Latest topics page 21

Topics ordered by most recent activity across all 71 subcategories.

1,535 topics · page 21 of 52

Topic	Participants	Replies	Views	Activity
Second pass at: Robustness: the parameters worth deliberately varying Analytics › Method validation linearity LOD & LOQ recovery system suitability On the subject in the title: Second pass at: Robustness: the parameters worth deliberately varying Working notes rather than a conclusion. Something about Robustness does not reconcile and I would like a…	+61	66	9.5k	3mo
A payment that went through twice: how it was resolved Sourcing › Payments payments research use only documentation quality Solved Closed A payment that went through twice: how it was resolved Writing it up because I had to work it out twice and would rather nobody else did. A payments question, with the mechanics separated from the money. What…	+20	24	55k	3mo
Deletion sequences: expected mass shifts by residue Analytics › Impurities & related substances water content endotoxin testing forced degradation HPLC Deletion sequences: expected mass shifts by residue — setting out what I have, and where I think it stops being reliable. Deletion sequences keeps being re-asked here and I think that is because the answer is…		2	59	3mo
Adducts: sodium, potassium, and the peak you did not expect — does this still hold? Analytics › Mass spectrometry high-resolution MS charge states mass error (ppm) MALDI-TOF Solved Asking directly, because I could not find a straight answer: Adducts: sodium, potassium, and the peak you did not expect — does this still hold? Adducts keeps being re-asked here and I think that is because…	+113	119	1.7k	3mo
Ultrasound and skinfolds: operator dependence in practice — what changed since Outcomes › Body composition data table DXA bioimpedance lean mass loss Posting this under the heading it deserves: Ultrasound and skinfolds: operator dependence in practice — what changed since Everything below is what sits behind that. What changes if the standard account of…	+32	37	7.4k	3mo
Follow-up: Lyophilisation and why the cake looks the way it does Pharmacology › Formulation chemistry bacteriostatic water cloudy or discoloured solution sterile water Solved Lyophilisation and why the cake looks the way it does Writing it up because I had to work it out twice and would rather nobody else did. I was wrong about Lyophilisation in a thread last spring and I would…	+10	14	11k	3mo
Light exposure: how much protection is proportionate? Practice › Storage & stability beyond-use date freeze-thaw cold chain cloudy or discoloured solution The question in the title: Light exposure: how much protection is proportionate? I will give what I have already checked below so nobody repeats it. Trying to establish the boundary conditions on light…		2	59	3mo
Charge states for a 4 kDa peptide, worked through — the long version Analytics › Mass spectrometry LC-MS high-resolution MS mass error (ppm) Charge states for a 4 kDa peptide, worked through — the long version Writing it up because I had to work it out twice and would rather nobody else did. Working through the identity arithmetic and I would like…		2	293	3mo
Where impurities in solid-phase peptide synthesis come from Analytics › Impurities & related substances water content data table HPLC endotoxin testing Solved Where impurities in solid-phase peptide synthesis come from Writing it up because I had to work it out twice and would rather nobody else did. Impurities in solid-phase peptide synthesis, and specifically the…	+54	59	14k	3mo
Turnaround times and what they mean for a decision Sourcing › Independent verification PeptideMeter Medutest Janoshik Analytical VendorInvestigate Turnaround times and what they mean for a decision Writing it up because I had to work it out twice and would rather nobody else did. A question about turnaround times that I think has a definite answer,…		4	29k	3mo
GLP-1 receptor distribution: central and peripheral — one year on Pharmacology › Receptor biology long read retatrutide amylin analogues semaglutide GLP-1 receptor distribution: central and peripheral — one year on — setting out what I have, and where I think it stops being reliable. An honest uncertainty about GLP-1 receptor distribution rather than a…	+7	11	43k	3mo
Why a compound being unapproved is not the same as being illegal to possess Sourcing › Regulatory FDA MHRA research use only EMA Why a compound being unapproved is not the same as being illegal to possess I have a specific reason for asking rather than idle curiosity, and the context is below. Collecting what is known about compound…	+72	78	23k	3mo
List price versus negotiated price versus what you pay Access › Pricing formulary data table compounding Under review On the subject in the title: List price versus negotiated price versus what you pay Working notes rather than a conclusion. List price versus negotiated price — I have the observation and I do not trust my…	+99	115	11k	3mo
[2026 update] Buffers, pH and why a formulation is a formulation Pharmacology › Formulation chemistry counter-ion content storage bacteriostatic water cloudy or discoloured solution Posting this under the heading it deserves: Buffers, pH and why a formulation is a formulation Everything below is what sits behind that. A formulation question rather than a pharmacological one, though the…		2	773	3mo
Shoulders, tangent skims, and defensible integration — the long version Analytics › HPLC & UHPLC HPLC system suitability peak integration data table Shoulders, tangent skims, and defensible integration — the long version Writing it up because I had to work it out twice and would rather nobody else did. Setting out an integration problem with the actual…	+16	20	27k	3mo
