Physical therapy for acute and sub-acute low back pain: A systematic review and expert consensus.

OBJECTIVE: To review the effectiveness of different physical therapies for acute and sub-acute low back pain supported by evidence, and create clinical recommendations and expert consensus for physiotherapists on clinical prescriptions. DATA SOURCES: A systematic search was conducted in PubMed and the Cochrane Library for studies published within the previous 15 years. REVIEW METHODS: Systematic review and meta-analysis, randomized controlled trials assessing patients with acute and sub-acute low back pain were included. Two reviewers independently screened relevant studies using the same inclusion criteria. The Physiotherapy Evidence Database and the Assessment of Multiple Systematic Reviews tool were used to grade the quality assessment of randomized controlled trials and systematic reviews, respectively. The final recommendation grades were based on the consensus discussion results of the Delphi of 22 international experts. RESULTS: Twenty-one systematic reviews and 21 randomized controlled trials were included. Spinal manipulative therapy and low-level laser therapy are recommended for acute low back pain. Core stability exercise/motor control, spinal manipulative therapy, and massage can be used to treat sub-acute low back pain. CONCLUSIONS: The consensus statements provided medical staff with appliable recommendations of physical therapy for acute and sub-acute low back pain. This consensus statement will require regular updates after 5-10 years.

The association of the localized pain sensitivity in the residual limb and prosthesis use in male veterans with transtibial amputation.

The association of localized pain sensitivity in the residual limb and prosthesis use has clinical implications, however, rarely been assessed. This study aimed to investigate pain sensitivity and explore its range, variability, and association with prosthesis use alongside other demographic and clinical characteristics of veterans with transtibial amputation. Pain sensitivity was determined as pressure pain threshold (PPT) and pressure tolerance (PT) in 19 male veterans with a mean age of 49.5 years using pressure algometry at 12 anatomical locations on the residual limb. A comparison of pain sensitivity at each location, and among anatomical locations and participants was explored using independent t-test, analysis of variance, and Kruskal-Wallis tests, respectively. Pain sensitivity range (PSR), the difference between PT and PPT, was significantly different (p < 0.05) at mid-patellar tendon, medial tibial flare, and the distal end of the tibia. The lowest PPT and PT (20.5 and 33 Ncm-2, p = 0.13) were recorded at the distal end of the residual limb, and the highest PPT and PT (73.4 and 94.3 Ncm-2, p = 0.03) were recorded at the mid-patellar tendon. Pain sensitivity was significantly different among anatomical locations and participants. The correlation tests (Pearson and partial eta squared) showed non-significant associations of pain sensitivity with participants' demographic and clinical characteristics except for daily prosthesis use. The mid-patellar tendon, medial tibial flare, and distal end of the tibia revealed the lowest pain hypersensitivity due to higher PSR. Longer daily prosthesis use was associated with increased pain sensitivity.

The Convergence of Cell-Based Surface Plasmon Resonance and Biomaterials: The Future of Quantifying Bio-molecular Interactions-A Review.

Cell biology is driven by complex networks of biomolecular interactions. Characterizing the kinetic and thermodynamic properties of these interactions is crucial to understanding their role in different physiological processes. Surface plasmon resonance (SPR)-based approaches have become a key tool in quantifying biomolecular interactions, however conventional approaches require isolating the interacting components from the cellular system. Cell-based SPR approaches have recently emerged, promising to enable precise measurements of biomolecular interactions within their normal biological context. Two major approaches have been developed, offering their own advantages and limitations. These approaches currently lack a systematic exploration of 'best practices' like those existing for traditional SPR experiments. Toward this end, we describe the two major approaches, and identify the experimental parameters that require exploration, and discuss the experimental considerations constraining the optimization of each. In particular, we discuss the requirements of future biomaterial development needed to advance the cell-based SPR technique.

Comparison of Metal-Ammine Compounds Binding to DNA and Heparin. Glycans as Ligands in Bioinorganic Chemistry.

