A New Method for Calculating the Relative Permeability Curve of Polymer Flooding Based on the Viscosity Variation Law of Polymer Transporting in Porous Media.

Relative permeability of polymer flooding plays a very important role in oil field development. This paper aimed to measure and calculate the relative permeability curves of polymer flooding more accurately. First, viscosity variation law of polymer in porous media was studied. Rock particles of different diameters and cementing agent were used to make artificial cores and hydrophobically associating polymer solutions were prepared for experiments. Polymer solutions were injected into the cores filled with crude oil and irreducible water. In the process of polymer flooding, produced fluid was collected at different water saturations and locations of the core. Polymer solutions were separated and their viscosities were measured. With the experimental data, the viscosity variation rule of polymer transporting in porous media was explored. The result indicates that the viscosity retention rate of polymer solutions transporting in porous media has power function relationship with the water saturation and the dimensionless distance from the core inlet. Finally, the relative permeability curves of polymer flooding were measured by unsteady state method and the viscosity variation rule was applied to the calculation of the relative permeability curves.

The comparison of reproductive hormone receptor expressions of the sheep ovary and hormone concentrations in two Chinese breeds.

The aim of this research was to investigate the changes in reproductive hormone receptor expressions of the ovary and hormone concentrations between oestrous cycle pattern of two different sheep breeds in China. Ovarian tissues were collected from Chinese Merino (Junken type) and Hu sheep with different reproductive states in spring and autumn. Serum samples were assayed for oestrogen (E2), progesterone (P), luteinizing hormone (LH) and follicle-stimulating hormone (FSH) concentrations by radioimmunoassay during spring. The ovarian expression of hormone receptors (ERα, ERß, PR, LHR and FSHR) was analysed using real-time reverse transcription polymerase chain reaction (RT-PCR). In Chinese Merino, there was no corpora lutea and ovulation point on the surfaces of ovaries in spring and low basal levels of both LH and P in serum. ERα, ERß and FSHR were expressed significantly higher in Merino ovaries during anoestrus compared with oestrous or luteal phases of Hu sheep (p < 0.05 or p < 0.01). However, both varieties of sheep exhibited a similar tendency to secrete E2 and FSH. Compared with Hu sheep, FSH levels were slightly higher in Merino serum. In Hu sheep, ERα, ERß, FSHR, LHR and PR expressed in luteal phase ovaries during spring were significantly lower (p < 0.05, p < 0.01 or p < 0.001) than autumn. Interestingly, LHR and PR expressed in anoestrous ovaries were similar to that in oestrous phase of both sheep breeds. The above results suggest that seasonal reproductive sheep increased the expression of E2 and FSH receptors in ovary during spring may enhance the effects of E2 and FSH on follicular development. It is likely that this enhancement prevents the ovary from progressing to the luteal phase.

Effect of lamina open angles in expansion open-door laminoplasty on the clinical results in treating cervical spondylotic myelopathy.

