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  • Pierre Mubiayi Kalenga added an answer in Filters:
    Can i filter nanoparticles by using 0.025 micrometer filter?

    can i filter nanoparticles by using 0.025 micrometer filter?

    Pierre Mubiayi Kalenga · University of the Witwatersrand

    You can use that filter. Excess of solvent may allow the collection of most of the particles. However, I would suggest a trial of analysis for the size of  the particles you have in your sample before choosing your filter. Obviously optimizing your yield may play a role if the size distribution is quite huge and because any size greater than 25 nm won't be collected using that filter. Are you targeting something like " self-assembly" ?

  • Xingxing Liu added an answer in ANSYS Workbench:
    How can I apply an angular velocity to the body in transient structures simulation in ANSYS workbench?

    Thanks in advance for your replies.

    Xingxing Liu · Université de Technologie de Compiègne

    Hi, you can right click on "Initial conditions", insert velocity, then in the menu of "input type"(left bottom corner of the window), you choose angular velocity, voila, you inserted a angular velocity. I have attached a capture of my screen in the attached picture.

  • Kamila Bacigálová added an answer in Beetles:
    How can I best extract DNA from museum beetle specimens?

    Even I have tried several kits and protocols, I almost always fail to extract DNA from the museal specimens (ca 10-20 years old) of beetles. I would need to amplify commonly used fragments like COI, 16S, 18S but failed. Does anybody have a good experience with this? If yes, please could you provide me with suggestions and protocols? Thanks   

    Kamila Bacigálová · Slovak Academy of Sciences

    We have not satisfy results until now

  • Tomás Cordero added an answer in Kinetics:
    Could you explain what is the kinetic study and how to calculate values from thermal studies?

    I got Tg-Dta datas for my samples, but I have no idea how to calculate kinetic values from my data.  What are the basic parameter values for calculations?

    Please recommend any kinetic related papers?

    Tomás Cordero · University of Malaga

    Hi, balaji Murugan,

    I recomended you the follows papers  published for us msome years ago but I think that it will give you an idea about Isothermal and non isothermal TGA and how obtainede kinetics parameters, the papers are:

    T. Cordero, F. García Herruzo y J.J. Rodríguez.
    A kinetic study of holm-oak wood pyrolysis from dynamic and isothermal TG experimets.
    Thermochimica Acta, 149, (1989), 225-237. A

    J.M. Blasco, T. Cordero, J.P. Gómez Martín y J.J.Rodríguez.
    A kinetic study on chemical activation of holm-oak Wood.
    Journal Anal. and Appl. Pyrolysis, 18, (1990), 117-126. A

    T. Cordero, J.M. Rodríguez Maroto, J. Rodríguez Mirasol y J.J. Rodríguez.
    On the kinetics of thermal decomposition of wood and wood components.
    Thermochimica Acta, 164, (1990), 135-144. A

    T. Cordero, J.M. Rodríguez Maroto, F.García Herruzo y J.J. Rodríguez.
    Thermal decomposition of wood in oxidizing atmosphere. A kinetic study from non-isothermal TG experiments.
    Thermochimica Acta, 191, (1990), 161-178. A

  • Harry ten Brink added an answer in Greenhouse Gases:
    Is CO2 increasing in all the levels of troposphere? If yes, in which way the global warming is influenced by the different temperature of CO2 layers?

    In climate change/global warming studies, the Stefan Boltzmann
    formula is often used to estimate the amount of radiant energy which
    escapes outward into outer space from earth. The formula is derived
    under the assumption that the relevant emissivity of the emitter is a
    constant for all wave lengths, and its temperature exponent is 4. However,
    the earth’s greenhouse gases permit radiations to pass through
    the atmosphere freely only in some specific wave length windows. It is
    shown that the wave length dependence of emissivity can change the
    effective temperature exponent of the Stefan Boltzmann formula. (Source: Lam, H. S. (2007). On the Effective Stefan-Boltzmann Temperature Exponent of the Earth).

    Harry ten Brink · Energy Research Centre of the Netherlands


    Temperatures went UP. One cannot take one single year as the reference year for a trend in temperature. I repeat 1998 was an exceptional year because of one of the strongest el Nino's. The real fat is that the recent decade is again warmer than the decade before and so on so why are you repeating that global temperature decreased?

