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.
- 4Does anyone know where can I find out nanofiltration membrane for bench-scale level in Canada?
Does anyone know where can I find out nanofiltration membrane for bench-scale level (small facially) in Canada?
Who is selling them, which company , quality...etc
Much appreciated Mr.Muttuswamy SivakumaranFollowing
- 4How two check whether several sets of randoms are drawn from the same superset?
There are several (lets say N) sets of randoms (300 random variables each). How can we check that all these sets came from the same superset (N*300). Everything is simple if we have only a pair - we can just use a Kolmogorov-Smirnov test.
Is KS test still applicable (each vs each) for such test or there is another method that can give us a cumulative result showing that all the set follow the same probability function?
Thank you for the interesting answer. Unfortunately the shape of distribution is unknown. In this case we have indeed a sequence of random numbers with no respect to any distribution function. These numbers can be fitted by a stable distribution, but the problem is that the size of each set is small (300 numbers) and such fitting doesn't guarantee satisfactory results.Following
- NewCan anyone suggest from where I can get a vial of A549 cells that have been used for in vivo experiments?
I want to use these cells for tail vein injections in mice. I want to get it from someone who has already tested them in vivo. The reason for this is that the ones I have are not able to metastasize or form subcutaneous tumors in vivo.Following
- 5Is there any other way to coat catalyst on the GC electrode other than using prepared ink from nafion solution?
I study ORR electrocatalysis. For some materials i prepared, the ink prepared is not getting coated properly. As it gets dried, it comes out of the surface. Any other way out?
you're using too much catalyst. how about diluting your ink 10 times? In this way, you can also run 10 times more experiment!Following
- 1How to observe growing fungal stage under AFM? What are the methods for sample preparation?
I want to study intact growth of fungi. How would i go about this?
Dear Smita Londhe,
AFM can be used at room temperature and atmospheric pressure and in general you don't need any special sample preparation for solid samples, but you should check the AFM system requirements. For convenience the sample should be flat at the bottom.
You should also have in attention the following:
- the AFM provides measurements of the surface heigh of your sample, for example, if you have features like spheres you can only 'see' the top part of the sphere;
- the area of measurement of the AFM is in general very small, like 100 x 100 microns or less and heigh is limited to few microns. You should check the AFM manual and if it is enough for your experiment.
- Assuming you have limited AFM time and you can not let the sample in the AFM for all the time it takes to grown the fungal, you need to find a way to mark the sample so that you can always return to the same position.
Good luck with your experiment.Following
- 2How much concordance is there between Immunohistochemistry (IHC) & FISH testing for detecting mutation-dependent overexpression of target kinase ?
There is a good /validated antibody for doing the IHC.
Thanks Jukka ! Though I do wonder what FISH would bring to the table, especially for stratification of patients for targeted therapies. As you could possibly only detect a single variant with a single set of FISH probes which would cost you 3-4 times an IHC. Whereas in case of IHC you would recognise the end product (protein) regardless of the upstream rearranged variant. Ofcourse IHC is as good as the antibody and the controls.Following
- 2What is the recently concept of kinesiology, and the interesting studies?
In the last decade, the concepts of many sciences were varied according the new studies that depend on the measurement tools, and the desired aims.
Thank you for your answer and I respect your opinion, but this concept is general and contains many branches such as Biomechanics, Motor control, Physiology, occupational therapy, psychology, and many sciences in sports. Recently, every branch of previous is separated science. However, does the kinesiology equal human movement science?, and depend on intersections between several sciences such as Biomechanics and motor control. Really, I need to know an accurate and determinant concept.
- 5What is a negative GTN tilt table test?
1. Is it similar to somatoform disorder?
2. If not, what is the next test(s) to address the recurrent syncope?
Thanks and best regards
Dear Dr Bahram,
FYI, the patient did not faint during the tilt table test even though his BP dropped at 100/50 when his HR was consistent at 110 without GTN induction.
Best regards - MariamFollowing
- 1Would you like to take part in my questionnaire?
f you are a resident of the UK, aged 18+, and you are not a mental health professional, I would like to invite you to take part in my final year project for my degree. The topic of the study is the relationships between gender and mental health knowledge, and attitudes towards Schizophrenia and anticipated help seeking. If you would like to take part, please click the online questionnaire link below:
Dear Dr. del Castillo, I would like to cooeprate but I am Psychisgrist, and I read that you are searching for no professionals of mental health. Sincerely, Pascual
- 6Is it possible to achieve Five or Six electron transfer in ORR?