We present spectroscopic and biophysical approaches to examine the affinity of metal-ammine coordination complexes for heparin as a model for heparan sulfate (HS). Similar to nucleic acids, the highly anionic nature of heparin means it is associated in vivo with physiologically relevant cations, and this work extends their bioinorganic chemistry to substitution-inert metal-ammine compounds (M). Both indirect and direct assays were developed. M compounds are competitive inhibitors of methylene blue (MB)-heparin binding, and the change in the absorbance of the dye in the presence or absence of heparin can be used as an indirect reporter of M-heparin affinity. A second indirect assay uses the change in fluorescence of TAMRA-R9, a nonaarginine linked to a fluorescent TAMRA moiety, as a reporter for M-heparin binding. Direct assays are surface plasmon resonance (SPR) and isothermal titration calorimetry (ITC). The Kd values for TriplatinNC-heparin varied to some extent depending on the technique from 33.1 ± 2 nM (ITC) to 66.4 ± 1.3 nM (MB absorbance assay) and 340 ± 30 nM (SPR). The differences are explained by the nature of the technique and the use of heparin of differing molecular weight. Indirect probes using the displacement of ethidium bromide from DNA or, separately, fluorescently labeled oligonucleotide (DNA-Fl) can measure the relative affinities of heparin and DNA for M compounds. These assays showed essentially equivalent affinity of TriplatinNC for heparin and DNA. The generality of these methods was confirmed with a series of mononuclear cobalt, ruthenium, and platinum compounds with significantly lower affinity because of their smaller overall positive charge but in the order [Co(NH3)6]3+ > [Ru(NH3)6]3+ > [Pt(NH3)4]2+. The results on heparin can be extrapolated to glycosoaminoglycans such as HS, emphasizing the relevance of glycan interactions in understanding the biological properties of coordination compounds and the utility of the metalloglycomics concept for extending bioinorganic chemistry to this class of important biomolecules.

Exercise intervention for unilateral amputees with low back pain: study protocol for a randomised, controlled trial.

BACKGROUND: Atraumatic lower limb amputation is a life-changing event for approximately 185,000 persons in the United States each year. A unilateral amputation is associated with rapid changes to the musculoskeletal system including leg and back muscle atrophy, strength loss, gait asymmetries, differential mechanical joint loading and leg length discrepancies. Even with high-quality medical care and prostheses, amputees still develop secondary musculoskeletal conditions such as chronic low back pain (LBP). Resistance training interventions that focus on core stabilization, lumbar strength and dynamic stability during loading have strong potential to reduce LBP and address amputation-related changes to the musculoskeletal system. Home-based resistance exercise programs may be attractive to patients to minimize travel and financial burdens. METHODS/DESIGN: This study will be a single-assessor-blinded, pre-post-test randomised controlled trial involving 40 men and women aged 18-60 years with traumatic, unilateral transtibial amputation. Participants will be randomised to a home-based, resistance exercise group (HBRX) or a wait-list control group (CON). The HBRX will consist of 12 weeks of elastic resistance band and bodyweight training to improve core and lumbopelvic strength. Participants will be monitored via Skype or Facetime on a weekly basis. The primary outcome will be pain severity (11-point Numerical Pain Rating Scale; NRSpain). Secondary outcomes will include pain impact on quality of life (Medical Outcomes Short Form 36, Oswestry Disability Index and Roland Morris Disability Questionnaire), kinematics and kinetics of walking gait on an instrumented treadmill, muscle morphology (muscle thickness of multifidus, transversus abdominis, internal oblique), maximal muscle strength of key lumbar and core muscles, and daily step count. DISCUSSION: The study findings will determine whether a HBRX program can decrease pain severity and positively impact several physiological and mechanical factors that contribute to back pain in unilateral transtibial amputees with chronic LBP. We will determine the relative contribution of the exercise-induced changes in these factors on pain responsiveness in this population. TRIAL REGISTRATION: ClinicalTrials.gov, ID: NCT03300375 . Registered on 2 October 2017.

Muscle activation comparisons between elastic and isoinertial resistance: A meta-analysis.