    As for models: yes often simple models do as well a job as much more complex models. Models are there for GUIDANCE. similar to the scientific forecast that can be found on Weatherunderground where the meteorologist makes a best estimate forecast based on projections from models that often have different outcomes. and the forecast is improving year by year, still the real weather may strongly deviate from the projection by a different turn in events.

    Climate models should not be confused with models in basic physics that often consist of one or a couple of equations with exact outcome.

  • Geoffrey Truchetti added an answer in Medetomidine:
    What is the mechanism behind the increase in heart rate after injection of Lidocaine (around 2 mg/kg IV) we can observed in patient with bradycardia?

    In Veterinary medicine, in healthy dogs, for  our premedication prior to general anaesthesia we tend to use an alpha-2 adrenoceptor agonist such as medetomidine or its active enantiomer, dexmedetomidine. The resulting bradycardia, although being a normal response, can be disconcerting for some practitioners who then tend to reverse the alpha-2 and lose, with the sedation, its analgesic effect. Others, although discouraged by different papers in the literature, give an anticholinergic which then results in hypertension. Following the advice of a more experience anaesthetist, I tend nowadays to give 2 mg/kg IV of lido to increase the HR in those patients. The effect is usually a mild increase and of short duration. The experimented anaesthetist referred to a technique or info from the 70"s. I have asked around me since, and can not get the explanation for the mechanism. Naturally, I would have expected an injection of lido to result in a decrease of the HR as we observed when we treat ventricular rhythm disturbances such as V-Tach. Even when I look at data sheets, slower HR (bradycardia) is a side-effect, not faster heart rate. Does anyone have any idea?


  • Debendra Neupane asked a question in Tris Buffer:
    How to increase the pH of solution from about 4 or 5 to more than 7 gradually?

    Hello there!

    I am mixing two chemicals (M1phosphate and M2nitrate salts), both of these are acidic. Naturally, the product is also acidic. The final pH is about 4.

    I have already tried using buffer solution. I prepared tris buffer solution of pH 8 and mixed M1phosphate on it. The pH did not change. Afterwards, I mixed M2nitrate. Suddenly, the pH dropped to 4-5.

    The lower pH is important for me, because if the pH is more than 7, the reaction between phosphate and nitrate occurs soon after the mixing hence, the solution goes cloudy (which I don`t like). If the pH is 4-5, the reaction takes place slowly (starts after about 30 minutes) that is what I want. 

    However, I can not use this solution if it`s pH is less than 7.0. I heard that there are some chemicals which can increase the pH slowly by slowly neutralizing H+ ion. Would you please teach me the chemicals that increases the pH slowly.



  • Which questionnaires are useful for analyzing "emotional intelligence" and "organizational citizenship behavior" among nurses?

    The research attempts to investigate the critical role that emotional intelligence plays in determining the level of organizational citizenship behavior and also to detect the essence of the correlation between these two variables among the nurses.

    Masoud shajari PM · Iran University of Medical Science

    سلام حضور سرکارخانم کاظمی

    از اسم شما متوجه شدم ایرانی هستید ومن تصمیم گرفتم از زبان  فارسی استفاده کنم

    موضوع هوش احساسی ورفتارشهروندی سازمانی نسبتا جدید می باشد اما در پرستاری کاملا جدید می باشد پیشنهاد من استفاده از تکنیک های تصمیم گیری چند معیاره می باشد اگر تعداد متغیرهای شما در هر پرسشنامه زیر بیست باشد ازتحلیل سلسله مراتب  وگرنه ازتحلیل ویکور استفاده نمائید در صورت نیاز من به همراه شما  می توانم با استفاده از چارچوب مفهومی مد نظر شما پرسشنامه ای ایجادومفهوم مورد نظر شما را در هر بخش بیمارستانی اندازه گیری وسپس اولویت بندی ورتبه سنجی نمایم   

  • Can someone help me with a big problem in extesion PCR?