I am looking forward to know the possibility of five or six electron transfer in ORR with some references. We are following Manganese oxides based catalyzed oxygen reduction reaction. I am aware that theoretically it should be 4. But we got in the range of 5-6. We do not understand the possible reason. Any suggestion?
Thanking you in advance.
Did you get the result using CV or RDE or both? what is your supporting electrode? GCE? are you using carbon nanotubes or similar to aide electrical connection? O2/H2O has to involve 4 e while O2/H2O2 is 2e. MnO2 is a very good CHEMICAL catalyst for H2O2/O2.... May I suggest my latest article DOI: 10.1039/C6SC00139DFollowing
- 10How to convert a file to .asc format?
I have a problem with the following: I have altered my raster .tif resolution in ArcGIS and again tried to convert it by ARC toolbox to ASCII (asc) format. So i confronted an error during this process with the name of "ERROR 010267: Syntax error in parsing grid expression. Failed to execute (RasterToASCII)." Can anyone give me a mind regarding this? How can i fix this?
Your contributions were great, i finally solved my problem regarding the issue.
- 2Is there a linear elastic region existing in viscoelastic materials (low strains)?
I am trying to model an adhesive which has a viscoelastic behaviour and my expected strain is just 0,01%. So can I expect the material to return to its original position immediately (without any viscous delay). According to the book "Handbook of Adhesion Technology", till a certain point the adhesive behaves with linear elasticity. is that true for viscoelastic materials?
0.01% = 0.0001
It is indeed small deformatin. I would have no doubt about suitability of elastic model. Under such a deformation, it shoud be linear.
And as stated above, the higher the rate of deformation, the short time for relaxation.
But do not confuse "elastic behavior" and "elastic model". Your material will not be elastic, but under specific conditions could be modeled as elastic.Following
- 2Space group not valid in High score plus?
I wanna carry out rietveld analysis of Bi2Te3 and used the CIF file but High score gives the message "space group not available or invalid".Following
- NewHow would I model a frequency-selective channel (e.g., a 2 tap channel) in terms of small and large scale fading for a massive MIMO study?
On its seminal paper, Dr. Thomas Marzetta, considers the the complex propagation cofficients into the frequency domain, however, for my study I need to know how the coefficients would be into time domain. If we take the IFFT of the coefficients on Marzetta's paper we would have coefficients with the same distribution, i.e., an independent of time index large scale term and a time-index dependent small-scale term (with variance proportional to NFFT). My question is related to the independence of the large scale fading term regarding the time index of a channel. Is it the same for all the paths (or taps of a tap-delayed line filter) comprising a channel?Following
- 2How can Gravitational Waves Detection is going to benefit our society?
Recently, Gravitational waves detection have been observed by scientists which was predicted by Albert Einstein in year 1916. Now, the real question is, how can it going to benefit our society?
I think many people have been quite happy to have so little data on black holes to interrupt their publication train. The big benefit may be to stop some of the runaway math fest of theoretical physics. The string theorists have kept themselves cleverly safe for now.Following
- 1Can anybody provide me the detailed procedure of estimating invertase and alpha amylase activity of potato?
I am doing a research on the storage-ability of different processing potato varieties. I have to check the invertase and alpha amylase enzymes' activity of potato at different intervals during different storage conditions.
Enzyme assay: About 50 g of potato were peeled and cut into small pieces and homogenized well with cold
buffer of respective pH (for amylase, invertase, cellulase: 0.1 M sodium acetate buffer, pH 6 and pH 5 , respectively. The extracts were filtered by few layer of cheesecloth and further clarified by centrifugation at 6000 rpm for 15 minutes at 4oC. The clear supernatant was collected and used as crude enzyme extract.
Amylase and invertase activities were assayed as described by Mahadevan and Sridhar (1982) using starch (1%) as a substrate.
For more information see attached file named Potato 1.
Assay for amylase and invertase activity (see attached file named Potato 2):
ESTIMATION OF ASSAY OF AMYLASE ENZYME BY DNS
Starch + H2O alpha-amylase Reducing groups (Maltose)
One unit will liberate 1.0mg of maltose from starch in 3 minutes at pH 6.9 at 20ºC
CONDITION: Temp. = 20ºC, pH= 6.9, Absorbance at 540 nm, Light path= 1cm
PREPARATION OF REAGENTS
All reagents are prepared in Distilled water
Hoping this will be helpful,
- 2Which probe should be chosen?
