A kaleidoscope of photosynthetic antenna proteins and their emerging roles.

Photosynthetic light-harvesting antennae are pigment-binding proteins that perform one of the most fundamental tasks on Earth, capturing light and transferring energy that enables life in our biosphere. Adaptation to different light environments led to the evolution of an astonishing diversity of light-harvesting systems. At the same time, several strategies have been developed to optimize the light energy input into photosynthetic membranes in response to fluctuating conditions. The basic feature of these prompt responses is the dynamic nature of antenna complexes, whose function readily adapts to the light available. High-resolution microscopy and spectroscopic studies on membrane dynamics demonstrate the crosstalk between antennae and other thylakoid membrane components. With the increased understanding of light-harvesting mechanisms and their regulation, efforts are focusing on the development of sustainable processes for effective conversion of sunlight into functional bio-products. The major challenge in this approach lies in the application of fundamental discoveries in light-harvesting systems for the improvement of plant or algal photosynthesis. Here, we underline some of the latest fundamental discoveries on the molecular mechanisms and regulation of light harvesting that can potentially be exploited for the optimization of photosynthesis.

Associations between delirium and SARS-CoV-2 pandemic visitor restrictions among hospitalized patients.

OBJECTIVES: Delirium is associated with increased morbidity and mortality, but environmental and behavioral factors may decrease the risk of developing delirium and thus must be considered. To investigate trends in delirium prevalence and examine associations of visitor restrictions with delirium diagnoses among all patients hospitalized during and prior to the novel coronavirus SARS-CoV-2 (COVID-19) pandemic. STUDY DESIGN: Retrospective epidemiological assessment. METHODS: The medical records of all patients (n = 33,141) hospitalized within a three-hospital academic medical center system in a large Midwestern metropolitan area from March 20, 2019, through March 19, 2021, were analyzed. RESULTS: The overall prevalence of delirium during COVID-19 was 11.26% (confidence interval [CI]: 10.79%, 11.73%) compared to 9.28% (CI: 8.82%, 9.73%) before COVID-19. From our adjusted logistic regression analyses, we observed that the odds of delirium among non-isolated patients were significantly higher during COVID-19 visitor restrictions (adjusted odds ratio [aOR]: 1.354; 95% CI: 1.233, 1.488; P < 0.0001) than before. The odds of delirium among isolated patients were not significantly higher during COVID-19 visitor restrictions (aOR: 1.145; 95% CI: 0.974, 1.346; P = 0.1006) than before. CONCLUSIONS: Medically isolated patients remained at high risk of developing delirium both prior to and during COVID-19 era visitor restrictions. However, non-medically isolated patients had a significantly increased risk of delirium during the social isolation of visitor restrictions compared to prior to visitor restrictions.

Anterior deltoid muscle reflection using a deltopectoral approach is safe and does not influence outcome of reverse shoulder arthroplasty.

BACKGROUND: The deltopectoral approach is well accepted for shoulder arthroplasty procedures. The extended deltopectoral approach with detachment of the anterior deltoid from the clavicle allows increased joint exposure and can protect the anterior deltoid from traction injury. The efficacy of this extended approach has been demonstrated in anatomic total shoulder replacement surgery. However, this has not been shown in reverse shoulder arthroplasty (RSA). The primary aim of this study was to evaluate the safety of the extended deltopectoral approach in RSA. The secondary aim was to evaluate the performance of the deltoid reflection approach in terms of complications and surgical, functional, and radiologic outcomes up to 24 months after surgery. METHODS: A prospective, nonrandomized comparative study was performed between January 2012 and October 2020 including 77 patients in the deltoid reflection group and 73 patients in the comparative group. The decision for inclusion was based on patient and surgeon factors. Complications were recorded. Patients were followed up for ≥24 months to evaluate their shoulder function and undergo ultrasound evaluation. Functional outcome measures included the Oxford Shoulder Score, Disabilities of the Arm, Shoulder and Hand score, American Shoulder and Elbow Surgeons score, pain intensity (rated on visual analog scale [VAS] from 0 to 100), and range of motion (forward flexion, abduction, and external rotation). A regression analysis was performed to evaluate any factors of influence on the VAS score. RESULTS: There were no significant differences in the complication rate between the 2 groups (14.5% in deltoid reflection group and 13.8% in comparative group, P = .915). Ultrasound evaluation was available in 64 patients (83.1%), and no proximal detachment was observed. In addition, there were no significant differences in functional outcome measures both preoperatively and at 24 months after surgery between the groups assessed based on the mean VAS pain score, Oxford Shoulder Score, Disabilities of the Arm, Shoulder and Hand score, American Shoulder and Elbow Surgeons score, forward flexion, abduction, and external rotation. Adjustment for possible confounders in a regression model indicated that only prior surgery significantly influenced the VAS pain score after surgery (P = .031; 95% confidence interval, 0.574-11.67). Deltoid reflection (P = .068), age (P = .466), sex (P = .936), use of glenoid graft (P = .091), prosthesis manufacturer (P = .382), and preoperative VAS score (P = .362) were not of influence. DISCUSSION: The results of this study show that an extended deltopectoral approach for RSA is safe. Selected reflection of the anterior deltoid muscle improved exposure and prevented anterior deltoid muscle injury followed by reattachment. Patients had similar functional scores preoperatively and at 24 months postoperatively compared with a comparative group. Furthermore, ultrasound evaluation showed intact reattachments.