    I want to fuse a fragment with 1722 length to a 1778 fragment with very stable secondary structures.
    Overlaping primers have 53 bp.
    End primers have cut sites.
    Firstly, I have amplified two fragments and obtained specific band. I extracted two fragmets from agarose gel.
    Then I diluted two fragments to1/20. At the next step, I did SOEing PCR ..
    I have problem overlap extension pcr for two fragments from viral DNA. ....the length fragments are 1722-1778 respectively. i was amplify this fragments by taq polymerase. but I can't bind their. i used from Hot Star Taq but I can't amplify their. I would be very thankful if you help me to solve this problem.
    This situations didn't answer
    94 degree 5 minute without primers
    Put in room temperature 15-10 minute or ice
    Extension 72 degree 3 minute
    94 degree 1 minute
    60 degree 40 second 25-15-30 different cycles
    72 degree 3 minute
    72 degree 10 minute

    I would be very thankful if you help me to solve this problem.

    Nadine Cristina · University Joseph Fourier - Grenoble 1

    Hi Masoud,

    All classic Taq add an A at 3'end and so your first elongation after incubation in ice can't occur. So, you should use a special polymerase for amplification of your two 1.7 Kb fragments. In addtion, the fragment you want to amplified is very long (3,5 Kb), so you should also try a polymerase dedicated to long fragment for it. the polymerases work usually at 1000 pb / min and your elongation time is perhaps too short: try 3.5-4 min.

    Good luck

  • Can anybody tell me if I can use MTT assay for measuring cell proliferation in co-culture conditions?

    I want to check the proliferation of my Transgenic CD8+ T cell clones after their treatment  with a specific peptide. Since I need to co-culture them along with APCs (Irradiated splenocytes), is it feasible to use MTT assay to measure the proliferation in co-culture conditions? If so, what can be the rationale to determine the cell proliferation in this case?

    Guillaume M Charrière · Université de Montpellier, France

    In my point of view, MTT may not be as reliable and accurate as using BrdU incorporation or CFSE proliferation assays.  The splenocytes may react to MTT, as some of their metabolic activities could remain after irradiation. 

  • Coral Salido added an answer in Glaucoma:
    What is the main reason why transcleral diode laser cyclophotocoagulation is not a popular choice for primary or initial glaucoma treatment?

    Is losing vision the main reason? What are the reasons for losing vision?

    Coral Salido · Hospital Universitario del Sureste

    I agree with previous answers, 

  • Will nano particle generation using laser ablation work on rare earth glasses ?


    I was thinking of ultrafast ablation using a femto second laser of A Yb3+ glass for nano particle generation but for the few attempts I had I couldn't observe any absorption in the expected region for Yb3+ (even any where near to that, if there are shifts due to confinement)

    femto second laser Ablation
    84.696 MHz
    Rep rate- .1 Hz

    Krishnakumar Chullipalliyalil · University College Cork

    Vitaly Gruzdev Indeed, that makes sense. I had actually tried to take the particles our by centrifuging, and then drying them to change the solvent. But again I used ethanol, another polar protic solvent. Probably that again caused the particle to settle in a minute.

  • Which technique to use for prior sample size calculation in SEM?

    I am using structural equation modelling (SEM) in my research and looking for the right technique for sample size determination. I was using prior statistical calculator from the web (http://www.danielsoper.com/statcalc3/calc) so do you think this is the right technique to use. In the literature I find some guidelines like 5, 10 and 20 subjects per parameter and others. Which method do you think is appropriate to use.


    Robert James McClelland · Liverpool John Moores University

    Try this article: Lower bounds on sample size in structural equation modeling by Westland


    Link: http://www.sciencedirect.com/science/article/pii/S1567422310000542

    Also here is a calculator you may find useful:


  • Ihtesham Ul haq asked a question in Bovine:
    How i can interpret my results of WB, if my desire band is lower or higher then the expected band?

    I am doing Wb to see the expression of ISG15 its 15 KDa gene in bovine PBMC;s. I get the results having two band one is lower then 15Kda marker and one upper then f15kda marker? what is the possible reason and how to interpret my reults? which band i should consider for ISG15?

