Controlled patterning of crystalline domains by frontal polymerization.

Materials with hierarchical architectures that combine soft and hard material domains with coalesced interfaces possess superior properties compared with their homogeneous counterparts1-4. These architectures in synthetic materials have been achieved through deterministic manufacturing strategies such as 3D printing, which require an a priori design and active intervention throughout the process to achieve architectures spanning multiple length scales5-9. Here we harness frontal polymerization spin mode dynamics to autonomously fabricate patterned crystalline domains in poly(cyclooctadiene) with multiscale organization. This rapid, dissipative processing method leads to the formation of amorphous and semi-crystalline domains emerging from the internal interfaces generated between the solid polymer and the propagating cure front. The size, spacing and arrangement of the domains are controlled by the interplay between the reaction kinetics, thermochemistry and boundary conditions. Small perturbations in the fabrication conditions reproducibly lead to remarkable changes in the patterned microstructure and the resulting strength, elastic modulus and toughness of the polymer. This ability to control mechanical properties and performance solely through the initial conditions and the mode of front propagation represents a marked advancement in the design and manufacturing of advanced multiscale materials.

Impact of Stenting Long Lesions on Clinical Outcomes in Patients Presenting With Acute Coronary Syndrome and Multivessel Disease: Data From the BIOVASC Trial.

An increased total stent length (TSL) might be associated with a higher risk of clinical events; however, in patients with multivessel disease (MVD), a considerable TSL is often required. In patients presenting with acute coronary syndrome and MVD, immediate complete revascularization was associated with shorter TSL in the BIOVASC Trial. This is a subanalysis of the BIOVASC trial comparing clinical outcomes in patients with either <60 or ≥60 mm TSL. The primary outcome was a composite of all-cause mortality, myocardial infarction, any unplanned ischemia driven revascularization, or cerebrovascular events at 2 years after the index procedure. A total of 1,525 patients were enrolled in the BIOVASC trial, of whom 855 had a TSL of ≥60 mm (long TSL). No significant difference was established when comparing patients treated with either long or short TSL in terms of the primary outcome at 2-year follow-up, which occurred in 117 patients (13.7%) in the ≥60 mm group and 69 patients (10.3%) in the <60 mm group (adjusted hazard ratio 1.25, 95% confidence interval 0.92 to 1.69, p = 0.16). Furthermore, no significant differences were observed in the secondary end points. In conclusion, in patients with acute coronary syndrome and MVD, long stenting did not show a significant difference in clinical event rate compared with short stenting.

CDK5-cyclin B1 regulates mitotic fidelity.

CDK1 has been known to be the sole cyclin-dependent kinase (CDK) partner of cyclin B1 to drive mitotic progression1. Here we demonstrate that CDK5 is active during mitosis and is necessary for maintaining mitotic fidelity. CDK5 is an atypical CDK owing to its high expression in post-mitotic neurons and activation by non-cyclin proteins p35 and p392. Here, using independent chemical genetic approaches, we specifically abrogated CDK5 activity during mitosis, and observed mitotic defects, nuclear atypia and substantial alterations in the mitotic phosphoproteome. Notably, cyclin B1 is a mitotic co-factor of CDK5. Computational modelling, comparison with experimentally derived structures of CDK-cyclin complexes and validation with mutational analysis indicate that CDK5-cyclin B1 can form a functional complex. Disruption of the CDK5-cyclin B1 complex phenocopies CDK5 abrogation in mitosis. Together, our results demonstrate that cyclin B1 partners with both CDK5 and CDK1, and CDK5-cyclin B1 functions as a canonical CDK-cyclin complex to ensure mitotic fidelity.

A qualitative analysis of parents' beliefs about portable pool safety behaviours.

