{"id":"cc9fddb9-8e46-4011-bc3c-9c5753f2590f","arxiv_id":"2505.12726","paper_version":2,"verdict":"CONDITIONAL","confidence":"MODERATE","novelty_score":6.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":8,"one_line_summary":"A self-consistent field theory model of lipid and cholesterol as diblock copolymers with an explicit cholesterol headgroup reproduces the condensation effect, membrane thickening, and the linear cholesterol chemical potential regime seen in experiments.","lead":"This paper models lipid and cholesterol molecules as two kinds of block copolymers and uses self-consistent field theory to simulate their bilayer membrane. It shows that giving cholesterol a small headgroup in the model reproduces known effects like area condensation, membrane thickening, and reduced lipid tilt, which matters for designing biomimetic vesicles and understanding cholesterol's role in membranes.","discovery_kind":"extension","skeptic_critique":{"model":"deepseek-v4-flash","headline":"The stability of the C_s phase is only established at zero cholesterol; at finite cholesterol the tilted branch approaches A_s without a free-energy comparison, so the reported equilibrium predictions may describe a metastable state.","rationale":"The reader's weakest assumption is the hand-set parameterization of the Flory-Huggins and Maier-Saupe terms. That is a real quantitative concern, but parameter sensitivity is secondary to whether the reported C_s branch is actually the equilibrium state. Even with perfectly correct parameters, a converged tilted solution at finite cholesterol is only a local extremum unless the A_c and A_s branches are explicitly compared. The paper's own language—'approaches the A_s-phase' and 'structural transition from the C-phase to the A-phase'—suggests the untilted branch may become competitive or favored at high cholesterol, yet no free-energy comparison is shown there. The proposed check uses the paper's existing machinery, so it is inexpensive and decisive. If A_s or A_c wins at any studied concentration, the abstract's 'minimum free energy configuration' claim and the quantitative statements about condensation and chemical potential would need to be restricted to the pure-lipid and low-cholesterol regimes. If C_s remains lowest, the paper should show that comparison to support its central claim. The absence of code and supporting materials is a secondary verification barrier, but the phase-stability gap is the more immediately load-bearing scientific issue.","tokens_in":19681,"tokens_out":7903,"duration_ms":90178,"concrete_test":"Recompute the SCFT free energy for the A_c, A_s, and C_s initial states at cholesterol concentrations φ_DE = 0.1, 0.2, 0.375, and 0.5 using the same numerical protocol and the Table 1 parameters, optimizing the computational domain l* for each phase as in Appendix A.2. Report the free-energy differences and the tilt of the C_s branch at each concentration. If A_s or A_c is lower than C_s at any φ_DE, the C_s-based curves in Figs. 5–6 are metastable and the conclusion must be revised; if C_s remains lowest everywhere, the paper should include a phase-stability plot to make that claim auditable.","verdict_should_be":"UNCHANGED","load_bearing_attack":"Section 3.1 compares free energies of the A_c, A_s, and C_s phases only for cholesterol-free bilayers (Fig. 4a) and concludes that C_s is the equilibrium state. All cholesterol-dependent results in Section 3.2—chemical potential, condensation, thickness, and tilt—are then computed on the C_s branch without reporting the same free-energy comparison at finite cholesterol concentration. The paper itself notes in Section 3.3.2 that at high cholesterol 'the bilayer structure approaches that of the A_s-phase' and refers to a 'structural transition from the C-phase to the A-phase.' If A_s or A_c becomes lower in free energy at φ_DE = 0.2, 0.375, or 0.5, then the C_s-branch curves in Figs. 5 and 6 describe a metastable state, and the claimed quantitative agreement with experiment would not validate the equilibrium model. The abstract's central assertion—that the simulations identify a minimum free energy configuration characterized by tilted tails—therefore rests on an unverified assumption about the phase diagram at the concentrations where the main predictions are made.","agreement_with_reader":"disagree"},"referee_report":{"model":"deepseek-v4-flash","summary":"This paper develops a self-consistent field theory (SCFT) model of phospholipid/cholesterol bilayers, representing the phospholipid as a rod-coil diblock copolymer (flexible headgroup B and rigid tail C) and cholesterol as a second rod-coil diblock copolymer with an explicit flexible headgroup D and rigid hydrophobic block E, immersed in a solvent A. The authors fix model parameters from geometric considerations and from their prior headless-cholesterol SCFT study [31], compare three candidate phases (A_c, A_s, C_s), and report that the tilted C_s phase has the lowest free energy for cholesterol-free bilayers. They then compute, on the C_s branch, the cholesterol chemical potential, area condensation, bilayer thickness, and lipid tilt as functions of cholesterol concentration, finding a linear chemical potential regime at high cholesterol concentration, a condensation effect, and decreasing tilt with increasing cholesterol. They also study the influence of headgroup volume fraction, hydrophobic length, and headgroup interaction parameters. The main claims are that the model identifies a tilted gel phase as the equilibrium configuration and captures the experimentally known condensation, thickening, and reduced-tilt trends, with quantitative agreement for the cholesterol chemical potential.","tokens_in":20036,"tokens_out":11969,"duration_ms":114303,"significance":"If the central claims are substantiated, this is a useful contribution to coarse-grained modeling of lipid-cholesterol bilayers. The explicit representation of the cholesterol headgroup is an advance over the authors' earlier headless-cholesterol model, and the SCFT framework is standard and the numerics appear carefully executed. The model yields several falsifiable predictions (e.g., the linear high-concentration chemical potential, the unit-area reduction, and the tilt reduction) that can be compared with experiments, and it offers a practical route to designing biomimetic polymer membranes. The authors are honest in the conclusion about the model's limitations, including the qualitative nature of the structural predictions and the unknown mapping between polymer deformation and real molecular interactions. However, the abstract overstates the quantitative character of the condensation result, and the phase stability of the C_s state at finite cholesterol concentration is not established, which undermines the equilibrium claim at the concentrations where the main predictions are made.","major_comments":[{"comment":"The stability of the C_s phase is established only for cholesterol-free bilayers (φ_DE = 0) in Fig. 4(a). All finite-cholesterol results in Section 3.2—chemical potential, condensation, thickness, and tilt—are computed on the C_s branch without a free-energy comparison against the A_c and A_s phases at the same cholesterol concentration. The paper itself states in Section 3.2.3 that at φ_DE = 0.5 'the bilayer structure approaches that of the A_s-phase' and in Section 3.3.2 refers to a 'structural transition from the C-phase to the A-phase.' If the A_s or A_c free energy is lower at φ_DE = 0.2, 0.375, or 0.5, then the C_s-branch curves in Figs. 5 and 6 describe a metastable state, and the abstract's assertion that the simulations identify a minimum free-energy configuration is not supported at the concentrations where the main predictions are made. Please report the free energies of all three phases as functions of φ_DE, or explicitly delimit the stability window of the C_s phase.","section":"Sections 3.1 and 3.2, Figs. 4-6"},{"comment":"The abstract claims the model 'quantitatively captures the well-known area condensation effect,' but Section 3.2.2 (Fig. 6(a)) presents no quantitative comparison to experimental area data; the text only states that the predictions are 'consistent with experimental measurements [23].' Section 4 explicitly limits structural agreement to 'qualitatively reproduces structural trends' and restricts quantitative agreement to the chemical potential. This is an internal inconsistency. Please either add a quantitative overlay of model and experimental areas (e.g., data from Ref. [23]) with an error metric, or revise the abstract to say, for example, 'qualitatively captures' the condensation effect.","section":"Abstract vs. Section 4, Section 3.2.2"},{"comment":"The interaction parameters χ_BD N = −30, χ_CD N = χ_DE N = 40, χ_CE N = 0, and η N = 30 are assigned by hand based on 'previous studies [1,31]' and on qualitative reasoning such as 'we chose a moderate interaction parameter' (Section 3.1). The central predictions—condensation magnitude, tilt angle, and chemical potential slope—depend on these values, yet no sensitivity analysis is provided for χ_CE, χ_BD, or η; the parameter variations in Sections 3.3 and 3.4 concern headgroup volume ratios and headgroup interaction parameters only. Because the paper claims quantitative agreement for the chemical potential and the abstract claims quantitative capture of the condensation effect, please include a sensitivity study for these key parameters or otherwise justify their transferability from the headless-cholesterol model of Ref. [31] to the present model with an explicit cholesterol headgroup.","section":"Section 3.1, Table 1"},{"comment":"The model sets the cholesterol hydrophobic rod length equal to the lipid tail length: f_E = f_C and L_E = L_C = f_C β_C. This geometric assumption is introduced