  • Ilian Atanassov added an answer in LC-MS:
    How unprecise are absolute protein abundances obtained with label-free LC-MS/MS?

    Shorly, I'm looking for any research comparing absolute protein abundances obtained with label-free LC-MS/MS and isotope labeling MS or any other precise technique for identification of protein sample composition. Label-free data should be without processing in sofware like APEX, emPAI or Top3.

    In more details, I need to roughly evaluate quantitative composition of plasma proteins in Danio rerio, and I found a paper (see attached) with label-free LC-MS/MS data about zebrafish plasma proteome. Along with this paper authors provide a dataset with the protein abundances exported from "Progenesis LC-MS" software. However, these abundances are, of course, not absolute and I'm completely not shure whether I can directly use these data to (roughly) evaluate protein ratio in ONE sample, not between two. So, I need to know how big is inaccuracy of absolute protein abundances obtained with label-free LC-MS/MS, which I cannot find at all.

    Of course, I also can try to somehow analyze the dataset with emPAI and similar software, but it will take a plenty of time.

    Thanks for any response!

    Ilian Atanassov · Max Planck Institute for Biology of Ageing

    This shapes as a nice discussion.
    Can anyone share some experience with the price of doing label free vs metabolic labeling / heavy peptide standards for protein(ome) quantification or complex stoichiometries? This is an important factor that a would steer experiments to one side or another.

  • Is there a way to analyse prokaryotic and eukaryotic RNA at once on the Agilent Bioanalyzer or do I need to always run two chips?

    Is there a way to analyse the data from an environmental sample at once, I mean prokaryotic and eukaryotic RNA at the same time, or do I need to run the samples on two different chips to obtain the respective quality?

    I am analysing an anaerobic reactor sample containing bacteria, archaea and anaerobic fungi.

    Sabine Marie Podmirseg · University of Innsbruck

    Ok thanks for the information. We are using the Pico chips and the prokaryotic and eukaryotic RNA would be mixed within each sample....And I wasn't sure about the within sample discrimination. Thanks for your help in advance!

  • Steven Goossens added an answer in Metabolics:
    Did anyone used an inducible system that express rtTA ubiquitously in transgenic mice?

    We are engaged in a metabolic project where we want to express our gene in a whole body and inducible fashion (or at least in important metabolic tissues as muscle, WAT, BAT and liver).

    Do anyone know a model to express rtTA ubiquitously?


    Steven Goossens · Monash University (Australia)

    Rosa26 is one of the few loci that are really ubiquiteously expressed and expression is similar in most tissues/cell types which is an advantage ... However, the rosa26 promoter is a very moderate promoter and transgene expression is rather low (compared to a CMV promoter). But for rtTA this should not be a problem . And you even can breed them to homozygocity, doubling the amount of the rtTA trangene, if you think this will be a problem (but we never had to do this).

    Expression of transgene rtTA from an exogeneous promoter like CMV will yield much higher expression but expression is very variable as these promoters often get silenced in certain cell types and conditions depending on the locus where they get integrated.

    If we do not see expression from a dox-inducible transgene expression system  it is rather due to silencing of the tetO promoter element than due to levels of rtTA, so I would rather worry about this.

  • Mirthe Demaerel asked a question in Housing:
    How is architecture used as a tool to divide, to assimilate or to create a culture of one's own in the history of Chinese Indonesians?

    I want to write a text about the interwinement of the different attitudes towards the Chinese Indonesians (for example the period of racial segregation under the regime of the Dutch) and architecture (for example the way Chinese Indonesian houses or housing districts differed from others). Does anybody know papers on this subject?

  • How can I calculate appropriate frequency range for a stack of fuel cell from frequency range of a single cell, for application in fuel cells?

    I have performed electrochemical impedance measurements on a single cell of Vanadium Redox Flow battery (VRFB). The suitable frequency range for this single cell is 10kHz-20mHz. Now, I want to perform another EIS measurement on a stack of VRFB which is made up of six cells. In this case, I was wondering whether the frequency range should be changed. Should I decrease the lower limit of the frequency range?

    I am really grateful for your help.

