Spatially resolving amplitude and phase of light with a reconfigurable photonic integrated circuit

Photonic integrated circuits (PICs) play a pivotal role in many applications. Particularly powerful are circuits based on meshes of reconfigurable Mach-Zehnder interferometers as they enable active processing of light. Various possibilities exist to get light into such circuits. Sampling an electromagnetic field distribution with a carefully designed free-space interface is one of them. Here, a reconfigurable PIC is used to optically sample and process free-space beams so as to implement a spatially resolving detector of amplitudes and phases. In order to perform measurements of this kind we develop and experimentally implement a versatile method for the calibration and operation of such integrated photonics based detectors. Our technique works in a wide parameter range, even when running the chip off the design wavelength. Amplitude, phase and polarization sensitive measurements are of enormous importance in modern science and technology, providing a vast range of applications for such detectors

Simulation in coronary artery anastomosis early in cardiothoracic surgical residency training: The Boot Camp experience

We evaluated focused training in coronary artery anastomosis with a porcine heart model and portable task station

Electron beam irradiation of low-density polyethylene filled with metal hydroxides for wire and cable applications

The effects of electron beam irradiation for crosslinking of polymers used for wire and cable insulations are still being researched. In this research, the influence of electron beam irradiation on the different blends of low-density polyethylene (LDPE) filled with aluminum trihydrate and magnesium hydroxide (ATH, MH) were studied. It was revealed by melt flow index, tensile strength, and elongation at break tests that addition of MH to LDPE increases the adhesion forces inside polymer matrices more efficient than similar ATH/LDPE compounds. Field emission scanning electron microscopy test showed that MH is platy in structure and more homogenous mixed than ATH with LDPE. The results on thermogravimetric analysis and limiting oxygen index tests revealed that the thermal stability and incombustibility properties of MH blends are more efficient than similar ATH blends. Meanwhile, it was observed by smoke density test that MH blends produce the lowest smoke density compared with virgin LDPE and similar ATH blends. It was also observed that increasing irradiation by electron beam had impressive affections on the density, gel content, and mechanical properties for all the polymeric samples in this study

Relationship Between ADPKD and Post-Renal Transplant Diabetes Mellitus

Background: Autosomal-dominant polycystic kidney disease (ADPKD), a common hereditary disease, is characterized by the progressive development and enlargement of multiple cysts in both kidneys, and typically resulting in end stage renal disease (ESRD) by the fifth decade of life. Post-transplant diabetes mellitus (PTDM), a common complication after transplantation with an incidence rate of 2.5-20%, is associated with poor graft and patient survival. In few studies, PTDM has been more frequent in ADPKD transplanted patients. In the present study, we investigated whether there is any association between PTDM and ADPKD in our patients. Methods: In this prospective study, 140 non-diabetic and nonsmoker successfully transplanted patients (27 ADPKD and 113 non ADPKD patients) were enrolled during three years. Both groups were matched for age, sex, body mass index (BMI), duration of renal replacement therapy before transplantation and also immunosuppressive protocols after transplant. Post-transplant diabetes mellitus was defined as Clinical Practice Guidelines advocated by Canadian Diabetes Association. All patients were followed for 12 months. Results: PTDM occurred in 11.1% of ADPKD patients and in 13.1% of control group which was statistically insignificant (P > 0.05). The development of PTDM in ADPKD group was not related to sex, age, and hypertension, duration of renal replacement therapy before transplantation, BMI and serum creatinine levels (P > 0.05). Conclusion: Post-transplant diabetes mellitus appears not to be associated with autosomal-dominant polycystic kidney disease as an etiology of end stage renal disease

Gamma Knife surgery combined with resection for treatment of a single brain metastasis: preliminary results.

OBJECT: Resection and whole-brain radiation therapy (WBRT) have classically been the standard treatment for a single metastasis to the brain. The objective of this study was to evaluate the use of Gamma Knife surgery (GKS) as an alternative to WBRT in patients who had undergone resection and to evaluate patient survival and local tumor control. METHODS: The authors retrospectively reviewed the charts of 150 patients treated with a combination of stereotactic radiosurgery and resection of a cranial metastasis at their institution between April 1997 and September 2009. Patients who had multiple lesions or underwent both WBRT and GKS were excluded, as were patients for whom survival data beyond the initial treatment were not available. Clinical and imaging follow-up was assessed using notes from clinic visits and MR imaging studies when available. Follow-up data beyond the initial treatment and survival data were available for 68 patients. RESULTS: The study included 37 women (54.4%) and 31 men (45.6%) (mean age 60 years, range 28-89 years). In 45 patients (66.2%) there was systemic control of the primary tumor when the cranial metastasis was identified. The median duration between resection and radiosurgery was 15.5 days. The median volume of the treated cavity was 10.35 cm(3) (range 0.9-45.4 cm(3)), and the median dose to the cavity margin was 15 Gy (range 14-30 Gy), delivered to the 50% isodose line (range 50%-76% isodose line). The patients\u27 median preradiosurgery Karnofsky Performance Scale (KPS) score was 90 (range 40-100). During the follow-up period we identified 27 patients (39.7%) with recurrent tumor located either local or distant to the site of treatment. The median time from primary treatment of metastasis to recurrence was 10.6 months. The patients\u27 median length of survival (interval between first treatment of cerebral metastasis and last follow-up) was 13.2 months. For the patient who died during follow-up, the median time from diagnosis of cerebral metastasis to death was 11.5 months. The median duration of survival from diagnosis of the primary cancer to last follow-up was 30.2 months. Patients with a pretreatment KPS score ≥ 90 had a median survival time of 23.2 months, and patients with a pretreatment KPS score \u3c 90 had a median survival time of 10 months (p \u3c 0.008). Systemic control of disease at the time of metastasis was not predictive of increased survival duration, although it did tend to improve survival. CONCLUSIONS: Although the debate about the ideal form of radiation treatment after resection continues, these findings indicate that GKS combined with surgery offers comparable survival duration and local tumor control to WBRT for patients with a diagnosis of a single metastasis

Craniofacial Approaches to Large Juvenile Angiofibromas: Clinical Article

Object. Craniofacial approaches provide excellent exposure to lesions in the anterior and middle cranial fossae. The authors review their experience with craniofacial approaches for resection of large juvenile nasopharyngeal angiofibromas. Methods. Between 1992 and 2009, 22 patients (all male, mean age 15 years, range 9-27 years) underwent 30 procedures. These cases were reviewed retrospectively. Results. Gross-total resection of 17 (77%) of the 22 lesions was achieved. The average duration of hospitalization was 8.2 days (range 3-20 days). The rate of recurrence and/or progression was 4 (18%) of 22, with recurrences occurring a mean of 21 months after the first resection. All patients underwent preoperative embolization. Nine patients (41%) developed complications, the most common of which was CSF leakage (23%). The average follow-up was 27.7 months (range 2-144 months). The surgery-related mortality rate was 0%. Based on their mean preoperative (90) and postoperative (90) Karnofsky Performance Scale scores, 100% of patients improved or remained the same. Conclusions. The authors\u27 experience shows that craniofacial approaches provide an excellent avenue for the resection of large juvenile nasopharyngeal angiofibromas, with acceptable rates of morbidity and no deaths