without justification, although in reality the rigid hydrophobic portion of cholesterol is shorter than a DPPC acyl chain. The tail-length study in Section 3.3.2 varies L_C while keeping L_E fixed, so the equal-length assumption is never tested against the physically more plausible L_E < L_C case. Since the tilt and thickness predictions are likely sensitive to the relative rod lengths, please test at least one case with L_E < L_C or provide a geometric/conceptual justification for the equal-length choice.","section":"Section 3.1"}],"minor_comments":[{"comment":"The text states L_B = 2√(f_B R_g); this is dimensionally incorrect. The intended expression is L_B = 2√(f_B) R_g (since R_B^g = √(f_B) R_g).","section":"Section 3.1"},{"comment":"The table row reading 'χ_AB N = χ_AD N = χ_BE = 0' appears to contain a typo: the text sets χ_AB N = χ_AD N = χ_BD N = 0, and χ_BE is not otherwise defined in the paper. Please correct.","section":"Table 1"},{"comment":"The DOIs for references [47] and [48] appear to be swapped: [47] (JACS 2005) is assigned 10.1021/nn3023602 and [48] (ACS Nano 2012) is assigned 10.1021/ja043600x. Please verify and correct these DOIs.","section":"References [47] and [48]"},{"comment":"The caption lists several fitted curves with R^2 values from Ref. [24] but does not identify which curve is the SCFT result; a legend or explicit labeling of the SCFT curve would make the comparison clear.","section":"Figure 5 caption"},{"comment":"The sentence 'the density distribution of phospholipid headgroups also increases along the tangential direction of the bilayer membrane interface' is confusing because the model is solved in a one-dimensional normal direction; consider rewording to refer to the areal density or lateral packing density.","section":"Section 3.2.2"},{"comment":"There are several typographical errors, including 'weuseself-consistentfieldtheory' in the abstract, 'Shownsisthe tilt' in the Fig. 4 caption, 'examble' in Section 3.3.2, and an unmatched parenthesis in Section 3.2.3 after the Maier-Saupe energy comparison. Please copyedit.","section":"General"},{"comment":"The text says the BC and DE copolymers 'were preassembled into bilayer membranes' while elsewhere the system is described as self-assembled; clarifying that the preassembled structure is only the initial condition for the SCFT minimization would remove the apparent inconsistency.","section":"Section 2.1"},{"comment":"The two hydrophobic-length cases are written as 'L_C = f_C β_C = 0.75 * 4 = 3 R_g and L_C = f_C β_C = 0.800625 * 4.1 = 3.2826 R_g'; the second expression is a new value of L_C, so the text should say something like 'and for the longer tail, L_C = f_C β_C = 0.800625 × 4.1 = 3.2826 R_g' for clarity.","section":"Section 3.3.2"}],"recommendation":"major_revision","confidential_remarks":"The paper presents a plausible coarse-grained SCFT approach to lipid-cholesterol bilayers, but two issues need to be resolved before publication: (i) the free-energy comparison of the C_s phase with the A phases must be extended to finite cholesterol concentrations, since the current equilibrium claim rests on a cholesterol-free comparison; and (ii) the abstract's 'quantitatively captures' for the condensation effect is not supported by the manuscript's own conclusion that structural trends are qualitative. The hand-set interaction parameters also deserve a sensitivity analysis given the quantitative language used. These are fixable within the scope of the paper, so I recommend major revision rather than rejection. The reference and typographical issues are minor but should be cleaned up."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"Colleague,\n\nThis is a useful step forward in coarse-grained SCFT for lipid-cholesterol bilayers. The new piece is the explicit cholesterol headgroup (D block) attached to the rigid E rod, and the physics it unlocks: the headless version [31] missed the condensation effect, while this one reproduces it, along with membrane thickening, reduced lipid tilt, and the linear cholesterol chemical-potential regime at 37–50%. Those trends emerge from the model, not from fitting to the target experiments. That is a real result and worth taking seriously.\n\nWhat I like: the parameterization is grounded in DPPC geometry (f_B:f_C = 1:3, f_D = 0.025), the chemical-potential comparison to Shaw et al. is an external benchmark rather than a fit, and the explanation of condensation via headgroup shielding is concrete and consistent with the umbrella model. The paper is also honest in the conclusion that quantitative agreement is mainly for the chemical potential, with structural trends qualitative.