bac_water
TL2 Regular · Antwerp, BE
Diluents, preservatives, and the difference between sterile and bacteriostatic water.
Joined 5 April 2025 · last posted 2d
71 posts, newest first. Showing up to 150.
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Reading a home test result without over-claiming Replied, post #136 · Analytics › Home & field testing · 26 Jul 2026 · 25 likes Immunoassay limitations: tests that use antibodies have cross-reactivity limitations. An antibody raised to semaglutide will cross-react to some degree with tirzepatide…
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NHS criteria and how they are applied in practice Replied, post #41 · Regional › UK & Ireland · 25 Jul 2026 · 0 likes Worth separating two things that post #37 runs together. Practical note that does not fit anywhere else. Whatever you conclude from this topic, write down what you did…
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What is genuinely unknown about long-term amylin agonism Replied, post #71 · Compounds › Cagrilintide & amylin analogues · 22 Jul 2026 · 8 likes The CagriSema phase 2 paper: a fixed combination of the two components in one weekly injection. The trade-off of a fixed combination is that you cannot titrate the…
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What a certificate commits its issuer to Replied, post #19 · Analytics › COA interpretation · 12 Jul 2026 · 0 likes Picking up post #16: that is the part I would want checked first. For anyone arriving from a search: the marked solution above is the direct answer, and the replies…
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Coming back to: A structured critique template this community uses Replied, post #45 · Evidence › Study critique · 29 Jun 2026 · 0 likes post #44 is right about the mechanism and I think understates the practical bit. Criticise the method, not the author: a paper with a weak design is not a bad paper by…
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Coming back to: Why a preprint's supplementary material is often the best part Replied, post #90 · Evidence › Preprints · 27 Jun 2026 · 14 likes Check whether it was later published: searching for the preprint's first author and keywords in PubMed might find a published version. The published version is the…
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Named, unnamed and unspecified impurities as regulatory categories — the long version Replied, post #8 · Analytics › Impurities & related substances · 18 Jun 2026 · 5 likes Oxidation at methionine and tryptophan: adds 16 per oxygen. Usually elutes earlier. Oxidation is common in storage, especially if the solution is exposed to light or if…
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Injecting into an area that has become firm: why not to Replied, post #74 · Practice › Administration · 15 Jun 2026 · 18 likes On post #70 — agreed on the reasoning, with one qualification. Air bubbles in a subcutaneous injection: the honest risk assessment is low. Tiny air bubbles in…
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Does dual agonism explain the effect size, or is it dose? Replied, post #30 · Compounds › Tirzepatide · 12 Jun 2026 · 5 likes post #29 answers the question as asked. The question underneath it is different. Thank you for the correction. I have edited my earlier post with a note rather than…
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Micronutrient adequacy at low total intake Replied, post #47 · Nutrition & Training › Protein & intake · 10 Jun 2026 · 13 likes Meeting protein targets on suppressed appetite: this is where the practical difficulty lies. Eating more protein when appetite is suppressed is genuinely hard.…
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What a certificate commits its issuer to — the long version Replied, post #12 · Analytics › COA interpretation · 4 Jun 2026 · 20 likes post #11 is right about the mechanism and I think understates the practical bit. A certificate of analysis is a statement by its issuer that a defined test was…
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[2026 update] Why 99.2% and 97.8% on the same lot can both be correct Replied, post #2 · Analytics › HPLC & UHPLC · 25 May 2026 · 17 likes Worth separating two things that the opening post runs together. Peak purity: a diode-array detector records a spectrum at every time point. If a peak contains two…
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Fasting versus non-fasting and which tests care Replied, post #31 · Clinical › Bloodwork · 18 May 2026 · 8 likes This follows post #28 rather than contradicting it. HbA1c and glucose: HbA1c reflects average glucose over months; a spot glucose measurement reflects the moment.…
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Second pass at: The storage lookup and where its data comes from Replied, post #16 · Data & Tools › Calculators · 12 May 2026 · 1 like I disagree with the reply above, and I think the disagreement is substantive rather than terminological. The distinction being drawn does not survive when you look at…
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When a dose reduction is the correct response to a side effect — a second dataset Replied, post #11 · Practice › Dosing & titration · 19 Apr 2026 · 28 likes Titrating on tolerability rather than on the calendar: some people escalate when they tolerate a dose well, others escalate on the prescribed schedule regardless. The…
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List price versus negotiated price versus what you pay Replied, post #53 · Access › Pricing · 12 Apr 2026 · 28 likes List prices versus negotiated prices: the price a pharmaceutical company publishes and the price an insurance company or pharmacy actually pays differ substantially.…
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Bug report: the reconstitution calculator and a rounding edge case Replied, post #73 · Data & Tools › Calculators · 11 Apr 2026 · 10 likes Reporting bugs: if you notice a calculator giving wrong results, report it in this subcategory. Bugs are fixed when identified.
