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

  • Francesco Boldrin added an answer in Electron Microscope:
    How can I batch convert ".emi" to ".TIFF" pictures in Tecnai TIA ?

    Hi all,

    I would like to batch convert simultaneously pictures taken with TIA in a FEI Tecnai electron microscope from ".emi" to ".TIFF" format, instead of doing it one by one. I will appreciate if someone could give me some suggestions.

    Thank you very much


    Francesco Boldrin

    Thnk you very much Bert and Marin!!!

  • Hafij Ali added an answer in Natriuretic Peptides:
    Can anyone suggest which diagnostic tests would be better for the diagnosis of cardiac patients? 1. BNP or 2. NT-ProBN?

    Currently we are doing NT-ProBNP ( N-terminal pro b-type natriuretic peptide) test for the diagnosis of cardiac patients but some of the consultants are suggesting us to start BNP (b-type natriuretic peptide) test. As far I know the half life of BNP is lower than NT-ProBNP. So NT-ProBNP is better to perform this test in our laboratory. Even we can easily collect the blood sample from surrounding the areas.

    Hafij Ali

    Ihsan Atlas, BNPor NT-ProBNP is a substance secreted from the ventricles or lower chambers of the heart in response to changes in pressure that occur when heart failure develops and worsens. The level of BNP or NT-ProBNP in the blood increases when heart failure symptoms worsen, and decreases when the heart failure condition is stable. So any one easily can know his or her heart status by doing this blood test.

  • Lakshmi Gopakumar added an answer in Earthworm Taxonomy:
    Can anybody suggest an earthworm expert in India who can identify up to species level?

    Can anybody suggest experts in Earthworm Taxonomy in India who can help me in identification of some specimens

    Lakshmi Gopakumar

    Thanks for the mail. 

  • Akash Sood added an answer in MEA:
    How to blend two different chemical fluids?

    I am working on blending of fluids like MEA, DEA and TEA.

    Akash Sood

    Actually, I want to study the blends of Mono, Di & Tri-Ethanolamne at various level of concentration weather they increase there property of carbon absorption or decrease and many more other parameters.

  • Saeed Al-Muharrami asked a question in GDP:
    What is ideal rate of military expenditure of a country to its GDP?

    Is there an ideal rate of military expenditure to GDP?

  • Haizi Yao added an answer in Surface Plasmons:
    Does anyone know hot to calculate the forece induced on a nano (non metalic)particle by surface plasmons ?

    i am planning  a setup to manipulate nano particles with surface plasmonic waves.i am looking for a method to determine the laser source for the setup.in this i am looking for a method to calucluate the force induced on a nano particle(latex) by the plasmonic waves .

    it will be grateful if someone can help me find a method .

    Haizi Yao

    plasmonic wave? Maybe you can use the Maxwell tensor method to calculate the electromagnetic force on the particle.

  • Anand Prakash Maurya added an answer in Carbapenemase:
    What is the difference between Carbapenem ,imipenem, meropenem, ertapenem and doripenem in the assessment of carbapenemase producing bacteria?

    What is the difference between the use of Carbapenem ,imipenem, meropenem, ertapenem and doripenem in the assessment of carbapenemase producing bacteria? Is there a famous reference that provides details for such test? Thank you.

    Anand Prakash Maurya


    Dear Ragheb, Carbapenems is a class of antibiotics.  Imipenem, Meropenem, Ertapenem, Doripenem, Biapenem antibiotic are came under this class. 

    and for identification of carbapenemase producing isolates you can use imipenem/
    imipenem + ethylenediaminetetraacetic acid (EDTA) as for phenotypic identification and for molecular identification and characterization you can design the primer or you can use previously used primer.

    For Reference you can see this article: "The emergence of OXA-48- and NDM-1-positive Klebsiella pneumoniae in Riyadh, Saudi Arabia" Atef Shibl , Mohamed Al-Agamy, Ziad Memish, Abiola Senok, Shamshad Abdul Khader, Abdullah Assiri. "

  • Katja Kritzler added an answer in Oral Rehabilitation:
    TMJ clicking is nowadays classified as a noisy annoyance. Is there any evidence when and how it should be treated?