\n\nSoft spots, in order:\n\n1. The phase-stability claim is only checked at zero cholesterol. Fig. 4(a) compares A_c, A_s, and C_s free energies for phi_DE = 0. All results in Sec. 3.2 are then computed on the C_s branch, and the paper itself says at high cholesterol the bilayer approaches A_s. If A_s or A_c is lower at phi_DE = 0.2–0.5, the reported curves describe a metastable C_s branch, not the equilibrium state. The authors need to report the same free-energy comparison at finite cholesterol before claiming the model identifies the minimum free energy configuration.\n\n2. The abstract's \"quantitatively captures the area condensation effect\" is not supported by a quantitative comparison to experimental areas. The condensation plot is qualitative (area per polymer decreases); there is no number for the reduction or a measured area curve. Temper the wording or add the comparison.\n\n3. The interaction parameters are mostly hand-set from prior work, with chi_BD N = -30 and chi_CD N = chi_DE N = 40 chosen without sensitivity analysis. This is not fatal—the results are not fitted to the target data—but a sensitivity sweep over the key parameters would strengthen confidence.\n\n4. Minor: no code or supporting materials, several typos, and a few inconsistent notations (e.g., Table 1 entries and the 3.2826 R_g line).\n\nThe stress-test note about finite-cholesterol phase stability lands; that is the main substantive issue. The central modeling idea still holds up as a plausible new framework, but the equilibrium claim needs revision.\n\nWho is this for: people modeling biomimetic polymer/lipid vesicles and cholesterol effects at mean-field level. It deserves a serious referee and revision rather than desk rejection. I would ask for the missing free-energy comparison and a tempered abstract; then it would be a solid contribution.","headline":"A plausible headgroup-aware SCFT model that recovers cholesterol's condensation and chemical-potential trends, but only establishes phase stability at zero cholesterol and overstates the quantitative match.","tokens_in":20446,"tokens_out":2828,"would_cite":true,"duration_ms":30296,"reading_group":"maybe","serious_thinker":"yes","would_accept_peer_review":true},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":[],"model":"deepseek-v4-flash","headline":"The paper argues that modeling a phospholipid–cholesterol bilayer as two diblock copolymers, with cholesterol given an explicit headgroup, makes the tilted gel phase the free-energy minimum and quantitatively reproduces cholesterol's…","keywords":["Bilayer membrane","Self-assembly","Cholesterol","Lipid","Polymer","Self-consistent field theory","Condensation effect","Tilted gel phase"],"falsifier":"Re-run the SCFT calculations with cholesterol's rigid E rod shorter than the lipid tail (for example $f_E = 0.65$ with $f_C = 0.75$) while keeping every interaction parameter at the paper's default values; if the tilted $C_s$ phase no longer is the free-energy minimum or the 37–50% linear chemical-potential regime disappears, the central claims are tied to the assumed $f_E=f_C$ geometry.","tokens_in":19533,"feed_emoji":"🫧","tokens_out":11100,"duration_ms":114729,"temperature":0.7,"pith_summary":"This paper tries to show that a phospholipid–cholesterol bilayer can be accurately described as a self-assembled mixture of two diblock copolymers in water: one polymer with a flexible head and rigid tail for the lipid, and one with a small flexible head and rigid rod for cholesterol. When cholesterol carries an explicit headgroup, the model's lowest-free-energy state is a tilted gel phase, like the experimentally observed $L_{\\beta'}$ phase of DPPC. From that state, with a fixed parameter set, the model reproduces four established cholesterol effects: area condensation, membrane thickening, a fall in lipid tilt from about $43^\\circ$ toward near zero, and a chemical potential that rises linearly with cholesterol concentration between 37% and 50%. This matters because the same field-theoretic machinery could then be used to compute structural and thermodynamic properties of biomimetic polymer–lipid membranes and to design vesicle platforms for drug delivery.","feed_headline":"Cholesterol's membrane effects emerge from a block-copolymer model","feed_subtitle":"Explicit cholesterol headgroup yields tilted gel phase, condensation, and the measured chemical-potential slope.","key_machinery":"The machinery that carries the argument is self-consistent field theory for a canonical ensemble of three polymers in one spatial dimension: water as a flexible A homopolymer, the phospholipid as a BC rod–coil diblock with flexible head B and rigid tail C, and cholesterol as a DE rod–coil diblock with small flexible head D and rigid rod E. The free energy combines Flory–Huggins isotropic interactions among all five species, a Maier–Saupe orientational term that aligns the rigid rods through the tensor $\\mathbf{S}$, and coil stretching entropy. The new element relative to the authors' earlier model is the explicit D headgroup on cholesterol, whose small volume ratio $f_D:f_B = 1:10$ forces the phospholipid headgroups to stretch sideways to