On-the-fly Raman microscopy guaranteeing the accuracy of discrimination.

Accelerating the measurement for discrimination of samples, such as classification of cell phenotype, is crucial when faced with significant time and cost constraints. Spontaneous Raman microscopy offers label-free, rich chemical information but suffers from long acquisition time due to extremely small scattering cross-sections. One possible approach to accelerate the measurement is by measuring necessary parts with a suitable number of illumination points. However, how to design these points during measurement remains a challenge. To address this, we developed an imaging technique based on a reinforcement learning in machine learning (ML). This ML approach adaptively feeds back "optimal" illumination pattern during the measurement to detect the existence of specific characteristics of interest, allowing faster measurements while guaranteeing discrimination accuracy. Using a set of Raman images of human follicular thyroid and follicular thyroid carcinoma cells, we showed that our technique requires 3,333 to 31,683 times smaller number of illuminations for discriminating the phenotypes than raster scanning. To quantitatively evaluate the number of illuminations depending on the requisite discrimination accuracy, we prepared a set of polymer bead mixture samples to model anomalous and normal tissues. We then applied a home-built programmable-illumination microscope equipped with our algorithm, and confirmed that the system can discriminate the sample conditions with 104 to 4,350 times smaller number of illuminations compared to standard point illumination Raman microscopy. The proposed algorithm can be applied to other types of microscopy that can control measurement condition on the fly, offering an approach for the acceleration of accurate measurements in various applications including medical diagnosis.

Flame Retardancy of Short Flax Fibers Modified by Radiation-Induced Grafting of Phosphonated Monomers: Comparison between Pre- and Simultaneous Irradiation Grafting.

Short flax fibers have been modified by radiation-induced grafting using methacrylate monomers containing phosphorus to give them a flame-retardant character. Two methodologies, namely pre-irradiation and simultaneous irradiation grafting, were examined. Certain parameters, notably the dose and the irradiation source (e-Beam and γ rays), were evaluated. The grafting efficiency, in terms of phosphorus content (mass percentage), was measured by X-ray fluorescence spectrometry (XRF). Using simultaneous irradiation, 2.39 wt% phosphorus could be obtained from 10 kGy, compared to 100 kGy in pre-irradiation. Furthermore, for similar phosphorus levels, the location of the grafted polymer chains was different for the two methodologies. The effect of phosphorus content on thermal properties and fire behavior was evaluated on a microscopic scale using a pyrolytic flow combustion calorimeter (PCFC) and on a laboratory scale using a cone calorimeter. It was then pointed out that flammability was linked to the phosphorus content and likely its location, which is associated with the radiation-induced grafting methodology, showing that the grafting conditions influence the final fire properties. Simultaneous irradiation, thus, proved to be more interesting in terms of efficiency and final properties.

Geometrical analysis identified morphological features of hydrogel-induced cancer stem cells in synovial sarcoma model cells.

Cancer stem cells (CSCs) has been a key target to cure cancer patients completely. Although many CSC markers have been identified, they are frequently cancer type-specific and those expressions are occasionally variable, which becomes an obstacle to elucidate the characteristics of the CSCs. Here we scrutinized the relationship between stemness elevation and geometrical features of single cells. The PAMPS hydrogel was utilized to create the CSCs from mouse myoblast C2C12 and its synovial sarcoma model cells. qRT-PCR analysis confirmed the significant increase in expression levels of Sox2, Nanog, and Oct3/4 on the PAMPS gel, which was higher in the synovial sarcoma model cells. Of note, the morphological heterogeneity was appeared on the PAMPS gel, mainly including flat spreading, elongated spindle, and small round cells, and the Sox2 expression was highest in the small round cells. To examine the role of morphological differences in the elevation of stemness, over 6,400 cells were segmented along with the Sox2 intensity, and 12 geometrical features were extracted at single cell level. A nonlinear mapping of the geometrical features by using uniform manifold approximation and projection (UMAP) clearly revealed the existence of relationship between morphological differences and the stemness elevation, especially for C2C12 and its synovial sarcoma model on the PAMPS gel in which the small round cells possess relatively high Sox2 expression on the PAMPS gel, which supports the strong relationship between morphological changes and the stemness elevation. Taken together, these geometrical features can be useful for morphological profiling of CSCs to classify and distinguish them for understanding of their role in disease progression and drug discovery.

The relationship between semantic and episodic memory: evidence from a case of severe anterograde amnesia.

