Q&A

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

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
  • Hicham Riba added an answer in Dental Caries:
    Does flossing play a role in caries prevention?

    Do we have a research study related to this?

    Hicham Riba · King Saud bin Abdulaziz University for Health Sciences

    Brushing could not remove the plaque in the interproximal areas. That is when flossing comes handy. 

  • Shoeb Ahmed added an answer in Cancer Cell Line:
    Does anyone know a suitable kit to measure cells proliferation?

    Greeting everyone,

    I have cancer cell line, and I need to measure cells proliferation.  Does anyone have experience with this assay?

    Thanks 

    shaima Jabbar 

    Shoeb Ahmed · Bangladesh University of Engineering and Technology

    You can use any automated cell counter or hemocytometer to count cell. Just make multiple wells with same seed concentration and remove and count cells from each well at a particular time. Should give you pretty good accuracy. 

  • Luc Bulot added an answer in Iran:
    Can anyone name the specimen of this belemnite found in the Toarcian-Bajocian in Kerman, Iran?

    This specimen found in the Badamu formation.

    Luc Bulot · Centre Européen de Recherche et d’Enseignement des Géosciences de l’Environnement

    Here is the Pinard et al. paper...

  • Gautam Ray added an answer in Adiponectin:
    Should obesity be classified as an independent disease?

    Obesity may be secondary to endocrine  diseases (hypothyroidism,  Addison, etc). Primary obesity, which has became highly prevalent in many western countries,is due to a combination of metabolic, dietary and life style disorders.It has been observed in experimental studies including human beings, that adipose tissue in primary obesity and overweight (particularly visceral  ) may be in constant inflammatory state (adipositis?) .  Adipose tissue in these circumstances secretes chemical mediators known as adipokynes (TGF β-1, leptin, TNFα, adiponectin, etc),  most of them inducing  metabolic impairment, inflammation and fibrosis acting in other distal organs  leading to insulin resistance.  The morbidity and mortality observed in obese and overweighted individuals is well known: (Diabetes, arterial hypertension, dyslipidemia, cardiovascular disease, cerebral vascular stroke, renal failure, NASH , liver cirrhosis, etc.).

    It is clear that obesity fits clear definition of disease. If we take into account this premise,  should obesity  be classified as an independent disease?  It may be a warning for affected people leading them to treatment search, for physicians in order of avoiding negligence in the treatment of this condition and may be beneficial for ¨patients¨ regarding insurance covering.

    Gautam Ray · B.R.Singh Railway Hospital, Kolkata, India

    It is difficult to be sure whether obesity changed the gut microbiota or the reverse. Hepatic steatosis may be the confounding variable related to both. But of course different microbiota cause different metabolic alterations. There are a lot of juvenile obesity in developed countries. One can study the microbiota in obese infants and toddlers from developed countries and compare them to that of non obese infants and obese adults

  • Flemming B. Grumsen added an answer in SAED:
    Does anyone know about 1/Gm scale in SAED pattern?

    I have done HRTEM imaging and Surface area electron diffraction (SAED) analysis of my nanoparticles, the results are fine, but the scale in SAED diffraction image is 10.0 1/Gm, not in nm. Does anyone know about it? How to convert it in nanoscale? 

    Flemming B. Grumsen · Technical University of Denmark

    1/ Gm is  nonsense, however 1/ m^-9 = Gm and not 1/Gm

  • Debora Lia added an answer in mtDNA:
    Could someone suggest a good protocol for mtDNA amplification?

    Hi,

    I'm trying to amplify mtDNA but I always obtain very different results in terms of efficiency (most of the time the short fragment is not amplified).

    The primers I'm using are:

    Long fragment (8.9 kb)
    Mitolong_for 5’-TCT AAG CCT CCT TAT TCG AGC CGA-3’
    Mitolong_rev 5’-TTT CAT CAT GCG GAG ATG TTG GAT GG-3’

    Short fragment (221 bp)
    Mitoshort_for 5’-CCC CAC AAA CCC CAT TAC TAA ACC CA-3’
    Mitoshort_rev 5’-TTT CAT CAT GCG GAG ATG TTG GAT GG-3’ 

    Any suggestions will be very appreciated. Have a nice day! Deb.

