Optical Receiver with an Inductorless Continuous-Time Feed-Forward Equalizer

The exponential growth in Internet traffic is partially an outcome of increasing social networking, cloud computing and the arrival of a variety of applications, for example, video streaming. Accordingly, it necessitates the deployment of robust data centers providing data transport at sufficiently high speed. By 2020, 77% of global data networking stays within data centers and the data traffic between data centers is about 9% reported by the Cisco Global Index 2014-2019. Short reach optical interconnects in the data centers satisfy the demand for transfer of such an increasing volume of data. In the year 2017, the ratio of optical to copper cabling in the data center has reached 60%. The firrst stage in an optical receiver is a transimpedance amplifier (TIA) which converts a small photocurrent into a voltage signal. Considering the thermal noise of the optical receiver as the dominant source of noise, improving the sensitivity of the optical receiver will lessen the transmitted optical power to establish a given bit error rate (BER). In a conventional TIA, the realizable gain declines as the data rate is pushed higher, requiring additional stages of main amplifiers and leading to a power-hungry receiver. Recently, high-gain but limited bandwidth front ends are proposed to achieve a high data rate with better noise performance and reduced power dissipation compared to conventional approaches. However, the reduced bandwidth introduces significant intersymbol interference (ISI). Discrete time feedforward equalization (DT-FFE) can cancel ISI. Nevertheless, charge injection and clock feedthrough in the sampling circuit can degrade the signal. Certain problems associated with discrete time approach is eliminated in proposed design employing a continuous time FFE (CT-FFE). The signal-to-noise ratio (SNR) at the output of TIA determines the sensitivity of the front-end optical receiver. Modeling both the TIA and its thermal noise, by the second-order response, the eye height and the root mean square (RMS) of the TIA thermal noise are investigated against the typical characteristics of the model. The root mean square (RMS) is formulated independently from the data rate. Consequently, the conditions for which SNR reaches the highest value are extracted. Afterward, a case study has been done for the shunt-feedback TIA using the above expressions to extract TIA design parameters with and without an equalizer. The gaol is to reduce the power consumption by increasing the sensitivity of the TIA. To this end, the above analyses assist us to replace a conventional TIA following by the power-hungry stages of amplifiers by a low-bandwidth TIA following with an equalizer. The proposed CT-FFE is designed in CMOS 65 nm technology. The power dissipation for the receive and decision circuit is about 13.15 mW from a 1-V supply. The front-end has an equivalent gain of 66dB. It has an input referred noise of 0.32 uArms, leading to an estimated noise-limited sensitivity of 4.48 uAp-p in the presence of a pad/photodiode capacitance of 100 fF

Comparing Pre-Writing Skills in Childern Having Attention Deficit and Hyperactivity Disorder (ADHD) with Normal Children of 4-6 Years of Old in Arak City in 2003-2004

Objectve: Attention deficit with hyperactivity disorder is one of the most important mental disorders in childhood (ADHD). The American Psychiatric Associated has estimated it’s out bread between 3-5 Percent. On the other hand, writing is also one of the special needs in every Body’s life, and any disorders and difficulties in it, may lead to Many problems in making social communication and learning. In the study, using one of the most efficient Prehensioble tests, and furtherly analyzed the pre – writing skills in ADHD children. The goal of this study is to compare ADHD children with normal children in age group of 4-6 years of old. Materials & Methods: The present study is a cross-sectional&case-control Study on 21 boys of about 4-6 years of old, without any mental disease record, orthopedic disease in hand either out any other affected diseases, and without the application of any occupational therapy. 21 boys of the some age were chosen as a control group. Pre – writing skills were analyzed utilizing EDPA test, and in two sections of pencil grasp and drawing skills. Test score’s ranking valued “between” 1-4 in every question. Results: The T test results showed that the Pencil grasps and drawing skills in ADHD Children and normal Children are different. According to the T test, the average scores in ADHD children in pencil grasp is lower than normal children. The T test also showed differences between the two groups in drawing skills. Conclusion: Generally, the results of this study showed ADHD children have weaker pre – writing skills than the normal children

RANTES release by human adipose tissue in vivo and evidence for depot-specific differences

Obesity is associated with elevated inflammatory signals from various adipose tissue depots. This study aimed to evaluate release of regulated on activation, normal T cell expressed and secreted (RANTES) by human adipose tissue in vivo and ex vivo, in reference to monocyte chemoattractant protein-1 (MCP-1) and interleukin-6 (IL-6) release. Arteriovenous differences of RANTES, MCP-1, and IL-6 were studied in vivo across the abdominal subcutaneous adipose tissue in healthy Caucasian subjects with a wide range of adiposity. Systemic levels and ex vivo RANTES release were studied in abdominal subcutaneous, gastric fat pad, and omental adipose tissue from morbidly obese bariatric surgery patients and in thoracic subcutaneous and epicardial adipose tissue from cardiac surgery patients without coronary artery disease. Arteriovenous studies confirmed in vivo RANTES and IL-6 release in adipose tissue of lean and obese subjects and release of MCP-1 in obesity. However, in vivo release of MCP-1 and RANTES, but not IL-6, was lower than circulating levels. Ex vivo release of RANTES was greater from the gastric fat pad compared with omental (P = 0.01) and subcutaneous (P = 0.001) tissue. Epicardial adipose tissue released less RANTES than thoracic subcutaneous adipose tissue in lean (P = 0.04) but not obese subjects. Indexes of obesity correlated with epicardial RANTES but not with systemic RANTES or its release from other depots. In conclusion, RANTES is released by human subcutaneous adipose tissue in vivo and in varying amounts by other depots ex vivo. While it appears unlikely that the adipose organ contributes significantly to circulating levels, local implications of this chemokine deserve further investigation

International Nosocomial Infection Control Consortiu (INICC) report, data summary of 43 countries for 2007-2012. Device-associated module

We report the results of an International Nosocomial Infection Control Consortium (INICC) surveillance study from January 2007-December 2012 in 503 intensive care units (ICUs) in Latin America, Asia, Africa, and Europe. During the 6-year study using the Centers for Disease Control and Prevention's (CDC) U.S. National Healthcare Safety Network (NHSN) definitions for device-associated health care–associated infection (DA-HAI), we collected prospective data from 605,310 patients hospitalized in the INICC's ICUs for an aggregate of 3,338,396 days. Although device utilization in the INICC's ICUs was similar to that reported from ICUs in the U.S. in the CDC's NHSN, rates of device-associated nosocomial infection were higher in the ICUs of the INICC hospitals: the pooled rate of central line–associated bloodstream infection in the INICC's ICUs, 4.9 per 1,000 central line days, is nearly 5-fold higher than the 0.9 per 1,000 central line days reported from comparable U.S. ICUs. The overall rate of ventilator-associated pneumonia was also higher (16.8 vs 1.1 per 1,000 ventilator days) as was the rate of catheter-associated urinary tract infection (5.5 vs 1.3 per 1,000 catheter days). Frequencies of resistance of Pseudomonas isolates to amikacin (42.8% vs 10%) and imipenem (42.4% vs 26.1%) and Klebsiella pneumoniae isolates to ceftazidime (71.2% vs 28.8%) and imipenem (19.6% vs 12.8%) were also higher in the INICC's ICUs compared with the ICUs of the CDC's NHSN