Coming back to: Half-life, steady state, and accumulation worked through Pharmacology › Pharmacokinetics tirzepatide liraglutide worked example semaglutide On the subject in the title: Half-life, steady state, and accumulation worked through Working notes rather than a conclusion. Working through the kinetics rather than the pharmacology, because I think the…	+14	18	15k	3mo
Second pass at: Fasting versus non-fasting and which tests care Clinical › Bloodwork lipase & amylase liver enzymes lipid panel HbA1c On the subject in the title: Second pass at: Fasting versus non-fasting and which tests care Working notes rather than a conclusion. Posting a small dataset on Fasting versus non-fasting. It is mine, it is…	+20	25	21k	3mo
Choosing which test to pay for, given a fixed budget Sourcing › Independent verification third-party testing VendorInvestigate Medutest Janoshik Analytical On the subject in the title: Choosing which test to pay for, given a fixed budget Working notes rather than a conclusion. A question about how a record should be read rather than about a supplier. We have…	+60	70	49k	3mo
Open-label extensions: what survives and what does not Evidence › Trials discontinuation & dropout randomised trial estimand Closed Posting this under the heading it deserves: Open-label extensions: what survives and what does not Everything below is what sits behind that. I have spent a fortnight trying to pin open-label extensions down…		4	22k	3mo
Oral semaglutide bioavailability and its variability between people Compounds › Oral incretins SOUL trial oral semaglutide randomised trial Posting this under the heading it deserves: Oral semaglutide bioavailability and its variability between people Everything below is what sits behind that. I would like to know what people here actually do…	+44	48	574	3mo
A plateau that disappeared when I changed how I measured Outcomes › Progress reports DXA long read effect size Posting this under the heading it deserves: A plateau that disappeared when I changed how I measured Everything below is what sits behind that. I was wrong about plateau in a thread last spring and I would…	+27	31	7.2k	3mo
Packaging that arrived damaged: documenting it properly — a second dataset Sourcing › Logistics customs shipping temperature excursion Posting this under the heading it deserves: Packaging that arrived damaged: documenting it properly — a second dataset Everything below is what sits behind that. A logistics question, since the answers here…	+68	73	20k	4mo
Second pass at: What pooling buys you and what it destroys Evidence › Meta-analyses risk of bias meta-analysis heterogeneity Posting this under the heading it deserves: Second pass at: What pooling buys you and what it destroys Everything below is what sits behind that. Something about pooling buys does not reconcile and I would…	+32	36	19k	4mo
Reflux appearing for the first time at a dose step Practice › Side effects vomiting fatigue hair shedding constipation Reflux appearing for the first time at a dose step — setting out what I have, and where I think it stops being reliable. Reporting something rather than asking about it, in case the pattern is useful to…		4	36k	4mo
Endotoxin and why it is a separate question from purity Analytics › Impurities & related substances water content counter-ion content forced degradation HPLC Endotoxin and why it is a separate question from purity Writing it up because I had to work it out twice and would rather nobody else did. A question about endotoxin that I think has a definite answer, unlike…		2	22k	4mo
Bug report: the reconstitution calculator and a rounding edge case Data & Tools › Calculators worked example site feedback syringe units concentration maths Bug report: the reconstitution calculator and a rounding edge case — setting out what I have, and where I think it stops being reliable. Posting the calculation with the inputs, so that somebody can disagree…	+68	72	28k	4mo
Spike-and-recover accuracy for a peptide assay Analytics › Method validation linearity system suitability stability-indicating method LOD & LOQ Wiki Posting this under the heading it deserves: Spike-and-recover accuracy for a peptide assay Everything below is what sits behind that. Asking about spike-and-recover accuracy on behalf of the question I keep…	+121	126	1.5k	4mo
Prediction intervals and why they are more honest than confidence intervals Evidence › Meta-analyses heterogeneity risk of bias effect size publication bias Solved Closed Posting this under the heading it deserves: Prediction intervals and why they are more honest than confidence intervals Everything below is what sits behind that. I have spent a fortnight trying to pin…	+21	25	46k	4mo
Second pass at: Adsorptive losses at low concentration, and why dilute solutions are fragile Practice › Storage & stability beyond-use date freeze-thaw cloudy or discoloured solution storage Closed On the subject in the title: Second pass at: Adsorptive losses at low concentration, and why dilute solutions are fragile Working notes rather than a conclusion. The question about Adsorptive losses that I…	+77	87	58k	4mo
Request: export my own posts — one year on Meta › Feature requests site feedback wiki post translation Request: export my own posts — one year on — setting out what I have, and where I think it stops being reliable. A methods question rather than a substantive one, about export. Everyone quotes the same figure…	+62	70	14k	4mo