Ninety-day complication rate based on 532 Latarjet procedures in Dutch hospitals with different operation volumes.

BACKGROUND: In this study, we aimed to provide insight into the 90-day complication rates following the Latarjet procedure. Data from 2015 were collected from multiple hospitals in the Netherlands, with different volumes of Latarjet procedures. Our second aim was to examine which patient and surgical factors were associated with complications. METHODS: We conducted a retrospective chart review of 13 hospitals between 2015 and 2022. Data regarding complications within 90 days of Latarjet procedures were extracted. The effect of sex, age, body mass index (BMI), smoking, previous shoulder operations, fixation material, hospital volume, screw size, and operation time on the complication rate was assessed by multivariable logistic regression analysis. RESULTS: Of the 532 included patients, 58 (10.9%) had complications. The most common complications were material failure (n = 19, 3.6%) and nerve injury (n = 13, 2.4%). The risk of complications was lower for male patients than for female patients (odds ratio, 0.40; 95% confidence interval, 0.21-0.77; P = .006). Age, BMI, smoking, previous shoulder operations, type of fixation material, hospital volume, screw size, and operation time were not associated with complications. CONCLUSION: The 90-day complication rate after the Latarjet procedure was 10.9% and was higher in female patients than in male patients. Age, BMI, smoking, previous shoulder operations, type of fixation material, hospital volume, screw size, and operation time did not affect complication rates. We advise setting up a national registry to prevent under-reporting of complications.

Revealing the architecture of the photosynthetic apparatus in the diatom Thalassiosira pseudonana.

Diatoms are a large group of marine algae that are responsible for about one-quarter of global carbon fixation. Light-harvesting complexes of diatoms are formed by the fucoxanthin chlorophyll a/c proteins and their overall organization around core complexes of photosystems (PSs) I and II is unique in the plant kingdom. Using cryo-electron tomography, we have elucidated the structural organization of PSII and PSI supercomplexes and their spatial segregation in the thylakoid membrane of the model diatom species Thalassiosira pseudonana. 3D sub-volume averaging revealed that the PSII supercomplex of T. pseudonana incorporates a trimeric form of light-harvesting antenna, which differs from the tetrameric antenna observed previously in another diatom, Chaetoceros gracilis. Surprisingly, the organization of the PSI supercomplex is conserved in both diatom species. These results strongly suggest that different diatom classes have various architectures of PSII as an adaptation strategy, whilst a convergent evolution occurred concerning PSI and the overall plastid structure.

Unique organization of photosystem II supercomplexes and megacomplexes in Norway spruce.