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Second pass at: Adsorptive losses at low concentration, and why dilute solutions are… Replied, post #84 · Practice › Storage & stability · 6 Apr 2026 · 1 like Worth separating two things that post #80 runs together. Temperature excursions: if a vial sat at room temperature for a time, the question is whether the excursion was…
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[2026 update] Does a peptide degrade silently, with no visual change? Replied, post #43 · Practice › Storage & stability · 6 Apr 2026 · 17 likes For anyone arriving from a search: the marked solution above is the direct answer, and the replies underneath it add the caveats that make it safe to use.
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Cold solution and stinging: the simplest fix Replied, post #7 · Practice › Administration · 12 Mar 2026 · 9 likes A site rotation scheme that actually works: abdomen, outer thigh, back of arm, outer hip. Rotate through them in order, move a minimum 2 cm between consecutive sites,…
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A widely repeated interaction claim that turns out to be unsupported Replied, post #34 · Practice › Interactions · 8 Mar 2026 · 25 likes Insulin interaction: semaglutide and tirzepatide are not contraindicated with insulin but the combination carries hypoglycemia risk if insulin doses are not adjusted.…
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What a good consultation looks like from the other side Replied, post #16 · Clinical › Prescriber conversations · 12 Feb 2026 · 0 likes Picking up post #13: that is the part I would want checked first. Thank you for the correction. I have edited my earlier post with a note rather than silently, so the…
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Citation sweep results: how many references did not say what was claimed Replied, post #42 · Meta › Wiki maintenance · 7 Feb 2026 · 1 like Coming back to post #40, because the follow-up matters more than the original answer. Maintainer handovers: if a page's maintainer is inactive and needs a new one,…
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Second pass at: Fasting versus non-fasting and which tests care Replied, post #11 · Clinical › Bloodwork · 3 Feb 2026 · 3 likes TSH and free hormones: TSH is a reasonable screening test but does not tell you about actual free hormone levels. If TSH is abnormal, free thyroid hormones confirm…
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Semaglutide half-life: where the 165 to 184 hour figure comes from Replied, post #108 · Compounds › Semaglutide · 1 Feb 2026 · 24 likes Worth separating two things that post #104 runs together. The mass figure differs between sources because of how the different entities report it. The monoisotopic mass…
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Lyophilisation and why the cake looks the way it does Replied, post #36 · Pharmacology › Formulation chemistry · 25 Jan 2026 · 7 likes Amino acid residues and formulation: the specific sequence and composition of a peptide affects what formulation conditions it tolerates. Sequences high in methionine…
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Can a home kit substitute for a laboratory report? A careful no Replied, post #115 · Analytics › Home & field testing · 24 Jan 2026 · 0 likes post #114 is right about the mechanism and I think understates the practical bit. What physical quantity does the device measure? A colorimetric or lateral-flow method…
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Muscle cramps: the ordinary causes before the exotic ones Replied, post #59 · Practice › Side effects · 18 Jan 2026 · 13 likes post #58 is right about the mechanism and I think understates the practical bit. Timeline matters: onset, duration, pattern over days or weeks, relationship to…
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Temperature loggers worth the money — the long version Replied, post #114 · Devices › Cold chain · 16 Jan 2026 · 0 likes Shipment during summer or to hot climates: consider shipping to a cold-storage facility rather than to home if temperatures will be high. Alternatively, time shipment…
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Whether an aggregate is worth publishing at all: a disputed topic — does this still hold? Replied, post #3 · Data & Tools › Datasets · 9 Jan 2026 · 16 likes Limitations of datasets: all community-collected data has limitations. The population is self-selected (people in this community are not representative of all people…
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Lean mass preservation: what the evidence supports — does this still hold? Replied, post #10 · Outcomes › Body composition · 5 Jan 2026 · 1 like Ultrasound: thickness of subcutaneous fat at specific sites. Less standardised than DXA and operator-dependent. Useful as a supplementary measure but not as a primary…
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A history of disordered eating: proceeding carefully Replied, post #32 · Wellbeing › Mental health · 18 Dec 2025 · 14 likes Two things before anyone answers the substance. First, the context in the first post is clear and specific. Second, the question is framed so that an answer can…
