ResearchGate Q&A lets scientists and researchers exchange questions and answers relating to their research expertise, including areas such as techniques and methodologies.

Browse by research topic to find out what others in your field are discussing.

Browse Topics

  • Alexander Feckler added an answer in Ecotoxicology:
    How do I calculate a NOEC for ecotoxicology test?

    I need to calculate a NOEC, but i have 10% immobilisation in my control; will this effect my NOEC ?

    And how do i calculate it ? 

    Alexander Feckler

    Just a short comment from my side: if you observe a mortality of 10% in your control after only 2 hours, there might be something wrong with your test system. Was this mortality observed consistently or only during one run of the experiment?

  • Andrey S Bavykin added an answer in Lysis Buffer:
    Do any of you have experience with RNA extraction from Caco2 cells differentiated on filters?

    I used RNAeasy Plus minikit but I didn't get any RNA. I extracted RNA in parallel from Hela cells and I obtained the expected yield. The lysis buffer was added directly on Transwell filters in 6 well plates after removal of the growth medium. After extensive pipetting at RT the samples were transferrred to 1,5 ml reaction tubes and immediately processed according to manufacturer protocol with addition of the QIAshredder step.

    Andrey S Bavykin

    Hi Simona. In my experience Caco2 monolayer forms strong intercellular interactions. You may try to increase the volume of lysis buffer and to incubate cells longer time in lysis buffer, (than it is prescripted in the protocol) with slightly pipeting during incubation.

  • Elek Telek added an answer in Current - Voltage:
    Does anyone have an idea what kind of parameters/compounds can influence the current and voltage during Western Blot?

    I have performed several times Western blot but in this case the current does not go up around 25-30 mA even if I adjusted 300 V, however, I did everything as the same like last few times when the current went up around 25-30 mA, as we expected even at lower voltage. Despite I did everything as the same  don't know  what kind of compounds or parameters or something can influence the protein transfer to the membrane. I guess that if the current is low that means proteins can not transfer to the membrane quite well, isn't it?

    How could I gain better protein transformation on the membrane?

    Thank you in advance!

    Elek Telek

     Dear Francisco,

    If I put the membrane into dH2O after methanol activation should I incubate in cold dH2O as well if ht buffer is cold dH2O because before this I stored simply in room temperature distilled water not in cold water and may be the gel also should be soaked in cold dH2O before assembling the sandwich. Perhaps this was the reason why the current was not appropriate. 
    Do you have any advice performing western blot about this cold water buffer-based type of western blot?

    Thank you in advance!

  • Hans van Leunen added an answer in Special Relativity:
    Can someone re-write the Einstein field equations in such a way that c becomes a global constant?

    I recently showed that the equivalence principle observes this constraint. This fact is trivial because the equivalence principle is based on special relativity alone.

    Therefore, the full field equations must be capable of being re-written in this form. Otherwise, the equivalence principle would no longer fit in.

    So the proposed transform sought is the so far missed "physically correct version" of the Einstein field equations.

    Hans van Leunen

    Something changes with huge distances. That is what Hubble discovered. It is the relation between space and proper time. The model makers have decided that space changes and not proper time.

  • Juliet Sheela K A asked a question in Monovalent Cations:
    What is the principal models of charge compensation when divalent impurity cations are substituted for monovalent cations in a crystal lattice?

    Ram Kripal, Department of Physics, University of Allahabad, India

  • Andre N Baranov added an answer in Carbofuran:
    What is the best ratio of GO with TiO2?

    Dear All

    I used TiO2/GO 5% wt composite to degrade carbofuran at UV 350 nm and the activity of P25 was better than P25/GO 5% wt composite Also I used in visible range and there is no any activity of P25/GO. I do not know what is the reason that GO suppress P25 activity.


    Andre N Baranov

    I think that PhCat activity of TiO2/GO composites is strongly dependent on quality of GO. 

  • Krushna Chandra Mishra added an answer in Sentence Processing:
    Can anyone express the relationship between word order and communication?

    does anyone express the relationship between the word order and communication ?

    Krushna Chandra Mishra

    Every live communication situation derives strength for its health from patient participation of parties engaged in the exchange of words in a given regular order depending on how well the business is progressing without blocking meaning that is constantly emerging and on the addition to draw to a satisfactory end.Irrespective of languages and the grammatical structures , we have to keep in mind the curiousity of the meaning-getting party to keep involved in getting words in a flow and in the available and evolving order.If zero syntax idea is well to serve here, we need to follow that word order is quite vital to the communication successes.One word utterances in this case is a help to put things in perspective.Actually, what the questioner ideally appears to be interested in is the sentence order which we may also here loosely understand as word order in the turn-taking sequences of the parties engaged in communication.