Photosystem II (PSII) complexes are organized into large supercomplexes with variable amounts of light-harvesting proteins (Lhcb). A typical PSII supercomplex in plants is formed by four trimers of Lhcb proteins (LHCII trimers), which are bound to the PSII core dimer via monomeric antenna proteins. However, the architecture of PSII supercomplexes in Norway spruce[Picea abies (L.) Karst.] is different, most likely due to a lack of two Lhcb proteins, Lhcb6 and Lhcb3. Interestingly, the spruce PSII supercomplex shares similar structural features with its counterpart in the green alga Chlamydomonas reinhardtii [Kouril et al. (2016) New Phytol. 210, 808-814]. Here we present a single-particle electron microscopy study of isolated PSII supercomplexes from Norway spruce that revealed binding of a variable amount of LHCII trimers to the PSII core dimer at positions that have never been observed in any other plant species so far. The largest spruce PSII supercomplex, which was found to bind eight LHCII trimers, is even larger than the current largest known PSII supercomplex from C. reinhardtii. We have also shown that the spruce PSII supercomplexes can form various types of PSII megacomplexes, which were also identified in intact grana membranes. Some of these large PSII supercomplexes and megacomplexes were identified also in Pinus sylvestris, another representative of the Pinaceae family. The structural variability and complexity of LHCII organization in Pinaceae seems to be related to the absence of Lhcb6 and Lhcb3 in this family, and may be beneficial for the optimization of light-harvesting under varying environmental conditions.

PSI of the Colonial Alga Botryococcus braunii Has an Unusually Large Antenna Size.

PSI is an essential component of the photosynthetic apparatus of oxygenic photosynthesis. While most of its subunits are conserved, recent data have shown that the arrangement of the light-harvesting complexes I (LHCIs) differs substantially in different organisms. Here we studied the PSI-LHCI supercomplex of Botryococccus braunii, a colonial green alga with potential for lipid and sugar production, using functional analysis and single-particle electron microscopy of the isolated PSI-LHCI supercomplexes complemented by time-resolved fluorescence spectroscopy in vivo. We established that the largest purified PSI-LHCI supercomplex contains 10 LHCIs (∼240 chlorophylls). However, electron microscopy showed heterogeneity in the particles and a total of 13 unique binding sites for the LHCIs around the PSI core. Time-resolved fluorescence spectroscopy indicated that the PSI antenna size in vivo is even larger than that of the purified complex. Based on the comparison of the known PSI structures, we propose that PSI in B. braunii can bind LHCIs at all known positions surrounding the core. This organization maximizes the antenna size while maintaining fast excitation energy transfer, and thus high trapping efficiency, within the complex.

Compensatory Movement Patterns Are Based on Abnormal Activity of the Biceps Brachii and Posterior Deltoid Muscles in Patients with Symptomatic Rotator Cuff Tears.

BACKGROUND: Abnormal movement patterns due to compensatory mechanisms have been reported in patients with rotator cuff tears. The long head of the biceps tendon may especially be overactive and a source of pain and could induce abnormal muscle activation in these patients. It is still unknown why some patients with a rotator cuff tear develop complaints and others do not. QUESTIONS/PURPOSES: (1) Which shoulder muscles show a different activation pattern on electromyography (EMG) while performing the Functional Impairment Test-Hand and Neck/Shoulder/Arm (FIT-HaNSA) in patients with a symptomatic rotator cuff tear compared with age-matched controls with an intact rotator cuff? (2) Which shoulder muscles are coactivated on EMG while performing the FIT-HaNSA? METHODS: This comparative study included two groups of people aged 50 years and older: a group of patients with chronic symptomatic rotator cuff tears (confirmed by MRI or ultrasound with the exclusion of Patte stage 3 and massive rotator cuff tears) and a control group of volunteers without shoulder conditions. Starting January 2019, 12 patients with a chronic rotator cuff tear were consecutively recruited at the outpatient orthopaedic clinic. Eleven age-matched controls (randomly recruited by posters in the hospital) were included after assuring the absence of shoulder complaints and an intact rotator cuff on ultrasound imaging. The upper limb was examined using the FIT-HaNSA (score: 0 [worst] to 300 seconds [best]), shoulder-specific instruments, health-related quality of life, and EMG recordings of 10 shoulder girdle muscles while performing a tailored FIT-HaNSA. RESULTS: EMG (normalized root mean square amplitudes) revealed hyperactivity of the posterior deltoid and biceps brachii muscles during the upward phase in patients with rotator cuff tears compared with controls (posterior deltoid: 111% ± 6% versus 102% ± 10%, mean difference -9 [95% confidence interval -17 to -1]; p = 0.03; biceps brachii: 118% ± 7% versus 111% ± 6%, mean difference -7 [95% CI -13 to 0]; p = 0.04), and there was decreased activity during the downward phase in patients with rotator cuff tears compared with controls (posterior deltoid: 89% ± 6% versus 98% ± 10%, mean difference 9 [95% CI 1 to 17]; p = 0.03; biceps brachii: 82% ± 7% versus 89% ± 6%, mean difference 7 [95% CI 0 to 14]; p = 0.03). The posterior deltoid functioned less in conjunction with the other deltoid muscles, and lower coactivation was seen in the remaining intact rotator cuff muscles in the rotator cuff tear group than in the control group. CONCLUSION: Patients with a symptomatic rotator cuff tear show compensatory movement patterns based on abnormal activity of the biceps brachii and posterior deltoid muscles when compared with age-matched controls. The posterior deltoid functions less in conjunction with the other deltoid muscles, and lower coactivation was seen in the remaining intact rotator cuff muscles in the rotator cuff tear group than the control group. CLINICAL RELEVANCE: This study supports the potential benefit of addressing the long head biceps tendon in the treatment of patients with a symptomatic rotator cuff tear. Moreover, clinicians might use these findings for conservative treatment; the posterior deltoid can be specifically trained to help compensate for the deficient rotator cuff.

