Science topics: Chemistry
Chemistry - Science topic
Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds.
Questions related to Chemistry
I need to convert from micromoles per second per liter (µmol s⁻¹ L⁻¹) to millimoles per gram of dry cell weight per hour (mmol gDCW-1h-1)
How long (approximately) would it take to learn DFT calculations from scratch so as to be able to obtain the first reasonable results? The aim would be to design materials with intended properties (for example, topological materials or thermoelectrics).
The starting point would be basic knowledge of quantum mechanics from a master's studies in chemistry and the basic skills in programming using c++ language.
We have to perform MD simulations on a limited number of protein:ligand complexes.
Since we aren't MD specialists we are trying to use charmm-gui.org to make the work easier.
The input pdb file contains protein + ligand coordinates. We have produced a .mol2 file using https://www.cheminfo.org/Chemistry/Cheminformatics/FormatConverter/index.html
We also saw that sometimes there are problems with .mol2 files and there is a script that may solve these problems (sort_mol2_bonds.pl).
When running charmm-gui , Solution Builder, then the program fails every time at the stage of generate.pdb with this error message (whichever of the two .mol2 files is used, either coming out of OpenBabel or after running the sort_mol2_bonds.pl) : "skipped empty mol2 file".
The mol2 files we are using are not empty.
Hence the questions are: is charmm-gui broken somehow? Or is there a solution to this problem allowing us to perform MD simulations on these protein:ligand complexes?
Thanks in advance.
Whenever I like an article in which regression analysis is used, I ask the authors if they can share some raw (!) data, because I'm writing a book and software about this topic, and I want to include very diverse real examples.
But, to my disappointment, practically nobody even reacts! Why?
Are people affraid that a new light on their data might disrupt their conclusions?
I thought openness was considered a virtue in the world of science?
But if I want to see articles that include data, I have to dig in the very old ones!
What are your thoughts?
P.S.: I can still use simple datasets from physics to psychology, from chemistry to sociology, anything...(just 1 independent variable, preferably with information about the measurement imprecision). Of course I quote you as the source. Thanks in advance!
Hi, I want to perform chromatography on viruses which are larger than the protein targets people typically use chromatography columns on. Because of this I need to use 2% agarose beads which have the largest pore size, however this is a niche use case so I cannot find an off the shelf solution.
I cannot find a protocol on the web. Would a standard EDC-NHS conjugation approach be suitable? Are any linker molecules needed? Are there better chemistries that target specific moieties on streptavidin to better orient it on the bead? I have done some bead conjugation work before, I only require a protocol that outlines linkers, chemistry etc. Or can anyone point me to a supplier. Thank you.
Hello all dear
It happens at a constant temperature of 140(Tb)
The composition is similar to gasoline
Can you introduce an equation?
Thanks in advance
Hi, I am looking for ways to help improve bonding of terfenol-d particles in polymer composites and was wondering if maybe surface treatments of these particles would in anyway affect their composition. I am specifically looking at surface treatment using silane (Triethylsilane). I know Terfenol-D does oxidize and degrade if left in air but was wondering if maybe we could apply some surface treatments without degrading their other properties.
Is it possible to detect any protein in the cell using click-iT chemistry (Nobel Prize, 2022) in the living cells?
Thank you, Lenka
Many years ago while studying for my PhD I was interested in forming a salt that would provide direct evidence for the tetrahedral intermediate,
I had read that tertiary amines do not react with acetyl chloride,
However, when I dissolved hexamethylenetramine in dry chloroform and added acetyl chloride I produced an immediate white precipitate.
This salt was highly hygroscopic.
Elemental analysis gave conflicting results probably due to some hydrolysis,
I was sure I had produced direct evidence for the tetrahedral intermediate acetylhexaminium chloride,= and was most excited.
However, I then wondered if perhaps one or more of the methylene bridges had cleaved giving iminium salt formation.
I know Gold has done an enormous amount of work on this but sadly my imminne chemistry was most certainly not up to his standard.
I would like the opinion of others especially hexamine or immine chemistry specialists,
I would be most grateful for any input or redirection to papers etc,
I have previously posted part of my thesis which gives the experimental details and some NMR work on this,
Hello all dear
If the pressure is high and the temperature is low (below the dew point) at the same time, will the amount of solvent vapor condensate increase?