  • In-Woong Um added an answer in Implant:
    Is ridge mapping with panorama alone enough before implant replacement in posterior edentolous region without using CBCT?

    as ridge mapping can give idea about Bucco-linual width not giving by panorama

    In-Woong Um · Korea Tooth Bank

    Resorption patterns of buccal-crestal area in posterior make it difficult to locate appropriate place to put implant. So that I always use CBCT to measure the width and find out exact locations. In addition, if we have to do bone graft, there would be a lot of things to be considered. So in my personal opinion, panorama itself is not enough in many cases.

  • Simone Nava added an answer in Visual Motion:
    Does anyone know of an article suggesting visual motion or processing disturbances many years after a concussive event?

    The asymmetry could be in reaction time, sensitivity to movement or to brightness, postural adaptations, etc.   I found an article regarding 30 days post injury, but am interested in scientific documentation of years after injury. .

    Simone Nava · Fondazione I.R.C.C.S. Istituto Neurologico Carlo Besta


    besides the many sports related works in this field, you may find this useful:

    Front Hum Neurosci. 2012 Jun 19;6:160. doi: 10.3389/fnhum.2012.00160. eCollection 2012.Longitudinal diffusion tensor imaging and neuropsychological correlates in traumatic brain injury patients.
    Farbota KD1, Bendlin BB, Alexander AL, Rowley HA, Dempsey RJ, Johnson SC.

    There are some considerations on visuomotor speed and diffusivity in visual processing related white matter tracts. 

  • Yuri Rylov asked a question in Coordination:
    How does one define equality of two vectors in the space-time geometry of Minkowski?

    There are two versions of this definition (1) vectors AB and CD are equal, if their coordinates in inertial coordinate system are equal, (2) vectors AB and CD are equal, if scalar product (AB.CD} =|AB| |CD| and |AB|=|CD|. This definitions are equivalent for timelike vectors, but they are different for spacelike vectors. For instance, if AB1 =(r,r,0,z),  AB2 =(r,0,r,z),  CD=(0,0,0,z), then AB1=CD, AB2=CD, but AB1 is not equal to AB2.

  • John H. Hudson added an answer in Mental Health:
    Does anyone have a short Questionnaire on mental health?

    mental health, wellbeing

    John H. Hudson · University of Salford

    Hi Farid,

    As Adrian said, it depends what you are looking for - the WHO-5 assesses mental well-being, but has been well-validated in relation to psychological health-related scales, such as the GHQ-12, PHQ-9 etc, so may be worth a look.


    Good luck,


  • Philippe Mateu added an answer in Anesthesia:
    A formula to calculate Pa02 from Sp02%, anyone have any recommendations?

    I have Sp02% and Fi02%, and I want to calculate a Pa02/Fi02 quotient. Is it possible to calculate a Pa02 from Sp02%? If yes, does anyone have any reliable formulas?

    Philippe Mateu · CHG de Charleville-Mezieres,

    A formula cannot exist, because the relationship between PO2 and SpO2 is not linear. Oxymeter is calibrate for a single value : PaO2 60mmHg = SpO2 90%+/-5% aproximativement.

  • Koen Van Turnhout asked a question in Academic:
    Is there a good article describing the do's and don't of an empircal literature study?

    Empirical literature studies: studying academic literature as a shortcut to learning about academic practice are common in many fields. 

    Bryman, Alan. "Why do researchers integrate/combine/mesh/blend/mix/merge/fuse quantitative and qualitative research." Advances in mixed methods research (2008): 87-100.

    (we used the technique in)

     van Turnhout, K, et al. "Design patterns for mixed-method research in HCI." Proceedings of the 8th Nordic Conference on Human-Computer Interaction: Fun, Fast, Foundational. ACM, 2014.

    However, are there any academic standards for this aproach? Is there a good article describing rules for sampling, analysis and conclusions etc. 

  • John George Hardy added an answer in Xylenes:
    Which functional groups (OH or COOH) is suitable for better dispersion of CNTs in SWCNTs-HDPE composite with Xylene solvent?

    we use solution processing with xylene. 

  • Sergei Malykhin added an answer in PWSCF:
    Quantum Espresso users! Do you know how to enforce triplet multiplicity in a PWscf calculation?