The aim of this study was to develop an in-depth understanding of the beliefs parents hold regarding portable pool safety behaviours using the theory of planned behaviour (TPB). Semi-structured interviews were conducted with parents (N = 15) of children aged 5 years and younger who owned a portable pool. Interviews examined three key safety behaviours: supervising within arms' reach, fencing portable pools deeper than 30 cm, and emptying and storing portable pools safely after use. Parents identified a range of advantages, disadvantages, normative influences, and facilitators and barriers towards the three behaviours. The identification of these salient behavioural, normative, and control beliefs enrich limited understandings of portable pool safety behaviours of parents with young children. Current findings fill a knowledge gap in portable pool safety and provide potential targets for messages to improve parents' behaviours for their young children around portable pools in the hope of preventing loss of life.

Variation of skin hydration profile with biophysical factors and lifestyle revealed by in vivo terahertz sensing.

The skin, being the body's largest organ, plays a pivotal role in protecting the body against dangerous external factors. The maintenance of adequate hydration levels is essential for the skin to fulfill this protective function. However, skin hydration depends upon different biophysical factors and lifestyles, such as ethnicity, sex, age, water consumption, and many more. Consequently, methods to assess skin hydration in a precise and non-invasive manner are in high demand. In this paper, using a portable and handheld terahertz (THz) probe, we systematically examine the correlation between diverse biophysical factors and skin hydration profile in a population exceeding 300 participants. Through comparative analysis of THz light reflected from the skin against a dielectric model, we successfully extracted the thickness and hydration percentage of the outermost layer of the epidermis, the stratum corneum (SC). Our findings indicate that SC hydration and thickness are associated with variables such as daily water consumption, age, drinking coffee, and exercise. Additionally, our measurements reveal distinctions in the skin's hydration properties concerning susceptibility to UV-induced effects by bringing in the Fitzpatrick skin types. This THz-based technique holds the potential for facile integration into clinical settings for the evaluation and diagnosis of various skin-related conditions.

Effects of Glial Derived Neurotrophic Factor on Remodeling and Mitochondrial Function in Human Airway Smooth Muscle Cells.

Airway smooth muscle (ASM) cells play important roles in airway remodeling of asthma. Our previous studies show that in vivo administration of glial derived neurotrophic factor (GDNF) in mice induces thickening and collagen deposition in bronchial airways, while chelation of GDNF by GFRα1-Fc attenuates airway remodeling in the context of allergen exposure. To determine whether GDNF has direct effects on ASM, in this study, we examined GDNF in ASM cells from normal vs. asthmatic humans. We found that GDNF treatment of human ASM cells had only minor effects on cell proliferation, intracellular expression or extracellular deposition of collagen I, collagen III, and fibronectin. Endoplasmic reticulum (ER) stress response and mitochondrial function have been implicated in asthma. We investigated whether GDNF regulates these aspects in human ASM. We found that GDNF treatment did not affect ER stress protein expression in normal or asthmatic cells. However, GDNF treatment impaired mitochondrial morphology in ASM but without significant effects on mitochondrial respiration. Thus, it is likely that in vivo effects of GDNF on airway remodeling per se involve cell types other than those on ASM, and thus ASM may serve more as a source of GDNF rather than a target.

Idiosyncratic genome evolution of the thermophilic cyanobacterium Synechococcus at the limits of phototrophy.

Thermophilic microorganisms are expected to have smaller cells and genomes compared with mesophiles, a higher proportion of horizontally acquired genes, and distinct nucleotide and amino acid composition signatures. Here, we took an integrative approach to investigate these apparent correlates of thermophily for Synechococcus A/B cyanobacteria, which include the most heat-tolerant phototrophs on the planet. Phylogenomics confirmed a unique origin of different thermotolerance ecotypes, with low levels of continued gene flow between ecologically divergent but overlapping populations, which has shaped the distribution of phenotypic traits along these geothermal gradients. More thermotolerant strains do have smaller genomes, but genome reduction is associated with a decrease in community richness and metabolic diversity, rather than with cell size. Horizontal gene transfer played only a limited role during Synechococcus evolution, but, the most thermotolerant strains have acquired a Thermus tRNA modification enzyme that may stabilize translation at high temperatures. Although nucleotide base composition was not associated with thermotolerance, we found a general replacement of aspartate with glutamate, as well as a dramatic remodeling of amino acid composition at the highest temperatures that substantially differed from previous predictions. We conclude that Synechococcus A/B genome diversification largely does not conform to the standard view of temperature adaptation. In addition, carbon fixation was more thermolabile than photosynthetic oxygen evolution for the most thermotolerant strains compared with less tolerant lineages. This suggests that increased flow of reducing power generated during the light reactions to an electron sink(s) beyond carbon dioxide has emerged during temperature adaptation of these bacteria.