We have Lightcycler 2.0. for RRT-PCR in our laboratory. Based on our two previous experiments; LightCycler 2.0. cannot detect MGB probe ( were labelled with FAM and VIC). What will happen If labelling the same probe sequences with FAM and TAMRA ? Does it work again? Or any TM changes ?
Many thanks for your answers in advance
MGB is not a probe, so it is not emitted fluorescence. Select "NONE" option in the equipment . The MGB increases the annealing temperature (TM) probe. So, if you use the TAMRA, your TM will change.Following
- NewIs anyone familiar with system dynamics method for waste management?
System dynamics is a computer-aided approach to policy analysis and design. It applies to dynamic problems arising in complex social, managerial, economic, or ecological systems — literally any dynamic systems characterized by interdependence, mutual interaction, information feedback, and circular causality. I want to know how the application of this method in the management of waste.Following
- 11Can EDTA induce precipitaion to his-tagged purified proteins?
I have expressed my 70 kD protein (pI 6.7) in BL21 E.coli cells and purified it using TALON metal affinity resin (cobalt-based resin). My elution buffer is 20 mM Hepes Ph 7.6, 500 mM NaCl, 10 % glycerol, 1mM TCEP, and 150 mM imidazole. My previous experience with this protein had shown that it tends to form some sort of dimers/aggregates thus I added 1 % octyl-glucoside (OG) and 5 mM EDTA to the eluted protein that were in a buffer mentioned above. Although addition of 1% OG was borne fine, upon addition of 5 mM EDTA the solution went cloudy and after 48 hour incubation at 4 degrees there were lots of aggregates in the solution. I spun down the aggregates and tried to resuspend in 8M urea but it wasn’t successful attempt.
I thought addition of EDTA might be beneficial through chelation of any leached cobalt ions. Is it a possibility that chelating leached cobalt ions also precipitated my protein?
Or chelation of useful divalent ions knocked my proteins out and precipitated them?
Thanks Rosa for your response, i didn't have EDTA in my purification buffer, i added it later after my his-tag purification. I think i will have to add OG to my purification buffer and keep EDTA out of my buffrs at all time.Following
- 2Can you suggest research topics in the field of IoT?
I am from computer science backgroud having expertise in AI/Machine Learning and Data Science. I was wondering how my knowledge can be leveraged for research in IoT field.Thanks.
I advise you to take a look on data fusion techniques from multiple sources (which are the objects of the IoT).
some keywords : Data Fusion; Dempster shafer theory, combination rules, etc.
- 42Are there any of the mysteries of physics that are beyond our intellectual capacity to conceptually understand?
Richard Feynman said, "If you think you understand quantum mechanics, you don't understand quantum mechanics.” Is the problem that the human intellect is incapable of understanding some aspects of quantum mechanics or are we merely missing a model which will make the mysteries of quantum mechanics conceptually understandable? Another quote attributed to Feynman is “Shut-up and calculate”. This implies that a student is being told to suppress their natural desire for conceptual understanding and instead work on mathematical analysis. Do you feel that some questions are beyond our intellectual capacity to successfully answer? If so, perhaps you should identify these to stimulate discussion. For example, questions about the composition of fundamental particles or string theory strings are often treated as unanswerable. What are your thoughts?
thanks for your paper. I will read with great interest.
- 11How can I convert a raster curve to a vector curve?
I want to calculate the length of a fiber in a raster image as accurately as possible. Maybe using a vector curve I will get it.
Do you have an image of your skeletal raster curves computed from the binary image overlayed on top of the original image? That way we can see the quality of the skeleton vs the original image.Following
- 7How to prepare ink of metal oxides to be used as an electrocatalyst,after loading it on glassy carbon?
The catalyst after loading on GC needs to be studied for OER,ORR.
In my opinion, 0.3 mm dia. is awfully small for dropcasting. Ca you use an ordinally sized gce? 0.3 mm is already too large to assume radial diffusion. if spilling out is the problem, use small droplets as suggested earlier and try not to worry about covering entire gce surface. Nafion (or other binders) is not needed for some metal oxides if the amount casted is small (probably up to several monolayers).Following
- 20Why nobody see that Higgs boson and gravitational waves are the pure theoretical failures?