BACKGROUND: Elastic resistance has been commonly used in the therapeutic and fitness setting; however, the ability of elastic resistance to overload and activate muscles has been questioned because of linear increase in elastic resistance as the device is elongated. The purpose of this meta-analysis was to examine the available literature on muscle activation associated with isoinertial and elastic resistance exercises, and to provide a quantitative summary comparing the two resistance training modes. METHODS: In a random-effects model, the Hedge's g effect size was used to calculate the biased corrected standardized mean difference between the elastic and isoinertial resistance activation of prime movers (agonist), antagonists, assistant movers and stabilizer muscles. FINDINGS: There was a lack of significant difference with the prime movers (effect size=-0.037, confidence interval: -0.202 to 0.128, p=0.660), antagonists (effect size=0.089, confidence interval: -0.112 to 0.290, p=0.385), synergists (effect size=-0.133, confidence interval: -0.342 to 0.076, p=0.213) and stabilizer (effect size=0.142, confidence interval: -0.006 to 0.289, p=0.060) muscle electromyography activity recorded during similar exercises using elastic and isoinertial resistance. INTERPRETATION: Elastic resistance provides similar prime mover, antagonist, assistant movers and stabilizer muscle activation as isoinertial resistance; contradicting the traditional criticism that the elastic band would not elicit comparable levels of muscle activation as isoinertial resistance exercise. Since development of muscle strength is closely related to the duration of muscle tension, relatively equal muscle adaptations could be expected following the two modes of training provided that equal external resistance is employed between the two exercises. LEVEL OF EVIDENCE: 2a.

ECCENTRIC AND CONCENTRIC JUMPING PERFORMANCE DURING AUGMENTED JUMPS WITH ELASTIC RESISTANCE: A META-ANALYSIS.

INTRODUCTION: The initial rapid eccentric contraction of a stretch-shortening cycle (SSC) activity is typically reported to accentuate the subsequent concentric jump performance. Some researchers have rationalized that adding elastic resistance (ER) to explosive type activities (e.g. countermovement jumps and drop jumps) would increase excitatory stretch reflex activity and mechanical recoil characteristics of the musculotendinous tissues. The purpose of this meta-analysis was to examine the available literature on jumping movements augmented with ER and to provide a quantitative summary on the effectiveness of this technique for enhancing acute eccentric and concentric jumping performance. METHODS: In a random-effects model, the Hedges`s g effect size (ES) was used to calculate the biased corrected standardized mean difference between the augmented and similar non-augmented jumps. RESULTS: The results demonstrated that augmented jumps provided a greater eccentric loading compared to free jumps (Hedges`s g ES = 0.237, p = 0.028). However the concentric performance was significantly impaired, particularly if the downward elastic force was used during concentric phase as well (ES = -2.440, p < 0.001). Interestingly, no performance decrement was observed in those studies, which released the bands at the beginning of the concentric phase (ES = 0.397, p = 0.429). DISCUSSION: The authors postulated that the excessive eccentric loading might trigger reflex inhibition, alter the muscle stiffness, increase downward hip displacement and dissipate mechanical recoil properties. These results suggest that the release of elastic force at the beginning of the concentric phase seems to be a critical point to avoid impairment of acute concentric performance in augmented jumps. LEVEL OF EVIDENCE: 2a.

A small molecule agonist of EphA2 receptor tyrosine kinase inhibits tumor cell migration in vitro and prostate cancer metastasis in vivo.

During tumor progression, EphA2 receptor can gain ligand-independent pro-oncogenic functions due to Akt activation and reduced ephrin-A ligand engagement. The effects can be reversed by ligand stimulation, which triggers the intrinsic tumor suppressive signaling pathways of EphA2 including inhibition of PI3/Akt and Ras/ERK pathways. These observations argue for development of small molecule agonists for EphA2 as potential tumor intervention agents. Through virtual screening and cell-based assays, we report here the identification and characterization of doxazosin as a novel small molecule agonist for EphA2 and EphA4, but not for other Eph receptors tested. NMR studies revealed extensive contacts of doxazosin with EphA2/A4, recapitulating both hydrophobic and electrostatic interactions recently found in the EphA2/ephrin-A1 complex. Clinically used as an α1-adrenoreceptor antagonist (Cardura®) for treating hypertension and benign prostate hyperplasia, doxazosin activated EphA2 independent of α1-adrenoreceptor. Similar to ephrin-A1, doxazosin inhibited Akt and ERK kinase activities in an EphA2-dependent manner. Treatment with doxazosin triggered EphA2 receptor internalization, and suppressed haptotactic and chemotactic migration of prostate cancer, breast cancer, and glioma cells. Moreover, in an orthotopic xenograft model, doxazosin reduced distal metastasis of human prostate cancer cells and prolonged survival in recipient mice. To our knowledge, doxazosin is the first small molecule agonist of a receptor tyrosine kinase that is capable of inhibiting malignant behaviors in vitro and in vivo.

