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Add PDPC lipid and ULV SAXS form-factor experiments (Marquardt et al.…#283

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comcon1 merged 24 commits intoNMRLipids:mainfrom
AvNeEsH71-iam:add-pdpc-ulv-saxs
Feb 8, 2026
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Add PDPC lipid and ULV SAXS form-factor experiments (Marquardt et al.…#283
comcon1 merged 24 commits intoNMRLipids:mainfrom
AvNeEsH71-iam:add-pdpc-ulv-saxs

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This pull request adds new PUFA-containing lipid data and corresponding
experimental SAXS form-factor measurements to the NMRlipids/BilayerData
repository.

Added content:

  • PDPC lipid definition (membrane lipid, phosphatidylcholine)
  • ULV SAXS form-factor experiments for PDPC and SDPC at 30 °C
  • Experimental data measured at CHESS (2012)

The experimental data are taken from:
Marquardt et al., Chem. Phys. Lipids 229 (2020) 104892
DOI: 10.1016/j.chemphyslip.2020.104892

AvNeEsH71-iam and others added 10 commits February 6, 2026 19:06
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Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
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Metadata should be filled by template. We have a documentation piece about it:
https://nmrlipids.github.io/FAIRMD_lipids/stable/contrib/addingMolecule.html
please read it. And please check the template. You can also read metadata files of other lipids.
Note that you may not fill "image" and "alternative names" - they will be filled automatically.

facility:
name: CHESS
year: 2012
data_file: PDPC_ULV@30C_share.xff
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data file should be converted to json. We have small convertors directly in BilayerData/experiments/

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Thanks. It's much better. See the rest of small things.

PDPC: 1
SOLUTION_COMPOSITION:
H2O: 1.0 # SAXS measurements
D2O: VARIABLE # 100%, 75%, 50% for SANS contrasts
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This is for SAXS experiment. For SANS experiment the record should be different and we currently don't support SANS.

SOLUTION_COMPOSITION:
H2O: 1.0 # SAXS measurements
D2O: VARIABLE # 100%, 75%, 50% for SANS contrasts
TOTAL_HYDRATION: "full hydration"
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TOTAL_HYDRATION is water mass %. If lipid concentration is 12 mg/ml, then it is (1000-12)/1000 which is close to 99%. So there you should put 99.

("full hydration" we use for outdated fields. I will fill them in the end. We will remove outdated fields soon, but they are still with us.)

REAGENT_SOURCES:
PDPC: Avanti Polar Lipids
H2O: High-Q purification system
D2O: Cambridge Isotopes
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remove

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(I mean only D2O)

PDPC films were prepared from chloroform stock solutions, dried under Ar gas
with gentle heating and further dried in vacuo for at least 4 h.
Samples were hydrated using 7 freeze–thaw–vortex cycles with ultrapure H2O
(for SAXS) or 100% D2O (for SANS).
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remove SANS

@@ -0,0 +1,30 @@
DOI: 10.1016/j.chemphyslip.2020.104892
TEMPERATURE: 303 K # K (30 °C)
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remove 'K'. Should be number. Can keep in the comment.

@@ -0,0 +1,30 @@
DOI: 10.1016/j.chemphyslip.2020.104892
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this is ARTICLE_DOI. We don't use just DOI anymore. We use ARTICLE_DOI and DATA_DOI if the data is deposited separately.

@@ -0,0 +1,29 @@
DOI: 10.1016/j.chemphyslip.2020.104892
TEMPERATURE: 303 K # K (30 °C)
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Please modify the file in the same way as previous one.

AvNeEsH71-iam and others added 2 commits February 8, 2026 18:00
Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Comment on lines 8 to 29
TOTAL_HYDRATION: "full hydration"
REAGENT_SOURCES:
SDPC: Avanti Polar Lipids
H2O: High-Q purification system
D2O: Cambridge Isotopes
SAMPLE_PROTOCOL: >
SDPC lipid films were prepared from chloroform stock solutions and dried
under Ar gas with gentle heating, followed by vacuum drying for at least 4 h.
Samples were hydrated with ultrapure H2O or D2O using repeated freeze–thaw cycles.
Vesicles were extruded through 50 nm polycarbonate membranes to form ULVs.
Final lipid concentration was approximately 12 mg/ml.
All handling was performed under an Ar atmosphere to limit lipid oxidation.
XRAY:
SOURCE: CHESS G-1 station
LAMBDA: 1.18 # Å
BEAMSIZE: 0.24 x 0.24 mm
DETECTOR: FLICAM CCD camera
PIXEL_SIZE: 71 x 71 µm
DISTANCE: 0.4236 # m
SAMPLE_CONTAINER: 1 mm quartz capillary
DATATYPE: ULV
SAMPLE_TYPE: ULV
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Why did you remove all the metadata? I asked you to remove only stuff related to SANS (including D2O, because D2O is used only as a contrast in neutron scattering). Everything from SAXS experiment MUST be in.

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I am very sorry sir, it was an accident.

I have added back all of the data and updated both of the files.

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I have made the above mentioned changes. I am sorry for the mistake.

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comcon1 commented Feb 8, 2026

I have made the above mentioned changes. I am sorry for the mistake.

Ok. Thanx! It should be fine. The mapping file we will checked after at least one trajectory will be added. Don't worry. It's half a problem of our documentation. I will insert some outdated fields because they are still required.

Updated sample type from ULV to SUV and added outdated fields for molar fractions and ion concentrations.
Updated sample type from ULV to SUV and added outdated fields for molar fractions and ion concentrations.
@comcon1 comcon1 merged commit d05bc44 into NMRLipids:main Feb 8, 2026
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2 participants