Complications After Surgical Treatment of Geriatric Ankle Fractures.

The incidence of geriatric ankle fractures is rising and the potential for complications is high in this population. Little is known about factors associated with increased postoperative complications after surgical fixation of ankle fractures in older-age patients. The purpose of this retrospective cohort study was to assess the epidemiology and risk factors for complications after surgically treated ankle fractures in geriatric patients. All patients who were 65 years or older and had a surgically treated ankle fracture were included. Pilon fractures, patients who were initially treated conservatively or who had less than 1 month of follow-up were excluded. Postoperative complications, demographic-, fracture- and surgical data of 282 patients were recorded from two level 2 trauma centers between 2012 and 2017. A total of 87 (30.9%) patients developed a complication, of which wound related complications were most frequently reported. Superficial and deep wound infections were observed in 27 (9.6%) and 18 (6.4%) patients, respectively. Multivariate regression analysis demonstrated increased age to be an independent predictive variable for the occurrence of postoperative complications (odds ratio 1.04; 95% confidence interval 1.00-1.09), while cast immobilization for more than 2 weeks was a protective factor for the development of wound related complications (odds ratio 0.34; 95% confidence interval 0.17-0.66). In conclusion, the incidence of postoperative complications among geriatric patients after surgical treatment of ankle fractures is high and patients should be informed accordingly.

Arthroscopic isolated long head of biceps tenotomy in patients with degenerative rotator cuff tears: mid-term clinical results and prognostic factors.

INTRODUCTION: The long head of biceps tendon is frequently involved in degenerative rotator cuff tears. Therefore, this study explored the clinical results of an isolated biceps tenotomy and identified prognostic factors for improvement in pain and function. MATERIALS AND METHODS: Between 2008 and 2017, an arthroscopic isolated biceps tenotomy was performed on 64 patients with a degenerative rotator cuff tear (> 65 years). Primary outcome was patient-perceived improvement in pain and function. Potential prognostic factors for improvement in pain and function were identified. RESULTS: A perceived improvement in pain was reported in 78% of the patients at three months after surgery and in 75% at a mean follow-up of 4.2 years (1-7 years; n = 55). A perceived improvement in function was observed in 49% of patients at three months and in 76% of patients at follow-up. Patients with a preoperatively normal acromiohumeral distance (> 10 mm) reported an improvement in pain and function significantly more often. Retraction of the supraspinatus tendon Patte 3 was significantly associated with worse functional outcome. CONCLUSIONS: A biceps tenotomy can be a reliable treatment option for patients with symptomatic degenerative cuff tears who fail conservative treatment and have a normal acromiohumeral distance (> 10 mm).

A Technical Introduction to Transmission Electron Microscopy for Soft-Matter: Imaging, Possibilities, Choices, and Technical Developments.

With a significant role in material sciences, physics, (soft matter) chemistry, and biology, the transmission electron microscope is one of the most widely applied structural analysis tool to date. It has the power to visualize almost everything from the micrometer to the angstrom scale. Technical developments keep opening doors to new fields of research by improving aspects such as sample preservation, detector performance, computational power, and workflow automation. For more than half a century, and continuing into the future, electron microscopy has been, and is, a cornerstone methodology in science. Herein, the technical considerations of imaging with electrons in terms of optics, technology, samples and processing, and targeted soft materials are summarized. Furthermore, recent advances and their potential for application to soft matter chemistry are highlighted.

