Risk factors for shoulder osteoarthritis with rotator cuff tear in the elderly general population.

HYPOTHESIS AND/OR BACKGROUND: The relationship between shoulder osteoarthritis (OA) and rotator cuff tear (RCT) is unclear. We hypothesized that there is a difference between the pathogenesis of OA complicating RCT and that of RCT complicating OA. In this study, our primary objective was to determine the prevalence of shoulder OA without RCT, RCT without OA, and OA with RCT in the general older population. Our secondary objective was to identify risk factors for the association with OA+RCT in shoulder OA alone or RCT alone, respectively. METHODS: We enrolled patients from the public health checkup conducted in Gunma prefecture (Japan) in 2014. Subjects' shoulder pain at rest, during motion, and at night was evaluated using a questionnaire. Moreover, active and passive range of motions (ROMs) in flexion, abduction, and external rotation were measured. For RCT parameters, we evaluated as no tear, partial-thickness supraspinatus (SSP) tear, full-thickness SSP tear, and SSP-infraspinatus tears. For further analysis, the shoulders were divided into three groups according to the presence of RCT and/or OA: OA, RCT, and OA + RCT groups. Risk factors for OA + RCT were identified in a logistic regression analysis. RESULTS: Overall, 944 of 1148 shoulders were eligible for inclusion. The prevalence rates of shoulder OA, RCT, and OA + RCT were 5.8%, 21.1%, and 4.2%, respectively. Furthermore, 650 shoulders were excluded, and 55, 199, and 40 shoulders had OA, RCT, and OA + RCT, respectively. There were significant differences for age, ROM of active external rotation, strength of abduction, external rotation, and morphology of the rotator tears. However, there were no significant differences for pain visual analog scale score, passive ROM, Simple Shoulder Test, and grades of OA. Older age decreased active ROM in external rotation, and the presence of both subscapularis and SSP-infraspinatus tears was a risk factor for the association of OA with an RCT shoulder. Older age, weaker power in external rotation, and affected dominant side were risk factors for the association of RCT with an OA shoulder. DISCUSSION AND/OR CONCLUSION: This study is the first to report risk factors by considering both shoulder OA and RCT in the general population. Our findings will be useful for the treatment and management of OA and RCT as well as for the prevention of these conditions in the older adults.

A New Platform of B/N-Doped Cyclophanes: Access to a π-Conjugated Block-Type B3 N3 Macrocycle with Strong Dipole Moment and Unique Optoelectronic Properties.

We herein describe a new design principle to achieve B/N-doped cyclophane where an electron-donor block of three triarylamines (Ar3 N) and an acceptor block of three triarylboranes (Ar3 B) are spatially separated on opposite sides of the π-extended ring system. DFT computations revealed the distinct electronic structure of the block-type macrocycle MC-b-B3N3 with a greatly enhanced dipole moment and reduced HOMO-LUMO energy gap in comparison to its analogue with alternating B and N sites, MC-alt-B3N3. The unique arrangement of borane acceptor Ar3 B and amine donor Ar3 N components in MC-b-B3N3 induces exceptionally strong intramolecular charge transfer in the excited state, which is reflected in a largely red-shifted luminescence at 612 nm in solution. The respective linear open-chain oligomer L-b-B3N3 was also synthesized for comparison. Our new approach to donor-acceptor macrocycles offers important fundamental insights and opens up a new avenue to unique optoelectronic materials.

Electrochromic Polycationic Organoboronium Macrocycles with Multiple Redox States.

Polycationic macrocycles are attractive as they display unique molecular switching capabilities arising from their redox properties. Although diverse polycationic macrocycles have been developed, those based on cationic boron systems remain very limited. We present herein the development of novel polycationic macrocycles by introducing organoboronium moieties into a conjugated organoboron macrocyclic framework. These macrocycles consist of four bipyridylboronium units that are connected by fluorene and either electron-deficient arylborane or electron-rich arylamine moieties. Electrochemical studies reveal that the macrocycles undergo reversible multi-step redox processes with transfer of up to 10 electrons. Switchable electrochromic behavior is demonstrated via spectroelectrochemical studies and the observed color changes are rationalized by correlation with computed electronic transitions using DFT methods.

Entropy-Driven Cooperativity in the Guest Binding of an Octaphosphonate Bis-cavitand.

