492 research outputs found
Increasing trap stiffness with position clamping in holographic optical tweezers
We present a holographic optical tweezers system capable of position clamping multiple particles. Moving an optical trap in response to the trapped object's motion is a powerful technique for optical control and force measurement. We have now realised this experimentally using a Boulder Nonlinear Systems Spatial Light Modulator (SLM) with a refresh rate of 203Hz. We obtain a reduction of 44% in the variance of the bead's position, corresponding to an increase in effective trap stiffness of 77%. This reduction relies on the generation of holograms at high speed. We present software capable of calculating holograms in under 1ms using a graphics processor unit. © 2009 Optical Society of America
Social network analysis of Iranian researchers on medical parasitology: A 41 year co-authorship survey
Background: The aim of this study was to survey the Iranian Parasitology researchers� performance, and analyse and visualize the scientific outputs of their co-authorship network. Methods: This study was conducted using scientometric method and social network analysis (SNA). The data extracted from the Web of Science (WoS) databases in July 10th 2014. Totally, 1048documents of all types in research area of Parasitology during 1972-2013 by Iranian researches retrieved. The coauthorship map was drawn utilizing NETDRAW, Coauthor.exe, and UCINET softwares and was analysed based on SNA measures. Results: The researchers� co-authorship network consisted of 78 authors and its density degree is 0.57. �Mohebali� ranked top in all of centrality measures.The most of the publications were related to 2012, �Mohebali� with about 9 of all documents was the Iranian most prolific author in Parasitology field. The Iranian researches have published mostly (266 documents) in �Iranian Journal of Parasitology�, and the most of the documents belong to �Tropical Medicine� subject field. The most of Iranian researchers� scientific cooperation was performed with England and United States. Conclusion: Bringing forth density degree (is 0.57) showed that this network has an almost medium density. Indeed, the authors have had relations in moderate level with each other in the network. The findings of this study can be identified aspects of scientific collaboration, and help policy makers of Parasitology field research. © 2016, Tehran University of Medical Sciences (TUMS). All rights reserved
The potential use of crushed waste glass as a sustainable alternative to natural and manufactured sand in geotechnical applications
The increasing price and diminishing reserves of construction sand encourage a need to develop its sustainable and cost-effective replacement, helping the transition towards a circular economy. Waste glass is a derivative of natural sand and could potentially show similar geotechnical behaviour. Using crushed waste glass (CWG) as an alternative to traditional sand would potentially offer a double-duty benefit by helping to address the geo-environmental challenges of natural sand depletion and disposal of ever-increasing waste glass, together. This study investigated the geotechnical, mineralogical and morphological behaviour of CWG and compared it with that of natural sand (NS) and manufactured sand (MS). The geotechnical characterisation results showed that the behaviour of CWG is similar to the other two sands studied, with CWG showing the highest permeability and abrasion resistance. Surprisingly, the shear strength testing showed that the friction angle of CWG was higher under saturated conditions than under dry conditions, indicating the stability of CWG under saturated conditions. The mineralogical analysis was conducted using x-ray fluorescence (XRF) spectroscopy and revealed that silica is the dominant mineral in all three materials, indicating a similarity in their chemical composition. The morphological analysis was performed to quantify the particle shape of each material in terms of roundness index using digital images obtained through an optical microscope. The results demonstrated that MS showed the highest particle angularity, followed by CWG and NS. Overall, it was concluded that CWG could potentially act as a next-generation alternative and smart geomaterial, replacing traditional sands in several geotechnical applications
Transumbilical versus transvaginal retrieval of surgical specimens at laparoscopy: a randomized trial.
Objective
We sought to compare transumbilical (TU) and transvaginal (TV) route for retrieval of surgical specimens at laparoscopy.
Study design
Women scheduled for a laparoscopic resection of an adnexal mass were randomized to have their surgical specimen removed either through a posterior colpotomy (n = 34) or the umbilical port site (n = 32). Group allocation was concealed from patients and bedside clinicians. The primary outcome was postoperative incisional pain assessed by a 10-cm visual analog scale at 1, 3, and 24 hours after surgery.
Results
TV retrieval caused less postoperative pain than TU specimen extraction at each time point (visual analog scale score at 1 hour: 2.6 \ub1 2.9 vs 1.2 \ub1 2.0, P = .03; at 3 hours: 2.4 \ub1 2.0 vs 1.4 \ub1 2.0, P = .02; and at 24 hours: 1.1 \ub1 1.5 vs 0.5 \ub1 1.4, P = .02). A higher proportion of women in the TU group than in the TV group indicated the umbilicus as the most painful area at 1 and 3 hours postoperatively. Two months after surgery, the participants scored similarly as to their overall satisfaction, cosmetic outcome, and dyspareunia upon resumption of intercourse.
