1,773 research outputs found
Evaluation of diagnostic value of PH in differentiation of pleural effusion
چکیده: زمینه و هدف: PH مایع جنب یکی از عمده ترین شاخص ها در تعیین نوع افیوژنهای پلور و تصمیمگیری برای نصب Chest-tube بوده و معیاری حساس برای تعیین سرنوشت یک پلورزی است. این مطالعه با هدف تعیین ارزش تشخیصی میزان PH در افتراق مایع پلور انجام شد. روش بررسی: این مطالعه با روش تشخیصی و تکنیک مشاهده ای روی 350 نفر بیمار مبتلا به افیوژن پلور مراجعه کننده به بیمارستان های تحت پوشش دانشگاه علوم پزشکی شهید بهشتی انجام گردید. مقدار cc 30-20 مایع پلور بیماران اخذ و مقادیر پارامترهای قند، پروتئین، گلبول سفید و لیپوپروتئین با دانسیته بالا (HDL) و اندازه گیری شد. حساسیت، اختصاصیت، ارزش پیشگویی کننده مثبت و منفی و کارآیی اندازه گیری هر یک از این فاکتورها در مقایسه با چهار فاکتور دیگر در افتراق افیوژن های پلور به اگزوداتیو و ترانسوداتیو بررسی و محاسبه گردید. یافته ها: از 350 نمونه مایع پلور 266 نفر اگزوداتیو و 84 نفر ترانسوداتیو بودند. بر اساس نوع مایعات تعیین شده حساسیت، ارزش پیش گویی کننده مثبت، کارآیی، ارزش پیش گویی کننده منفی و PH به ترتیب 75، 72، 61، 26 به دست آمد. نتیجه گیری: با توجه به اینکه هنوز در اکثر بخشها توصیه به انجام تمامی تستها جهت افتراق افیوژنهای پلور میگردد و این میتواند علاوه بر هزینه و صرف زمان دارای خطا و اشتباه باشد به نظر میرسد که تعیین میزان PH تنها جهت افتراق افیوژنهای پلور بدور از هرگونه خطا و اشتباه باشد
Computational problems in autoregressive moving average (ARMA) models
The choice of the sampling interval and the selection of the order of the model in time series analysis are considered. Band limited (up to 15 Hz) random torque perturbations are applied to the human ankle joint. The applied torque input, the angular rotation output, and the electromyographic activity using surface electrodes from the extensor and flexor muscles of the ankle joint are recorded. Autoregressive moving average models are developed. A parameter constraining technique is applied to develop more reliable models. The asymptotic behavior of the system must be taken into account during parameter optimization to develop predictive models
Numerical evaluation of mean-field homogenisation methods for predicting shale elastic response
Homogenisation techniques have been successfully used to estimate the mechanical response of synthetic composite materials, due to their ability to relate the macroscopic mechanical response to the material microstructure. The adoption of these mean-field techniques in geocomposites such as shales is attractive, partly because of the practical difficulties associated with the experimental characterisation of these highly heterogeneous materials. In this paper, numerical modelling has been undertaken to investigate the applicability of homogenisation methods in predicting the macroscopic, elastic response of clayey rocks. The rocks are considered as two-level composites consisting of a porous clay matrix at the first level and a matrix-inclusion morphology at the second level. The simulated microstructures ranged from a simple system of one inclusion/void embedded in a matrix to complex, random microstructures. The effectiveness and limitations of the different homogenisation schemes were demonstrated through a comparative evaluation of the macroscopic elastic response, illustrating the appropriate schemes for upscaling the microstructure of shales. Based on the numerical simulations and existing experimental observations, a randomly distributed pore system for the micro-structure of porous clay matrix has been proposed which can be used for the subsequent development and validation of shale constitutive models. Finally, the homogenisation techniques were used to predict the experimental measurements of elastic response of shale core samples. The developed methodology is proved to be a valuable tool for verifying the accuracy and performance of the homogenisation techniques
Operator-valued Schatten spaces and quantum entropies
Operator-valued Schatten spaces were introduced by G. Pisier as a
noncommutative counterpart of vector-valued -spaces. This family of
operator spaces forms an interpolation scale which makes it a powerful and
convenient tool in a variety of applications. In particular, as the norms
coming from this family naturally appear in the definition of certain entropic
quantities in Quantum Information Theory (QIT), one may apply Pisier's theory
to establish some features of those quantities. Nevertheless, it could be quite
challenging to follow the proofs of the main results of this theory from the
existing literature. In this article, we attempt to fill this gap by presenting
the underlying concepts and ideas of Pisier's theory in an almost
self-contained way which we hope to be more accessible, especially for the QIT
community at large. Furthermore, we describe some applications of this theory
in QIT. In particular, we prove a new uniform continuity bound for the quantum
conditional R\'enyi entropy.Comment: 41 page
The morphological characters of the male external genitalia of the European hedgehog (Erinaceus Europaeus)
This study was conducted to depict anatomical characteristics of the penis of hedgehog. Seven sexually mature male European hedgehogs were used. Following anaesthesia, the animals were scarified with chloroform inhalation. Gross penile characteristics such as length and diameter were thoroughly explored and measured using digital callipers. Tissue samples stained with haematoxylin and eosin and Masson’s trichrome for microscopic analysis. The penis of the European hedgehog was composed of a pair of corpus cavernosum penis and the glans penis without corpus spongiosum penis. The urethra at the end of penis, protruded as urethral process, on both sides of which two black nail-like structures, could be observed. The lower part was rounded forming a blind sac (sacculus urethralis) with a median split below the urethra. Microscopically, the penile bulb lacked the corpus spongiosum penis, but, corpus spongiosum glans was seen at the beginning of the free part. In the European hedgehog, entirely stratified squamous epithelium of penile urethra, absence of corpus spongiosum penis around the urethra and bilateral urethral glands are basically different compared with other mammals. This information is expected to contribute to comparative penile morphology as well as for testing phylogenic hypotheses and expanding knowledge about reproductive biology in this animal. (Folia Morphol 2018; 77, 2: 293–300
Systematic discovery of structural elements governing stability of mammalian messenger RNAs.