Dynamic acromiohumeral interval changes in baseball players during scaption exercises.

HYPOTHESIS: Elevation of the arm during a dynamic scaption exercise will result in a progressive narrowing of the acromiohumeral interval (AHI); however, the addition of a load will not significantly affect the AHI in healthy baseball players. MATERIALS AND METHODS: Thirteen healthy baseball players performed a seated scaption exercise from 0° to 90°, with and without a normalized additional load. Dynamic AHI intervals were measured using digital fluoroscopic videos with the arm at the side, and at 30°, 45°, 60°, and 75° of humeral elevation. RESULTS: The mean AHI for unloaded and loaded scaption decreased significantly (P < .001) from the arm at the side (12.7 mm) until 45° (4.9 mm), further changes in the mean AHI between 45°, 60°, and 75° were not significantly different. Generally, loaded scaption resulted in smaller AHI values at 45°, 60°, and 75°; however, only the differences at 60° (P = .005) and 75° (P = .003) were significant. DISCUSSION: Narrowing of the AHI during dynamic motion was similar to previous reports of static AHI, with the exception of the trend towards widening of the AHI seen at 75° during both conditions. The additional AHI narrowing observed at 60° and 75° during the loaded exercise may indicate that scapular positioning is more influential in this range. CONCLUSION: An additional AHI narrowing of 11% during loaded scaption, did not result in any clinical impingement during the exercise, but may have more serious implications in other healthy and pathologic populations.

Dynamics of loop 1 of domain I in human serum albumin when dissolved in ionic liquids.

We report on the rotational reorientation dynamics associated with loop 1 of domain I within a large multidomain protein (human serum albumin, HSA) when it is dissolved in binary mixtures of ionic liquid (1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C4mim][Tf2N]), 1-butyl-3-methylimidazolium tetrafluoroborate ([C4mim][BF4]), or 1-butyl-3-methylimidazolium hexafluorophosphate ([C4mim][PF6])) and distilled deionized water (ddH2O) as a function of temperature and water loading. In IL/2% ddH2O (v/v) mixtures, loop 1 of domain I is more significantly denatured in comparison to the protein dissolved in aqueous solutions containing strong chemical denaturants (e.g., 8 M guanidine HCl (Gu.HCl) or urea). As water loading increases, there is evidence for progressive refolding of loop 1 of domain I followed by recoupling with domains I, II, and III in the [C4mim][BF4]/ddH2O mixtures at 20 degrees C. Above 30% (v/v) water, where domain I appears refolded, the Ac reporter molecule's semiangle steadily decreases from 35 degrees to 20 degrees with increasing water loading. From the perspective of domain I in HSA, this behavior is similar to the effects of dilution from 4 to 0 M Gu.HCl in aqueous solution. Overall, these results lend insight into the tangle of biocatalytic and structural/dynamical mechanisms that enzymes may undergo in ionic liquid-based systems. It will be particularly motivating to extend this work to include enzyme-attuned ionic liquids shown to improve biocatalytic performance beyond that possible in the native (predominantly aqueous) setting.

Spectroscopic system for direct lanthanide photoluminescence spectroscopy with nanomolar detection limits.

A new spectroscopic system for direct photoluminescence of lanthanide ions (Ln(III)) through electronic transitions within the 4f(n) manifold is described. The system is based on an injection seeded frequency tripled (lambda = 355 nm) Nd:YAG pump laser coupled with a master oscillator power oscillator (MOPO). The MOPO delivers an average pulse energy of approximately 60 mJ/pulse, is continuously tunable from 425 to 690 nm (Signal) and 735 to 1800 nm (Idler) with a linewidth of <0.2 cm(-1), and has a pulse duration of 10-12 ns. Aqueous solutions containing two polyaminocarboxylate complexes, ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA), and Ln(3+) aqua ion for several lanthanides including Eu(III), Tb(III), Dy(III), and Sm(III)) are used as steady-state and time-resolved photoluminescence standards. The versatility of the instrument is demonstrated by excitation scans over a broad visible range for aqueous solutions of complexes of Eu(III), Dy(III), Sm(III), and Tb(III). The Eu(III) excitation band ((7)F(o)-->(5)D(o)) is recorded over a range of complex concentrations that are 1000-fold less than reported previously, including Eu(EDTA) (1.00 nM), Eu(DTPA) (1.00 nM), and Eu(III) aqua ion (50.0 nM). Emission spectra are recorded in the visible range for Ln(III) complexes at pH 6.5 and 1.00 mM. Excited-state lifetimes for the standards were constant as a function of concentration from 10.0 nM to 1.00 mM for Eu(EDTA) and Eu(DTPA) and from 100 nM to 1.00 mM for Eu(III) aqua ion. Photoluminescence lifetimes in H(2)O and D(2)O are recorded and used to calculate the number of bound water molecules for all complexes.