Thanks in advance
Hello all dear
Is it true that when the temperature of the solvent vapor is lower than the dew point, the first drop of liquid is formed, and if the temperature is reduced, the amount of condensation formed increases? And if the temperature is below the bubble point, will all the evaporating solvent condense?
(All temperature reductions should be at constant pressure)
I order too achieve partial coating of shell on core, how layer-by-layer method is applicable. Kindly helm me in getting the exact chemistry and procedure for the same
I have a curiosity about the different perspectives on emergence. In biology, we usually assume that there are diverse biological entities, such as cells, tissues, organs, systems, organisms, populations, and communities. We can study each entity from a reductionist perspective to describe how we can understand its properties based on its smaller components. We also study these entities from a holistic perspective because we assume that each entity has emergent properties that cannot be reduced to their smaller parts. Both approaches are necessary because there is dualism in emergence (i.e., we can identidy two different units), but they are not independent (i.e., tissues depend on cells to exist).
What exactly causes emergence? Is it the interaction between the components of the system (in a specific way)? And what are the limits to describe something as a new level of organization that cannot be reduced to its smaller parts? In summary, how can we recognize and classify something as presenting emergent properties in practice? I think these discussions are at the heart of many misinterpretations of scientific discoveries that are usually interpreted from either a reductionist or a holistic view, but not both.
Due to its unknown nature, we cannot perform a protocol for its entry into the gas phase and analysis using method GC/MS. Additionally, we cannot prepare a standard for its compounds and use method HPLC. Even for method LC/MS, which we have access to, it must enter the gas phase in the final stage, which is not possible, and on the other hand, we cannot concentrate it. Its water content is very high.
Hello all dear
Solvent enthalpy, amount of condensate in terms of time, temperature before and after solvent evaporation
According to a study by Ho et al. (2021b), there is a good correlation between the hemolysis, icterus, and lipemic (HIL) index values and the corresponding concentrations of hemoglobin, bilirubin, and intralipid in the concentration of interferences tested. Moreover, using the alinity c system by abbott company, it was stated that 12 of 35 chemistry assays were affected by hemolysis while bilirubin interfered with 4 assays and intralipid interfered with 3 assays.
Will there be any difference on the effects of HIL interferences using different spectrophotometric chemistry analyzers by different brands?
Ho, C. K. M., Chen, C., Setoh, J. W., Yap, W. W., & Hawkins, R. E. (2021b). Optimization of hemolysis, icterus and lipemia interference thresholds for 35 clinical chemistry assays. Practical Laboratory Medicine, 25, e00232. https://doi.org/10.1016/j.plabm.2021.e00232
I was examining a fluorite sample using EDAX and it didn't detect any uranium but when using XPS we detected U on the surface of the fluorite. Could this be interpreted as uranium salts being adsorbed say from hydrothermal solutions?
Note using XRF we detected U (1.4 ppm)
One of the 20 fundamental vibrations of benzene occurs at 1309.8 cm^-1, corresponding to the B_2u symmetry. According to the rule of mutual exclusion, this vibration is forbidden in Raman and ATR spectroscopy. However, in a complex with benzene, we observe strong IR activity at 1309.8 cm^-1 in ATR. Why is this?
I was wondering if I would need to break the disulfide in my compound and then protect the thiols before performing michael addition reaction on primary and seconadry amines?
Planning on doing the reaction at 90-95C for 3 days, no solvent
How many grams of K2Cr2O7 to dissolve it in 1 liter Distilled water to obtain 50 ppm of Chromium? to become aqueous solution, Is there a specific equation to apply? Thanks
As you can see in the picture, the reaction may involve Phenol to produce benzoxazole based product.
What can we do to react Amine with Aldehyde to produce related Imine without involving Phenol in the reaction? Any particular catalyst, synthesis method, solvent etc.?
If you know any related research paper, please feel free to mention it in your comment.
Thanks a LOT
I am currently seeking guidance and insights on the process of composing a comprehensive review article focused on the topic of "Photocatalysis of Cobalt Oxide Nanoparticles." While I have a keen interest in the subject matter, I am uncertain about the proper structure, content organization, and key points that should be covered in a review article.