STUDY DESIGN: A retrospective study. OBJECTIVE: To evaluate and compare the relation of the efficacy and clinical results of expansion open-door laminoplasty (EOLP) with different angles in lamina open-door. SUMMARY OF BACKGROUND DATA: EOLP is currently the most widely adopted surgical treatment for cervical spondylotic myelopathy. Although many long-term clinical follow-up studies have reported that most patients recover satisfactorily after EOLP, there have been numerous reports regarding postoperative complications, such as stubborn axial symptoms (AS) and C5 palsy. The lamina open-door angles in EOLP play a decisive role in determining the openness of the door that affects clinical outcomes. Nonetheless, no thorough studies on different angles in EOLP have been published. METHOD: A total of 198 cervical spondylotic myelopathy patients who underwent posterior cervical EOLP and at least 24 months follow-up treatment between July 2006 and January 2009 were selected as case studies. Among the 198 cases used, there were 39 double-segment cases with the location being C3-C5 in 11 cases and C4-C6 in 28 cases, 97 three-segments (C4-C7) and 62 four segments (C3-C7). All of the patients underwent x-ray, computed tomography, and magnetic resonance imaging images for evaluation of the cervical spine. According to different opening angles, measured by computed tomography scan after operation 1 week, the patients were divided into 2 groups, group A (>30 degrees, 76 patients including 44 males and 32 females) and group B (15-30 degrees, 122 patients including 71 males and 51 females). All patients were followed up for over 24 months, clinical results including operative duration, intraoperative bleeding volume, postoperative complications, C2-C7 Cobb angle, cervical curvature index (CI), range of motion (ROM), and values after the spinal cord backward shift were analyzed statistically, evaluating the neurological function at final follow-up and calculating the improvement rate of nerve function recovery. RESULTS: There was no statistically significant difference (P>0.05) between the 2 groups in the following areas: the Japanese Orthopedic Association scores, C2-C7 Cobb angle, cervical CI, and ROM. In addition, operative duration and intraoperative bleeding volume between A group and B group showed no significant differences (P>0.05). After surgery, 51 patients (67.1%) in group A had AS, 8 patients (10.4%) had C5 palsy, and 1 patient had mild cervical kyphosis. Whereas postoperatively group B contained 37 cases (10.5%) with AS, 3 (2.4%) with C5 palsy, and in 4 cases (3.28%) the lamina open-door had reclosed. The rate of patients with AS and C5 palsy in group A was higher than group B. The incidence of postoperative complications between the 2 groups have a significant difference (P<0.05). The rate of improvement of Japanese Orthopedic Association scores in last follow-up between group A and group B did not reach statistical significance (P>0.05). At the 1-month follow-up the range of the value of spinal cord backward shift was 0-7.95 mm with the average being 2.41±0.46 mm. C2-C7 Cobb angle, CI, and ROM between the 2 groups revealed no statistical significance (P>0.05). ROM comparisons preoperatively and postoperatively between the 2 groups were significantly different (P<0.05). CONCLUSIONS: In different angles of lamina open-door, the improvement rate of neurological function after surgery had no statistically significant difference between 2 groups. When the open-door angle is maintained between 15 and 30 degrees, it can reduce the incidence of C5 palsy in the hinge side and AS, but we should prevent reclosure of the lamina open-door.

[The analysis of prognostic factors in patients with thoracic ossification of the ligamentum flavum and thoracic ossification of posterior longitudinal ligament by posterior decompression].

OBJECTIVE: To investigate the prognostic factors for patients with thoracic ossification of the ligamentum flavum (OLF) and thoracic ossification of posterior longitudinal ligament (OPLL). METHODS: Clinical information of 83 patients suffering from thoracic OLF and OPLL was reviewed retrospectively from January 2006 to June 2010. The related factors such as gender, age, preoperative and postoperative Japanese Orthopedic Association (JOA) score, pathological segment, type of thoracic OPLL, degree of thoracic kyphosis, anteroposterior diameter of OPLL, range of circumferential decompression, cerebrospinal fluid leakage or not and dysfunction or not and carotid lumbar disorders or not were analyzed by Chi-square and Logistic regression. RESULTS: All cases were classified into desirable group (58 cases) and undesirable group (25 cases) based on the postoperative JOA score improvement rate. Comparison of physical characteristics between two groups of age, preoperative JOA and the course of the disease had not statistically significant (P > 0.05). Two groups in pathological segment of thoracic OPLL (χ(2) = 6.290, P = 0.043), the ossification type of OPLL (χ(2) = 5.361, P = 0.021) and dysfunction or not in preoperative (χ(2) = 27.711, P = 0.000) had significant difference. Logistic regression analysis showed that the upper thoracic segments (P = 0.044), beak type ossification (P = 0.023) and with dysfunction in preoperative (P = 0.009) were risk factors. There were 24 patients (28.9%) with cerebrospinal fluid leakage, 3 patients with early postoperative deep infection and neurological deterioration of 2 cases in postoperative. CONCLUSIONS: Patients with ossification on the upper section of thoracic have a better prognosis, but the beaked localized longitudinal ligament ossification in patients and associated with preoperative dysfunction show a poor prognosis, combined jumping segmental ossification and cervical or lumbar severe disorders are the influencing factor for poor prognosis.

Biomechanical effect of Coflex and X-STOP spacers on the lumbar spine: a finite element analysis.