    Debora Lia · Laboratory for Research in Genetic Instability (LRIG)

    Dear Amy, thank you for your answer, I will try and I will let you know!

    Benedict, I use the Phusion but I add also BSA instead of DMSO. Do you think there are some differences? And I use the Qiagen kit for the extraction of DNA from cells.

    I will try to "play" a bit with the Tm.

    Thank you all. Deb

  • Muhammad Asril added an answer in Ganoderma:
    Why is the application of antagonistic bacteria/fungi to inhibit fungal pathogens show better inhibition in the greenhouse than in field application?

    Why the application of antagonistic bacteria (ie. chitinolytic bacteria) or antagonistic fungus to inhibit fungal pathogens, especially Ganoderma boninense in the application in the greenhouse better than applications in the field (lower inhibitory)

    Muhammad Asril · Bogor Agricultural University

    Thank you Mrs. Obire Omokaro.

  • Marcella Bini added an answer in Molar:
    What is the best weight percent for making successful metal oxide doping?

    What is the best weight percent for making successful doping? Should I use 0.1, 0.3, 0.5..... molar ratios?. or 0.01,.0.02...or 0.001, 0.002..0.003 molar ratios? 

    Marcella Bini · University of Pavia

    I agree with Marcos, it is not possible to suggest an exact number, it depends on many variables and it depends also on the reasons for which the doping is performed. For some application very low amount of dopant are sufficient.

  • Mohan Ranganathan added an answer in Ductility:
    Does grain size have an influence on fracture surface?

    I have a bi-modal microstructure in my Oxide dispersion strengthened steel with some grains approx. 20 micron in size and some approx. 5 micron in size. As it is known that with increase in temperature fracture surface appears more ductile with formation of dimples. In my case i still see some flat facets like surface at high temperature (700C). Can grain size have an influence on this?

    Mohan Ranganathan · University of Tours

    typically environmentally assisted cracking takes place along grain boundaries as does intergarnular creep. You expect intergarnular fracture with littele evidence of slip in the grains. Mainly cleaveage in BCC metals. In such cases, frain size has a great influence.

  • Michelle Falkenbach asked a question in Austria:
    What are good ways to find a relevant and compelling thesis topic?

    I am looking for ways / ideas to find a relevant thesis topic that I could maybe even combine with an internship (preferably in Innsbruck, Austria).  What would be the best way to go about doing this?

    Any suggestions, has anyone done this?

    Many thanks

  • Yuan-Yeu Yau added an answer in Medicinal Plants:
    Please provide list of some most important medicinal plant which conservation or more study?

    for the research and study.

    Yuan-Yeu Yau · Northeastern State University

    Thanks for clarification, 'most important'.

  • Do we have enough information on the eradication of weeds like Eupatorium, Lantana etc. ?

    Can anyone suggest any experimental design for the eradication of weeds?

    Mohammed mahgoub Hassan · Environment and Natural Resources Research Institute, National Centre for Research, Ministry of Science and Technology

    Evasiveness:
    Many weeds like Lantana camara, Ocimum gratissimum,
    Stemodia viscosa, Cyathocline purpurea etc. are capable of
    evading destruction by animals and man because of their bitter
    taste, disagreeable odour etc.

    please find my attached file

    with regards

  • What is appropriate media for MSCs culture?

    I would like to know using Alpha MEM having ascorbic acid is good idea or not for mesenchymal stem cells culture. I generally use mice/rat bone marrow stromal cells for MSCs. using alpha MEM containing ascorbic acid induces differentiation of MSCs. I would be happy to know which media is best for MSCs culture.