It is increasingly being recognized that new declarative, consciously accessible information can be learned in anterograde amnesia, but it is not clear whether this learning is supported by episodic or semantic memory. We report a case of a 55-year-old man who experienced severe amnesia after limited damage to the medial temporal lobe following neurosurgical complications. His general cognitive performance and knowledge of new French words and public events that occurred before and after the onset of amnesia were assessed. Performance remained satisfactory on post-morbid vocabulary and public events, with a drop in performance observed for very recent public events only, while knowledge of very recent vocabulary was comparable to that of the control subjects. The implications of these findings for our understanding of the underlying learning mechanisms are discussed. This is the first report of acquisition of consciously accessible postmorbid knowledge of public events in a patient with severe amnesia.

Differentiability of cell types enhanced by detrending a non-homogeneous pattern in a line-illumination Raman microscope.

A line illumination Raman microscope extracts the underlying spatial and spectral information of a sample, typically a few hundred times faster than raster scanning. This makes it possible to measure a wide range of biological samples such as cells and tissues - that only allow modest intensity illumination to prevent potential damage - within feasible time frame. However, a non-uniform intensity distribution of laser line illumination may induce some artifacts in the data and lower the accuracy of machine learning models trained to predict sample class membership. Here, using cancerous and normal human thyroid follicular epithelial cell lines, FTC-133 and Nthy-ori 3-1 lines, whose Raman spectral difference is not so large, we show that the standard pre-processing of spectral analyses widely used for raster scanning microscopes introduced some artifacts. To address this issue, we proposed a detrending scheme based on random forest regression, a nonparametric model-free machine learning algorithm, combined with a position-dependent wavenumber calibration scheme along the illumination line. It was shown that the detrending scheme minimizes the artifactual biases arising from non-uniform laser sources and significantly enhances the differentiability of the sample states, i.e., cancerous or normal epithelial cells, compared to the standard pre-processing scheme.

Elevation alters ecosystem properties across temperate treelines globally.

Temperature is a primary driver of the distribution of biodiversity as well as of ecosystem boundaries. Declining temperature with increasing elevation in montane systems has long been recognized as a major factor shaping plant community biodiversity, metabolic processes, and ecosystem dynamics. Elevational gradients, as thermoclines, also enable prediction of long-term ecological responses to climate warming. One of the most striking manifestations of increasing elevation is the abrupt transitions from forest to treeless alpine tundra. However, whether there are globally consistent above- and belowground responses to these transitions remains an open question. To disentangle the direct and indirect effects of temperature on ecosystem properties, here we evaluate replicate treeline ecotones in seven temperate regions of the world. We find that declining temperatures with increasing elevation did not affect tree leaf nutrient concentrations, but did reduce ground-layer community-weighted plant nitrogen, leading to the strong stoichiometric convergence of ground-layer plant community nitrogen to phosphorus ratios across all regions. Further, elevation-driven changes in plant nutrients were associated with changes in soil organic matter content and quality (carbon to nitrogen ratios) and microbial properties. Combined, our identification of direct and indirect temperature controls over plant communities and soil properties in seven contrasting regions suggests that future warming may disrupt the functional properties of montane ecosystems, particularly where plant community reorganization outpaces treeline advance.

Effects of antipsychotic and anticholinergic medications on cognition in chronic patients with schizophrenia.

BACKGROUND: Patients with psychosis frequently use a variety of psychotropic medicines, many of which have anticholinergic effects that can impair cognition. Therefore, this study aimed to evaluate whether there is an association between medications used for neuropsychological disorders/symptoms and cognition in patients with schizophrenia, focusing on their anticholinergic load and antipsychotic doses. STUDY DESIGN: A cross-sectional study between July 2019 and Mars 2020 at the Psychiatric Hospital of the Cross-Lebanon enrolled 120 inpatients diagnosed with schizophrenia. The total anticholinergic burden was calculated based on the Anticholinergic Drug Scale (ADS), and the chlorpromazine equivalent dose was calculated using the Andreasen method to assess the relative antipsychotic dose. Also, the objective cognition was assessed using the Brief Assessment of Cognition in Schizophrenia (BACS) tool. STUDY RESULTS: A significantly higher BACS total score (r = -0.33, p < 0.001), higher verbal memory (r = -0.26, p = 0.004), higher working memory (r = -0.20, p = 0.03), higher motor speed (r = -0.36, p < 0.001), and higher attention and speed of information processing (r = -0.27, p = 0.003) were significantly associated with lower chlorpromazine equivalent dose. Higher ADS (Standardized Beta (SB) = -.22; p = .028), higher chlorpromazine equivalent dose (SB = -.30; p = .001), and taking mood stabilizer medications (SB = -.24; p = .004) were significantly associated with lower cognition. CONCLUSION: This study confirms that the cognitive functions of chronic patients with schizophrenia may be affected by medications and their anticholinergic burden. More studies are needed to explain the role of cholinergic neurotransmission and general neurochemical mechanisms in the cognitive impairment of patients with schizophrenia.

