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BACKGROUND: It is unclear whether men who experience sexual difficulty during partnered sex experience similar difficulty during masturbation. AIM: To determine whether sexual functionality and dysfunctionality were similar or different during masturbation vs partnered sex. METHODS: We compared sexual responsivity during masturbation vs partnered sex in a multinational sample of 4,209 men with and without a sexual dysfunction to determine whether dysfunctionality was greater, less, or about the same during these 2 types of sexual activity. OUTCOMES: Consistently lower impairment of sexual function was found during masturbation compared with partnered sex for all 3 sexual problems assessed: erectile dysfunction, premature ejaculation, and delayed ejaculation. CLINICAL TRANSLATION: These findings reiterate the potential value of assessing sexual responsivity during masturbation as well as melding masturbation strategies with couples therapy in order to attenuate impaired response during partnered sex. STRENGTH & LIMITATIONS: Although this study provides the first empirical evidence based on a large multinational sample indicating that sexual functionality is consistently higher during masturbation than partnered sex, it does not provide an empirically-derived explanation for this difference. CONCLUSION: Understanding a man's response potential during masturbation may be important to improving sexual response during partnered sex, with the need for more targeted research that more directly evaluates the use of such strategies in the treatment of men's sexual problems. Rowland DL, Hamilton BD, Bacys KR et al. Sexual Response Differs during Partnered Sex and Masturbation in Men With and Without Sexual Dysfunction: Implications for Treatment. J Sex Med 2021;18:1835-1842.

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Studies investigating women's attributions for positive and negative sexual experiences have been slow to adopt a cross-cultural perspective, resulting in a perspective defined by Western experiences. This cross-cultural analysis examined such attribution processes in 88 Pakistani and 187 USA women, and identified differences related to orgasmic difficulty and country-of-origin. Pakistani and USA women differed on both self-blame and relationship blame related to negative sexual outcomes, an effect intensified in Pakistani women who reported orgasmic difficulty during partnered sex. Differences are interpreted within a cultural context and underscore the importance of addressing women's sexual experiences in a more global context.

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The phase behaviors of crystalline solids embedded within nanoporous matrices have been studied for decades. Classic nucleation theory conjectures that phase stability is determined by the balance between an unfavorable surface free energy and a stabilizing volume free energy. The size constraint imposed by nanometer-scale pores during crystallization results in large ratios of surface area to volume, which are reflected in crystal properties. For example, melting points and enthalpies of fusion of nanoscale crystals can differ drastically from their bulk scale counterparts. Moreover, confinement within nanoscale pores can dramatically influence crystallization pathways and crystal polymorphism, particularly when the pore dimensions are comparable to the critical size of an emerging nucleus. At this tipping point, the surface and volume free energies are in delicate balance and polymorph stability rankings may differ from bulk. Recent investigations have demonstrated that confined crystallization can be used to screen for and control polymorphism. In the food, pharmaceutical, explosive, and dye technological sectors, this understanding and control over polymorphism is critical both for function and for regulatory compliance. This Account reviews recent studies of the polymorphic and thermotropic properties of crystalline materials embedded in the nanometer-scale pores of porous glass powders and porous block-polymer-derived plastic monoliths. The embedded nanocrystals exhibit an array of phase behaviors, including the selective formation of metastable amorphous and crystalline phases, thermodynamic stabilization of normally metastable phases, size-dependent polymorphism, formation of new polymorphs, and shifts of thermotropic relationships between polymorphs. Size confinement also permits the measurement of thermotropic properties that cannot be measured in bulk materials using conventional methods. Well-aligned cylindrical pores of the polymer monoliths also allow determination and manipulation of nanocrystal orientation. In these systems, the constraints imposed by the pore walls result in a competition between crystal nuclei that favors those with the fastest growth direction aligned with the pore axis. Collectively, the examples described in this Account provide substantial insight into crystallization at a size scale that is difficult to realize by other means. Moreover, the behaviors resulting from nanoscopic confinement are remarkably consistent for a wide range of compounds, suggesting a reliable approach to studying the phase behaviors of compounds at the nanoscale. Newly emerging classes of porous materials promise expanded explorations of crystal growth under confinement and new routes to controlling crystallization outcomes.

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Glycine nanocrystals, grown in aligned nanometer-scale cylindrical pores of nanoporous polystyrene-poly(dimethyl acrylamide) monoliths by evaporation of imbibed aqueous solutions, adopt preferred orientations with their fast-growth axes aligned parallel with the pore direction. X-ray diffraction analysis revealed the exclusive formation of the metastable beta-polymorph, with crystal size comparable with the 22 nm pore diameter, in contrast to the formation of alpha-glycine in the absence of nanoscale confinement. When grown from aqueous solutions alone, the nanocrystals were oriented with their [010] and [010] axes, the native fast growth directions of the (+) and (-) enantiomorphs of beta-glycine, respectively, aligned parallel with the pore direction. In contrast, crystallization in the presence of racemic mixtures of chiral auxiliaries known to inhibit growth along the [010] and [010] directions of the enantiomorphs produced beta-glycine nanocrystals with their [001] axes nearly parallel to the pore direction. Enantiopure auxiliaries that inhibit crystallization along the native fast growth direction of only one of the enantiomorphs allow the other enantiomorph to grow with the [010] axis parallel to the cylinder. Collectively, these results demonstrate that crystal growth occurs such that the fast-growing direction, which can be altered by adding chiral auxiliaries, is parallel to the pore direction. This behavior can be attributed to a competition between differently aligned crystals due to critical size effects, the minimization of the surface energy of specific crystal planes, and a more effective reduction of the excess free energy associated with supersaturated conditions when the crystal grows with its fast-growth axis unimpeded by pore walls. These observations suggest that the beta-glycine nanocrystals form by homogeneous nucleation, with minimal influence of the pore walls on orientation.

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A method to calculate the location of all Bragg diffraction peaks from nanostructured thin films for arbitrary angles of incidence from just above the critical angle to transmission perpendicular to the film is reported. At grazing angles, the positions are calculated using the distorted wave Born approximation (DWBA), whereas for larger angles where the diffracted beams are transmitted though the substrate, the Born approximation (BA) is used. This method has been incorporated into simulation code (called NANOCELL) and may be used to overlay simulated spot patterns directly onto two-dimensional (2D) grazing angle of incidence small-angle X-ray scattering (GISAXS) patterns and 2D SAXS patterns. The GISAXS simulations are limited to the case where the angle of incidence is greater than the critical angle (alpha(i) > alpha(c)) and the diffraction occurs above the critical angle (alpha(f) > alpha(c)). For cases of surfactant self-assembled films, the limitations are not restrictive because, typically, the critical angle is around 0.2 degrees but the largest d spacings occur around 0.8 degrees 2theta. For these materials, one finds that the DWBA predicts that the spot positions from the transmitted main beam deviate only slightly from the BA and only for diffraction peaks close the critical angle. Additional diffraction peaks from the reflected main beam are observed in GISAXS geometry but are much less intense. Using these simulations, 2D spot patterns may be used to identify space group, identify the orientation, and quantitatively fit the lattice constants for SAXS data from any angle of incidence. Characteristic patterns for 2D GISAXS and 2D low-angle transmission SAXS patterns are generated for the most common thin film structures, and as a result, GISAXS and SAXS patterns that were previously difficult to interpret are now relatively straightforward. The simulation code (NANOCELL) is written in Mathematica and is available from the author upon request.