shield the hydrophobic E rod from water. The equilibrium state is selected by minimizing the free energy with respect to the computational-domain length $l$, which for the pure bilayer places the tilted $C_s$ phase below both the interdigitated and non-interdigitated untilted phases; tilt is read from the spectral decomposition of the orientational density tensor of the C rods.","core_discovery":"In its own terms, this paper establishes that a diblock-copolymer SCFT model in which cholesterol is given a small explicit headgroup can account for the main structural and thermodynamic effects of cholesterol in saturated phospholipid bilayers. With volume fractions and chain lengths chosen to match DPPC and cholesterol ($f_B=0.25$, $f_D=0.025$, $f_C=f_E=0.75$, $\\beta_C=\\beta_E=4$), the tilted $C_s$ phase—lipids tilted away from the bilayer normal, as in the experimentally observed $L_{\\beta'}$ gel phase—is the global free-energy minimum, with an equilibrium tilt of about $43^\\circ$ at $l^*/R_g = 16.6$, below the metastable interdigitated and non-interdigitated untilted phases. As cholesterol concentration rises from 0 to 50%, the model produces a monotonic decrease in average area per molecule (the condensation effect), an increase in bilayer thickness from about $4.16R_g$ toward $5.64R_g$, a drop in lipid tilt from $43^\\circ$ to below $10^\\circ$, and a cholesterol chemical potential that increases linearly with concentration between 37% and 50%, in agreement with liposome experiments. The mechanism asserted is that phospholipid headgroups redistribute and stretch tangentially to shield cholesterol's small headgroup from water; the enthalpic gain from improved interactions, dominated by the Maier–Saupe orientational term, more than compensates the headgroup stretching entropy loss. The paper also claims that among headgroup interactions, the phospholipid headgroup–solvent term $\\chi_{AB}N$ is the dominant control on tilt and chemical potential, while cholesterol headgroup interactions have negligible influence.","pith_inferences":["Relaxing the geometric choice $f_E=f_C$ (cholesterol's rigid rod as long as the lipid tail) is the most direct calculation the paper leaves open; if shortening or lengthening the E rod breaks the 37–50% linear chemical-potential window, that window would be an artifact of the chosen geometry rather than a robust consequence of the headgroup mechanism.","If the $C_s$-phase ordering is robust to reasonable variation of the interaction parameters, the same machinery could predict how changing phospholipid headgroup size or hydrophilicity shifts the condensation percentage, since the paper only reports that quantity for one geometry.","The model's headgroup-shielding account of condensation is a quantitative realization of the umbrella picture; applied to lipids with different headgroup volumes, it would predict that the condensation effect weakens as cholesterol's headgroup becomes larger relative to the lipid headgroup.","Because the SCFT chemical potential is computed directly at each concentration, a natural next application is two-lipid mixtures, where the same computation could predict how cholesterol partitions between coexisting liquid-ordered and liquid-disordered domains without additional thermodynamic assumptions."],"forward_implications":["In a pure lipid bilayer, the equilibrium is the tilted gel phase $C_s$, with free energy lower than both interdigitated and non-interdigitated untilted phases; the model therefore gives an SCFT route to the $L_{\\beta'}$ phase of DPPC without hand-placing molecular orientations.","Adding cholesterol reduces the average area per molecule (condensation), increases bilayer thickness, and lowers lipid tilt, with structural changes saturating near 37–50% cholesterol; the theory attributes this to headgroup stretching that shields cholesterol from water.","Cholesterol's chemical potential rises monotonically and linearly in the 37–50% concentration range, in agreement with liposome measurements, and this curve is computed rather than fitted.","Varying phospholipid tail length changes tilt and the cholesterol concentration at which thickness saturates: longer tails keep the bilayer in the tilted phase at higher cholesterol content.","In headgroup interaction sweeps, the phospholipid headgroup–water interaction $\\chi_{AB}N$ is the dominant control on tilt and cholesterol chemical potential, while cholesterol headgroup interactions have little effect."],"supporting_citations":[{"why":"Supplies the liquid-crystalline rod–coil SCFT framework and the uniaxial assumption used to define tilt from the orientational density.","marker":"[1]"},{"why":"The authors' earlier headless-cholesterol SCFT model; its parameter values are carried over, and its failure to predict condensation motivates adding the cholesterol headgroup.","marker":"[31]"},{"why":"Provides the experimental cholesterol