Higgs boson does not interact with gluons which give energy for 99% of proton mass. How the Higgs boson gives mass to the proton, nobody has no clear answer. Why are we closing eyes and tolerating this model which does not have a minimal correspondence with physical existence? Energy and mass are both inherent physical properties of every particle. No particle can give mass to another particle; this is a complete misunderstanding. Higgs boson does not prove anything, Higgs boson is artificially made flux of energy and nothing more.
Energy and mass are both inherent physical properties of every particle. They have the origin in the diminished energy density of quantum vacuum. A given particle cannot be examined without this diminished energy density of quantum vacuum which determines its energy and mass. The idea that particles exist in an empty space deprived of physical properties is the biggest theoretical failure of physics since its existence. It has led to the idea of Higgs field and gravitational waves which are both pure theoretical failure. No particle can give mass to another particle; this is a complete misunderstanding. Higgs boson does not prove anything, Higgs boson is artificially made flux of energy and nothing more. And no wave can transmit gravity.
First , Higgs bosons (perhaps the whole set of vectorial bosons ) on the standard Weinberg Salam model are just phenomenological tools nothing more .Surely a very good improvement of the old Heisenberg Fermi four fermion interaction .....I expect that must exist a better theory in place of it .The same "Phenomenological" status happens with QCD ,whe precise strong interaction form factors are estimated numerically by lattice methods .And Baryons are very difficult to tackle upon on the formalism,specialy on Lattice .By the way , It is expected (but not proved!) that baryons are some sort of (quantum) solitons on the effective low energy meson theory obtained from QCD (SU(infinite)) (note that something should be expected for Higgs and all That!).
Related to gravity , well gravity is something very subtle and different from all others fields as far as I know .First and foremost it is not like the electromagnetic field or Yang Mills fields .It is a purely geometrical field (yours sticks and Clocks for the dynamics of other fields on the space time).An example :put a cosmological constant on Einstein theory that you obtain some sort of ..Yukawa short range -blinded wave field for the gravitational waves (like considering the photon a massive particle-The Proca Electromagnetic Field as emitted by...Magnetic Monopoles on the confined QCD vacuum ) .Mass for Gravitons means non vanishing cosmological constants (for negative cosmological constants ,perhaps you get a taquion .....).One more Pilt Down man on Science ?Following
- 2Why am I not getting a clear zone of inhibition with iron oxide nano particles?
I have synthesized iron oxide nanoparticles by the method of co-precipitation. But it is not showing any zone of inhibition for S.aureus and E.coli. What can be the possible reasons? I have tried conecnetrations from 0.1mg/ml to 100mg/ml.
I agree with Dr Shcherbakov. Iron oxide may not be the best material if you want to develop a bactericidal agent. That said, if you want to test why your particles are not producing the desired effect, you may want to compare it with a well characterised product (commercial or reference) that has been shown to have inhibitory effect. Because you are based in India, you may want to get hold of IO particles from other centres working in this field. This reference may help you. Rafi, M. M. et al., Malaysian Polymer Journal, Vol. 10, No. 1, p 16-22, 2015 (from Tamil Nadu, South India). Hope that helps you.Following
- 2How to couple the CMG with R?
Has anyone coupled the computer modeling group's software with R? for optimization processes.
The Computer Modeling Group's software is a multi-purpose packages for reservoir simulation to evaluate the fluid flow through the porous media. it is called as CMG and it is widely used from many university and oil companies.
For oil recovery optimization the CMG can be coupled with any computer codes such as Fortran, C, and also R.Following
- 2How to Design and Implementation Interdigital Capacitor in a Band-pass Filter?
I have being trying to replace the lumped element capacitors i have in the band-pass filter design with the Interdigital Capacitor, but i'm facing problems. In fact the interdigital capacitor was design using ADS, then putted together the rest of the circuit, that's where the problem comes. Because the filter response has change dramatically please advise on what to do?Following
- 3Any Russian speakers who would help me find out what Lioudmila Voropai is up to these days?
She wrote this very interesting paper for the 17th International Symposium for Electronic Art in Istanbul : https://goo.gl/VOEfXV
Thanks for your help!
Hans,I am glad that you have resolved your issue.
I wish you all the best in your endeavours.Following
- NewWhat is the standard method for detecting waste-water phenol content by utilizing UV-visible spectrophotometer?
I am treating oil waste water for decreasing its phenol content and other toxic contents. So, I am searching for standard, simple and acceptable method for detecting them.Following