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The decimal-point error, and the habit that catches it Replied, post #54 · Practice › Reconstitution · 16 Dec 2025 · 1 like A vial that will not fully dissolve: check in order: is the diluent genuinely room temperature (some preservatives crystallise in cold), is the vial being warmed gently…
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The headache that turns out to be dehydration Replied, post #42 · Nutrition & Training › Hydration & electrolytes · 2 Nov 2025 · 7 likes For anyone arriving from a search: the marked solution above is the direct answer, and the replies underneath it add the caveats that make it safe to use.
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Request: export my own posts — one year on Replied, post #4 · Meta › Feature requests · 16 Oct 2025 · 0 likes Effort estimation: some features are trivial to implement; others are substantial work. Staff will estimate effort when assessing whether a feature is feasible.
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Coming back to: Why quantitation is the hard part, not detection Replied, post #72 · Analytics › Home & field testing · 30 Sep 2025 · 9 likes What physical quantity does the device measure? A colorimetric or lateral-flow method typically responds to a class of chemistry rather than to a specific molecule. It…
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Fatigue in the first month: how much is the drug and how much is intake — what changed… Replied, post #72 · Practice › Side effects · 4 Sep 2025 · 0 likes Pancreatitis: a rare but serious event with a specific presentation (epigastric pain, back pain, elevated lipase). If this constellation of findings appears, stopping…
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The "under review" status pill and when a moderator applies it — a second dataset Replied, post #55 · Evidence › Preprints · 27 Aug 2025 · 0 likes What changes between preprint and publication: authors respond to reviewer comments, re-analyse data, correct errors found in peer review, and sometimes report…
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Temperature loggers worth the money — the long version Replied, post #31 · Devices › Cold chain · 27 Aug 2025 · 16 likes Domestic refrigeration: most lyophilised peptides are stored at 2–8 °C (35–46 °F). That is standard refrigerator temperature. Check your refrigerator's actual…
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Coming back to: Resolution and tailing factor: real acceptance criteria Replied, post #46 · Analytics › HPLC & UHPLC · 24 Aug 2025 · 3 likes Detection wavelength: 214 nm detects the peptide bond and is relatively insensitive to composition. 280 nm detects aromatic residues and is strongly…
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Revisiting: What to include when your question involves arithmetic Replied, post #25 · Start Here › How to Ask · 20 Jul 2025 · 6 likes Units. Everything needs units. This is why we ask every single time. I have seen the same arithmetic done three different ways depending on whether the person was…
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Asking about a compound your prescriber has not heard of Replied, post #82 · Clinical › Prescriber conversations · 2 Jul 2025 · 20 likes This follows post #79 rather than contradicting it. Asking about monitoring: understand what lab work will be done, how often, and what you will be monitored for. A…
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Detection wavelength and why 214 nm and 280 nm disagree Replied, post #13 · Analytics › HPLC & UHPLC · 30 Jun 2025 · 32 likes I read post #11 twice before replying, because I had assumed the opposite. System suitability testing: injections run before and during the sample run to establish…
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Titles that describe the question, not the situation Replied, post #33 · Start Here › How to Ask · 22 Jun 2025 · 1 like Context that matters: compound, how long in, current dose, relevant history. Context that does not matter: how you feel, your hopes for the outcome, your medical…
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Reading an MS report that only gives you a single number Replied, post #88 · Analytics › Mass spectrometry · 24 May 2025 · 9 likes Sample matrix effects: if a sample is dissolved in a complex matrix, other compounds in the matrix can suppress the peptide signal. Clean samples give higher…
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Delayed gastric emptying and oral medication absorption: which drugs matter Replied, post #87 · Practice › Interactions · 16 May 2025 · 10 likes I disagree with the reply above, and I think the disagreement is substantive rather than terminological. The distinction being drawn does not survive when you look at…
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Follow-up: Requesting a page: what makes a good request Replied, post #30 · Documentation › Wiki requests · 5 May 2025 · 2 likes Translation suggestions: if a maintained page should exist in another language, suggesting it here helps the maintainers prioritise multilingual work.