Specifically, I am seeking advice on the following points:
- Structuring the review article: How should I organize the content to ensure a coherent flow of information?
- Key elements to include: What are the essential components that must be addressed within the review to provide a comprehensive understanding of the subject?
- Literature synthesis: How do I effectively synthesize existing research and findings on the photocatalytic applications of cobalt oxide nanoparticles?
- Analyzing research gaps: What strategies can I employ to identify and analyze gaps in the current understanding or areas that require further research?
- Citing and referencing: What is the best approach to citing and referencing relevant sources in a review article of this nature?
Furthermore, I am open to suggestions for an appropriate title for the review article. Your expertise and insights would be greatly appreciated in helping me embark on this endeavor effectively and professionally.
The size differ little bit from one species to another, yet they have one size range. Also, the size of them in their native form so they don't lose their colour while isolation.
Can you describe your preferred teaching style when instructing university-level chemistry courses? How do you structure your chemistry lectures to ensure comprehension and engagement among university students?
I have a query about the SEM images; when I analyzed them, they showed some cracks; I stuck to why it can be shown this, what is the reason behind it, and what is the chemistry behind it. I request everyone, please give me an answer as soon as possible; thank you for your attention.
I am specifically referring to a product sold by sigma where they do not specify this information. The 10-15% was determined via Na2S2O3 titration, which makes me suspect that it is in w/w, but that is kind of useless given that I dont know the density of the solution. I would hope it is in w/v, meaning grams per liter. Anyone have any insight on this?
I called sigma and they didnt know
Product number: 14010 (Titanium(III)Chloride)
I work in a single-molecule analysis lab. I have been waiting on a supplier to send sodium bicarbonate for a while, and I want to begin experiments now. We have a stock of sodium bicarbonate from 2017 (five years old). Why can't I use this? Does it really have an expiration date?
I imagine if it does, it may have to do with coming into contact with the air after it was opened so many years ago.
Any help is appreciated. I dont want to do all the experiments only to have them invalidated by the fact that I used old sodium bicarbonate.
I want to simulate MXene by means of molecular dynamics method. But it seems that I need the Mxene atomic structure as a file in .cif, .pdb, or .mol format.
Is it possible for anyone to tell me how I can get the files or how I can build the atomic structure of MXene?
Thank you so much
I am currently seeking a collaborator who would be willing to cover the Article Processing Charges (APC) for the publication of my research article in the Arabian Journal of Chemistry (AJC). In return, I am offering a significant acknowledgement and co-authorship in our paper, as well as the opportunity to extend our research collaboration.
Research Field: Biophysics
Research direction: [antibacterial activity of nano-composite materials against MDR pathogens]
If you are interested in collaborating and supporting the publication of this research article, kindly reach out to me through private messaging. I would be happy to discuss the details and provide further information about the research and collaboration opportunity.
Thank you for your attention, and I look forward to potential collaborations.
Hello, I am trying to run GPC on my samples. However, the GPC available in our lab use THF as an eluent.
My polymer only partially dissolves in THF, but fully dissolve in Chloroform. Hence, I want to ask is it alright if I dissolve my polymer in Chloroform and run it on THF-eluent GPC?
Many Thanks in advance!
The protocol specifies to add sodium citrate to TiCl3 (0.5g, 3.24mmol). But this has confused me. How much TiCl3 do I use? I have a stock solution that is 15% TiCl3 (Sigma, product number 1401). The instructions are quite confusing to me.
I could calculate the volume of my stock solution that would contain 0.5g of TiCl3, but I dont understand where the 3.24mmol comes in.
Any help would be greatly appreciated.
The description that I am referencing has been attached as an image and is from the following paper:
Titanium(IV) Citrate Speciation and Structure under Environmentally and Biologically Relevant Conditions | Inorganic Chemistry (acs.org)
I am working on a research on achievement goal orientation as predictors of secondary school Chemistry students' achievement.
On further research I discovered that I can adopt the achievement goal theory in the course of this research.
I need to understand more about this, and how I can apply it in investigating academic achievement of secondary school Chemistry students'.
I want to use an offline application of a virtual Chemistry Laboratory software that can help students in institutions that lack some basic laboratory equipments to be able to understand chemistry practical.
