Subnoise detection of a fast random event.

Observation of random, nonrepetitive phenomena is of critical importance in astronomy, spectroscopy, biology, and remote sensing. Heralded by weak signals, hidden in noise, they pose basic detection challenges. In contrast to repetitive waveforms, a single-instance signal cannot be separated from noise through averaging. Here, we show that a fast, randomly occurring event can be detected and extracted from a noisy background without conventional averaging. An isolated 80-picosecond pulse was received with confidence level exceeding 99%, even when accompanied by noise. Our detector relies on instantaneous spectral cloning and a single-step, coherent field processor. The ability to extract fast, subnoise events is expected to increase detection sensitivity in multiple disciplines. Additionally, the new spectral-cloning receiver can potentially intercept communication signals that are presently considered secure.

Two-fold transmission reach enhancement enabled by transmitter-side digital backpropagation and optical frequency comb-derived information carriers.

We demonstrate a two-fold reach extension of 16 GBaud 16-Quadrature Amplitude Modulation (QAM) wavelength division multiplexed (WDM) system based on erbium doped fiber amplifier (EDFA)-only amplified standard and single mode fiber -based link. The result is enabled by transmitter-side digital backpropagation and frequency referenced carriers drawn from a parametric comb.

APPLIED OPTICS. Overcoming Kerr-induced capacity limit in optical fiber transmission.

Nonlinear optical response of silica imposes a fundamental limit on the information transfer capacity in optical fibers. Communication beyond this limit requires higher signal power and suppression of nonlinear distortions to prevent irreversible information loss. The nonlinear interaction in silica is a deterministic phenomenon that can, in principle, be completely reversed. However, attempts to remove the effects of nonlinear propagation have led to only modest improvements, and the precise physical mechanism preventing nonlinear cancellation remains unknown. We demonstrate that optical carrier stability plays a critical role in canceling Kerr-induced distortions and that nonlinear wave interaction in silica can be substantially reverted if optical carriers possess a sufficient degree of mutual coherence. These measurements indicate that fiber information capacity can be notably increased over previous estimates.

High-speed, rate-scalable photonic-assisted digitizer equalization by frequency comb referencing.

A scalable analog-to-digital converter based on polychromatic sampling and optical-domain frequency referencing is described. The new architecture relies on low-distortion replication of an optical signal to spectrally distinct copies and subsequent polychromatic parametric sampling. Frequency comb referencing of parametric replication and sampling was used to convert processor distortions into quasi-stationary impairments and enable a practical equalization implementation. The operation of the new digitizer was demonstrated at 30 GS/s, achieving 6.5 effective number of bits in the first Nyquist zone. In contrast to conventional analog-to-digital converters, the new preprocessor sampling bandwidth is not restricted to the first Nyquist zone, and can operate in the second and third Nyquist zones beyond 40 GHz.

Ultrafast optics. Ultrafast optical control by few photons in engineered fiber.

Fast control of a strong optical beam by a few photons is an outstanding challenge that limits the performance of quantum sensors and optical processing devices. We report that a fast and efficient optical gate can be realized in an optical fiber that has been engineered with molecular-scale accuracy. Highly efficient, distributed phase-matched photon-photon interaction was achieved in the fiber with locally controlled, nanometer-scale core variations. A three-photon input was used to manipulate a Watt-scale beam at a speed exceeding 500 gigahertz. In addition to very fast beam control, the results provide a path to developing a new class of sensitive receivers capable of operating at very high rates.

The correlation between parental education and their knowledge of asthma.

OBJECTIVE: To evaluate the impact of parental education on the success of Asthma Educational Intervention (AEI). METHODS: AEI took place after the children's hospitalisation. Parental asthma knowledge was assessed at three time points: before AEI, immediately after, and 12 months later. The Intervention (I) group of parents (N=231) received complete AEI. The Control (C) group of parents (N=71) received instructions for proper use of asthma medications and the handbook. RESULTS: Asthma knowledge in I group increased immediately after the AEI (p<0.01), and had not changed (p>0.05) 12 months later. There were four subgroups in group I divided based on education level: elementary school, high school, college, and university degrees. Taking into account the parental education level, there were no differences in the baseline and final knowledge of asthma between subgroups (p>0.05). The number of asthma exacerbations decreased after AEI (5.96:2.50, p<0.01), regardless of the parental degree. Knowledge of asthma in group C did not improve during the study (p=0.17). Final asthma knowledge was higher in group I compared to group C (p<0.01). CONCLUSION: The parental education level did not influence the level of asthma knowledge after the AEI. The motivation and the type of asthma education had the greatest input on the final results. PRACTICE IMPLICATIONS: All parents should be educated about asthma regardless of their general education.