    Does it matter whether a disk displacement is correctly identified at the early stage of assessment in a clinical setting? Do displaced disks represent a pathology that must be identified? Do displaced disks that do not cause pain or interference in joint movement represent a clinical problem requiring classification and, of greater concern, some type of treatment? 

    Ohrbach, R., & Greene, C. (2013). Temporomandibular joint diagnosis: striking a balance between the sufficiency of clinical assessment and the need for imaging. Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology, 116(1), 124–5. http://doi.org/10.1016/j.oooo.2013.03.021

    Naeije, M., te Veldhuis, A. H., te Veldhuis, E. C., Visscher, C. M., & Lobbezoo, F. (2013). Disc displacement within the human temporomandibular joint: a systematic review of a “noisy annoyance.” Journal of Oral Rehabilitation, 40(2), 139–158. http://doi.org/10.1111/joor.12016

    Katja Kritzler

    Hello Hala, I agree. If no dysfunction or pain can be diagnosed reciprocal clicking must not be treated because it represents an anatomical condition not an  disorder.  When the clicking joint is associated with pain or joint dysfunction in  most cases simple therapeutic interventions will be adequate to resolve the condition. These include patient education, self-care, physio-therapy, an occlusal appliance, and eventually pharmaco-therapy.

  • Gaurav Pandey asked a question in Solvents:
    Is HFIP ( 1,1,1,3,3,3-hexafluoro-2-propanol) a universal solvent for aggregating peptides?

    And can we use it for conversion of any of the peptide (in Beta form) to its monomer form?

  • Shreya Shripad Kaduskar added an answer in Shape Memory Alloys:
    How do I model shape memory alloy with concrete in ANSYS ?

     In ansys 15 i have modeled a reinforced concrete simply supported beam with a central load. In this same model i have to partially replace steel with shape memory alloys, but some how i am getting stuck up in between. For shape memory alloy as a reinforcement i am using beam 188 element, but when i am putting that problem for solve in ansys, it is showing me error i.e. "beam 188 element does't not support TB SMA". And even when i am using solid 185 and pipe 288 element it is showing me same error. Can u please help me how can i model SMA in ansys, along with concrete.Please help me out.
    please do reply me

    Shreya Shripad Kaduskar

    Sir i have tried to solve cantilever SMA beam with point load as well as UDL using solid 185 element for SMA and both the SMA beams are showing me the results.  The problem is coming when i am using concrete with SMA.

  • Ajay Saini added an answer in Euchromatin:
    Are the results of chromosome banding all the same in different tissues?

    We know that many genes are expressed in a tissue-specific manner. Mechanisms include the remodeling of heterochomatin and euchromatin. I wonder now  if there's any way of high-resolution chromosome banding could show such difference? Or is there any other ways of staining could indicate that one gene is located in heterochromatin or euchromatin?


    Ajay Saini


    Chromosome banding patterns show gross differences...they may or may not show fine tissue specific expression differences.....You may be able to use FISH analysis along with banding patterns to localize a  particular gene in a hetero- or euchromatic region..

  • Anne Panhelainen added an answer in Synaptosomes:
    How can I look at a presynaptic D2 (short?) receptor in striatum?

    Hi. Does somebody have an idea on how to quantify the presynaptic D2 receptor in mouse striatum? Should I prepare striatal synaptosomes and run western on them? Do good antibodies exist for D2 receptors? For mouse tissue? Does any antibody really select for D2 long form? Other ideas? Thank you!

    Anne Panhelainen

    Thank you all with your kind help! I will do qPCR, and also try something at the protein level, not sure yet what though :) It's a complicated circuitry, as everything is...

  • Saeed Al-Muharrami asked a question in GDP:
    What is the resonable or acceptable rate of national debt of a country to its GDP?

    When does the rate of national debt of a country to its GDP become critical?