Uncommon entropy-driven cooperativity is reported in the guest binding of an octaphosphonate bis-cavitand. Isothermal titration calorimetry determined the thermodynamic parameters for the 1:2 host-guest binding of bis-cavitands with ammonium guests in methanol, ethanol, 2-propanol, and chloroform. Chloroform drove uncommon entropy-driven cooperative binding, whereas the alcohols resulted in enthalpy-driven noncooperative binding. 1 H NMR studies revealed that each cavity contained six water molecules in chloroform, which were liberated on guest binding. The enthalpy-entropy compensation relationship produced a large positive intrinsic entropy in chloroform, which implies that water desolvation causes a considerable entropic gain by paying an enthalpic penalty due to breaking the hydrogen-bonding networks of the water clusters.

Conformation of K+(Crown Ether) Complexes Revealed by Ion Mobility-Mass Spectrometry and Ultraviolet Spectroscopy.

The conformation and electronic structure of dibenzo-24-crown-8 (DB24C8) complexes with K+ ion were examined by ion mobility-mass spectrometry (IM-MS), ultraviolet (UV) photodissociation (UVPD) spectroscopy in the gas phase, and fluorescence spectroscopy in solution. Three structural isomers of DB24C8 (SymDB24C8, Asym1DB24C8, and Asym2DB24C8) in which the relative positions of the two benzene rings were different from each other were investigated. The IM-MS results at 86 K revealed a clear separation of two sets of conformers for the K+(SymDB24C8) and K+(Asym1DB24C8) complexes whereas the K+(Asym2DB24C8) complex revealed only one set. The two sets of conformers were attributed to the open and closed forms in which the benzene-benzene distances in the complexes were long (>6 Å) and short (<6 Å), respectively. IM-MS at 300 K could not separate the two conformer sets of the K+(SymDB24C8) complex because the interconversion between the open and closed conformations occurred at 300 K and not at 86 K. The crown cavity of DB24C8 was wrapped around the K+ ion in the complex, although the IM-MS results availed direct evidence of rapid cavity deformation and the reconstruction of stable conformers at 300 K. The UVPD spectra of the K+(SymDB24C8) and K+(Asym1DB24C8) complexes at ∼10 K displayed broad features that were accompanied by a few sharp vibronic bands, which were attributable to the coexistence of multiple conformers. The fluorescence spectra obtained in a methanol solution suggested that the intramolecular excimer was formed only in K+(SymDB24C8) among the three complexes because only SymDB24C8 could possibly assume a parallel configuration between the two benzene rings upon K+ encapsulation. The encapsulation methods for K+ ion (the "wraparound" arrangement) are similar in the three structural isomers of DB24C8, although the difference in the relative positions of the two benzene rings affected the overall cross-section. This study demonstrated that temperature-controlled IM-MS coupled with the introduction of appropriate bulky groups, such as aromatic rings to host molecules, could reveal the dynamic aspects of encapsulation in host-guest systems.

Conformational Characteristics of Feet-to-Feet-Connected Biscavitands.

X-ray crystallography of an acetoxy-protected bisresorcinarene and biscavitands possessing phosphonate and dialkylsilyl bridges revealed that the bisresorcinarene and the biscavitands adopt helical forms in the solid state. Helical conformations were also found in solution. The helix-helix interconversions of the biscavitands occurred with high activation barriers of more than 50 kJ mol-1. The activation parameters of the helix-helix interconversions were determined using exchange spectroscopy (EXSY). The positive activation enthalpies and the negative activation entropies suggest that the transition states of the helix-helix interconversion process are most likely more strained and symmetric than the ground states. The compensatory enthalpy-entropy correlation is found in the series of activation parameters, giving rise to a compensation temperature of 254 K.

Intraoperative neuromonitoring during reverse shoulder arthroplasty.

BACKGROUND: The aim of this study was to evaluate the risk of nerve injury with neuromonitoring during reverse total shoulder arthroplasty. MATERIALS: This study included 15 shoulders of 15 patients (11 females and 4 males) who underwent reverse total shoulder arthroplasty. The mean age was 74.8 ± 4.4 years. Nine shoulders had cuff tear arthropathy, 4 had massive rotator cuff tears, 2 had osteoarthritis, and 1 had rheumatoid arthritis. The somatosensory evoked potentials of the median nerve, transcranial motor evoked potentials, and free-electromyograms from 6 upper-extremity muscles were measured intraoperatively. We defined a nerve alert as 50% amplitude attenuation or 10% latency prolongation of the somatosensory evoked potentials and transcranial motor evoked potentials and sustained neurotonic discharge on free-electromyogram. RESULTS: Thirty-one alerts were recorded in 11 patients. The axillary nerve was associated with 17 alerts. Eleven alerts occurred during the glenoid procedure and 5 alerts occurred during the humeral procedure. One patient who did not recover from the alert of the axillary nerve had clinically incomplete paralysis of the deltoid muscle. CONCLUSION: The present findings suggest that the axillary nerve was the nerve most frequently exposed to the risk of injury, especially during glenoid and humeral implantation.