Applications or softwares that can help them practice simple chemical reactions.
I do have a couple of virtual applications but I need a few suggestions. Thank you
I tried to visit the official website for the journal but i can't find the accepted similarity index for a review paper or an article
I recently received invitations to contribute an article to the current issue of the Journal of Brilliant Engineering (BEN) and Chemistry and Biochemistry. Can anyone with experience or knowledge about these journals confirm their originality?
I am currently doing my master thesis and I have to analyse an IR spectrum of multiple samples. The given sample is supposed to be a specific polymer whose individual monomers i know. It is PBAT (polybutylene adipate terephthalate) which is a random co-polymer made of adipic acid, 1,4-butanediol and terephthalic acid.
Since I have a biology background and not that much chemistry i am struggling a little bit to do the IR spectrum analysis. I read that there are programs or tool with which one can simulate or predict an IR spectrum to compare that with experiment data of actual FTIR scans of the sample.
Anyone has a suggestion what to use or any other tips for me?
Thanks alot for helping out!
Best regards Dominik
Does anyone know how I can find the specific substructure of each bit in CDK fingerprints and CDK extended fingerprints which are implemented in PaDEL-descriptor and Chemistry Development Kit (CDK) software?
As an example, I am searching for SMILES representation of FP40.
I want to prepare 1000 ppm of cadmium using CdCl2.H2O
I got different suggestions.
1) Dissolve 2.036 g of CdCl2 in 1 litre of deionized water
1000 ppm = 1000mg/l Cd * 1 g Cd/1000 mg Cd * 201.32/112.411 = 1.790 g Cd/l H2O
where 201.32 = mol wt of cdCl2.H2O
112.411 = elemental mass of Cd
( suggestion was we are to prepare ppm solution of cd and not CdCl2.H2O)
3) Cd (in CdCl2.H2O) equivalent to 1 g elemental Cd
= Mol wt of CdCl2.H2O*100/ At Wt of Cd * Purity of CdCl2.H2O
= 201.32*100/112.411* 98 (% purity of CdCl2.H2O)
= 1.8274 g/l
With different metals, g/l amount for ppm concentration will vary. Am I missing any concept?
Any specific formula for this?
Hi, my name is Bram Wolters and I'm a student of the University of Applied Sciences Arnhem and Nijmegen in the Netherlands. I'm working on a project to make sustainable disposable items for the foodservice industry. The disposable items are made of reed, include forks, knives, spoons, cups, hamburger boxes, bowls etc. We want to pulp it, shape it, cut it and dry it. Only I don't really know which binding material and coating to use. I believe it is possible to use cellulose, but have no expert to confirm. Can someone help me?
in order to quantify the concentration of Glycerol monostearate in aqueous solution by UV spectrophotometer, what is the maximum lambda of Glycerol monostearate?
I see that artbitrary units are commonly used for absorbance, however, as far as I know, this is discouraged, not even officially accepted by IUPAC. However, there are many papers in high impact journals where this is done. The question is: under what conditions is this considered appropriate?
I am trying to clean/hydroxylate the surface of a blank silicon chip (with SiO2 layer on surface) by using piranha. I have freshly prepared a 2.5:1 solution of piranha solution (with new peroxide that has been stored in the fridge) and soaked the chips for 30 mins or 90 mins.
I then rinsed the chips with DI water 3x and took a contact angle measurement using DI water within 10 minutes of the piranha treatment and the CA was 45 degrees (an average of 4 measurements on different areas of the chip surface). I have seen in the literature that the CA for a freshly piranha treated Si chip should be around 0-10 degrees, based on the hydrophilic Si-OH surface. Any ideas where this could be going wrong?
I bought indium nitrate hydrate (alfa aesar - purity 99.99%) which is said to be water soluble. However, it does not dissolve well both deionized water and organic solvents, above 20 mM.
Could you please tell me the reason for this?
I am currently involved in research for controlling weevils in stored wheat using different essential oils.
What could be the best concentration (microlitres per litre of air) of essential oils for comparison?
We wish to test all the oils at one fixed concentration. We are trying to shortlist a few effective essential oils and test them out at different concentrations.
Is it a good idea?