    William Richard Webb · Keele University

    DMEM, 10% FBS, 1% L-glut, 1% NEAA, 1% pen/strep

  • Jorge Gomes added an answer in IT Governance:
    Is there a method for calculating the monetary value of IT for an organization, taking tangibles and intangibles into account?
    We are currently researching the impact and importance of IT from an insurance perspective - here the monetary value of IT becomes very important. Is anybody aware of an (established) method which is not necessarily estimating, but rather calculating the value? In addition, we are not looking for just the tangible elements/assets, but also the intangibles, especially the possibility of quantifying the monetary dependencies for the business model itself.
    Jorge Gomes · University of Lisbon

    I share the opinion of the HANS. Must do a literature review on the benefits management approach. This approach was developed especially with the focus on identifying, structuring, monitoring the benefits from the investments IS / IT in organizations.

  • Wouter Maijenburg added an answer in Nanowires:
    Template-based synthesis of nanowire

    I have some information about template-based synthsis of nanowire. Is anyone that has any information?

    Wouter Maijenburg · GSI Helmholtzzentrum für Schwerionenforschung

    If you're new in the field and want to see how other people make their nanowires by templated electrodeposition: Please check my video in the Journal of Visualized Experiments:
    https://www.jove.com/video/51547/preparation-use-photocatalytically-active-segmented-agzno-coaxial

  • Who knows why the DNA concentration measured by a Nanodrop is different from the concentration measured by a Qubit?
    We did SNP array with Agilent chip. But sometimes we would get noisy data. We tried a lot of methods to fix this but failed to do so. We are sure our DNA has no RNA or protein contamination or degradation. Only the DNA concentration is different between the Nanodrop and Qubit methods. Once the DNA concentration measured by the two methods is the same, we will get good data. I have already asked Agilent support, but they couldn't give me an answer.
    Filipe Alberto Marques Teixeira · University of Coimbra

    I would give a look to the Trinean's instruments. They have this new technology which allows you to measure 96 samples in 6 minutes without any dyes, and still get Qubit accuracy.

    It's quite new but still worth to try it.

  • Elia Zomot added an answer in TCA Precipitation:
    Aggregation problem with MAL-PEG thiol-labelling of plant proteins and SDS-PAGE

    I am trying to determine the in vivo redox states of several stromal proteins in Arabidopsis chloroplasts by labelling them with MAL-PEG and then running on an SDS-PAGE. MAL-PEG binds to reduced thiols in proteins, increasing their molecular mass so that the reduced and oxidised forms of proteins can be separeted on a gel. I extract my proteins by TCA precipitation (which preserves the in vivo redox state). I have 4 different treatments for each sample: 1: DTT, then MAL-PEG --> fully reduced control. 2: NEM, then MAL-PEG --> Blocked thiols (by NEM) control, no MAL-PEG should bind. 3: NEM (block thiols), then DTT (reduce disulphides), then MAL-PEG --> in vivo oxidised forms bound with MAL-PEG. 4: MAL-PEG only --> in vivo reduced forms bound with MAL-PEG.

    Now, treatments 2 and 3 work great and run nicely in SDS-PAGE. Treatments 1 and 4, however, are giving me headaches. They are the most "MAL-PEG-heavy" samples, which seems to cause them to aggregate and not run properly in SDS-PAGE. I get almost no signal from those samples with my antibodies, and when I stain my membrane with coomassie, there is indeed very little protein on the membrane for those samples. I am not sure if the proteins aggragate on the gel and can't get past the stacking gel, or already earlier in the tube. 

    I ran 15% polyacrylamide gels with 6M urea, and also tried 12% gels and loaded less sample to see if the looser gel would help, but it made no difference. Now, the 2 working treatments alredy do give me nice results but it would be nice to get all 4 working to have good controls and more conclusive results. Any suggestions?

    Elia Zomot · Weizmann Institute of Science

    Thing is I need to do Mal-PEG labeling to see if the cysteines are accessible under native conditions and to what degree. Disappearance problem is with samples treated with Mal-PEG both under native or denaturing conditions. Samples treated with NEM prior to Mal-PEG are just fine, but I still need to be able to see if there are any bands with higher molecular mass. 