Exposure to tobacco smoke among asthmatic children: parents' smoking habits and level of education.

SETTING: Children's Hospital for Respiratory Diseases and Tuberculosis, Belgrade, Serbia. OBJECTIVES: To compare parents' educational level and smoking habits with asthma in children exposed to environmental tobacco smoke (ETS) and in those not exposed. METHODS: In this cross-sectional study, 231 asthmatic children (average age 10.6 years, 49% boys) from smoking and non-smoking families were compared by birth weight, birth length, first episode of wheezing, number of respiratory infections and exacerbations per year, severity of asthma, number of hospitalisations, total serum immunoglobulin E (IgE), skin prick tests and allergic manifestations. RESULTS: In our study, 77% of the children were from smoking families: 45.9% had active smoking mothers and 51% active smoking fathers. Smoking was more common among parents with lower education level. The mother being the only smoker in the family had a greater impact on respiratory infections and asthma exacerbations in the first years of life; however, after the third year, the effect of having both smoking parents was important. Children exposed to ETS had more allergic manifestations. The percentage of children with both non-smoking parents decreased and that of children with both smoking parents increased with increasing asthma severity (χ(2) = 17.73, P < 0.05). CONCLUSION: ETS has a negative impact on illness among children with asthma.

Duckweed Lemna minor as a tool for testing toxicity and genotoxicity of surface waters.

In this investigation growth parameters and certain endpoints (pigment content, peroxidase activity, lipid peroxidation and alkaline comet assay) were used to detect the toxic and genotoxic effects of surface water samples on duckweed plants. The surface waters of different origin and pollutant burdens were collected monthly over a 3-month monitoring period at three sampling sites along the river Sava and its confluents (Croatia). Physicochemical characterization of the water samples included measurements of conductivity, chemical and biological oxygen demand, levels of total suspended solids, nitrate, nitrite, ammonium, Kjeldahl nitrogen and orthophosphate. Surface water samples collected from three stations caused reduction of duckweed growth rates, chlorophylls and carotenoid contents and peroxidase activity. In contrast, damage to membrane lipids (estimated by malondialdehyde content) and especially to DNA (estimated by tail extent moment) markedly increased in duckweed exposed to industrial wastewater samples. The results from the study indicate the ability of selected biomarkers to predict the phyto- and genotoxic effects of complex water mixtures on living organisms as well as the relevance of duckweed as a sensitive indicator of water quality.

Perfil clínico, epidemiológico y quirúrgico de pacientes operados por cáncer renal en el Hospital Naval Almirante Nef / Clinical, epidemiological and surgical profile of renal cancer patients at Hospital Naval Almirante Nef

Introducción: El cáncer renal ocupa el tercer lugar dentro de los tumores genitourinarios y el 3 por ciento de los tumores malignos primarios, siendo el cáncer urológico con mayor mortalidad y cuya incidencia ha aumentado a nivel mundial. Material y método: Revisión retrospectiva de las fichas de todos los pacientes con diagnóstico de cáncer renal que fueron nefrectomizados o tumorectomizados entre los años 1999 y 2009 en el Hospital Naval Almirante Nef de Viña del Mar, con un total de 135 pacientes. Resultados: Observamos un aumento importante en el número de casos el año 2009, siendo más frecuente en hombres durante los diez años revisados. La media de la edad fue de 61,81 años y la mayoría no presentaba factores de riesgo. Cuarenta y ocho por ciento de los casos diagnosticados fueron hallazgos y 60 por ciento de éstos se encontraban en etapa I. El síntoma más frecuente fue el dolor abdominal. Setenta por ciento de los casos fueron diagnosticados por ecotomografía abdominal y 12 por ciento por pielotac. El 11 por ciento de los pacientes presentaron metástasis posquirúrgicas, siendo la mayoría a pulmón seguido de hígado. De éstos, 20 por ciento habían presentado tumores primarios menores de 7 cm. Conclusión: La incidencia del cáncer renal va en aumento y el diagnóstico precoz de lesiones asintomáticas y de bajo volumen que presentan un porcentaje no despreciable de infiltración tumoral, sugieren un manejo quirúrgico agresivo.