OBJECTIVE: To explore the biomechanical differences between Coflex and X-STOP devices by finite element analysis. METHODS: Based on the normal lumbar CT images from a healthy adult volunteer, four finite element models including the healthy lumbar segment model, the mild degenerated lumbar segment model, a Coflex fixed lumbar segment model and X-STOP fixed lumbar segment model were constructed. A simulation analysis under the conditions of flexion, extension, lateral bending, and rotation was performed to compare range of motion (ROM), intradiscal pressure, the facet joint force, the maximum Von Mises stress and the peak facet contact forces, between Coflex and X-STOP devices. RESULTS: Compared to the mild degenerated lumbar segment model at surgical level L4-L5, Coflex and X-STOP could reduce ROM in extension by 98.34% and 95.86%, respectively, decrease peak stress of intervertebral discs in extension by 59.4% and 66.17%, respectively, and release peak force of facet joint in extension by 97.09% and 95.42%, respectively. Both devices had no significant impact on adjacent levels. The maximum Von Mises stress in Coflex device was 637.56 Mpa in flexion, 528.86 Mpa in extension, while the maximum Von Mises stress in X-STOP device was 476.65 Mpa at extension position. The peak facet contact forces of Coflex and X-STOP devices appeared in extension and were 19.76 Mpa and 49.28 Mpa, respectively. CONCLUSIONS: Coflex and X-STOP devices can effectively decrease the ROM and intradiscal pressure in extension, without affecting the adjacent levels.

Construction and validation of nomogram to predict distant metastasis in osteosarcoma: a retrospective study.

BACKGROUND: Osteosarcoma is most common malignant bone tumors. OS patients with metastasis have a poor prognosis. There are few tools to assess metastasis; we want to establish a nomogram to evaluate metastasis of osteosarcoma. METHODS: Data from the Surveillance, Epidemiology, and End Results (SEER) database of patients with osteosarcoma were retrieved for retrospective analysis. We identify risk factors through univariate logistic regression and multivariate logistic regression analysis. Based on the results of multivariate analysis, we established a nomogram to predict metastasis of patients with osteosarcoma and used the concordance index (C-index) and calibration curves to test models. RESULTS: One thousand fifteen cases were obtained from the SEER database. In the univariate and multivariate logistic regression analysis, age, primary site, grade, T stage, and surgery are risk factors. The nomogram for metastasis was constructed based on these factors. The C-index of the training and validation cohort was 0.754 and 0.716. This means that the nomogram predictions of patients with metastasis are correct, and the calibration plots also show the good prediction performance of the nomogram. CONCLUSION: We successfully develop the nomogram which can reliably predict metastasis in different patients with osteosarcoma and it only required basic information of patients. The nomogram that we developed can help clinicians better predict the metastasis with OS and determine postoperative treatment strategies.

Bioinformatics analysis, codon optimization and expression of ovine pregnancy associated Glycoprotein-7 in HEK293 cells.

Pregnancy-associated glycoproteins (PAGs) are widely used as powerful markers for early pregnancy diagnosis in livestock. To improve expression efficiency of recombinant ovine pregnancy-associated glycoprotein-7 (ovPAG-7) in HEK293 cells, the codon usage bias of the ovPAG-7 gene was analyzed using bioinformatic approaches, after which the DNA sequence encoding ovPAG-7 was designed, synthesized, and expressed in HEK293. The structure and function of ovPAG-7 were predicted using bioinformatics software and online databases. The results showed that the effective number of codons (NEC) of the ovPAG-7 gene was 56.82, indicating that the ovPAG-7 gene was weakly biased. ovPAG-7 gene had 26 biased codons (relative synonymous codon usage (RSCU) > 1), 15 of which were biased towards G/C at the third position. After codon optimization, the codon adaptation index of the ovPAG-7 gene increased from 0.74 to 0.96, and its GC content changed from 46.6 to 58.6%. The amino acid sequence encoded by the optimized gene was entirely consistent with those published in Gen Bank. Western blot analysis indicated that the recombinant ovPAG-7 protein with a relative molecular mass of 48 kDa was successfully expressed in HEK293 cells. The bioinformatics prediction results showed that ovPAG-7 protein contained 3 N-glycosylation sites, 13 B-cell epitopes, and a signal peptide consisting of 15 amino acids at the N terminus. The secondary structure of the ovPAG-7 protein was predicted to consist of random coils (46.85%), extended strands (32.05%), α-helices (16.16%), and ß-turns (4.93%). This study provided a tool for the screening of monoclonal antibodies and functional research on ovPAG-7.