Wilkie's syndrome in a patient with Duchenne's muscular dystrophy: A Case Report.

Superior mesenteric artery syndrome, or Wilkie's syndrome, is one of the rarest gastrointestinal disorders known to medical science. It is characterized by the vascular clamp of the third portion of the duodenum, between the superior mesenteric artery and the aorta. It presents as an uncommon cause of upper intestinal obstruction. Imaging is required, preferably with a contrast-enhanced CT or an MRI; conservative management is preferred, leaving surgery for the most complex cases. We present the case of a 34-year-old man with Duchenne's muscular dystrophy and a history of substantial weight loss after hospital admission for aspiration pneumonia. He underwent an abdominal CT scan that showed enlargement of the stomach, the second and third parts of the duodenum; without observing masses, the patient received conservative management with a nasojejunal feeding tube. At the outpatient reevaluation, 1 month postdischarge, he became asymptomatic and had progressive weight gain.

Real-world impact of transitioning from one lipoprotein(a) assay to another in a clinical setting.

Background and aims: Different lipoprotein(a) [Lp(a)] assays may affect risk stratification of individuals and thus clinical decision-making. We aimed to investigate how transitioning between Lp(a) assays at a large central laboratory affected the proportion of individuals with Lp(a) result above clinical thresholds. Methods: We studied nationwide clinical laboratory data including 185,493 unique individuals (47.7 % women) aged 18-50 years with 272,463 Lp(a) measurements using Roche (2000-2009) and Siemens Lp(a) assay (2009-2019). Results: While the majority of individuals (66-75 %) had low levels of Lp(a) (<30 mg/dL) independent of the assay used, the Roche assay detected 20 % more individuals with Lp(a) >50 mg/dL, 40 % more individuals with Lp(a) >100 mg/dL and 80 % more individuals with Lp(a) > 180 mg/dL than the currently used Siemens assay, likely due to calibration differences. Conclusion: Transitioning from one Lp(a) immunoassay to another had significant impact on Lp(a) results, particularly in individuals approaching clinically relevant Lp(a) thresholds.

Early Circulating Tumor DNA Shedding Kinetics for Prediction of Platinum Sensitivity in Patients With Small Cell Lung Cancer.

PURPOSE: Small cell lung cancer (SCLC) is characterized by rapid progression after platinum resistance. Circulating tumor (ctDNA) dynamics early in treatment may help determine platinum sensitivity. MATERIALS AND METHODS: Serial plasma samples were collected from patients receiving platinum-based chemotherapy for SCLC on the first 3 days of cycle one and on the first days of subsequent cycles with paired samples collected both before and again after infusions. Tumor-informed plasma analysis was carried out using CAncer Personalized Profiling by deep Sequencing (CAPP-Seq). The mean variant allele frequency (VAF) of all pretreatment mutations was tracked in subsequent blood draws and correlated with radiologic response. RESULTS: ctDNA kinetics were assessed in 122 samples from 21 patients. Pretreatment VAF did not differ significantly between patients who did and did not respond to chemotherapy (mean 22.5% v 4.6%, P = .17). A slight increase in ctDNA on cycle 1, day 1 immediately post-treatment was seen in six of the seven patients with available draws (fold change from baseline: 1.01-1.44), half of whom achieved a response. All patients who responded had a >2-fold decrease in mean VAF on cycle 2 day 1 (C2D1). Progression-free survival (PFS) and overall survival (OS) were significantly longer in patients with a >2-fold decrease in mean VAF after one treatment cycle (6.8 v 2.6 months, log-rank P = .0004 and 21.7 v 6.4 months, log rank P = .04, respectively). CONCLUSION: A >2-fold decrease in ctDNA concentration was observed by C2D1 in all patients who were sensitive to platinum-based therapy and was associated with longer PFS and OS.