Pseudorotaxanes in the gas phase: structure and energetics of protonated dibenzylamine-crown ether complexes.

We observe UV spectra of protonated dibenzylamine (dBAMH+) and its complexes with 15-crown-5 (dBAMH+-15C5), 18-crown-6 (dBAMH+-18C6), and 24-crown-8 (dBAMH+-24C8) under cold (∼10 K) gas-phase conditions by UV photodissociation (UVPD) and UV-UV hole-burning (HB) spectroscopy. The UVPD spectrum of the dBAMH+-15C5 complex shows an extensive low-frequency progression, which originates from a unique conformation of the dBAMH+ part with benzene rings facing closely to each other, while UVPD and calculation results suggest open conformations of the dBAMH+ part for dBAMH+-18C6 and dBAMH+-24C8. UV-UV HB spectra of the dBAMH+-24C8 complex indicate that there exist at least two conformers; multiple conformations can contribute to high stability of dBAMH+-24C8 pseudorotaxane due to "conformational" entropic effects. The UVPD experiment indicates that the dissociation probability of dBAMH+-24C8 into dBAMH+ and 24C8 is substantially smaller than that of dBAMH+-15C5 and dBAMH+-18C6, which can be related to the barrier height in the dissociation process. The energetics of the dBAMH+-24C8 complex is investigated experimentally with NMR spectroscopy and theoretically with the global reaction route mapping (GRRM) method. An energy barrier of ∼60 kJ mol-1 is present in the pseudorotaxane formation in solution, whereas there is no barrier in the gas phase. In the course of the photodissociation, excited dBAMH+-24C8 complexes can be trapped at many local minima corresponding to multiple conformations. This can result in effective dissipation of internal energy into degrees of freedom not correlated to the dissociation and decrease the dissociation probability for the dBAMH+-24C8 complex in the gas phase. The energy barrier for the pseudorotaxane formation in solution originates not simply from the slippage process but rather from solvent effects on the dBAMH+-24C8 complex.

Synthesis and Structure of Feet-to-Feet Connected Bisresorcinarenes.

Bisresorcinarenes 1a-d were obtained in excellent yields, and 1e was finally obtained in 50% yield. X-ray diffraction analysis showed that 1a and 1b adopted helical conformations, whereas the two resorcinarenes of 1c-e were in parallel orientations in which the clefts of the aliphatic chains entrapped one or two solvent molecules. The conformational study revealed that the helix interconversion between the (P)- and (M)-helical conformers depended on the length of the aliphatic chains. 1a had the largest energetic barrier to helix interconversion, while in 1b, its more flexible aliphatic chains lowered its energetic barriers. The P/M interconversion of 1a was coupled with the clockwise/anticlockwise interconversion of the interannular hydrogen bonding of the two resorcinarenes. The large negative entropic contributions indicate that the transition state is most likely more ordered than the ground states, suggesting that the transition state is most likely symmetric and is solvated by water molecules. Calculations at the M06-2X/6-31G(d,p) level revealed that the more stable (P)-conformation has clockwise interannular hydrogen bonding between the two resorcinarenes.

Prospective multifactorial analysis of preseason risk factors for shoulder and elbow injuries in high school baseball pitchers.

