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991.
Erosive wear due to the fact of sand severely affects hydrocarbon production industries and, consequently, various sectors of the mineral processing industry. In this study, the effect of the elbow geometrical configuration on the erosive wear of carbon steel for silt–water–air flow conditions were investigated using material loss analysis, surface roughness analysis, and microscopic imaging technique. Experiments were performed under the plug flow conditions in a closed flow loop at standard atmospheric pressure. Water and air plug flow and the disperse phase was silt (silica sand) with a 2.5 wt % concentration, and a silt grain size of 70 µm was used for performing the tests. The experimental analysis showed that silt impact increases material disintegration up to 1.8 times with a change in the elbow configuration from 60° to 90° in plug flow conditions. The primary erosive wear mechanisms of the internal elbow surface were sliding, cutting, and pit propagation. The maximum silt particle impaction was located at the outer curvature in the 50° position in 60° elbows and the 80° position in 90° elbows in plug flow. The erosion rate decreased from 10.23 to 5.67 mm/year with a change in the elbow angle from 90° to 60°. Moreover, the microhardness on the Vickers scale increased from 168 to 199 in the 90° elbow and from 168 to 184 in the 60° elbow.  相似文献   
992.
BACKGROUND: Results of core vitrectomy in post-traumatic endophthalmitis are poor. Our initial results of complete vitrectomy with primary silicone oil endotamponade were promising. A comparative study of this procedure with conventional core vitrectomy was therefore carried out. METHODS: A prospective randomized controlled study of 24 consecutive cases of post-traumatic endophthalmitis was conducted. Patients were randomized into two groups in the absence of clinical improvement after primary tap and treatment with intravitreal vancomycin and amikacin: group 1 consisted of patients who underwent core vitrectomy alone, group 2 of patients who underwent complete vitrectomy with silicone oil endotamponade. All patients included in the study received intravenous antibiotics and underwent lensectomy. Patients were followed up 1, 2, 4 and 12 weeks postoperatively. In all patients of group 2, silicone oil was removed 6 weeks after primary surgery. The mean duration of follow-up was 112+/-55 days. RESULTS: Vision of 20/400 or better was obtained in 58.33% of cases (14/24). Visual acuity of only one patient in group 1 was >or=20/200, compared with that of 58.3% of patients (7/12) in group 2 ( P=0.02). Intra-operative retinal breaks were found in 50% (6/12) of the patients belonging to group 1, but did not affect the final visual outcome. In group 1, 33.33% (4/12) developed rhegmatogenous retinal detachment in the immediate post-operative period. Only one of these patients had useful final visual outcome after resurgery. CONCLUSION: Complete vitrectomy with primary silicone oil endotamponade is a useful treatment modality which improves the anatomical and functional results in post-traumatic endophthalmitis.  相似文献   
993.

Introduction

Lung cancer is a leading cause of cancer-related mortality in North America. In addition to tobacco smoking, inherited genetic factors can also influence the development of lung cancer. These genetic factors may lead to biologically distinct subsets of cancers that have different outcomes. We evaluated whether genetic sequence variants (GSVs) associated with lung cancer risk are associated with overall survival (OS) and progression-free survival (PFS) in stage-III-IV non-small-cell lung cancer (NSCLC) patients.

Methods

A total of 20 candidate GSVs in 12 genes previously reported to be associated with lung cancer risk were genotyped in 564 patients with stage-III or IV NSCLC. Multivariate Cox proportional hazard models adjusted for potential clinical prognostic factors were generated for OS and PFS.

Results

After taking into account multiple comparisons, one GSV remained significant: rs4975616 on chromosome 5p15.33, located near the TERT-CLPTM1L gene. The adjusted hazard ratio (aHR) for OS was 0.75 (0.69–0.91), p = 0.002; for PFS aHR was 0.74 (0.62–0.89), p < 0.001 for each protective variant allele. Results were similar in both Stage III (OS: aHR = 0.70; PFS: aHR = 0.71) and Stage IV patients (OS: aHR = 0.81; PFS: aHR = 0.77).

Conclusion

A GSV on 5p15.33 is not only a risk factor for lung cancer but may also be associated with survival in patients with late stage NSCLC. If validated, GSVs may define subsets of patients with different risk and prognosis of NSCLC.  相似文献   
994.
Type 2 diabetes mellitus (T2DM) and its associated complications have become a crucial public health concern in the world. According to the literature, chronic inflammation and the progression of T2DM have a close relationship. Accumulated evidence suggests that inflammation enhances the insulin secretion lost by islets of Langerhans and the resistance of target tissues to insulin action, which are two critical features in T2DM development. Based on recently highlighted research that plasma concentration of inflammatory mediators such as tumor necrosis factor α and interleukin-6 are elevated in insulin-resistant and T2DM, and it raises novel question marks about the processes causing inflammation in both situations. Over the past few decades, microRNAs (miRNAs), a class of short, noncoding RNA molecules, have been discovered to be involved in the regulation of inflammation, insulin resistance, and T2DM pathology. These noncoding RNAs are specifically comprised of RNA-induced silencing complexes and regulate the expression of specific protein-coding genes through various mechanisms. There is extending evidence that describes the expression profile of a special class of miRNA molecules altered during T2DM development. These modifications can be observed as potential biomarkers for the diagnosis of T2DM and related diseases. In this review study, after reviewing the possible mechanisms involved in T2DM pathophysiology, we update recent information on the miRNA roles in T2DM, inflammation, and insulin resistance.  相似文献   
995.
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