Organization of Plant Photosystem II and Photosystem I Supercomplexes.

In nature, plants are continuously exposed to varying environmental conditions. They have developed a wide range of adaptive mechanisms, which ensure their survival and maintenance of stable photosynthetic performance. Photosynthesis is delicately regulated at the level of the thylakoid membrane of chloroplasts and the regulatory mechanisms include a reversible formation of a large variety of specific protein-protein complexes, supercomplexes or even larger assemblies known as megacomplexes. Revealing their structures is crucial for better understanding of their function and relevance in photosynthesis. Here we focus our attention on the isolation and a structural characterization of various large protein supercomplexes and megacomplexes, which involve Photosystem II and Photosystem I, the key constituents of photosynthetic apparatus. The photosystems are often attached to other protein complexes in thylakoid membranes such as light harvesting complexes, cytochrome b 6 f complex, and NAD(P)H dehydrogenase. Structural models of individual supercomplexes and megacomplexes provide essential details of their architecture, which allow us to discuss their function as well as physiological significance.

Long-term clinical outcome of arthroscopic Bankart repair with suture anchors.

BACKGROUND: The most common surgical technique in traumatic anterior shoulder instability is the arthroscopic Bankart repair, which has excellent short-term results. The long-term results of the arthroscopic Bankart repair are less frequently studied, with a high recurrence rate of 23% to 35%. The aim of this study was to evaluate the medium-term to long-term results of arthroscopic Bankart repair using suture anchors and to identify specific risk factors for recurrent instability. METHODS: Included were 147 patients after traumatic anterior shoulder dislocation who underwent an arthroscopic Bankart repair. The primary outcome was recurrent instability, defined as dislocation or subluxation as perceived by the patients. The secondary outcome was subjective shoulder stability and function as well as quality of life, evaluated using the Western Ontario Shoulder Instability Index, the Simple Shoulder Test, and the 12-Item Short Form Health Survey. Prognostic factors for recurrent instability were analyzed. RESULTS: Recurrent instability occurred in 22% of patients with a mean follow-up of 6.3 years. Survival at 5 and 10 years without recurrent instability was 79% and 78%, respectively (95% confidence interval, 72%-85% and 71%-85%, respectively). The Western Ontario Shoulder Instability Index score, the Simple Shoulder Test score, and the 12-item Short Form Physical Component Summary improved significantly in the nonrecurrence group (P < .001, P = .004, and P = .002, respectively). Younger age and use of fewer than 3 anchors were associated with a higher risk of recurrent dislocation (P = .008 and P = .039, respectively). CONCLUSION: We found an overall recurrent instability rate of 22% (dislocation or subluxation). Good long-term results were observed after arthroscopic Bankart repair in patients older than 20 years with 3 or more suture anchors used.

Appropriate care for orthopedic patients: effect of implementation of the Clinical Practice Guideline for Diagnosis and Treatment of Subacromial Pain Syndrome in the Netherlands.

Background and purpose - The multidisciplinary Clinical Practice Guideline for diagnosis and treatment of subacromial pain syndrome (SAPS) was created in 2012 by the Dutch Orthopedic Association. In brief, it stated that SAPS should preferably be treated nonoperatively. We evaluated the effect of the implementation of the guideline on the number of shoulder surgeries for SAPS in the Netherlands (17 million inhabitants). Patients and methods - An observational study was conducted with the use of aggregated data from the national database of the Dutch Health Authority from 2012 to 2016. Information was collected on patients referred to and seen at orthopedic departments. Data from the following Diagnoses Related Groupings were analyzed: 1450 (tendinitis supraspinatus) and 1460 (rotator cuff tear). Results - In 2016 fewer patients were diagnosed with tendinitis supraspinatus than in 2012-a decrease from 49,491 to 44,662 (10%). Of the patients diagnosed with tendinitis, 14% were treated surgically in 2012; this number dropped to 9% by 2016. More patients with a rotator cuff tear were diagnosed in 2016 than in 2012, an increase from 17,793 to 23,389 (32%), fewer were treated surgically: 30% in 2012, compared with 25% in 2016. Interpretation - After introducing the multidisciplinary Clinical Practice Guideline "Diagnosis and treatment of subacromial pain syndrome," a decrease in shoulder surgeries for related diagnoses was observed in the Netherlands. The introduction and dissemination of this guideline seems to have contributed to the implementation of more appropriate health care and prevention of unnecessary surgeries.