Graphene Oxide Nanoparticle-Loaded Ginsenoside Rg3 Improves Photodynamic Therapy in Inhibiting Malignant Progression and Stemness of Osteosarcoma.

Osteosarcoma serves as a prevalent bone cancer with a high metastasis and common drug resistance, resulting in poor prognosis and high mortality. Photodynamic therapy (PDT) is a patient-specific and non-invasive tumor therapy. Nanoparticles, like graphene oxide have been widely used in drug delivery and PDT. Ginsenoside Rg3 is a principal ginseng component and has presented significant anti-cancer activities. Here, we constructed the nanoparticles using GO linked with photosensitizer (PS) indocyanine green (ICG), folic acid, and polyethylene glycol (PEG), and loaded with Rg3 (PEG-GO-FA/ICG-Rg3). We aimed to explore the effect of PEG-GO-FA/ICG-Rg3 combined with PDT for the treatment of osteosarcoma. Significantly, we found that Rg3 repressed proliferation, invasion, and migration, and enhanced apoptosis and autophagy of osteosarcoma cells, while the PEG-GO-FA/ICG-Rg3 presented a higher activity, in which NIR laser co-treatment could remarkably increase the effect of PEG-GO-FA/ICG-Rg3. Meanwhile, stemness of osteosarcoma cell-derived cancer stem cells was inhibited by Rg3 and PEG-GO-FA/ICG-Rg3, and the combination of PEG-GO-FA/ICG-Rg3 with NIR laser further significantly attenuated this phenotype in the system. Moreover, NIR laser notably improved the inhibitor effect of PEG-GO-FA/ICG-Rg3 on the tumor growth of osteosarcoma cells in vivo. Consequently, we concluded that PEG-GO-FA/ICG-Rg3 improved PDT in inhibiting malignant progression and stemness of osteosarcoma cell. Our finding provides a promising and practical therapeutic strategy for the combined treatment of osteosarcoma.

LncRNA ZFAS1 promotes growth and metastasis by regulating BMI1 and ZEB2 in osteosarcoma.

Osteosarcoma (OS) is the most common malignant bone tumor in children and adolescents. LncRNAs have recently gained widespread attention and have been shown to have crucial roles in various biological regulatory processes. ZFAS1, a newly identified lncRNA, was shown to be dysregulated in several cancers. However, little is known about the alteration and functional significance of ZFAS1 in OS. In the present study, for the first time, we revealed a functional role of ZFAS1 on OS growth and metastasis. The expression of ZFAS1 was significantly overexpressed in OS samples and cell lines, and upregulation of ZFAS1 is significantly associated with unfavorable prognosis of OS patients. Functional assays also demonstrated that ZFAS1 enhanced the growth and metastatic ability of OS cells in vitro and in vivo. Mechanistically, we found that ZFAS1 positively regulated malignant phenotypes by competitively binding the miR-200b and miR-200c and upregulating BMI1. ZFAS1 also interacted with ZEB2 and regulated ZEB2 protein stability. Furthermore, we demonstrated that SP1 functions as an upstream activated factor of ZFAS1. ZFAS1 may be a potential therapeutic target for OS tumorigenesis and progression.

Flexible meso-Bis(sulfinyl) Ligands as Building Blocks for Copper(II) Coordination Polymers: Cavity Control by Varying the Chain Length of Ligands.

Fillings and cavities: Three novel pseudo-octahedral metal-organic frameworks, 1-3, consisting of macrometallacyclic noninterpenetrating meso networks and exhibiting weak antiferromagnetic interactions, have been constructed from CuII centers and structurally flexible R,S-bis(sulfinyl) ligands. Varying the chain length of ligands is found to control the cavity sizes of the networks.

[Comparison of effectiveness between laminoplasty and laminectomy decompression and fusion with internal fixation for cervical spondylotic myelopathy].