chemical potentials in DPPC liposomes against which the model's 37–50% linear regime is compared.","marker":"[24]"},{"why":"Provides experimental measurements of the condensing effect that support the model's area-per-molecule versus cholesterol concentration trend.","marker":"[23]"},{"why":"Used as experimental reference for cholesterol-induced changes in bilayer thickness and area.","marker":"[28]"},{"why":"Supplies the experimental DPPC gel-phase tilt near 30 degrees against which the model's 43-degree equilibrium tilt is judged.","marker":"[35]"},{"why":"Introduces the chemical-potential measurement approach for membrane cholesterol that was applied to liposomes in the experimental comparison.","marker":"[3]"},{"why":"The umbrella model for condensation via headgroup shielding; the paper's mechanism is an explicit, quantitative version of this idea.","marker":"[11]"}],"fun_headline_variants":["Block-copolymer model reproduces cholesterol's membrane effects","Copolymer model captures cholesterol condensation and tilt","Cholesterol's linear chemical potential emerges in copolymer bilayer","Tilted gel phase from cholesterol block-copolymer model"],"cache_read_input_tokens":3200,"weakest_assumption_plain":"The load-bearing premise is that the ten interaction-energy parameters and the single rod-alignment parameter, most taken from an earlier headless-cholesterol model and a few chosen by hand, together with the assumption that cholesterol's rigid part is exactly as long as the lipid tail, truly represent how cholesterol and phospholipids interact; if those choices are wrong, the predicted phase ordering and the agreement with experiments would not follow.","fun_headline_variants_meta":{"raw":{"variants":["Block-copolymer model reproduces cholesterol's membrane effects","Copolymer model captures cholesterol condensation and tilt","Cholesterol's linear chemical potential emerges in copolymer bilayer","Tilted gel phase from cholesterol block-copolymer model"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.000747,"raw_usage":{"total_tokens":3395,"prompt_tokens":1080,"completion_tokens":2315,"prompt_tokens_details":{"cached_tokens":384},"prompt_cache_hit_tokens":384,"prompt_cache_miss_tokens":696,"completion_tokens_details":{"reasoning_tokens":2253}},"tokens_in":696,"tokens_out":2315,"duration_ms":17991,"temperature":1.0,"reasoning_tokens":2253,"cache_read_input_tokens":384,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-15T20:27:41.137555+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"Re-run the SCFT calculations with cholesterol's rigid E rod shorter than the lipid tail (for example $f_E = 0.65$ with $f_C = 0.75$) while keeping every interaction parameter at the paper's default values; if the tilted $C_s$ phase no longer is the free-energy minimum or the 37–50% linear chemical-potential regime disappears, the central claims are tied to the assumed $f_E=f_C$ geometry.","supporting_citations":[{"cited_title":"Liquid crystalline bilayers self-assembled from rod–coil diblock copolymers[J]","cited_arxiv_id":null,"evidence_quote":"Supplies the liquid-crystalline rod–coil SCFT framework and the uniaxial assumption used to define tilt from the orientational density."},{"cited_title":"Mimicking effects of cholesterol in lipid bilayer membranes by self-assembled am- phiphilic block copolymers[J]","cited_arxiv_id":null,"evidence_quote":"The authors' earlier headless-cholesterol SCFT model; its parameter values are carried over, and its failure to predict condensation motivates adding the cholesterol headgroup."},{"cited_title":"Chemical potential measurements constrain models of cholesterol-phosphatidylcholine interactions[J]","cited_arxiv_id":null,"evidence_quote":"Provides the experimental cholesterol chemical potentials in DPPC liposomes against which the model's 37–50% linear regime is compared."},{"cited_title":"https://doi.org/10.1529/biophysj.106.099234","cited_arxiv_id":null,"evidence_quote":"Provides experimental measurements of the condensing effect that support the model's area-per-molecule versus cholesterol concentration trend."},{"cited_title":"Cholesterol per- turbs lipid bilayers nonuniversally[J]","cited_arxiv_id":null,"evidence_quote":"Used as experimental reference for cholesterol-induced changes in bilayer thickness and area."},{"cited_title":"Order and disor- der in fully hydrated unoriented bilayers of gel-phase dipalmi- toylphosphatidylcholine[J]","cited_arxiv_id":null,"evidence_quote":"Supplies the experimental DPPC gel-phase tilt near 30 degrees against which the model's 43-degree equilibrium tilt is judged."},{"cited_title":"The chemical potential of plasma membrane cholesterol: implications for cell biology[J]","cited_arxiv_id":null,"evidence_quote":"Introduces the chemical-potential measurement approach for membrane cholesterol that was applied to liposomes in the experimental comparison."}],"review_version":1}