Surgical treatment of Neer type II and type V lateral clavicular fractures: comparison of hook plate versus superior plate with lateral extension: a retrospective cohort study.

PURPOSE: Different fixation methods are used for treatment of unstable lateral clavicle fractures (LCF). Definitive consensus and guidelines for the surgical fixation of LCF have not been established. The aim of this study was to compare patient-reported functional outcome after open reduction and internal fixation with the clavicle hook plate (CHP) and the superior clavicle plate with lateral extension (SCPLE). METHODS: A dual-center retrospective cohort study was performed. All patients operatively treated for unstable Neer type II and type V LCF between 2011 and 2016, with the CHP (n = 23) or SCPLE (n = 53), were eligible for inclusion. The primary outcome was the QuickDASH score. Secondary outcomes were the numerical rating scale (NRS) pain score, complications, and implant removal. RESULTS: A total of 67 patients (88%) were available for the final follow-up. There was a significant difference in bicortical lateral fragment size, 15 mm (± 4, range 6-21) in the CPH group compared to 20 mm (± 8, range 8-43) in the SCPLE group (p ≤ 0.001). There was no significant difference in median QuickDASH score (CHP; 0.00 [IQR 0.0-0.0], SCPLE; 0.00 [IQR 0.0-4.5]; p = 0.073) or other functional outcome scores (NRS at rest; p = 0.373, NRS during activity; p = 0.559). There was no significant difference in median QuickDASH score or other functional outcome scores between Neer type II and type V fractures. There was no significant difference in complication rate, CHP 11% and SCPLE 8% (relative risk 1.26; [95% CI 0.25-6.33; p = 0.777]). The implant removal rate was 100% in the CHP group compared to 42% in the SCPLE group (relative risk 2.40; [95% CI 1.72-3.35; p ≤ 0.001]). CONCLUSION: Both the CHP and SCPLE are effective fixation methods for the treatment of unstable LCF, resulting in excellent patient-reported functional outcome and similar complication rates. SCPLE fixation is an effective fixation method for the treatment of both Neer type II and type V LCF. The SCPLE has a lower implant removal rate. Therefore, if technically feasible, we recommend SCPLE fixation for the treatment of unstable LCF.

Structural variability of plant photosystem II megacomplexes in thylakoid membranes.

Plant photosystem II (PSII) is organized into large supercomplexes with variable levels of membrane-bound light-harvesting proteins (LHCIIs). The largest stable form of the PSII supercomplex involves four LHCII trimers, which are specifically connected to the PSII core dimer via monomeric antenna proteins. The PSII supercomplexes can further interact in the thylakoid membrane, forming PSII megacomplexes. So far, only megacomplexes consisting of two PSII supercomplexes associated in parallel have been observed. Here we show that the forms of PSII megacomplexes can be much more variable. We performed single particle electron microscopy (EM) analysis of PSII megacomplexes isolated from Arabidopsis thaliana using clear-native polyacrylamide gel electrophoresis. Extensive image analysis of a large data set revealed that besides the known PSII megacomplexes, there are distinct groups of megacomplexes with non-parallel association of supercomplexes. In some of them, we have found additional LHCII trimers, which appear to stabilize the non-parallel assemblies. We also performed EM analysis of the PSII supercomplexes on the level of whole grana membranes and successfully identified several types of megacomplexes, including those with non-parallel supercomplexes, which strongly supports their natural origin. Our data demonstrate a remarkable ability of plant PSII to form various larger assemblies, which may control photochemical usage of absorbed light energy in plants in a changing environment.

Solvent Mixing To Induce Molecular Motor Aggregation into Bowl-Shaped Particles: Underlying Mechanism, Particle Nature, and Application To Control Motor Behavior.