  • Hosny Abbas added an answer in Universe:
    Why is there something instead of nothing ?

     LET US START BY WHAT  Robert Adler  WROTE   ON 6 NOVEMBER 2014--:
    People have wrestled with the mystery of why the universe exists for thousands of years. Pretty much every ancient culture came up with its own creation story - most of them leaving the matter in the hands of the gods - and philosophers have written reams on the subject. But science has had little to say about this ultimate question.

  • Farnaz Fahimi asked a question in Microsystems:
    Does any one know any explanatory paper on neural stimulation microsystems?

    does any one know any explanatory paper on neural stimulation microsystems?

  • Micheál Bernard Byrne added an answer in Block Design:
    How do I go about setting up a randomized block design from scratch?

    520 pots in total. 2 plants per pot.

    13 different treatments including the control.

    4 reps per treatment and 10 pots per rep.

    Micheál Bernard Byrne

    Rahmat thanks a million for the help!

  • Javier Lumbreras Fernández added an answer in Chronic Kidney Disease:
    How can we identify CKDU patients in their early stages of stage 1 and 2?

    In Sri Lanka, CKDu patients come to know about their disease only when they reach stages 3 and above, by which time their kidneys are mostly damaged. If there is a way in which we could identify the CKDu patients in early stages, through awareness programs they could be motivated to seek treatment at the hospitals, and as a result their life span can be prolonged. 

    Javier Lumbreras Fernández

    You can look for early alterations like loss of concentration ability . That could be done even with a simple urianalysis (density) after water restriction, as previously mentioned. Also look for proteinuria.

  • V. N. Ravi Kishore V. added an answer in Spectroscopy:
    What does large stokes shift mean ?

    The compound under study exhibits large stokes shift in polar and nonpolar solvents ranging from 90:170 nm. what are all rationale for this large shift?


    - excited state intramolecular hydrogen transfer

    - aggregates

    - exciplex

    ....... etc

    V. N. Ravi Kishore V.

    To add to what has been said. Large Stokes shift can also occur if emission is from a intramolecular charge transfer state.  When a molecule absorbs light it is excited to a locally excited state (LE state) and from the LE state the excitation is transferred to a intramolecular charge transfer (ICT state) and emission occurs from the ICT state. Excitation transfer from LE state to ICT state occurs on a fast time scale. It is another type of excited state reaction as mentioned by Prof. Gert.

  • Muayed Fadhil Abbas added an answer in Chemical Analysis:
    Are there any correlation between nitrogen, potassium and phosphate concentration in plant tissue?

    I want to estimate the concentration of potassium and phosphate in plant tissue with non destructive method or using nitrogen content as base of independent variabel in mathematic modeling so I don't need to used chemical analysis.

    Muayed Fadhil Abbas

    The physiological functions of N,P,K, are well known.however, in my experience, there are  no relationship among those elements to the point, that one could estimate one of them,  and get the other elements using mathematical models. over the last 36 years, i always, estimate the three elements in my work.

  • Edlira Zere added an answer in Chromosome 22:
    What is the most suitable Dental Mangement in The 22q11.2 Deletion Syndrome?

    A 22q11.2 distal deletion is a rare genetic condition caused by a tiny missing part of one of the body’s 46 chromosomes – chromosome 22.

    What is Dental  Mangement in The 22q11.2 Deletion Syndrome?

  • Ebrahim Zarghani added an answer in Mites:
    How can I identify oribatid mites?

    When i try to make a slide mount (using hoyer's or PVA), my oribatid always broken especially the "shell/shield". And also, where can i find the best key for Oribatida?

    Ebrahim Zarghani

    Thank you Dear Matt Colloff.

    I used of your contents.

  • Sofia Moura added an answer in Molecular Biological Techniques:
    How do I extract DNA from Human Placenta for analysis of PMS2 gene?

    I have never worked with human placenta before and now as my final year dissertation that is that type of sample that is going to be provided. I also have to do a business plan but I cannot find anywhere how much would cost me to get a sample of human placenta. Any help? Also what are the best kits ?


    Sofia Moura

    Thank you so much Rafik, it helped a lot.

    Many thanks,


  • Mahsa Zolfaghari added an answer in Antennas:
    Which software is best for design of flexible antennas

    Which software is best for design of flexible antennas

    Mahsa Zolfaghari

    I used ADS and matlab for planner antenna design . ADS simulation results were good for UWB time domain characterisation. I am happy specially with new company called keysight and a gentleman Francesco.palomba@keysight.com.

  • Kritika Khulbe asked a question in Griess Assay:
    How can I detect (NO3- ) and (NO2-) in micro molar concentration simultaneously ?

    Actually I want to detect Nitrite (NO2-) in presence of Nitrate (NO3-).

