > 320 U/L) and lymphadenectasis were independent risk factors associated with non-infectious diseases. The odds ratios were 14.74, 5.84 and 5.11 (P ≤ 0.01) , respectively. In ROC analysis, the sensitivity and specificity of the positive predictive values was 62.1% and 89.1%, respectively, while that of negative predicting values were 75% and 81.7%, respectively (AUC = 0.76, P = 0.00).

Conclusions The combination of WBC < 4.0×109/L, LDH > 320 U/L and lymphadenectasis may be useful in discriminating infectious diseases from non-infectious diseases in patients hospitalized as FUO.

Abstract

Objective To investigate the relationship between single nucleotide polymorphisms (SNPs) of the interleukin-4 (IL-4) gene and outcome of hepatitis B virus (HBV) infection in a Chinese Han population.

Methods Total of 501 patients with chronic hepatitis B virus (HBV) infection and 301 controls with selflimiting HBV infection were studied. Three tag SNPs in the IL-4 gene (rs2227284G/T, rs2243283C/G and rs2243288A/G) were genotyped by the Multiplex snapshot technique. The genotype and allele frequencies were calculated and analyzed.

Results The three SNPs showed no significant genotype/allele associations with chronic HBV infection. Overall allele P values were: rs2227284, P = 0.655, odds ratio (OR) [95% confidence interval (CI)] = 1.070 (0.793-1.445); rs2243283, P = 0.849, OR (95% CI) = 0.976 (0.758-1.257); rs2243288, P = 0.659, OR (95% CI) = 1.060 (0.818-1.375). Overall genotype P values were: rs2227284, P = 0.771; rs2243283, P = 0.571; rs2243288, P = 0.902. There were no statistically significant differences between patients with chronic HBV infection and controls. Haplotypes generated by these three SNPs also had no significant differences between the two groups.

Conclusions The three tag SNPs of IL-4 were not associated with the outcome of HBV infection in the Han Chinese population.

Abstract

Pinus massoniana (masson pine) is the most important native pine in southern China. High-density genetic maps have not been constructed for the species. In this study, a genetic linkage map with 251 markers (47 SSRs, 23 ESTPs and 181 SRAPs) was constructed using a F1 progeny mapping population derived from controlled pollination of two parents of different provenances. At LOD 7.0, a total of 17 linkage groups were constructed with twelve groups having nine or more markers and five other groups of two to four markers each. The total map length was 1,956 cM with an average of 8.4 cM among individual loci. The current linkage map represented 93% of the estimated genome length of 2,114 cM for masson pine. Such linkage map are useful for future genomic studies of masson pine including comparative mapping in Pinaceae and quantitative trait loci (QTL) mapping for economically important traits.

Abstract

The connected dominating set (CDS) has become a well-known approach for constructing a virtual backbone in wireless sensor networks. Then traffic can forwarded by the virtual backbone and other nodes turn off their radios to save energy. Furthermore, a smaller CDS incurs fewer interference problems. However, constructing a minimum CDS is an NP-hard problem, and thus most researchers concentrate on how to derive approximate algorithms. In this paper, a novel algorithm based on the induced tree of the crossed cube (ITCC) is presented. The ITCC is to find a maximal independent set (MIS), which is based on building an induced tree of the crossed cube network, and then to connect the MIS nodes to form a CDS. The priority of an induced tree is determined according to a new parameter, the degree of the node in the square of a graph. This paper presents the proof that the ITCC generates a CDS with a lower approximation ratio. Furthermore, it is proved that the cardinality of the induced trees is a Fibonacci sequence, and an upper bound to the number of the dominating set is established. The simulations show that the algorithm provides the smallest CDS size compared with some other traditional algorithms.

Abstract

Background: At present, patients with end-stage renal failure (ESRD) face the question of how to achieve adequate dialysis to maintain their survival with the best quality of life as long as possible. Therefore, the choice of suitable dialysis methods and dialysis dose is important.