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Second pass at: Gauge and length selection for subcutaneous injection Replied, post #53 · Devices › Syringes & needles · 11 Apr 2025 · 22 likes Needle length: typical lengths for subcutaneous injection are 4-6 mm (short), 8 mm (standard), or 10-12 mm (longer). Longer needles are needed for deeper tissue or if…
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Airline travel with a temperature-sensitive injectable — what changed since Replied, post #12 · Devices › Cold chain · 28 Mar 2025 · 0 likes Worth separating two things that post #8 runs together. Freeze-thaw: some peptides tolerate freezing; others do not. Check your compound's labelling. Generally,…
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Why we hide unevidenced fraud accusations and log the hiding Replied, post #70 · Sourcing › Red flags · 24 Mar 2025 · 0 likes I read post #68 twice before replying, because I had assumed the opposite. Inability to trace lots: if you ask "where was this synthesised, by whom, under what…
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Adjudicated events and why the definition matters — the long version Replied, post #47 · Evidence › Trials · 14 Mar 2025 · 2 likes Dropout is information: high dropout rates can indicate tolerability problems or lower efficacy than the summary suggests. Where the analysis handled dropouts matters.…
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Requesting a page: what makes a good request Replied, post #20 · Documentation › Wiki requests · 11 Mar 2025 · 3 likes Worth separating two things that post #16 runs together. Format suggestions: if you think a maintained page could be clearer in its presentation (different section…
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Second pass at: Cross-border purchase within the EU: the actual rules Replied, post #59 · Access › International · 22 Feb 2025 · 28 likes Currency and exchange rates: paying in different currencies has different costs and risks. Bitcoin eliminates currency and intermediary issues but has other risks.