A global benchmark study using affinity-based biosensors.

To explore the variability in biosensor studies, 150 participants from 20 countries were given the same protein samples and asked to determine kinetic rate constants for the interaction. We chose a protein system that was amenable to analysis using different biosensor platforms as well as by users of different expertise levels. The two proteins (a 50-kDa Fab and a 60-kDa glutathione S-transferase [GST] antigen) form a relatively high-affinity complex, so participants needed to optimize several experimental parameters, including ligand immobilization and regeneration conditions as well as analyte concentrations and injection/dissociation times. Although most participants collected binding responses that could be fit to yield kinetic parameters, the quality of a few data sets could have been improved by optimizing the assay design. Once these outliers were removed, the average reported affinity across the remaining panel of participants was 620 pM with a standard deviation of 980 pM. These results demonstrate that when this biosensor assay was designed and executed appropriately, the reported rate constants were consistent, and independent of which protein was immobilized and which biosensor was used.

The local microenvironment surrounding dansyl molecules attached to controlled pore glass in pure and alcohol-modified supercritical carbon dioxide.

We report on the local microenvironment surrounding a free dansyl probe, dansyl attached to controlled pore glass (D-CPG), and dansyl molecules attached to trimethylsilyl-capped CPG (capped D-CPG) in pure and alcohol-modified supercritical CO2. These systems were selected to provide insights into the local microenvironment surrounding a reactive agent immobilized at a silica surface in contact with pure and cosolvent-modified supercritical CO2. Local surface-bound dansyl molecule solvation on the CPG surface depends on the dansyl molecule surface loading, the surface chemistry (uncapped versus capped), the bulk fluid density, and the alcohol gas phase absolute acidity. At high dansyl loadings, the surface-bound dansyl molecules are largely "solvated" by other dansyl molecules and these molecules are not affected significantly by the fluid phase. When the dansyl surface loading decreases, dansyl molecules can be accessed/solvated/wetted by the fluid phase. However, at the lowest dansyl loadings studied, the dansyl molecules are in a fluid inaccessible/restrictive environment and do not sense the fluid phase to any significant degree. In uncapped D-CPG, one can poise the system such that the local concentration of an environmentally less responsible cosolvent (alcohol) in the immediate vicinity of surface-immobilized dansyl molecules can approach 100% even though the bulk solution contains orders of magnitude less of this less environmentally responsible cosolvent. In capped C-CPG, the surface excess is attenuated in comparison to that of uncapped D-CPG. The extent of this cosolvent surface excess is discussed in terms of the dansyl surface loading, the local density fluctuations, the cosolvent and surface silanol gas phase acidities, and the silica surface chemistry. These results also have implications for cleanings, extractions, heterogeneous reactions, separations, and nanomaterial fabrication using supercritical fluids.

A proposal for a new screening paradigm and tool called Exercise Assessment and Screening for You (EASY).

The Exercise Assessment and Screening for You (EASY) is a tool developed to help older individuals, their health care providers, and exercise professionals identify different types of exercise and physical activity regimens that can be tailored to meet the existing health conditions, illnesses, or disabilities of older adults. The EASY tool includes 6 screening questions that were developed based on an expert roundtable and follow-up panel activities. The philosophy behind the EASY is that screening should be a dynamic process in which participants learn to appreciate the importance of engaging in regular exercise, attending to health changes, recognizing a full range of signs and symptoms that might indicate potentially harmful events, and becoming familiar with simple safety tips for initiating and progressively increasing physical activity patterns. Representing a paradigm shift from traditional screening approaches that focus on potential risks of exercising, this tool emphasizes the benefits of exercise and physical activity for all individuals.