    I'm a beginning QE user. I would like to perform a calculation of TiO2 surface with O-vacancy. Since two of the surface Ti's will most likely have 3+ charge, there will be two unpaired electrons in the system. Unfortunately the QE manual is very unclear about it, and one needs to set several keywords like "nspin" and "starting magnetization". I want to actually check in the beginning if the closed shell and spin polarized calculations converge to the same of different minima, to be sure what to do in further steps. Do you have any ideas for a proper set of settings in the input file? What about the DFT+U correction?

    Thanks in advance for help!

    Sergei Malykhin · Boreskov Institute of Catalysis

    Hi! The "tot_magnetization = n" value is constraint for 2Sz, it is not connected with starting_magnetization(i) array which is provided to make some proper initial guess. Therefore, tot_magnetization = 2 is always for triplet. Remember that tot_magnetization = Na - Nb. You may find that  starting_magnetization(1) = 0.1, starting_magnetization(2) = 0.1 together with tot_magnetization = 2 may also converge SCF to the same desired triplet state.

    The tot_magnetization = 1 constraint will give you spin density half singlet half triplet.

    Simple DFT+U correction (lda_plus_u_kind = 0) is penalty function for total energy: E(DFT+U) = E(DFT) + U/2*ni*(1-ni). When the electron occupation number ni is fractional, i.e. when electron is artificially delocalized over 2 or more Ti ions, the addendum becomes positive non-zero, making conductive electron-delocalized solution higher in energy, than localized one (ni = 1 or 0). For some U value insulating localized solution will be the ground state. Now if you are know in advance, that system under consideration is really insulator, but pure DFT makes it conductive, you may want to apply DFT+U scheme to select proper ground state. The energy of the electronic state selected this way as you may make sure of is independent on U.

    Therefore, triplet state where electrons are already localized do not require DFT+U scheme. However, there is an ambiguity with calculating an occupation number.  Localized orbitals for which occupation numbers are calculated is not orthogonal to each other (default case in QE) therefore +U correction affects other orbitals, such as Ti-O bonds etc. This cause energy dependence on the applied U term. Many researchers use this "feature"  as an additional fit of the theory to experiment, unfortunately. More rigorous method is applying DFT+U scheme on the orthogonal set of localized orbitals, such is maximally localized Wannier functions, but QE still has no possibility to do geometry optimization with them.

    Anyway, just remember that DFT+U scheme is not a fit, but a scheme to select proper electronic state.

    Good luck!

  • Ahmad Bazzi added an answer in Frequency:
    Do any one have matlab code for digital down conversion with band pass filtering?

    my matlab code for digital down converter give addition frequency component but  do not gives difference frequency component in spectra. please give me the working matlab code for digital down converter with band pass filtering so that i can verify my code with that.

    Ahmad Bazzi · Institut Mines-Télécom

    Hello Drashti,

    Well, you have two ways:

    1)The easy way:
    Youcan use the matlab fdatool for designing filters, please refer to this: http://fr.mathworks.com/help/signal/ug/opening-fdatool.html

    2)The hard way:

    You have to know the fourier transforms, i.e in frequency domain the filter is a function of the rect(f) function where :
    H1(f) = rect(f) = 1 if f is between plus or minus 1/2
                             0 if it is greater than 1/2 or less than -1\2 
                             0.5 if it is equal to plus or minus 1/2
    Now you need to scale with the appropriate bandwidth which is  
    B  = 1MHz - 150KHz 

    Your new filter would be H2(f) = H1(f/B) = rect(f/B)

    So H2(f) is a rectangular pulse but of bandwidth B instead of 1. 

    Finally you need to shift H1(f) to the center of the band which is
    Bmid = (150KHz + 1MHz )/2

    Finally H(f) = H2(f-Bmid) = H1((f-Bmid)/B)

    So H(f) is your filter:

    So now you either apply an FFT to your signal and multiply it in frequency domain with H(f) and then convert it to time domain with an IFFT 


    equivalently you could apply an IFFT to H(f) i.e. h(t) and apply a convolution with the signal you want to filter in time domain 

    Hope this helps :)