PURPOSE: To prospectively identify preseason physical factors for shoulder and elbow injuries during the season in high school baseball pitchers. METHODS: The study included 105 high school baseball pitchers [median age 16 (15-17) years]. The range of motion of the shoulder (90° abducted external and internal rotation) and elbow (extension/flexion), shoulder muscle strength (abduction and prone internal and external rotation), shoulder and elbow laxity, horizontal flexion, and scapular dyskinesis were assessed. After the season, the participants completed questionnaires regarding shoulder and/or elbow injuries, with injury defined as an inability to play for ≥1 week due to elbow/shoulder problems. The results of two groups (injured and noninjured) were compared using t tests and Chi-square analyses. Stepwise forward logistic regression models were developed to identify risk factors. RESULTS: Twenty-one injuries were observed. In univariate analysis, 90° abducted internal rotation and total arc of the dominant shoulder and the ratio of prone external rotation in the dominant to nondominant sides in the injured group were significantly less than those in the noninjured group (P = 0.02, 0.04, and 0.01, respectively). In logistic regression analysis, 90° abducted internal rotation in the dominant shoulder and prone external rotation ratio were significantly associated with injuries (P = 0.02 and 0.03, respectively). CONCLUSION: A low prone external rotation ratio and decreased 90° abducted internal rotation in the dominant shoulder in the preseason were significant risk factors for shoulder and elbow injuries in high school baseball pitchers. The results may contribute to reduce the incidence of these injuries. LEVEL OF EVIDENCE: II.

Does successful rotator cuff repair improve muscle atrophy and fatty infiltration of the rotator cuff? A retrospective magnetic resonance imaging study performed shortly after surgery as a reference.

BACKGROUND: Muscle atrophy and fatty infiltration in the rotator cuff muscles are often observed in patients with chronic rotator cuff tears. The recovery from these conditions has not been clarified. METHODS: Ninety-four patients were included in this study. The improvement in muscle atrophy and fatty infiltration in successfully repaired rotator cuff tears was evaluated by magnetic resonance imaging at 1 year and 2 years after surgery and was compared with muscle atrophy and fatty infiltration observed on magnetic resonance imaging at 2 weeks after surgery to discount any changes due to the medial retraction of the torn tendon. The patients' muscle strength was evaluated in abduction and external rotation. RESULTS: Muscle atrophy and fatty infiltration of the supraspinatus were significantly improved at 2 years after surgery in comparison to 2 weeks after surgery. The subjects' abduction and external rotation strength was also significantly improved at 2 years after surgery in comparison to the preoperative values. Patients whose occupation ratio was improved had a better abduction range of motion, stronger abduction strength, and higher Constant score. Patients whose fatty infiltration was improved had a better range of motion in flexion and abduction, whereas the improvements of muscle strength and the Constant score were similar in the group that showed an improvement of fatty infiltration and the group that did not. CONCLUSION: Muscle atrophy and fatty infiltration can improve after rotator cuff repair. The strengths of abduction and external rotation were also improved at 2 years after surgery.

Compensatory hypertrophy of the teres minor muscle after large rotator cuff tear model in adult male rat.

BACKGROUND: Rotator cuff tear (RCT) is a common musculoskeletal disorder in the elderly. The large RCT is often irreparable due to the retraction and degeneration of the rotator cuff muscle. The integrity of the teres minor (TM) muscle is thought to affect postoperative functional recovery in some surgical treatments. Hypertrophy of the TM is found in some patients with large RCTs; however, the process underlying this hypertrophy is still unclear. The objective of this study was to determine if compensatory hypertrophy of the TM muscle occurs in a large RCT rat model. METHODS: Twelve Wistar rats underwent transection of the suprascapular nerve and the supraspinatus and infraspinatus tendons in the left shoulder. The rats were euthanized 4 weeks after the surgery, and the cuff muscles were collected and weighed. The cross-sectional area and the involvement of Akt/mammalian target of rapamycin (mTOR) signaling were examined in the remaining TM muscle. RESULTS: The weight and cross-sectional area of the TM muscle was higher in the operated-on side than in the control side. The phosphorylated Akt/Akt protein ratio was not significantly different between these sides. The phosphorylated-mTOR/mTOR protein ratio was significantly higher on the operated-on side. CONCLUSION: Transection of the suprascapular nerve and the supraspinatus and infraspinatus tendons activates mTOR signaling in the TM muscle, which results in muscle hypertrophy. The Akt-signaling pathway may not be involved in this process. Nevertheless, activation of mTOR signaling in the TM muscle after RCT may be an effective therapeutic target of a large RCT.

The morphologic change of the ulnar collateral ligament of elbow in high school baseball pitchers, with and without symptoms, by sonography.