    I've had this issue with different (single or double) cysteine mutants of my multidrug transporter, both in the purified/solubilized form and in the membrane with total proteins. So I should only have one or two Mal-PEG groups bound to every protein. I used 2.5-5 mM Mal-PEG and total protein conc. of 0.5-1 ug/ul  (upon labeling).

  • Kamlesh Shah asked a question in Mycology:
    How to extract mycotoxin from fusarium sp. grow in fungal medium?

    Mycology, Plant pathogen

  • Can I use nanodrop to measure DNA concentration after PCR run?
    What is the blank used in this case? I want to know the concentration of DNA after PCR run. Can I simply use nanodrop or other component of mastermix would interfere with my result?
    Filipe Alberto Marques Teixeira · University of Coimbra

    If it is a purified sample I would measure it on a Trinean instrument. They have two instruments, that allow quantification without any dye.

  • Christophe Sandt added an answer in Amides:
    Why is FTIR spectra of rat brain tissue showing different peaks at 1750-1400 region?

    I am performing FTIR spectroscopy analysis of rat brain tissues but in comparison to earlier studies there is an alteration in spectra. All the earlier studies show amide I peak at 1600-1690 and amide II between 1480-1575. But in my case there is a peak at 1592-1594 may be for amide I and another at 1563-1467 may be for amide II (similar patterns). So, here I want to know- where is the problem that causes alteration in peaks?

    I am using a Bruker ALPHA spectrometer to scan powered brain tissue using KBr pellets.

    Christophe Sandt · SOLEIL synchrotron

    The amide region of the brain tissue should not change as strongly as you described under normal conditions. It is difficult to estimate what's going on without a proper visual inspection of the spectra so I suggest that you show us your data to obtain a good answer.

    The changes in the secondary structure of proteins can not cause such a strong shift. The maximum shift related to protein structure would be a shift in amide I position to 1630 cm-1 as in the case of amyloid plaques with almost no change in amide II band.

    Scattering may cause a slight shift of the amide bands, especially Mie scattering, but it does not cause such a strong shift (but cause shift from 1654-1656 cm-1 for amide I to 1640-1645 cm-1).

    I suppose you could have some contamination of your sample. Do you use any resin for inclusion such as paraffin or OCT ?

  • Krishnan Umachandran added an answer in Papers:
    How i can get doi?

    Hi dear researchers;

    i have a question. how i can get a free doi (digital object identifier)for my papers?

    do you know a way that i can get it?

    Krishnan Umachandran · Professor

    A DOI is a unique and permanent number used to identify digital content. DOIs provide a reliable link to your work online, making it easy for others to cite you. Please make a note of your DOIs for future reference.

    Once a researcher publishes their  article in RG, the second screen penultimate row has a question "Do you want to generate a DOI and there are three options - Not required, System generated and the Your choice. The researcher needs to pick a choice.

    A email of system generated DOI will be sent to the author

  • Franco Concli added an answer in OpenFOAM:
    How do specify periodic condition in OpenFoam?

    I try to solve axial turbine with periodic boundary condition. But I have used in periodic boundary conditions. But it is showing wrong.  Can any one help me how to implement periodic condition?

    Franco Concli · Libera Università di Bozen-Bolzano

    http://www.openfoam.org/version2.0.0/meshing.php

  • Harry Coules added an answer in Shot Peening:
    Can processes other than shot peening be employed to induce compressive stresses?

    Thanks.

    Harry Coules · University of Bristol

    Remember that (as Hamed mentioned) all of these processes only produce a compressive state of stress on the surface of the material - conventionally up to a maximum depth of 1-2 mm in metals for shot and laser peening and ball-burnishing. If you want to introduce compressive residual stress at greater depths, you need a process which introduces more severe plastic deformation, such as localised rolling (see Coules et al. "Effect of high pressure rolling on weld-induced residual stresses", Science and Technology of Welding and Joining, 17(5), pp.394-401, 2012) ... Of course, compressive residual stresses have always got to be equilibrated by tensile ones somewhere else in the material though!