OBJECTIVE: To compare the clinical and radiographic outcomes between laminoplasty and laminectomy compression and fusion with internal fixation to treat cervical spondylotic myelopathy. METHODS: Between September 2006 and September 2009, 143 cases of multilevel cervical myelopathy (the affected segments were more than 3) were treated by laminoplasty in 87 cases (group A) and by laminectomy decompression and fusion with lateral mass screw fixation in 56 cases (group B). There was no significant difference in gender, age, disease duration, pathological type, and affected segments between 2 groups (P > 0.05). The operation time, intraoperative blood loss, improvement of neurological function [Japanese Orthopaedic Association (JOA) 17 score], and the incidences of complications were observed; the cervical curvature index (CCI), range of motion (ROM), and symptoms of neck and shoulder pain [visual analogue scale (VAS) and neck disability index (NDI) scores] were recorded and compared. RESULTS: There was no significant difference in operation time and intraoperative blood loss between 2 groups (P > 0.05). All patients were followed up 18-30 months (mean, 24 months). C5 nerve root palsy occurred in 4 cases (4.60%) of group A and in 5 cases (8.93%) of group B, showing no significant difference (chi2 = 0.475, P = 0.482). No complication of deep infection, pseudarthrosis, or screw loosening occurred. No closure of opened laminae was observed in group A; and no screw extrusion, breakage, or nerve injury was observed in group B. At last follow-up, neck axial symptoms appeared in 35 cases (40.23%) of group A and in 11 cases (19.64%) of group B, showing significant difference (chi2 = 6.612, P = 0.009). No significant difference was found in JOA score, CCI, ROM, or VAS scores between 2 groups at preoperation (P > 0.05); the JOA score, ROM, and VAS scores of groups A and B and CCI of group A at last follow-up were significantly improved when compared with preoperative ones (P < 0.05). No significant difference was found in the JOA score, improvement rate, and VAS score between 2 groups (P > 0.05); however, significant differences were found in ROM and CCI between 2 groups (P < 0.05). There were significant differences (P < 0.05) in pain intensity, lifting, work, reaction, driving, and total score between 2 groups at last follow-up. CONCLUSION: Laminectomy decompression and fusion with internal fixation can effectively relieve pain, but it will greatly reduce the ROM; laminoplasty has less complications and satisfactory outcome. The two methods have similar effectiveness in the improvement of neurological function.

[Clinical analysis of C5 nerve root palsy in hinge side and different angles in lamina open-door after expansion of open-door cervical laminoplasty].

OBJECTIVE: To evaluate and compare the relation of the clinical results of expansion of open-door cervical laminoplasty (EOLP), C5 nerve root palsy in hinge side, and reclose of the opened laminae with different angles in lamina open-door. METHODS: Between July 2006 and January 2009, 198 patients with cervical myelopathy were treated by EOLP. According to different opening angles which were measured by CT scan after operation, the patients were divided into group A (> 30 degrees, 76 patients including 44 males and 32 females) and group B (15-30 degrees, 122 patients including 71 males and 51 females). There was no significant difference in gender, age, disease duration, and segmental lesions between 2 groups (P > 0.05). The Japanese Orthopaedic Association (IOA) score before and after operation was used for neurological assessment and improvement rate, and the postoperative C5 nerve root palsy and reclose of the opened laminae were recorded. RESULTS: There was no significant difference in operation time, bleeding volume, and hospitalization days between 2 groups (P > 0.05). After 3 weeks of operation, C5 nerve root palsy in the hinge side occurred in 7 patients (9.2%) of group A, and in 2 patients (1.6%) of group B, were restored after symptomatic treatment, showing significant difference between 2 groups (chi2 = 4.568, P = 0.033). All patients were followed up 24 to 48 months. Between group A and group B, no significant difference was found in JOA improvement rate at 24 months after operation (P > 0.05), and in JOA score at preoperation and at 24 months after operation (P > 0.05), but JOA score was significantly improved at 24 months after operation when compared with preoperative score in the same group (P < 0.05). The function of limb lifting restored in 9 cases of C5 nerve root palsy at 24 months after operation; CT examination revealed that no reclose occured in group A and reclose occurred in 4 cases (3.3%) of group B, but no persistent symptoms or worsen situation were found during follow-up. CONCLUSION: Different angles in lamina open-door have the same clinical result; C5 nerve palsy has good prognosis. The opening angle between 15 degrees and 30 degrees will reduce the incidence of C5 nerve root palsy in the hinge side, but the open side should be firmly fixed to prevent further reclose of the opened laminae.