Carbon nanostructure-reinforced SiCw/Si3N4 composite with enhanced thermal conductivity and mechanical properties

Carbon nanostructures (CNS) as a kind of reinforcement material can remarkably enhance the mechanical and thermal properties of ceramics. This research presents an analysis of the influence of CNS on the thermal conductivity and mechanical properties of SiC_w/Si₃N₄ composites. The SiC_w/Si₃N₄ composites containing various types of CNS e.g. carbon nanofibers (CNF), multi-walled carbon nanotubes (MWCNT) and graphene nano-platelets (GNP) were fabricated by hot-press sintering. XRD analysis confirmed a complete transformation of α-Si₃N₄ to β-Si₃N₄ and microstructural analysis shows a uniform distribution, as well as a pullout and bridging mechanism of CNS. The results revealed that the thermal conductivity and mechanical properties of SiC_w/Si₃N₄ composites increased with the addition of CNS. Maximum values of fracture toughness (9.70 ± 0.8 MPa m^1/2) and flexural strength (765 ± 58 MPa) have been achieved for the MWCNT-containing SiC_w/Si₃N₄ composite, whereas the maximum values of Young''s modulus (250 ± 3.8 GPa) and hardness (27.2 ± 0.9 GPa) have been achieved for the CNF-containing SiC_w/Si₃N₄ composite. Moreover, thermal conductivity also improved with the addition of CNS and reached a maximum value of 110.6 W m⁻¹ K⁻¹ for the CNF-containing SiC_w/Si₃N₄ composite. This work provides a useful approach for the fabrication of high-performance multifunctional composites for emerging engineering applications.

Carbon nanostructures (CNS) as a kind of reinforcement material can remarkably enhance the mechanical and thermal properties of ceramics.     

鼻内镜下鼻中隔-歪鼻整形术后疗效评估方法的综合应用

目的：探讨鼻内镜下鼻中隔-歪鼻整形术后疗效的综合评估方法。方法：选择2006年12月～2011年12月入住我院整形科和耳鼻喉科需手术治疗的176例歪鼻并鼻中隔偏曲患者,应用VAS主观评估鼻外形满意度及鼻塞情况、鼻外形分度、鼻阻力测定、外鼻相关指标测量的方法对该组患者进行疗效评估。结果：176例患者术后鼻外形满意度为96.02%,100%患者鼻塞改善。从鼻外形分度来看,92.04%患者鼻外形恢复正常,100%的患者治疗有效。鼻阻力测定术后鼻腔0～5cm容积较术前明显增大;术后阻塞侧鼻腔的鼻气道阻力较术前也明显降低,差异具有统计学意义（P〈0.05）。外鼻相关指标的测量,鼻长、鼻深术后较术前有所增加,鼻背坡长、鼻面角、鼻额角、鼻翼角术后较术前有所缩小,差异具有统计学意义（P〈0.05）。结论：对于鼻内镜下鼻中隔-歪鼻整形术后疗效的评估,建议运用综合的评估方法,包括主观鼻外形满意度、鼻塞改善程度,鼻外形分度,鼻阻力测定,外鼻相关指标测量。     

The impact of lymph node status and features on oncological outcomes in urothelial carcinoma of the upper urinary tract (UTUC) treated by nephroureterectomy

Purpose

Prognostic impact of lymphadenectomy during radical nephroureterectomy (RNU) for urothelial carcinoma of the upper urinary tract (UTUC) is controversial. Our aim was to assess the impact of lymph node status (LNS) on survival in patients treated by RNU.

Methods

In our multi-institutional, retrospective database, 714 patients with non-metastatic UTUC had undergone RNU between 1995 and 2010. LNS was tested as prognostic factor for survivals through univariate and multivariable Cox regression analysis.

Results

Median age was 70 years [interquartile range (IQR), 60–75] with median follow-up of 27 months (IQR, 10–50). Overall, lymphadenectomy was performed in 254 patients (35.5 %). Among these patients, 204 (80 %) had negative lymph nodes (pN0) and 50 (20 %) had positive lymph nodes (pN1/2). The 5-year cancer-specific survival (CSS) was 81 % [95 % confidence interval (CI), 73–88 %] for pN0 patients, 85 % (95 % CI, 80–90 %) for pNx patients and 47 % (95 % CI, 24–69 %) for pN1/2 patients (p < 0.001). Metastasis-free survival (MFS) and overall survival (OS) rates were significantly lower in pN1/2 patients than in pN0 and pNx patients (p < 0.05). On multivariable analysis, LNS did not appear as an independent prognostic factor for CSS, OS or MFS (p > 0.05). In case of lymph node involvement, extra-nodal extension was marginally associated with worse CSS (log rank p = 0.07). The retrospective design was the main limitation.

Conclusion

LNS is helpful for survival stratification in patients treated with RNU for UTUC. However, LNS did not appear as an independent predictor of survival in this retrospective series and needs to be investigated in a large multicentre, prospective evaluation.     

Is there a relationship between attention deficit/hyperactivity disorder and Osgood–Schlatter disease?

Purpose

The purpose of this prospective study is to investigate the relationship between Osgood–Schlatter disease (OSD) and attention deficit/hyperactivity disorder (ADHD).

Methods

Seventy-four children with a diagnosis of OSD were referred to child and adolescent psychiatry department for the evaluation of ADHD. Diagnostic and Statistical Manual of Mental Disorders was used for diagnostic criteria.

Results

Diagnosis of ADHD was made in 56 (75.6 %) out of 74 children.

Conclusions

Results of this study suggest that ADHD is a significant risk factor for OSD. During the evaluation of a patient with OSD, a thorough history should be obtained about the behavioral symptoms that indicate underlying ADHD. In case of suspicion, these patients should be referred for an additional evaluation by a child psychiatrist.

Level of evidence

II.     

Unexpectedly ease surgery for a worrisome abdominal mass: Pedunculated GISTs

INTRODUCTIONDiscovery of abdominal masses often poses significant diagnostic difficulties. GISTs are mesenchymal masses, with specific histological features. Dimensions may vary from millimeters to giant tumours. We would like to present our case, which had an unexpectedly easy operative course which was easily handled with a simple surgical excision with a short operative duration.PRESENTATION OF CASEA 38 years old female patient was diagnosed to have an abdominal heterogen mass of 15 cm × 12 cm × 10 cm in dimension. Abdominal computed tomography revealed the solid mass between the stomach and pancreas corpus and tail, possibly orginating from the pancreas. With the preoperative diagnosis of locally invasive distal pancreas cancer the patient underwent laparotomy, following the dissection, the mass was observed to be originating from the posterior gastric Wall, extending exophytically with a peduncle of 5 cm in width, without any visual evidence for peritoneal invasion and metastasis. The tumour and the peduncle was resected with stapler device. Total operation time was 30 min. Postoperative course was uneventful. Pathologic diagnosis was gastrointestinal stromal tumour (GIST).DISCUSSIONPedunculated large GISTs are not frequent and they can enlarge as 15 cm in diameter and compress the neighbouring organs. When they were huge, it is difficult to differentiate the origin of the masses. GISTs should be considered in differential diagnosis of giant abdominal masses.CONCLUSIONWhen GISTs are huge and pedunculated, it can be difficult to differentiate the origin of the masses. This case report presents unexpectedly ease surgery for a worrysome abdominal mass.