Objective: To find suitable dialysis methods and an appropriate dialysis dose for patients with ESRD.

Methods: Our research compares the long-term clinical effects between the patients undergoing continuous ambulatory peritoneal dialysis (CAPD), daytime ambulatory peritoneal dialysis (DAPD), and hemodialysis (HD). Thirty-two patients subjected to peritoneal dialysis were selected and divided into group A (n = 16) and group B (n = 16), group A was treated by using the traditional CAPD pattern; group B was treated by using DAPD. Forty-six patients of renal failure at final stage were divided into group A (n = 23) and group B (n = 23), group A was treated by using a HD method, group B was treated by using a DAPD method.

Results: When the same dialysis dose was applied, the patients with long-term DAPD treatment can obtain satisfactory clinical therapeutic efficacy for the period of maintenance dialysis, thoroughness of dialysis, maintenance of nutritional status, blood pressure regulation, reduction in incidence rate of peritoneal infection, maintenance of relatively high activity in daily life and alleviation in depression, comparable to patients treated with traditional CAPD or HD methods.

Conclusion: The long-term clinical effects of DAPD are comparable to CAPD or HD.

Abstract

Background: Cyclin-dependent kinase inhibitor p27Kip1 is a new class of tumor suppressor in a dosage dependent manner to control cell cycle progression. Human epididymis protein 4 (HE4) is a potentially useful biomarker for ovarian carcinoma, comparable with cancer antigen 125 in identifying women with ovarian cancer, both localized and advanced. However, the prognostic significance of p27Kip1 and HE4 in ovarian cancer is unclear.

Objective: Investigate the expression of p27Kip1 and HE4 in the progression of human ovarian cancer.

Material and method: Immunohistochemical analysis was performed on formalin-fixed paraffin sections of 61 specimens. The association between HE4 and p27Kip1expression and clinicopathological features was analyzed using χ2-test. For analysis of survival data, Kaplan-Meier curves were constructed, and the log-rank test was performed.

Results: The expression of p27Kip1 negatively related with HE4 expression, but it correlated significantly with lymph nodes. On the other hand, HE4 expression correlated significantly with disease stage and lymph nodes. Kaplan-Meier analysis of the survival curves of p27Kip1 and HE4 revealed a highly significant separation between low vs. high expressers in ovarian carcinoma.

Conclusion: Expression of HE4 was up-regulated significantly in human ovarian carcinoma. Overexpression of HE4 might be responsible for oncogenesis and development of ovarian carcinoma. HE4 and p27Kip1 may be of prognostic significance in human ovarian cancer.

Abstract

Background: Repair of facial defects is a unique challenge because it is critical that donor tissues match the tissues in the affected region and provide good functional as well as aesthetic outcomes.

Objective: Summarize the outcomes of the use of expanded forehead flaps to repair extensive facial defects in 13 patients.

Methods: Axial expanded forehead flaps pedicled on the superficial temporal vessels and supraorbital and supratrochlear neurovascular bundles were used to repair defects of the nose, eyelids, and mouth. Seven cases involved damage to the nose and lip and six cases involved the forehead and nose. Among the latter six cases, three had skin surface tumors involving the forehead together with the upper eyelid and the nose, in which one was pigmented nevus, one was neurofibroma, and one was hemangioma.

Results: A total of 34 flaps, ranging in size from 2.5-4 cm to 12-9 cm, were used to repair facial defects in the 13 patients (five males, eight females; median age, 32 years). There were no surgical or postoperative complications, and all flaps survived. In all cases, cosmetic and functional outcomes were considered satisfactory.

Conclusion: The expanded forehead flap provides a large amount of tissue with color and texture similar to that of facial structures, and avoids significant donor sight scars. In addition, the extensive blood supply of the forehead helps to ensure flap survival. Expanded forehead flaps are useful for the repair of large facial defects.