Complete morphologic response to gilteritinib in ALK-rearranged acute myeloid leukemia.

The cytogenetic abnormality inv(2)(p23q13) in acute myeloid leukemia (AML) results in a fusion of RANBP2 with ALK. This fusion makes ALK constitutively active and acts as a driver for the proliferation of AML cell lines. Gilteritinib, a FLT3 inhibitor approved in AML, also can inhibit ALK among other receptor tyrosine kinases. A 75-year-old-woman with a history of essential thrombocythemia (ET) and a presumed germline DDX41 mutation developed ALK-fusion positive AML and despite standard therapies was transfusion-dependent and globally declining. The patient has been on gilteritinib with an ongoing response of more than one year with near normal blood counts and no evidence of AML. The fact that she was found to harbor a presumed germline DDX41 alteration may account for why she developed, and yet survived, two myeloid neoplasms (ET and AML). Additionally, this demonstrates that gilteritinib is clinically active as an ALK inhibitor, and could be considered for use in any AML patient presenting with an inv(2(p23q13)) translocation. Finally, it is an example of using a disease-agnostic, precision medicine approach to arrive at a beneficial treatment.

Treatment of Plagiocephaly With Orthotic Helmets: Prevalence, Costs, and Inequities in Massachusetts.

Positional plagiocephaly is a craniofacial condition resulting from infant positioning that applies pressure consistently to a part of the skull. This study analyzed the prevalence of, and costs associated with orthotic helmet treatment for positional plagiocephaly and assessed inequities in treatment between medically underserved areas (MUAs) and non-MUAs using health insurance claims data from the Center for Health Information and Analysis (CHIA) in Massachusetts for the years 2016-2021. The mean percentage of patients receiving orthotic helmet therapy was 4.3% (SD=0.49, 95% CI=3.88-4.91, P=0.44). MUAs contained 37.2% of patients with positional plagiocephaly and 2.9% of MUA patients were treated with helmets compared with 5.2% of non-MUA patients (P<0.01). There was a significant decline in the percentage of patients prescribed helmeting therapy over the course of the study (P<0.01). The average copay amount for public insurance was $0.00, and for private insurance, it was $559.8 (SD=160.7, 95% CI=529.1-590.5, P<0.01). Of 3295 claims for orthotic helmet treatment, 92 were fully denied (2.8%). Private insurers issued more fully denied claims (3.8%) than public insurance (1.1%) (P<0.01). We found that public insurance is favorable for patients seeking treatment due to a lower likelihood of full denial and lower copayments. In addition, we found that there is a significant disparity in the prevalence of helmet treatment in MUAs, and the percentage of patients treated with helmeting therapy has declined over time.

Clinical implications of combination proton pump inhibitor and triple therapies in patients with atrial fibrillation following percutaneous intervention: a guide for clinicians.

INTRODUCTION: Patients on systemic oral anticoagulation with vitamin K antagonists (VKA) or non-vitamin K oral anticoagulants (NOAC) often require triple therapy following percutaneous coronary intervention, substantially increasing the risk of bleeding. Gastroprotective agents like proton pump inhibitors (PPI) are often employed to mitigate this risk, despite potential competitive inhibition between P2Y12-receptor inhibitors, NOACs, and VKAs. While the interactions and clinical outcomes of PPIs and DAPT have been frequently explored in literature, not many studies have evaluated the same outcomes for triple therapy. AREAS COVERED: This comprehensive narrative review of three studies on PPIs and triple from the PubMed/MEDLINE database supplemented by 23 other relevant studies aims to use the available literature to analyze the potential interactions between PPIs and triple therapy while shedding light on their mechanisms, clinical implications, and areas for optimization. EXPERT OPINION: If triple therapy is indicated following PCI, then patients at high-risk for bleeding may benefit from transition to apixaban and a PPI to lower the risk of gastrointestinal bleeding. More research is needed to determine the role of PPIs in triple therapies in prevention of gastrointestinal bleeding or potentiation of other adverse outcomes.