  • Qubit vs. Nanodrop?
    Can someone tell me if Qubit is really better than Nanodrop in nucleic acids quantification, even for small concentrations?
    Filipe Alberto Marques Teixeira · University of Coimbra

    I would give a look to the Trinean's instruments. They have this new technology which allows you to measure 96 samples in 6 minutes without any dyes, and still get Qubit accuracy.

    It's quite new but still worth to try it.

  • Marcella Bini added an answer in Nickel:
    Can anyone help me to get a cif (Crystallographic information file) for Nickel and Nickel Phosphide?

    Dear Friends,

                     Anyone know about the Rietveld refinement using GSAS software means, can you please tell me how you can get the cif (Crystallographic information file) and give me the website link. I need cif file for Ni and Ni3P.

    Marcella Bini · University of Pavia

    here you are the cif files you need

  • Vincenzo Pasquale Giofré added an answer in Car:
    How to develop Adaptive Cruise Control for Indian Driving Scenario?

    Adaptive cruise control is an active safety system, widely used in Foreign countries. The German, Japanese and many more foreign car manufacturers launching luxurious cars in India, having Active safety fearutes like Adaptive cruise control.
    As per my knowledge the major control is by Camera and Radar Sensors. Will the same mapping or programming of ECU is compatible with Indian Driving scenario?
    The camera in the vehicle is used for lane assist and obstacle detection and RADAR mainly detects the vehicle in front.
    But for Indian road conditions where there is lack of lane markings and huge traffic of Two wheelers, how modifications are necessary ? or the same ECU programming is good enough to tackle the challenges in India ?

    Vincenzo Pasquale Giofré · Università della Calabria

    Why not try it with a smartphone?

    You can use its sensors to emit an acoustic signal and alert the driver to slow down interactively.

  • Sophy Nirmal added an answer in Bioactive Compounds:
    How long can we store plant extracts ( solvent extracted ) before using for bioassays ?

    How long will the bioactive compounds (in solvent extracts of plant ) show activity in bioassays if it is stored in 4 0 C.

    Sophy Nirmal · Loyola College

    Thank you so much for your valuable suggestions. This will surely help me out in my research. Thank you.

  • Jonathan Edwards added an answer in Consciousness:
    Is Will free, or does freedom exist without the presence of a Force of Will?

    Since Libett's work, there are many people who have questioned the idea of free will, since the fact that much of the work done before a decision is preconscious and consciousness only seems to come into play at a late stage in the process, calling into question the assumption that conscious choice is a factor in will.

    Others have asked if the idea of Will itself is questionable, in that it seems to assume a force that has a causal relationship to decisions. This is even more in question due to work done on attribution of blame that suggests that attribution is dependent on a kludge that links actions to previous steps in thinking whether or not they are actually causal.

    Many books have been published on this topic because it has legal and philosophical connotations, what is your opinion, and what is it based on.

    Jonathan Edwards · University College London

    Of course the other way to resolve the tension is to use Schopenhauer's sense of Wille as in Die Welt als Wille und Vorstellung. In this sense will is something a bit like 'momentum' in physics - just the acting out of the dynamic oomph that is everywhere in the world, in the waves of the sea or the force of the wind. So 'life force' is just that particular form of a general force or momentum that operates within living things. Maybe there are rather esoteric forces associated with conscious thinking that are both perception and will.

    The one thing I would query in Luder's analysis is that there is any single 'core' or command bridge. Neurobiology suggests that there will be lots of parallel sites of will at any one time. Because the brain has no mechanism for monitoring where anything is within itself, only the time it happens, it feeds itself a story of its own biography that seems to be at one place, but the anatomy tells us that it is not. Descartes's mistake was to think it must be in a single place, hence the pineal.