  • Sajad Vafaeenezhad asked a question in Kaolin:
    What chemical (Polysaccharide base) can I use instead of "Amijel (Cplus 12072, Cerestar, France)" as a binder for kaolin?

    There are different methods for preparing micro-filtration membranes based on Kaolin. Almost all of them use Amijel as the binder. I wanna use another binder. I think Polysaccharide base materials could  do the job. I am not sure about different celluloses, PEG, PVP,... 

    P.S. Corn starch & similar materials can't be used as Amijel.

    I would appreciate if anyone help me with this.

  • Markus Lindholm added an answer in Climate Reconstruction:
    How exactly does decentering of proxies affect resulting PCs in PCA?

    Transforming proxies into principal components (PCs) and using these PCs in building transfer models is usual in climate reconstruction. A common procedure before PCA is decentering (i.e. subtracting the mean) a group of e.g. tree-ring chronologies before principal components analysis. However, PCA and the resulting PCs seem to be sensitive to decentering. Presuming PCA is based on correlation matrix, what is the rationale behind this? Can anybody elaborate on this or point to a reference?

    Markus Lindholm

    Thank you very much for the informative answer and reference!

  • Ruediger Burkhard Richter added an answer in Waste Treatment:
    What are the recent research trends in enhancing the thermal treatment of mercury containing waste from Chlor alkali plants?

    I'm looking for the best way for enhancing thermal treatment for mercury containing waste from Chlor alkali plants.

    Ruediger Burkhard Richter

    Dear Prem,

    what you describe in your first answer is more applicable for mercury-contaminated water than for the treatment of soil or rubble from CAPs. The main Hg-contamination in CAP soil is beaded mercury which is basically not soluble in water. - Besides this a considerable high amount of mercury in such soils is adsorbed to carbon grains but also to brittle graphite from anodes which will be found in CAP soil quite often (spread by maintenance).

    kind regards


  • Jyoti Gavali asked a question in Ayurveda:
    How do we assess the marker in medicated oil prepared from many herbs together?

    During preparation of oils in Ayurveda,the lipid soluble and water soluble compounds present in the herbs get displaced into the oil.This medicated oil now contains active principles from many herbs which are used for preparation.It becomes difficult to identify a marker compound for it.

  • Haroon Rashid added an answer in Aptamers:
    Method for aptamer-gold conjugation

    What is more efficient method of conjugation of an aptamer to 40nm gold nanoparticles: using the thiolated aptamer or polyA one?

    Thank you.

    Haroon Rashid


  • Ajay Saini added an answer in Leukemia Cell Lines:
    How could analyse rt-qPCR expression in between untreated and treated Tyrosin Kinase Inhibitor in chronic myeloid leukemia BCR-ABL1 gene Expression???

    I am doing an experiment on Chronic myeloid Leukemia cell line K652 and facing problem in analysis of their expression on both treated with TKI and untreated sample of BCR-ABL1 gene, 

    Ajay Saini


    As mentioned above by Dr. Divaker...you may kindly elaborate the problem faced in the analysis.

  • John Schloendorn added an answer in Lipofectamine:
    Does somebody have experience with HEK293A transfection? Is work with low serum important or not?

    I try to transfect HEK293A with lipofectamine 2000 and PEI. I used 1.5µg of DNA. When i used 10%FBS i have RNA expression but not protein expression and when i used media with 2.5%FBS i have not RNA expression.

    Thanks in advance

    John Schloendorn

    If there are any conditions where you can get an appropriate amount of RNA without protein, then that would rather point to a problem with the vector design, and not the transfection method.  Are you sure your Kozak is OK? 

  • Simon James added an answer in Exponentiation:
    Can someone give details about how the Bonferroni Mean works over sets of data?.

    In the Bonferroni Mean, can the exponential coefficients be applied to one raw of data?, or it is necesarry to consider some of them depending on the amount of coefficients? If there is any example, I will be grateful for it.

    Simon James

    Depends what you're trying to do, Eddy. With various generalizations of the Bonferroni mean you can set a number of coefficients to 0 and so deal with any subset but i'm not sure whether you're just mainly hoping to transform some subset of your data with an index (which again there's no reason why you can't do it).