Conclusion
A TV approach for specimen removal after laparoscopic resection of adnexal masses offers the advantage of less postoperative pain than TU retrieva
The Risk of Thrombocytopenia During Valproic Acid Therapy : A Critical Summary of Available Clinical Data
Valproate is an effective anti-epileptic and mood stabilizer drug, but its prescription may be complicated by the development of thrombocytopenia. The purpose of the present manuscript is to provide a critical overview about the risk of thrombocytopenia during treatment with valproate. A search of the main database sources has been conducted to identify relevant papers about the topic. In the studies with a larger sample size (> 150 subjects), thrombocytopenia occurred in 12-18% of subjects receiving treatment with valproate. Advanced age, female gender, and high doses were found to be risk factors for the development of thrombocytopenia during treatment with valproate. Future research is needed to clarify the clinical impact of the occurrence of thrombocytopenia during valproate treatment (e.g., the risk of life-threatening events such as stroke or the development of thrombocytopenia during short- versus long-term administration, or oral versus intravenous formulations)
Perinatal major depression biomarkers: a systematic review
Postpartum depression, now termed perinatal depression by the DSM-5, is a clinically relevant disorder reaching 15% of incidence. Although it is quite frequent and associated with high social dysfunction, only recently its underpinning biological pathways have been explored, while multiple and concomitant risk factors have been identified (e.g. psychosocial stress). Peripartum depression usually has its onset during the third trimester of pregnancy or in the postpartum, being one of the most common medical complications in new mothers. Purpose of the present review is to summarize the state of art of biological biomarkers involved in the pathogenesis of perinatal depression, in view of the fact that suboptimal prenatal milieu can induce permanent damage in subsequent offspring life and have a negative impact on mother-child relationship. Furthermore, parents' biological changes due to medical/psychiatric disorders or stress exposure could influence offspring life: a concept known as 'intergenerational transmission', acting by variations into gametes and the gestational uterine environment. Given the evidence that perinatal mental disorders involve risks for the mother and offspring, the search for reliable biomarkers in high-risk mothers actually represents a medical priority to prevent perinatal depression
Kaolin clay reinforced with a granular column containing crushed waste glass or traditional construction sands
Installation of granular columns is a cost-effective and versatile in situ technique to improve the shear strength, settlement, and drainage behaviour of weak soils. It involves backfilling vertical boreholes in the ground with granular materials stiffer than the native soil, such as stone or compacted sand. However, the massive use and overexploitation of sand and natural aggregates have depleted their reserves in recent decades, causing damage to the environment, creating sand shortages and skyrocketing their price. Hence, it is essential to develop a sustainable alternative to natural aggregates to construct granular columns. The ever-increasing stockpiles of waste glass could be a potential replacement for natural sand in several geotechnical construction applications, noting that both materials have a similar chemical composition. Using crushed waste glass (CWG) as an alternative to traditional natural and manufactured (quarried) sands in granular columns could offer a multi75 pronged benefit by recycling non-biodegradable waste (glass) and by conserving a depleting natural resource (sand). Using a large direct shear (LDS) machine, this study investigated the shear strength behaviour of kaolin (to represent a typical weak soil) reinforced with a central granular column. Three different materials were separately used to backfill the column, including natural sand (NS), manufactured sand (MS) and CWG. The results revealed that the geocomposites containing the CWG column have the highest peak friction angle and relatively greater shear strength under high normal stresses, favouring the potential use of CWG as a green alternative to traditional sands in backfilling granular columns, ultimately supporting resource conservation, waste recycling and the paradigm shift towards a circular economy
Does the polydimethylsiloxane urethral injection (Macroplastique®) improve sexual function in women, in fertile age, affected by stress urinary incontinence?
Background and Objectives: Stress urinary incontinence (SUI) negatively affects women's quality of life, including sexual function. The aim of the current study was to evaluate the effect of polydimethylsiloxane (Macroplastique(R)) on sexual function in women of fertile age affected by SUI. Materials and Methods: Single-center prospective study. Sexually active women of fertile age with symptoms of pure SUI, which were urodynamically proven, were submitted to intraurethral Macroplastique(R) injection. At 6-months follow-up, their sexual function was evaluated with Female Sexual Function Index (FSFI), while the SUI cure rate was objectively assessed through a negative stress test and subjectively by a Patient Global Impression of Improvement (PGI-I) score < 3. The difference of coital incontinence prevalence was assessed between the baseline and the 6-month follow-up. Peri- and postoperative complications of Macroplastique(R) injection were recorded and classified according to the Clavien-Dindo system. Results: Twenty-one women fulfilled inclusion criteria and were submitted to Macroplastique(R) procedure. The concerning sexual function, desire, satisfaction, and overall FSFI score significantly improved. Since other domains were less impaired at the baseline, we could not assess significant improvement for all of them. We observed a complete regression of coital incontinence (0/21, 0%) in comparison with the baseline (5/21, 23.8%; p = 0.04). The objective SUI cure rate was 76% (16/21), while the subjective SUI cure rate was 80.9% (17/21). One woman developed de novo overactive bladder, and two women developed postoperative voiding dysfunction (self-solved in 24 h). Conclusions: The Macroplastique(R) urethral injection was demonstrated to be safe and effective in improving sexual function in sexually active women of fertile age affected by pure SUI, urodinamically proven at 6-months follow-up
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