Control over dynamic functions in larger assemblies is key to many molecular systems, ranging from responsive materials to molecular machines. Here we report a molecular motor that forms bowl-shaped particles in water and how confinement of the molecular motor affects rotary motion. Studying the aggregation process in a broader context, we provide evidence that, in the case of bowl-shaped particles, the structures are not the product of self-assembly, but a direct result of the mixing a good solvent and a (partial) non-solvent and highly independent of the molecular design. Under the influence of the non-solvent, droplets are formed, of which the exterior is hardened due to the increase in the glass transition temperature by the external medium, while the interior of the droplets remains plasticized by the solvent, resulting in the formation of stable bowl-shaped particles with a fluid interior, a glass-like exterior, and a very specific shape: dense spheres with a hole in their side. Applying this to a bulky first-generation molecular motor allowed us to change its isomerization behavior. Furthermore, the motor shows in situ photo-switchable aggregation-induced emission. Strong confinement prohibits the thermal helix inversion step while altering the energy barriers that determine the rotary motion, such that it introduces a reverse trans- cis isomerization upon heating. These studies show a remarkable control of forward and backward rotary motion by simply changing solvent ratios and extent of confinement.

Biceps Autograft Augmentation for Rotator Cuff Repair: A Systematic Review.

PURPOSE: To improve surgical outcomes in patients with massive cuff defects, different techniques and augmentations are proposed. The biceps tendon is easily available as an autograft. Our aim was to conduct a qualitative systematic review of various methods and surgical techniques that use a biceps autograft (BAG) for rotator cuff repair. Functional outcomes are also reported. We hypothesized that by using a BAG to treat massive rotator cuff tears, a more anatomic and biomechanical reconstruction could be achieved compared with other techniques. METHODS: A qualitative systematic review was conducted (MEDLINE and Embase databases) to inventory surgical techniques for use of a BAG for rotator cuff repair. The following search terms were used for MEDLINE: biceps AND (augment* OR autograft* OR transplantation* OR (cuff AND graft*) OR biceps-incorporat*). Studies were included if the following criteria were fulfilled: description of surgical technique, only human subjects, functional outcomes noted, all study designs except technical notes, and no restrictions on study date. The quality of the studies was assessed in a standardized manner using a tool based on the Cochrane handbook. RESULTS: We identified 981 studies; among these, 8 case series met the inclusion criteria. We identified 6 studies as high quality and 2 as medium quality. Different techniques for harvest and augmentation were used. Some studies left the proximal or distal portion intact, whereas others used it as a free graft. The clinical results of these studies showed significantly improved function, pain relief, and range of motion at follow-up, although this was not compared with a control group. The constructs were intact on magnetic resonance imaging in most patients (82%) within 2 years. CONCLUSIONS: It can be concluded that use of a BAG is an option for augmentation in massive rotator cuff tears, although no definitive recommendations can be given. This is based on Level IV medium- and high-quality studies. LEVEL OF EVIDENCE: Level IV, systematic review of Level IV studies.

Predictive findings on magnetic resonance imaging in patients with symptomatic acromioclavicular osteoarthritis.

BACKGROUND: A magnetic resonance imaging (MRI) scan of the shoulder can have added value in diagnosing symptomatic osteoarthritis of the acromioclavicular (AC) joint. Specific MRI signs have been recognized but not analyzed extensively before. This study aims to identify predictive MRI signs in patients with symptomatic AC osteoarthritis. METHODS: The MRI scans of 70 patients with symptomatic AC osteoarthritis were compared with those of 70 patients with subacromial pain syndrome and no clinical signs of symptomatic AC osteoarthritis. Seven variables were evaluated on the MRI scans of the AC joint: joint space narrowing, inferior osteophytes, joint effusion, osteolysis, bone marrow edema, impression on the supraspinatus, and inferior joint distension. Logistic regression analysis of these variables was performed. RESULTS: The presence of inferior osteophytes, bone marrow edema, impression on the supraspinatus, and inferior joint distension was individually associated with symptomatic AC osteoarthritis. Bone marrow edema was observed only in patients with symptomatic AC osteoarthritis. Multivariate analysis showed a significant association between inferior joint distension, as well as impression on the supraspinatus muscle, and symptomatic AC osteoarthritis. The area under the receiver operating characteristic curve in the multivariate logistic model was 0.839 (95% confidence interval, 0.771 to 0.907). Interobserver and intraobserver variability showed good to excellent κ values (range, 0.68 to 0.88). CONCLUSION: We identified predictive MRI signs in patients with symptomatic AC osteoarthritis. These findings, including bone marrow edema, inferior joint distension, and impression on the supraspinatus muscle, showed good discriminative ability. They are practical and easy to use and can assist the physician in diagnosing symptomatic AC osteoarthritis.