Comparison of dansylated aminopropyl controlled pore glass solvated by molecular and ionic liquids.

We compare how (i) four ionic liquids (ILs) (1-butyl-3-methylimidazolium tetrafluoroborate ([C4mim][BF4]), 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C4mim][Tf2N]), 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([C4mpy][Tf2N]), and trihexyltetradecylphosphonium bis(trifluoromethylsulfonyl)imide ([P(C6)3C14][Tf2N])) and (ii) two conventional molecular liquids (methanol and 1-octanol) solvate/wet luminescent organic moieties that are covalently attached to the surface of silica controlled pore glass (CPG). A series of aminopropyl CPG particles that have been covalently tagged with the solvatochromic fluorescent probe group dansyl were used in this study. The results demonstrate that ILs solvate/wet the silica surface differently in comparison to molecular liquids (MLs). Specifically, when comparing ILs and MLs that appear to solvate the free probe, dansylpropylsulfonamide (DPSA), equally in solution, we find that ILs do not solvate/wet the silica surfaces as well as the corresponding MLs. The cation component in these ILs is the significant factor in how the ILs solvate/wet silica surfaces. Solvation/wetting of surface-bound species at a silica surface depends on the cation size. Chlorosilane end-capping of the surface silanol and amine residues attenuates the cation's affects.

A cationic chalcogenoxanthylium photosensitizer effective in vitro in chemosensitive and multidrug-resistant cells.

Pentacyclic thio- (1) and seleno- (2) analogues of tetramethylrosamine (TMR) were prepared with a julolidyl fragment replacing the 3-dimethylamino substituent in the xanthylium core. The pentacylic structure increases the lipophilicity of 1 and 2 relative to TMR-S and TMR-Se and locks the lone-pair of electrons on the julolidyl N atom into conjugation with the xanthylium core. This conformational rigidization leads to longer wavelengths of absorption, but has little impact on other photophysical properties such as quantum yields for fluorescence and singlet-oxygen generation and fluorescence lifetimes in 1 and 2 relative to TMR-S and TMR-Se. Both 1 and 2 are effective photosensitizers against chemosensitive AUXB1 cells in vitro at 1x10(-7)M and compound 2 is an effective photosensitizer against multidrug-resistant CR1R12 cells in vitro at 1x10(-7)M. While the uptake TMR-S into CR1R12 cells as measured by fluorescence is significantly lower than uptake into chemosensitive AUXB1 cells, there is no significant difference in the uptake of 1 into either AUXB1 or CR1R12 cells. The addition of 2x10(-4)M verapamil to the cells prior to treatment with 1 had no significant effect on the uptake of 1 into either AUXB1 or CR1R12 cells. Treating lipid-activated, purified Pgp with 2 and light gave complete inhibition of Pgp ATPase activity.

Dansylated aminopropyl controlled pore glass: a model for silica-liquid solvation.

We have prepared a series of aminopropyl controlled pore glass (CPG) particles that have been labeled with a solvatochromic fluorescent probe molecule (dansyl). We report on the behavior of the attached dansyl reporter as a function of dansyl-to-amine molar ratio (i.e., dansyl loading), solvent dipolarity, and surface-residue end capping. In these experiments, we systematically adjust the dansyl loading by 10(5); a range much larger than ever explored. The dansylated CPG particles were also end capped with trimethylchlorosilane to derivatize most of the residual silanol and/or aminopropyl groups. The attached dansyl molecules can be surrounded by other dansyl molecules; they can be distributed within an ensemble of sites with differing physicochemical properties, and/or they can be distributed in sites that are restrictive to dansyl motion and/or solvent inaccessible. At high dansyl loadings, the majority of the dansyl groups are solvated by other dansyl moieties and solvent does not significantly alter the local microenvironment surrounding the average dansyl molecule (i.e., the cybotactic region) to any significant level. At intermediate dansyl loadings, the average distance between the dansyl groups increases and solvent is able to access/solvate/wet the dansyl groups and alter their cybotactic region to a greater extent. At the lowest dansyl loadings studied, the results suggest that these dansyl moieties are localized within solvent inaccessible/restrictive SiO2 sites (e.g., small pores).