    I have already done Griess assay (which is not 100% reliable method) and tried fluorescence based assay using 2,3 diaminonapthalene. 

  • Mehran Alidoost Nia added an answer in Devices:
    All IoT devices are device constrained ?

    hello people 

    i have a question, when people talk about IoT they always mentioned constrained devices but from my point of view ...

    i saw that not all IoT devices are device constrained .

    so any one can make this point more clear ?

    thank u in advance 

  • Syed Abbas Jafar added an answer in Climate Change:
    Are there authentic published work confidently pinpointing the sole anthropogenic factors contributing to Climate Change?

    Combined natural and anthropogenic factors (geologically recent phenomenon) govern Climate Change. It is, therefore, of paramount importance to discretely recognize the role of humans in Climate Change and to plan efficient strategy to mitigate it.

    Syed Abbas Jafar


    We don't belong to the creed branded as "Merchants of Doubt", but we do need to honestly understand your bold assertion, which should be backed by solid rationale and publications: " At the same time we know with the next thing to certainty that anthropogenic CO2 at current and projected levels is a huge forcer of climate change" How do we measure component of anthropogenic CO2 forcing Climate Change?This statement has far reaching implications and holds key to the subject matter of the debate here. We look forward to seeing your crisp response. 



  • Rozália Klára Bakó added an answer in Network Modeling:
    How can I measure the complexity of an information flow?

    Once an information flow (IF) can be represented as a process, can we measure your complexity as a network?
    According Brandes, Robins, McCranie & Wasserman (2013), in order to think in terms of network first is necessary to have elements (E) and processes (P) of a network model: phenomenon (E), which passes through an abstraction (P), making the concept of the (E) which may be represented (P) and data network (E).
    Taking the IF as a broad phenomenon, can we introduce the concept of network processes, which can be viewed as a web of interdependent tasks or activities, its products, which are more than the sum of its components and the participating organizations, can be understood as a network of people and communications?
    Which measure can be more appropriate in this case?

  • Andrey S Bavykin added an answer in RNA Extraction:
    Anyone familiar with RNA extraction from fish?

    hello i did extraction of RNA from fish using geneall kit and i used the TAE gel for rapid confirmation of RNA integrity.

    as I can see in the picture, i have the two bands of 26S and 18S but there is other bands in upper part.

    what is the possible cause of that? what is the nature of these bands?

    Andrey S Bavykin

    RNA degradation

  • Tina Thulasi added an answer in Accelerator Mass Spectrometry:
    Which benthic foraminifer is suitable for AMS dating?

    Which benthic foraminifer is suitable for AMS dating?

    Tina Thulasi

    AMS I meant is for radiocarbon dating.. There are particular species like G.bulloide, G.ruber, etc for isotopic studies.. In that way which benthic foraminifera species will be suitable for doing the same? Especially 2.8 M.A

  • Mohsen Bahrami asked a question in ZnO:
    Can we use ZnO instead of TiO2 when we want to produce masterbatch?

    Can we use ZnO instead of TiO2 when we want to produce masterbatch?

    for example, when we want to produce whiteness masterbatch, we use TiO2 and Polymer. Now can we use  ZnO instead of TiO2?

  • Shrinath Kannan asked a question in Variable Frequency Drive:
    How to calculate DC link capacitance and inductance in a variable frequency drive?

    I'm trying to design a variable frequency drive, looking for some reference papers to calculate the DC bus link values

  • Shafieeh Mansoori added an answer in Microbiology Techniques:
    Why we first make universal culture for bacterial growth then add it to large scale?

    Why do we first make universal culture for bacterial growth then add it to large scale?

    Shafieeh Mansoori

    Hi dear

    I Agree with Dan and Kuldeep answers. 

     First , we have to prepare seed culture for the microorganism passes the "lag phase" and enters into the "log phase" for the metabolites production. also, the amount of bacteria must be maximum. when the seed culture is added to the large scale, the lag phase will be shorter and the bacteria (with more numbers)  begin in the metabolite production  in the large scale sooner.

    The important point is that removing the seed culture will lead to the time consumption and the additional costs.

  • Abbas Paziresh added an answer in Translation Studies:
    Does anyone know any theory about the concept of 'lost in translation'?

    aspects of source text

    Abbas Paziresh

    Dear esteemed Cooper

    Thanks so much for trying to help me. you many scholars up to now talked of loss and gain in translation, but unfortunately no theory devised. selecting the appropriate and adequate translation theory in translating it is the first step towards a successful translation. Similarly, resorting to the free translation methods will
    erase the aroma and identity of the (ST) in (TT) which will affect the purpose of the (ST)
    eventually. so, we need to devise a theory now. i need assistance.