Decoding post-transcriptional regulatory programs in RNA is a critical step towards the larger goal of developing predictive dynamical models of cellular behaviour. Despite recent efforts, the vast landscape of RNA regulatory elements remains largely uncharacterized. A long-standing obstacle is the contribution of local RNA secondary structure to the definition of interaction partners in a variety of regulatory contexts, including--but not limited to--transcript stability, alternative splicing and localization. There are many documented instances where the presence of a structural regulatory element dictates alternative splicing patterns (for example, human cardiac troponin T) or affects other aspects of RNA biology. Thus, a full characterization of post-transcriptional regulatory programs requires capturing information provided by both local secondary structures and the underlying sequence. Here we present a computational framework based on context-free grammars and mutual information that systematically explores the immense space of small structural elements and reveals motifs that are significantly informative of genome-wide measurements of RNA behaviour. By applying this framework to genome-wide human mRNA stability data, we reveal eight highly significant elements with substantial structural information, for the strongest of which we show a major role in global mRNA regulation. Through biochemistry, mass spectrometry and in vivo binding studies, we identified human HNRPA2B1 (heterogeneous nuclear ribonucleoprotein A2/B1, also known as HNRNPA2B1) as the key regulator that binds this element and stabilizes a large number of its target genes. We created a global post-transcriptional regulatory map based on the identity of the discovered linear and structural cis-regulatory elements, their regulatory interactions and their target pathways. This approach could also be used to reveal the structural elements that modulate other aspects of RNA behaviour
Shear-Mode Viscoelastic Damage Formulation Interface Element
In this paper, a viscoelastic-damage cohesive zone model is formulated and discussed. The interface element constitutive law has two elastic and damage regimes. Viscoelastic behaviour has been assumed for the shear stress in the elastic regime. Three element Voigt model has been used for the formulation of relaxation modulus of the material. Shear Stress has been evaluated in the elastic regime of the interface with integration over the history of the applied strain at the interface. Damage evolution proceeds according to the bilinear cohesive constitutive law up to the complete decohesion. Numerical examples for one element model has been presented to see the effect of parameters on cohesive constitutive law
A new approach for trapezoidal approximation of fuzzy numbers using WABL distance
In this paper, we present a new approach to obtain trapezoidal approximation of fuzzy numbers with respect to weighted distance proposed by Nasibov [5] which the main property of this metric is flexibility in the decision maker's choice. Also, we prove some properties of the proposed method such as translation invariance, scale invariance and identity. Finally, we illustrate the efficiency of proposed method by solving some numerical examples
The effect of adjuvant vitamin C after varicocele surgery on sperm quality and quantity in infertile men: A double blind placebo controlled clinical trial
Varicocele is one of the most common causes of male infertility and spontaneous pregnancy rate after varicocelectomy is only about 30. The most important seminal antioxidant is vitamin C but recent studies about the effects of vitamin C on spermatogenesis are controversial; therefore, we decided to evaluate its role after varicocelectomy. In a double blind randomized controlled clinical trial, 115 men with infertility and clinical varicocele with abnormal semen analyses were recruited. After surgery, the intervention group received vitamin C (250 mg bid) and the control group received placebo for three months. Mean sperm count, motility, and morphology index of two semen analyses (before and after surgery) were compared between the two groups. Univariate general linear model and stepwise linear regression were used in analysis. The mean age (±SD) of participants was 27.6±5.3 years. Vitamin C group had statistically significant better normal motility (20.8 vs. 12.6, P=0.041) and morphology (23.2 vs. 10.5, P<0.001) than placebo group. Considering the values prior to surgery as covariate, vitamin C was not effective on sperm count (P=0.091); but it improved sperm motility (P=0.016) and morphology (P<0.001) even after excluding the confounding effect of age (P=0.044 and P=0.001, respectively). Vitamin C was also an independent factor in predicting motility and normal morphology after surgery. Ascorbic acid can play a role as adjuvant treatment after varicocelectomy in infertile men
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