Musculoskeletal models determine the effect of a soft active exosuit on muscle activations and forces during lifting and lowering tasks.

Exosuits have the potential to mitigate musculoskeletal stress and prevent back injuries during industrial tasks. This study aimed to 1) validate the implementation of a soft active exosuit into a musculoskeletal model of the spine by comparing model predicted muscle activations versus corresponding surface EMG measurements, and 2) evaluate the effect of the exosuit on peak back and hip muscle forces. Fourteen healthy participants performed squat and stoop lift and lower tasks with boxes of 6 and 10 kg, with and without wearing a 2.7 kg soft active exosuit. Participant-specific musculoskeletal models, which included the exosuit, were created in OpenSim. Model validation focused on the back and hip extensors, where temporal agreement between EMG and model estimated muscle activity was generally strong to excellent (average cross-correlation coefficients ranging from 0.84 to 0.98). Root mean square errors of muscle activity (0.05-0.10) were similar with and without the exosuit, and compared well to prior model validation studies without the exosuit (average root mean square errors ranging from 0.05 to 0.19). In terms of performance, the exosuit reduced the estimated peak erector spinae forces during lifting and lowering phases across all lifting tasks but reduced peak hip extensor muscles forces only in a squat lift task of 10 kg. These reductions in total peak muscle forces were approximately 1.7-4.2 times greater than the corresponding exosuit assistance force, which were 146 ± 19 N and 102 ± 14 N at the times of peak erector spinae forces in lifting and lowering, respectively. Overall, the results support the hypothesis that exosuits reduce soft tissue loading, and thereby potentially reduce fatigue and injury risk during manual materials handling tasks. Incorporating exosuits into musculoskeletal models is a valid approach to understand the impact of exosuit assistance on muscle activity and forces.

The Influence of State Restrictions on Opioid Prescribing: 2006-2018.

OBJECTIVE: To measure the longitudinal effect of opioid restrictions on prescribing patterns at the state and regional levels. DESIGN: Health policy evaluation using a Poisson regression of opioid metrics from federal repositories to model what the estimated opioid counts are for the next fiscal year. SETTING: State-specific prescribed opioid counts between 2006 and 2018 from CDC reports; population data were obtained from the U.S. Census Bureau for 2006-2018; and opioid prescribing restrictions were extracted from published reports and state regulatory databases. INTERVENTION: Poisson regression models were fitted to assess the relationship of statewide restrictions on opioid prescribing counts adjusting for states' population. MAIN OUTCOME MEASURE: Estimated opioid counts provided by the Poisson regression model. RESULTS: Per capita rates of prescribed opioids peaked in 2012 at 86.2 per 100 population. Prescribing restrictions are associated with statistically significant decreases in opioid prescribing. Controlling for population and year, we found for every 100 opioid prescriptions in a state without restrictions, only 98 opioid prescriptions are expected for every additional year in a state with restrictions in place. CONCLUSIONS: Contrary to other research conducted over a shorter study period, we found that restrictions do reduce opioid prescribing; however, a statistically significant change in rates may not be detectable in the early years after restrictions are enacted.

Effects of a 6-week treadmill training with and without virtual reality on frailty in people with multiple sclerosis: Frailty rehabilitation in multiple sclerosis.