Introduction: Renal cancer represents the third most common cancer within genitourinary tumors and3 percent of all primary malignant tumors. It is the urological cancer with the most mortality rate and it´s incidence has increased worldwide. Methods: Restrospective review of the medical records of every patient diagnosed with renal cancer who where nephrectomized or tumorectomized between the years 1999 and 2009 at Hospital Naval Almirante Nef, Viña del Mar, with a total of 135 patients. Results: There was an important increase in the number of cases in 2009. The higher frequency in men was maintained during the years studied. The mean age was 61.81 years and most of the patients didn’t have any risk factors. 40 percent of the diagnosed cases were asymptomatic findings and 60 percent of them where on stage I. The most frequent symptom was abdominal pain. 70 percent of all cases where diagnosed by abdominal ecotomography and 12 percent CT without contrast. 11 percent of the patients presented post-surgical metastasis, most of them to lung followed by liver. 20 percent of them had primary tumors smaller than 7 cm. Conclusion: The incidence of renal cancer is increasing and the early diagnosis of asymptomatic and small lesions which in an important percentage have tumoral infiltration suggest an aggressive surgical treatment.

Quantum frequency translation of single-photon states in a photonic crystal fiber.

We experimentally demonstrate frequency translation of a nonclassical optical field via four-wave mixing (Bragg-scattering process) in a photonic crystal fiber (PCF). The high nonlinearity and the ability to control dispersion in PCF enable efficient translation between nearby photon channels within the visible to-near-infrared spectral range, useful in quantum networks. Heralded single photons at 683 nm were translated to 659 nm with an efficiency of 28.6±2.2 percent. Second-order correlation measurements on the 683- and 659-nm fields yielded g(683)(2) (0)=0.21±0.02 and g(659)(2) (0)=0.19±0.05, respectively, showing the nonclassical nature of both fields.

Bandwidth-efficient phase modulation techniques for stimulated Brillouin scattering suppression in fiber optic parametric amplifiers.

Two novel bandwidth efficient pump-dithering Stimulated Brillouin Scattering (SBS) suppression techniques are introduced. The techniques employ a frequency-hopped chirp and an RF noise source to impart phase modulation on the pumps of a two pump Fiber Optical Parametric Amplifier (FOPA). The effectiveness of the introduced techniques is confirmed by measurements of the SBS threshold increase and the associated improvements relative to the current state of the art. Additionally, the effect on the idler signal integrity is presented as measured following amplification from a two pump FOPA employing both techniques. The measured 0.8 dB penalty with pumps dithered by an RF noise source, after accruing 160 ps/nm of dispersion with 38 dB conversion gain in a two-pump FOPA is the lowest reported to date.

Monitoring levels of nephrotoxicity of different aminoglycosides during febrile neutropenia caused by nephrotoxic chemotherapy: a single centre study.

PURPOSE: To investigate the possible existence of increased nephrotoxicity caused by once-daily aminoglycosides in febrile neutropenic patients who were previously treated with cisplatin-based nephrotoxic chemotherapy. METHODS: Thirty-one patients with metastatic tumors received chemotherapy and, as a result, developed febrile neutropenia. Patients were stratified with regard to chemotherapy with cisplatin (n=15) or without cisplatin (n=16). Both groups received i.v. empiric antibiotic treatment which included combinations of once-daily aminoglycosides (amikacin vs. gentamicin) with beta-lactams. RESULTS: Increased nephrotoxicity due to administered aminoglycosides appeared significantly more frequently (p<0.05) in patients who received cisplatin-based chemotherapy. Increased nephrotoxicity differed significantly between various aminoglycosides regimens (p<0.05), being greater in the gentamicin group. CONCLUSION: These results showed that cisplatin-based chemotherapy followed by a once-daily aminoglycosides regimen caused increased renal toxicity, which was more pronounced in patients treated with gentamicin vs. those treated with amikacin.

Short wavelength infrared frequency conversion in ultra-compact fiber device.

Linear and nonlinear characteristics of devices using millimeter-scale spools of highly nonlinear fiber are experimentally investigated within 2000-2400nm spectral range. Coils with radius larger than 3.5 mm indicate that macro-bending induced radiation loss is negligible up to 2400nm. Devices with smaller diameter coiling resulted in macro-bending losses that dominate over micro-bending losses beyond 2200nm. A tunable short-wave infrared source was constructed using a coin-sized fiber module to demonstrate an efficient nonlinear conversion from 1.26 to 2.2 microm.

1 micros tunable delay using para-metric mixing and optical phase conjugation in Si waveguides: comment.

A recent report of 1 micros all-optical delay using silicon convertor elements in the 1550-nm band is analyzed.

[Precision TACE in therapy of primary malignant tumors of liver/hepatocellular carcinoma (HCC)].