  • Ines Bayoudh Saâdi added an answer in eLearning:
    How can we rank e-learning problems like learning path sequencing, object recommendation?

    How can we rank e-learning problems like learning path sequencing, object recommendation etc..

    Ines Bayoudh Saâdi

    I recommand you this ressource:

    Franzoni Ana Lidia & Assar Saïd (2009). « Student Learning Styles Adaptation Method Based on Teaching Strategies and Electronic Media ». Educational Technology & Society, vol. 12, n° 4, p. 15–29.

  • Nobuhiro Takeuchi asked a question in Kidney:
    Does anybody have an idea whether right-sided kidney is more vulnerable to bacterial infection than left-sided kidney?

    I am sorry if this question does not make sense, but I am really curious about this. Recently, I experienced two cases of acute focal bacterial nephritis (an acute localized non-liquefactive infection of the kidney caused by bacterial infection). Both cases are female and affected right-sided kidney. Actually, in many medical reports, left-sided kidney may become a focus of bacterial infection in the same way as right-sided kidney. I just wonder if right-sided kidney is more easily affected than left-sided kidney by bacterial infection for some anatomical reasons.

  • Ulf Nobbmann added an answer in Dynamic Light Scattering:
    Why can't I obtain an appropriate particle size for graphene quantum dot by DLS?

    I synthesised it with pyrolysis of acid citric and then added NaOH in it. I filtered it by PTFE syringe filter after centrifuge at 5000 rpm for 30 min, and tested it for some concentration.

    Ulf Nobbmann

    A potential issue with quantum dots can be fluorescence. This can possibly be overcome by addition of a narrow band filter to reduce the influence of (incoherent) fluorescent light at the DLS detector. Many DLS instruments automatically scale the input and thus scattering intensity and would not necessarily show an intensity overload, however the intercept of the correlation function will be significantly reduced compared to non-fluorescent samples. This only happens if there is fluorescent light emitted and if it reaches the detectors. Adding a narrow band filter (for example 5-10nm band width) will reduce the "extra" non-scattered light and yield better correlation functions.

    However, the sample itself will have to be suitable, general sample preparation and data quality concerns remain. The intensity based size by DLS may be larger than a size obtained by other means (number based TEM for example.)

    + 1 more attachment

  • Alamelu Kannan Ramasami asked a question in Combustion Synthesis:
    Can a semiconductor have all the four types of transitions, viz. direct allowed, indirect allowed, direct forbidden and indirect forbidden band gaps?

    I had synthesized vanadium pentoxide nanowires by combustion synthesis. The UV- Vis. reflectance spectral data and Tauc's equation were used to calculate the band gap. I got a perfect fit for all four types of transitions. Is it possible for a semiconductor to have all of them (direct allowed, indirect allowed, direct forbidden, indirect forbidden)? 

  • Saurabh Kumar Singh added an answer in Organic Field Effect Transistors :
    Why does FET have higher bandwidth than BJT ?

    it is said that field effect transistor (fet ) has higher bandwidth than bjt  . please explain reason behind this.

    Saurabh Kumar Singh

    The bandwidth should be compared for some common parameter for a fair comparison.

    For integrated devices (on-chip devices) BJT is faster than FET for a given current. The reason being the higher gm offered by BJT per current. This is the reason that BiCMOS is used for hi speed chips where BJT is used where speed is critical.

    gm of BJT does not depend on geometry but only on current (and temperature) while FET gm strongly depends on its length. That is the reason the new MOSFET technologies are also faster (even better than BJT in some cases). But due to high field effects this increases is not a dramatic for nanometer MOSFET.

  • Muhammad Ali Shah asked a question in Electrodes:
    Anyone know how to fabricate a 3-axis MEMS gyroscope with beneath electrodes?

    I have designed a 3-axis MEMS gyroscope with two out-of-plane motions. Anyone know how to fabricate this device with beneath electrodes? Any special fabrication method?

