Education

IC50 ↔ Ki conversion for competitive, uncompetitive, and pure noncompetitive inhibition with mechanism notes, potency bands, and tight-binding caveats. Educational use only.

Education

kcat = Vmax ÷ [E]total in min⁻¹ and s⁻¹, entered as enzyme amount, enzyme concentration, or protein concentration + molecular weight; bands results from very slow to catalase-class. Educational use only.

Education

Beer–Lambert DNA quantitation: c = A260 × dilution factor × K / path length with 1 OD = 50 µg/mL dsDNA or 33 µg/mL ssDNA, plus ng/µL, total yield, and a 0.1–1.5 linear-range check. Derived from Marmur & Doty, Sambrook & Russell, Thermo Fisher NanoDrop notes. Educational use only.

Education

Convert DNA mass concentration to copies/µL via copies = c(g/µL) × Avogadro ÷ (bp × 660), with ng/µL–pg/µL–µg/µL units, pmol/µL output, total copies per volume, and A260-overestimation caveats. Lab-planning use only.

Education

Compute modified F2 phenotypic ratios from two-locus gene interaction: 9:7, 9:3:4, 12:3:1, 13:3, 15:1, 9:6:1 or 9:3:3:1, with expected counts and optional chi-square goodness-of-fit. Derived from Mendel 1866, Bateson & Punnett 1905, Griffiths, Hartl & Clark 2007. Educational use only.

Health

Compute LVEF = (EDV − ESV) / EDV. Normal 50–70%; <40% HFrEF; >70% hyperdynamic. Derived from Lang JASE 2015, Ponikowski ESC 2016, StatPearls, LITFL, Braunwald. Not medical advice.

Health

Calculate VD/VT using both the Bohr equation (PACO₂-based) and the Enghoff modification (PaCO₂-based). Normal ~0.20–0.40; >0.60 signals severe dead space in ARDS/PE. Derived from Bohr 1891, Enghoff 1938, Tusman 2012, LITFL, StatPearls. Not medical advice.

Education

Kinematics visualisation tutor: velocity-time curve (constant-acceleration SUVAT solver with displacement-area shading), projectile parabola (adjustable g + air-resistance toggle), and free-fall timing

Health

Compute daily kcal and protein targets for enterally fed adults from weight, kcal/kg and g/kg prescriptions, then translate them into product volume and starting rate. Targets from ASPEN/SCCM, ESPEN. Caveats: actual vs ideal weight, trophic feeding, gastric residual, aspiration precautions. Derived from McClave 2016, Singer/ESPEN 2019, Boullata 2017, MDCalc. Not medical advice.

Health

Estimate glomerular filtration rate (eGFR) with the CKD-EPI 2021 race-free creatinine equation: eGFR = 142 × min(SCr/κ, 1)^α × max(SCr/κ, 1)^(−1.200) × 0.9938^Age × 1.012 if female, where κ = 0.7 (female) / 0.9 (male) and α = −0.241 (female) / −0.302 (male). This 2021 update (Inker et al., NEJM 2021) removed the race multiplier from the 2009 equation and changed the leading coefficient from 141 to 142. Returns a BSA-INDEXED eGFR for CKD staging (G1–G5); for drug dosing use un-indexed CrCl (Cockcroft-Gault). Valid for stable adults, not AKI/pregnancy/amputees/extremes. Not medical advice.

Health

Estimate glomerular filtration rate (eGFR) with the simplified 4-variable MDRD equation (2006 re-expressed, IDMS-traceable): eGFR (mL/min/1.73 m²) = 175 × SCr^−1.154 × Age^−0.203 × (0.742 if female) × (1.212 if Black). The 175 constant replaced the original 186 after IDMS-standardized creatinine calibration. The legacy race coefficient 1.212 is OFF by default (the 2021 CKD-EPI race-free equation removed it) and is provided only for historical comparison. Returns a BSA-INDEXED eGFR for CKD staging (G1–G5); for drug dosing use un-indexed CrCl (Cockcroft-Gault). Derived from Levey AS et al., Ann Intern Med 2006. Valid for stable adults, not AKI/pregnancy/extremes. Not medical advice.

Health

Calculate an individualized drug dose from body surface area using the Mosteller formula: BSA (m²) = √(Height(cm) · Weight(kg) / 3600), then Dose = Drug_dose_per_m² × BSA. BSA is the recommended normalization for many cytotoxic and pediatric regimens because drug clearance scales more linearly with BSA than with body weight across patients of different sizes. Also reports the standard adult dose at the reference adult BSA of 1.73 m² for comparison. Valid only for linear drug clearance — BSA dosing does not apply to saturable (Michaelis-Menten) pathways. Not medical advice.