OBJECTIVE: To examine the effects of a cognitive-motor rehabilitation program consisting of treadmill training augmented by virtual reality (TT+VR) on frailty in people with multiple sclerosis (pwMS). DESIGN: Secondary analysis from a multi-center randomized controlled trial investigating the effects of TT+VR, compared to treadmill training (TT) only, on measures of mobility and cognitive function in pwMS. SETTING: Four university research laboratories in Israel, the United States, and Germany. PARTICIPANTS: A total of 124 pwMS were randomized into the parent trial. Here, we studied a subset of 83 participants (mean age=49.4±9.3 years, 73.5% female, EDSS range=2.0-6.0), who completed the intervention and had complete pre- and post-intervention frailty data. INTERVENTION: Participants were randomly allocated to TT+VR (n=44) or to TT (n=39). Both groups trained three times a week for six weeks. MAIN OUTCOME MEASURES: Frailty was assessed using a 40-item frailty index (FI) through standard validated procedures and represented the primary study outcome. Two exploratory frailty indices were also computed by isolating health-related deficits involving the cognitive (FI-physical) or physical (FI-cognitive) domains from the main FI. The assessments were performed at baseline and after six weeks, upon intervention completion. RESULTS: The mean FI of study participants at baseline was 0.33±0.13, indicating a moderate average level of frailty. FI scores improved in both TT+VR and TT participants (pooled mean ΔFI=0.024, 95%CI=0.010-0.038, F=10.49, p=0.002, ηp2=0.115), without any group-by-time interaction (F=0.82, p=0.367, ηp2=0.010). However, a significant group-by-time interaction was found for pre- and post-training changes in FI-cognitive (F=5.74, p=0.019, ηp2=0.066), suggesting a greater improvement for TT+VR participants than for TT participants. CONCLUSION: Treadmill training with or without virtual reality can reduce frailty levels in pwMS. While both TT and TT+VR had a positive impact on overall frailty, only TT+VR improved cognitive aspects of frailty and may represent an appropriate strategy for counteracting frailty in pwMS.

Neurologic Symptoms After 177Lu-Prostate-Specific-Membrane Antigen-617 Therapy: A Single-Center Experience.

Treatment with 177Lu-prostate-specific membrane antigen (PSMA)-617 (177Lu-vipivotide tetraxetan [Pluvicto]) prolongs both progression-free and overall survival in advanced PSMA-positive metastatic castration-resistant prostate cancer. Data examining specifically neurologic symptoms after 177Lu-PSMA-617 treatment are scarce. In this study, we aimed to review the neurologic findings in a large cohort of metastatic castration-resistant prostate cancer patients undergoing 177Lu-PSMA-617 therapy. Methods: The clinical records and imaging data of patients who received their initial dose of 177Lu-PSMA-617 between March 2022 and November 2022 were retrospectively reviewed. All patients presenting for medical evaluation, regardless of specific specialty appointments, with new or worsening neurologic symptoms were included in the study. Results: A total of 185 patients underwent 177Lu-PSMA-617 therapy. The median age was 70 y (range, 58-90 y). The mean follow-up time was 12.04 ± 2.87 mo. Fifty-five new or worsening neurologic symptoms were observed in 50 patients (27%, 50/185). Of these, 27 (11.9%, 27/185) reported altered taste. Eleven patients (6%, 11/185) experienced dizziness with no other clear etiology; 2 of these patients were admitted to the emergency department (ED). Paresthesia symptoms were reported in 6 patients (3.2%, 6/185). Five patients (2.7%, 5/185) reported headaches, 3 of these patients were admitted to the ED because of the severity of the symptoms. Two patients (1.08%, 2/185) presented with extremity weakness. Two patients (1.08%, 2/185) had an ischemic stroke and were admitted to the ED. One patient (0.05%, 1/185) exhibited gait disturbances. In total, 7 patients (3.78%, 7/185) were admitted to the ED because of neurologic symptoms. None of the patients discontinued or failed to complete the 177Lu-PSMA-617 therapy because of neurologic symptoms. Conclusion: After 177Lu-PSMA-617 treatment, the most common neurologic symptoms were dysgeusia and dizziness. In this study, our follow-up period and population size might not have been sufficient to detect delayed or uncommon neurologic symptoms. In patients without neurologic symptoms or central nervous system metastases before treatment, we found the development of severe neurologic problems to be rare and unlikely to require discontinuation of treatment.