  • TheParesh N. Naik added an answer in Force:
    How can i study the earth revolving around the sun computationally?

    The electron revolves around the nucleus of an atom  with an electrostatic force of attraction and the earth revolves around the sun with a gravitational force of attraction between the two. can the earth and the sun be simulated?? and how?

    any advise please?

    TheParesh N. Naik

    Yes Of Course the Earth and the Sun can be Stimulated.

    If electron and a nucleus can stimulated and if electron revolves around the nucleus, if this act is possible then the universal act of the Earth-Sun Stimulation Process also Exists in Nature.* The  Electron revolves around the Nucleus with the Help of a Electro-Static Force of it's attraction; like this stimulation also it is possible that the our Earth and Sun be Stimulated.* But Electron-Nucleus Process Occur with the Attraction & Repulsion Electro-Stactic Stimulation But Earth-Sun Stimulation Occur with the Gravitation Stimulation of Strong Gravitational Force.* 

    And Yes Of Course You Can Study the Earth Revolving around the Sun Computationally. There are Many Space Softwares Available For this..

    Thank You..**

  • Jo Barfield added an answer in Gram-Positive Cocci:
    Problem with PFGE - Why is my DNA smearing?

    I am attempting to work up a PFGE protocol for a Gram Positive cocci that is of interest to our lab. However, I am still getting a lot of undigested material stuck up in the loading well. I originally assumed that the SmaI digest was incomplete but we discovered it was the concentration of Lysostaphin relative to the cell suspension. Once we increased the Lysostaphin, we started to see faint bands however now all we are getting is smearing! (see attached) plus a lot of DNA still stuck in the loading well. Does rough handling of the cell suspension or delay in embedding the cells in agarose cause smearing? Or is there something wrong with the electrophoresis tank temperature or buffer temperature and the DNA is degrading? Or buffer, tubing, tank contaminants? Thanks in advance. 

    Jo Barfield

    Thanks for your advice. I have de-contaminated the tank and tubing, made sure everything is clean and sterile including all reagents.

    The plugs were washed 6X. I agree, there is either insufficient lysis or RE digestion. I have re-run the same plugs using only 1/4 slice with 75 U of RE. Could this be causing star activity? I still think the cell suspension ratio to Lysostaphin is the problem. Can I put them back into more Lysostaphin and go from there? This is how we made the plugs:

        i.            resuspend pellet with EC buffer to McFarland 6

       ii.            Transfer 150 uL of the cell suspension into a sterile microcentrifuge tube. Add 7 uL of Lysostaphin  (@ 1 mg/mL) followed immediately by 150 uL of 2.0% Certified PFGE agarose. 

       iii.        Transfer the plugs to tubes containing 500 uL of EC buffer and 10 uL of lysostaphin (1 mg/mL). Incubate overnight at 37 oC.

  • Stam Nicolis added an answer in Photons:
    How can you explain a possible inconsistency with the Bohr atom model?

    It is well known that Bohr model is not totally right. But I recently discovered a very curious inconsistency (if I am right) which I haven't seen explained anywhere.

    The first postulate of Bohr theory is that the Orbital momentum of the electron is quantized L=mvr=nh  (where h  means the Dirac constant). This means that if there is a transition between level n=5  to n=1  (Balmer series) the orbital momentum changes by 4h  !!! Based on this rule and his second postulate Bohr finds the right energy for this transition (and all others as well). But this transition is a release of just one photon and a photon has spin 1h  . It can add to L as (h,0,−h)  . So it can change the orbital momentum with 1,0  or −1  and not by 4.  I'm very surprised to make such conclusion.

    Am I wrong here?

    Stam Nicolis

    Indeed any claim that the Bohr model is suprseded by subsequent work isn't relevant, because the question refers to consistency, not experiment. The Bohr model is consistent, with respect to the issue raised, because the states with definite n are stationary states, so there isn't any transition possible from n=5 to n=1 at all, in the absence of an electric field. And in the presence of an electric field such a transition is possible, was measured, is known as the Stark effect and was explained, in detail, by Bohr and Sommerfeld.