BACKGROUND: Few reports in the literature relate morphologic changes of the ulnar collateral ligament (UCL) to prior elbow symptoms. This study used ultrasonography (US) to assess the ulnohumeral joint space width, with and without stress, and elucidate morphologic changes of the UCL of the elbow in high school pitchers with and without a history of elbow symptoms. METHODS: Each of 122 high school baseball pitchers who underwent US of the medial aspect of both elbows completed a self-administered questionnaire related to the self-satisfaction score (0-100) for pitching performance and throwing-related elbow joint pain sustained during the prior 3 years. We conducted gravity stress US elbow examination with 30° of flexion with and without valgus stress. Comparisons of the UCL thickness and ulnohumeral joint space width, with and without valgus stress, were made among the 122 high school pitchers with and without a history of elbow symptoms. RESULTS: Pitchers with an elbow symptom history exhibited a greater difference between the UCL thickness on the throwing side than those with no elbow symptom history (P = .0013). A negative significant association was found between UCL thickness on the pitching side and the self-evaluation score for pitching performance (r = -0.20, P = .04). CONCLUSIONS: US assessment demonstrated that the UCL in the dominant side with elbow symptom history was thicker than that with no elbow symptom history. The UCL thickness might reflect the prior pitching condition of high school baseball pitchers.

The impact of faulty posture on rotator cuff tears with and without symptoms.

HYPOTHESIS: We hypothesized that the prevalence of rotator cuff tears would be higher among individuals with poor posture, regardless of the presence of symptoms. METHODS: The study initially comprised 525 residents of a mountain village who participated in an annual health check. Participants completed a background questionnaire, and physical examinations were performed to evaluate shoulder function. Ultrasonographic examinations were also performed to identify rotator cuff tears, and participants were grouped according to the presence or absence of tears. Posture was classified by 2 observers into 4 types according to the classification of Kendall, as follows: ideal alignment, kyphotic-lordotic posture, flat-back posture, and sway-back posture. Univariate analyses were performed to compare differences in background characteristics between groups, then multivariate analysis was performed to identify those factors associated with rotator cuff tears. RESULTS: Final analysis was performed for 379 participants (135 men, 244 women; mean age, 62.0 years; range, 31-94 years) showing the same posture classification from both observers. Of these, 93 (24.5%) showed rotator cuff tear in one shoulder and 45 (11.9%) showed tears in both. Prevalence of rotator cuff tears was 2.9% with ideal alignment, 65.8% with kyphotic-lordotic posture, 54.3% with flat-back posture, and 48.9% with sway-back posture. Logistic regression analysis identified increased age, abnormal posture, and past pain as factors associated with rotator cuff tears. CONCLUSIONS: Postural abnormality represented an independent predictor of both symptomatic and asymptomatic rotator cuff tears. These results may help define preventive measures for rotator cuff tears and in design ing rehabilitation therapies for shoulder disease.

Prevalence of and risk factors for shoulder osteoarthritis in Japanese middle-aged and elderly populations.

BACKGROUND: The purpose of this study was to determine the prevalence of shoulder osteoarthritis (OA) in populations older than 40 years and to examine risk factors and the relationship with shoulder function. METHODS: The respondents in this study consisted of 541 patients who underwent general medical examinations in April 2012 as residents of a single village. The mean age was 65.2 ± 11.0 years (range, 40-89 years), and 341 (63.0%) of the respondents were women. Anteroposterior radiographs of the bilateral shoulder joints were obtained, and the subjects were classified into 3 groups (non-OA, mild OA, and moderate-severe OA) according to the Samilson-Prieto method. With respect to risk factors for shoulder OA, a logistic regression analysis was performed. RESULTS: Shoulder OA was detected in 17.4% (94 of 541) of the patients. The incidence of OA in both shoulders was 3.1% (17 of 541), and the prevalence of shoulder OA among the respondents 65 years of age or older (20.3%) was significantly higher than that observed among the respondents younger than 65 years (11.1%). The risk of shoulder OA increased according to age, with an odds ratio of 5.59 in the respondents 60 to 69 years of age (P = .027), 11.59 in the respondents 70 to 79 years of age (P = .004), and 10.77 in the respondents 80 years of age and older (P = .004). CONCLUSIONS: The prevalence of shoulder OA was 17.4%, and the risk factor for shoulder OA was age.

Synthesis of Network Biobased Aliphatic Polyesters Exhibiting Better Tensile Properties than the Linear Polymers by ADMET Polymerization in the Presence of Glycerol Tris(undec-10-enoate).