AIM: Hepatocellular carcinoma is one of the most frequent malignant tumors in general and most common liver malignancy. Aim of this study was to determine the therapeutic effect of chemoembolization with microspheres charged with doxorubicin in HHC patients. MATERIAL AND METHODS: During for period of four-year (November 2005- November 2009) at Institute of radiology CC Ni transarterial chemoembolization procedures (precision TACE) was performed on 27 patients. There were 17 male and 10 female patients with average age of 62 years. Total number of 64 TACE interventions were done in total, minimally one, maximally 6 per patient. HCC was pathophysiologically verified in all patients included in this study. After selective catheterization of tumor feeding artery, followed by application of microspheres a follow-up study with evaluation of therapeutic effects was conducted. RESULTS: Patients were enrolled in the study and followed four years in total. The therapy effects were estimated according to RECIST criteria. CONCLUSION: Precision TACE represents effective and controlled method for application of chemotherapeutic agencies with reduced systemic toxicity. Our preliminary results show increased therapeutic efficacy, diminished mortality and subsequently prolonged survival rate and improved quality of life in patients with HCC.

Agreement in patient-physician communication in primary care: a study from Central and Eastern Europe.

OBJECTIVE: Efficient patient-physician collaboration is proven to have a direct benefit on health care outcomes through improved compliance, appointment keeping and use of preventive services. The aim of this study was to evaluate the patient-physician agreement on communication during primary care consultations and consider possible discrepancies. METHODS: A cross-sectional survey using self-administered questionnaires was performed in primary care in four European countries (Lithuania, Slovenia, Serbia and Russia). Post-consultation evaluations of doctor-patient communication were made by patients and physicians and were compared with pre-consultation expectations of the patient. Discrepancies in these evaluations were determined for the entire database, and within groups of expectations, using factor analysis. RESULTS: One thousand three hundred and thirty-two sets of questionnaires were collected by the study team. In this sample, in more than 90% of consultations physicians and patients agreed about meeting patient expectations. Discrepancies were more likely to be identified when the patients were consulting the physician for the first time or had not seen that physician for more than 12 months (up to 26.1%). There is a significantly lower correlation between the physician recognising patient's unmet expectations for all factors if the physician had been working in Primary Care for between 6 and 10 years (8.6%). The results demonstrate that physicians working more than 16 years in practice are less likely to recognise that they have failed to meet the expectations of patients who are seeking reassurance (9%). CONCLUSION: Personal continuity of care is associated with a lower discrepancy between the opinions of patients and physicians regarding meeting patient expectations during consultations in primary care. The highest agreement is within first 6 years in practice, which may reflect long-term effects of training. PRACTICE IMPLICATIONS: Primary care physicians should put more emphasis on identifying and addressing patient expectations in primary care consultation, including agreement with patient. Existing discrepancies may be considered to be indicators of potential opportunities to improve physician's performance and overall quality of care.

Multicolor multipartite entanglement produced by vector four-wave mixing in a fiber.

Multipartite entanglement is a resource for quantum communication and computation. Vector four-wave mixing (FWM) in a fiber, driven by two strong optical pumps, couples the evolution of four weak optical sidebands (modes). Depending on the fiber dispersion and pump frequencies, the mode frequencies can be similar (separated by less than 1 THz) or dissimilar (separated by more than 10 THz). In this report, the discrete- and continuous-variable entanglement produced by vector FWM is studied in detail. Formulas are derived for the variances of, and correlations between, the mode quadratures and photon numbers. These formulas and related results show that the modes are four-partite entangled.

730-nm optical parametric conversion from near- to short-wave infrared band.

A record 730 nm parametric conversion in silica fiber from the near-infrared to the short-wave infrared band is reported and analyzed. A parametric gain in excess of 30 dB was measured for a signal at 1300 nm (with corresponding idler at 2030 nm). This conversion was performed in a travelling single-pass one-pump parametric architecture and high efficiency is achieved by a combination of high peak power and a nonlinear fiber with a reduced fourth-order dispersion coefficient.

Unimpaired phase-sensitive amplification by vector four-wave mixing near the zero-dispersion frequency.

Phase-sensitive amplification (PSA), which is produced by degenerate four-wave mixing (FWM) in a randomly-birefringent fiber, has the potential to improve the performance of optical communication systems. Scalar FWM, which is driven by parallel pumps, is impaired by the generation of pump-pump and pump-signal harmonics, which limit the level, and modify the phase sensitivity, of the signal gain. In contrast, vector FWM, which is driven by perpendicular pumps, is not impaired by the generation of harmonics. Vector FWM produces PSA with the classical properties of a one-mode squeezing transformation.