How to make ppb level concentration ?

Hi, I've N2 gas cylinder and 100 ppm NH3 gas cylinder. With these two cylinders, I'd like to make a ppb level (1- 100) concentration. Any idea how to do that?

01 February 2021 3,264 2 View

Whether L version and D version peptidesshould have identical NMR, especially in the state of self-assembly?

Whether L version and D version peptides should have identical NMR, especially in the state of self-assembly have to have identical NMR? How to use HRMS to confirm L version or D version...

01 February 2021 6,756 4 View

What will be the possible reasons to cause no bands on gel electrophoresis?

Hi, I am doing RNA extraction for my final year project. After extraction of RNA by using conventional method, I did quantification and qualification of RNA by using Nanodrop spec and gel...

11 January 2021 8,775 10 View

How to increase the attachment of the HEK293t cells to the glass coverslips or cell dishes?

Hey guys, I always have problems with the attachment of HEK293t cells to glass coverslips while doing IFA. They are so easy to detach from the coverslips while washing. The coverslips are already...

30 December 2020 8,381 3 View

Can anyone advise me on how to amplify V4 region of fecal DNA of dss-induced colitic mice for microbiota profiling?

Animals were fed DSS via drinking water and fecal samples were collected and DNA was isolated using Qiagen stool DNA isolation kit. The V4 region of extracted DNA was amplified with specific...

20 December 2020 1,739 3 View

Protocol for in vitro cytokine stimulation of immunized CD8+ T cells?

Hi, everyone: I want to determine whether IL-2 and IL-15 have different effects on immunized CD8+ T cell effector function. In this study, I immunize WT mice with peptide on day 0 and 7, and...

02 December 2020 9,413 3 View

Do I need to run a factor analysis on all the items used in the SEM to solve the multicollinearity issues?

Respected researchers, I conducted a SEM including 5 variables (two independent variables , two mediators, and a dependent variables), the correlations between these variables range vary from...

01 December 2020 1,338 5 View

Looking for a glass slide with very low Autofluorescence (GFP)?

Does anyone know any glass slides (thickness 0.1 to 1mm) that have very low autofluoresence (GFP). I am doing a very sensitive experiment that require my glass substrate to be as low fluoresence...

28 November 2020 1,917 6 View

Function of SDS in Northern Blot washing step?

In Northern blot, we normally use either 2*SSC+0.1% SDS or 0.1*SSC+0.1% SDS in washing step. Does anyone know what's the function of the SDS in the washing buffer? Thank you in advance

26 November 2020 2,432 1 View

How to calculate the analytical solution for the HYDRUS-3D model simulation of water and salt movement in soil?

Suppose an agricultural field with uniform soil texture and salinization. The groundwater depth is 20 meters, assuming that the depth of the groundwater and the concentration of salts remain...

25 November 2020 2,382 4 View

How to define and get results (stresses) for certain points of a model in abaqus, using python? When the size of the model changes?

I want to do a parameter study of a aixsymmetric cylinder in Abaqus. I want to create several jobs where I get the stresses for 3 different points in my model. These points are defined. I wrote a...

01 March 2021 10,078 1 View

LOAD DISPLACEMENT CURVES Stiffness increasing in ANSYS non linear analysis. HOW CAN I CORRECT IT?

Hi. I am doing non linear FE analysis using a new material beam under flexural 2 point loading using ANSYS. I have defined a bilinear material model. The solution has converged. In results I am...

01 March 2021 9,911 3 View

Benefits of the 24 welled plate?

We have always used the 96 welled plate, the 48 welled plate but apparently there is much evidence on the 24 welled plate and above all its benefits.It states it is the same you would use on ELISA...

28 February 2021 1,149 1 View

How relevant is Mini slump cone?

for all the rheology researchers, my question is, how relevant is a mini slump cone (smaller than a standard 50 cent rheometer). currently based on testing, the thickness of slumped material is...

26 February 2021 3,668 1 View

Stress/strain tensors decomposition ???

25 February 2021 6,760 1 View

How to reduce residual stresses in MD simulation?

I am working on a preparation of representative polymeric structures of some popular polymers, such as polyimide or PTFE for MD simulation, during which a single nitrogen or oxygen atom will be...

24 February 2021 8,105 3 View

Suggestions for occupational stress surveys?

I am currently writing a masters thesis on reasons for occupational stress in the early childhood classroom, and want to include a short survey assessing participants work-related stress levels. I...

24 February 2021 8,678 2 View

What does it require to be ready for e-Commerce in developing countries?

Most developing countries are not ready for e-Commerce? What dimensions and indicators are there to measure e-commerce readiness of a nation? Please share framework or model and evaluation...

22 February 2021 8,132 6 View

The most suitable method to calculate the stress intensity factor in the presence of contact between the crack lips?

I'm trying to study cracked structures under a compressive load taking into account contact between the crack lips. I would like to know if the method of extrapolation by displacement remains...

21 February 2021 8,694 4 View

Reliable and Valid Instrument for Causes of Medical Errors?

Is there any questionnaire/survey that measures the causes of medical errors? Example: physician negligence vs. systemic issues. Looking for a reliable and validated instrument. Thank you!

15 February 2021 2,874 4 View