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Oxidation and deamidation mass shifts, tabulated Replied, post #58 · Analytics › Mass spectrometry · 20 Feb 2025 · 1 like Quantitation by MS: most quantitation is done by LC-UV detection at 214 nm, not by MS, because extinction coefficients are better known. MS can quantify if an internal…
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[2026 update] What the GIP component of tirzepatide is thought to contribute, and how… Replied, post #12 · Compounds › Tirzepatide · 10 Feb 2025 · 9 likes Storage and stability: published data on licensed tirzepatide formulations exists and is worth reading directly rather than through summarised claims. Reconstituted…
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Distinguishing a deletion sequence by mass alone Replied, post #55 · Analytics › Mass spectrometry · 6 Feb 2025 · 3 likes post #54 is right about the mechanism and I think understates the practical bit. Resolution: "high resolution" commonly means
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BPC-157: what the rodent literature actually shows, and what it does not — a second… Replied, post #11 · Compounds › Repair & healing peptides · 2 Feb 2025 · 31 likes Why plausible mechanism is not evidence of effect: a mechanism that is chemically or biologically plausible can fail in practice for dozens of reasons —…
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Follow-up: Tesamorelin has an approved indication — what that changes about the evidence Replied, post #5 · Compounds › Secretagogues & GH axis · 1 Feb 2025 · 0 likes post #4 is right about the mechanism and I think understates the practical bit. Reading a rodent study on a secretagogue without over-extrapolating: rodent studies can…
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Ipamorelin selectivity claims and where they came from Replied, post #10 · Compounds › Secretagogues & GH axis · 1 Feb 2025 · 0 likes Picking up post #7: that is the part I would want checked first. GHRH analogues versus ghrelin mimetics are often conflated but they are different mechanisms. GHRH…
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Biased agonism: a real phenomenon, an over-used explanation — what changed since Replied, post #39 · Pharmacology › Receptor biology · 31 Jan 2025 · 8 likes Species differences: rodent studies show the same compounds produce effects in rodents that predict human effects reasonably well for semaglutide and tirzepatide. The…
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Revisiting: Bug report: the reconstitution calculator and a rounding edge case Replied, post #37 · Data & Tools › Calculators · 1 Jan 2025 · 0 likes Units: all calculators explicitly require units to be stated. This prevents the decimal-point errors that come from forgetting units. Always verify units in and out.
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Research-use-only status: what it means legally and practically — a second dataset Replied, post #42 · Compounds › Other compounds · 17 Dec 2024 · 8 likes Naming conventions for research peptides cause confusion because suppliers do not follow a standard. The same compound gets different names from different suppliers. If…
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Hypertension improvement and when medication needs revisiting — a second dataset Replied, post #101 · Clinical › Comorbidities · 25 Oct 2024 · 0 likes Cardiovascular disease: several compounds have cardiovascular outcome trials. SELECT was in people without diabetes; SUSTAIN 6 was in high-risk diabetes. Absolute…
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Transporting a vial for a weekend away Started this topic · Practice › Storage & stability · 21 Oct 2024 · 5 likes On the subject in the title: Transporting a vial for a weekend away Working notes rather than a conclusion. Practical question with the units stated, because I have…
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Irish differences from the UK position Replied, post #44 · Regional › UK & Ireland · 18 Oct 2024 · 4 likes Coming back to post #42, because the follow-up matters more than the original answer. Supply and shortage resilience: both UK and Ireland sourced primarily from…
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Converting between mg/mL and units per dose, both directions Replied, post #21 · Practice › Reconstitution · 16 Sep 2024 · 24 likes Osmolarity and reconstitution: the osmolarity of the reconstituted solution affects comfort on injection. Isotonic solutions (close to blood osmolarity) are less…
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Progressive overload when the scale is falling — one year on Replied, post #37 · Nutrition & Training › Resistance training · 8 Sep 2024 · 0 likes post #36 is right about the mechanism and I think understates the practical bit. Post-weight-loss training: once weight loss is complete and energy deficit ends,…
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Follow-up: Where the four-week escalation interval comes from, and what it is not Replied, post #56 · Practice › Dosing & titration · 2 Sep 2024 · 25 likes On post #52 — agreed on the reasoning, with one qualification. Stepping down deliberately: the withdrawal trials show that stopping is followed by regain. The step-down…
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Second pass at: Sodium, potassium and magnesium when intake drops Replied, post #59 · Nutrition & Training › Hydration & electrolytes · 26 Aug 2024 · 0 likes post #58 answers the question as asked. The question underneath it is different. Constipation and hydration: dehydration makes constipation worse. Increasing fluid…
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Second pass at: Journal club: LEADER as the historical anchor Replied, post #13 · Evidence › Journal club · 10 Jul 2024 · 4 likes Practical note that does not fit anywhere else. Whatever you conclude from this topic, write down what you did and when. The single most useful thing in your own…
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Cold packs, phase-change material, and what survives ten days Replied, post #59 · Sourcing › Logistics · 1 Jul 2024 · 31 likes Thank you for the correction. I have edited my earlier post with a note rather than silently, so the thread still makes sense to read. The error was mine and it was the…