A Mathematical Model of Diel Activity and Long Time Survival in Phototrophic Mixed-Species Subaerial Biofilms.

Subaerial biofilms (SAB) are intricate microbial communities living on terrestrial surfaces, of interest in a variety of contexts including cultural heritage preservation, microbial ecology, biogeochemical cycling, and biotechnology. Here we propose a mathematical model aimed at better understanding the interplay between cyanobacteria and heterotrophic bacteria, common microbial SAB constituents, and their mutual dependence on local environmental conditions. SABs are modeled as thin mixed biofilm-liquid water layers sitting on stone. A system of ordinary differential equations regulates the dynamics of key SAB components: cyanobacteria, heterotrophs, polysaccharides and decayed biomass, as well as cellular levels of organic carbon, nitrogen and energy. These components are interconnected through a network of energetically dominant metabolic pathways, modeled with limitation terms reflecting the impact of biotic and abiotic factors. Daily cylces of temperature, humidity, and light intensity are considered as input model variables that regulate microbial activity by influencing water availability and metabolic kinetics. Relevant physico-chemical processes, including pH regulation, further contribute to a description of the SAB ecology. Numerical simulations explore the dynamics of SABs in a real-world context, revealing distinct daily activity periods shaped by water activity and light availability, as well as longer time scale survivability conditions. Results also suggest that heterotrophs could play a substantial role in decomposing non-volatile carbon compounds and regulating pH, thus influencing the overall composition and stability of the biofilm.

Structural and physical-chemical properties of milk fat globules fractionated by a series of silicon carbide membranes.

Driven by the acknowledged health and functional properties of milk fat globules (MFGs), there is a growing interest to develop gentle methodologies for separation of fat from milk. In this study, separation of fat from raw milk and fractionation in streams containing MFGs of different size was achieved using a series of two silicon carbide ceramic membranes. A first step consisting of a 1.4 µm membrane aimed to concentrate the bulk of the fat, i.e. the larger MFGs (D[4,3] âˆ¼ 4 µm) followed by a 0.5 µm fractionation aimed to concentrate the residual milk fat in the permeate, i.e. fraction with the smaller MFGs (D[4,3] âˆ¼ 1.8-2.4 µm. The fat separation performance showed a yield of 92 % for the 1.4 µm membrane and 97 % for the 0.5 µm membrane. Both fat enriched retentates showed, by the confocal laser scanning microscopy, intact MFGs with limited damage in the MFG membrane. The fatty acid profile analysis and SAXS showed minor differences in fat acid composition and the crystallization behavior was related to differences in the fat content. The 0.5 µm permeate containing the smallest MFGs however showed larger aggregates and a trinomial particle size distribution, due to probably pore pressure induced coalescences. The series of silicon carbide membranes showed potential to concentrate some of MFGM proteins such as Periodic Schiff base 3/4 and cluster of differentiation 36 especially in the 0.5 µm retentates. A shift in casein to whey protein ratio from 80:20 (milk) to 50:50 was obtained in the final 0.5 µm permeate, which opens new opportunities for product development.

Exploring the Ligand Binding and Conformational Dynamics of the Substrate-Binding Domain 1 of the ABC Transporter GlnPQ.

The adenosine triphosphate (ATP)-binding cassette (ABC) importer GlnPQ from Lactococcus lactis has two sequential covalently linked substrate-binding domains (SBDs), which capture the substrates and deliver them to the translocon. The two SBDs differ in their ligand specificities, binding affinities and the distance to the transmembrane domain; interestingly, both SBDs can bind their ligands simultaneously without affecting each other. In this work, we studied the binding of ligands to both SBDs using X-ray crystallography and molecular dynamics simulations. We report three high-resolution structures of SBD1, namely, the wild-type SBD1 with bound asparagine or arginine, and E184D SBD1 with glutamine bound. Molecular dynamics (MD) simulations provide a detailed insight into the dynamics associated with open-closed transitions of the SBDs.