Development of biobased aliphatic polyesters with better mechanical (tensile) properties in film has attracted considerable attention. This report presents the synthesis of soluble network biobased aliphatic polyesters by acyclic diene metathesis (ADMET) polymerization of bis(undec-10-enyl)isosorbide diester [M1, dianhydro-D-glucityl bis(undec-10-enoate)] in the presence of a tri-arm crosslinker [CL, glycerol tris(undec-10-enoate)] using a ruthenium-carbene catalyst, and subsequent olefin hydrogenation using RhCl(PPh3)3. The resultant polymers, after hydrogenation (expressed as HCP1) and prepared in the presence of 1.0 mol% CL, showed better tensile properties than the linear polymer (HP1) with similar molecular weight [tensile strength (elongation at break): 20.8 MPa (282%) in HP1 vs. 35.4 MPa (572%) in HCP1]. It turned out that the polymer films prepared by the addition of CL during the polymerization (expressed as a 2-step approach) showed better tensile properties. The resultant polymer film also shows better tensile properties than the conventional polyolefins such as linear high density polyethylene, polypropylene, and low density polyethylene.

Synthesis of High Molecular Weight Biobased Aliphatic Polyesters Exhibiting Tensile Properties Beyond Polyethylene.

Synthesis of high molecular weight polyesters prepared by acyclic diene metathesis (ADMET) polymerization of bis(undec-10-enoate) with isosorbide (M1), isomannide (M2), and 1,3-propanediol (M3) and the subsequent hydrogenation have been achieved by using a molybdenum-alkylidene catalyst. The resultant polymers (P1) prepared by the ADMET polymerization of M1 (in toluene at 25 °C) possessed high Mn values (Mn = 44400-49400 g/mol), and no significant differences in the Mn values and the PDI (Mw/Mn) values were observed in the samples after the hydrogenation. Both the tensile strength and the elongation at break in the hydrogenated polymers from M1 (HP1) increased upon increasing the molar mass, and the sample with an Mn value of 48200 exhibited better tensile properties (tensile strength of 39.7 MPa, elongation at break of 436%) than conventional polyethylene, polypropylene, as well as polyester containing C18 alkyl chains. The tensile properties were affected by the diol segment employed, whereas HP2 showed a similar property to HP1.

Electrophilic and nucleophilic displacement reactions at the bridgehead borons of tris(pyridyl)borate scorpionate complexes.

Although a wide variety of boron-based "scorpionate" ligands have been implemented, a modular route that offers facile access to different substitution patterns at boron has yet to be developed. Here, we demonstrate new reactivity patterns at the bridgehead positions of a ruthenium tris(pyrid-2-yl)borate complex that allow for facile tuning of steric and electronic properties.

Neuroplasticity Caused by Peripheral Proprioceptive Deficits.

PURPOSE: Proprioceptive feedback is crucial for motor control and stabilization of the shoulder joint in everyday life and sports. Shoulder dislocation causes anatomical and proprioceptive feedback damage that contributes to subsequent dislocations. Previous recurrent anterior shoulder instability (RSI) studies did not investigate functional neuroplasticity related to proprioception of the injured shoulder. Thus, we aimed to study the differences in neuroplasticity related to motor control between patients with RSI and healthy individuals, using functional magnetic resonance imaging, and assess the effects of peripheral proprioceptive deficits due to RSI on CNS activity. METHODS: Using passive shoulder motion and voluntary shoulder muscles contraction tasks, we compared the CNS correlates of proprioceptive activity between patients having RSI (n = 13) and healthy controls (n = 12) to clarify RSI pathophysiology and the effects of RSI-related peripheral proprioceptive deficits on CNS activity. RESULTS: Decreased proprioception-related brain activity indicated a deficient passive proprioception in patients with RSI (P < 0.05 family-wise error, cluster level). Proprioceptive afferent-related right cerebellar activity significantly negatively correlated with the extent of shoulder damage (P = 0.001, r = -0.79). Functional magnetic resonance imaging demonstrated abnormal motor control in the CNS during voluntary shoulder muscles contraction. CONCLUSION: Our integrated analysis of peripheral anatomical information and brain activity during motion tasks can be used to investigate other orthopedic diseases.

Negative Cooperativity in Guest Binding of a Ditopic Self-Folding Biscavitand.

A brand-new self-folding biscavitand was synthesized from a feet-to-feet-connected bisresorcinarene. The X-ray crystal structure of the biscaivtand showed that the two cavities are tightly connected with four butylene linkages. The conformationally coupled two cavities accommodated two cationic guests, showing a homotropic negative cooperativity in nonpolar solvents (toluene and chloroform). A polar tetrahydrofuran solvent weakened the cyclic hydrogen bonding interactions of the biscavitand, which resulted in noncooperative guest binding.