Conception and Evaluation of a Library of Cleavable Mass Tags for Digital Polymers Sequencing.

A library of phosphoramidite monomers containing a main-chain cleavable alkoxyamine and a side-chain substituent of variable molar mass (i.e. mass tag) was prepared in this work. These monomers can be used in automated solid-phase phosphoramidite chemistry and therefore incorporated periodically as spacers inside digitally-encoded poly(phosphodiester) chains. Consequently, the formed polymers contain tagged cleavable sites that guide their fragmentation in mass spectrometry sequencing and enhance their digital readability. The spacers were all prepared via a seven steps synthetic procedure. They were afterwards tested for the synthesis and sequencing of model digital polymers. Uniform digitally-encoded polymers were obtained as major species in all cases, even though some minor defects were sometimes detected. Furthermore, the polymers were decoded in pseudo-MS3 conditions, thus confirming the reliability and versatility of the spacers library.

A Model of Care Optimized for Marginalized Remote Population Unravels Migration Pattern in India.

BACKGROUND AND AIMS: Access to basic health needs remains a challenge for most of world's population. In this study, we developed a care model for preventive and disease-specific health care for an extremely remote and marginalized population in Arunachal Pradesh, the northeasternmost state of India. APPROACH AND RESULTS: We performed patient screenings, performed interviews, and obtained blood samples in remote villages of Arunachal Pradesh through a tablet-based data collection application, which was later synced to a cloud database for storage. Positive cases of hepatitis B virus (HBV) were confirmed and genotyped in our central laboratory. The blood tests performed included liver function tests, HBV serologies, and HBV genotyping. HBV vaccination was provided as appropriate. A total of 11,818 participants were interviewed, 11,572 samples collected, and 5,176 participants vaccinated from the 5 westernmost districts in Arunachal Pradesh. The overall hepatitis B surface antigen (HBsAg) prevalence was found to be 3.6% (n = 419). In total, 34.6% were hepatitis B e antigen positive (n = 145) and 25.5% had HBV DNA levels greater than 20,000 IU/mL (n = 107). Genotypic analysis showed that many patients were infected with HBV C/D recombinants. Certain tribes showed high seroprevalence, with rates of 9.8% and 6.3% in the Miji and Nishi tribes, respectively. The prevalence of HBsAg in individuals who reported medical injections was 3.5%, lower than the overall prevalence of HBV. CONCLUSIONS: Our unique, simplistic model of care was able to link a highly resource-limited population to screening, preventive vaccination, follow-up therapeutic care, and molecular epidemiology to define the migratory nature of the population and disease using an electronic platform. This model of care can be applied to other similar settings globally.

Comparison of four correction techniques for posterior spinal fusion in adolescent idiopathic scoliosis.

INTRODUCTION: When performing posterior spinal fusion for adolescent idiopathic scoliosis (AIS), it is of major importance to address both coronal and sagittal deformities. Although several techniques have been described, few data exist comparing them. Our objective was to compare four techniques (in situ bending (ISB), rod derotation (RD), cantilever (C) and posteromedial translation (PMT)) for the correction of spinal deformity in AIS including thoracic deformity. MATERIAL AND METHODS: We conducted a multicenter retrospective study including 562 AIS patients with thoracic deformity with at least 24-month follow-up. Radiographic analysis was performed preoperatively, postoperatively and at last follow-up. The main outcomes were main curve correction and thoracic kyphosis restoration (TK). RESULTS: Coronal correction rate was significantly different among the four treatment groups (ISB 64% vs C 57% vs RD 55% vs PMT 67%, p < 0.001). Multivariate regression revealed that correction technique did not influence correction rate, whereas implant density, convex side compression and use of derotation connectors did. TK increase was significantly higher in the PMT group (average + 13°) than in DR (+ 3°), while ISB (-3°) and cantilever (-13°) resulted in TK decrease (p < 0.001). Multivariate analysis revealed that TK increase was only influenced by the reduction technique (p < 0.001) and preoperative TK (p < 0.001). DISCUSSION: The four techniques had the same ability to correct spinal deformity in the coronal plane. Three factors were identified to improve correction rate: implant density, convex compression and use of derotation connectors. On the other hand, PMT was more effective in restoring TK, particularly in hypokyphotic patients.

Thionolactone as a Resin Additive to Prepare (Bio)degradable 3D Objects via VAT Photopolymerization.

Three-dimensional (3D) printing and especially VAT photopolymerization leads to cross-linked materials with high thermal, chemical, and mechanical stability. Nevertheless, these properties are incompatible with requirements of degradability and re/upcyclability. We show here that thionolactone and in particular dibenzo[c,e]-oxepane-5-thione (DOT) can be used as an additive (2 wt %) to acrylate-based resins to introduce weak bonds into the network via a radical ring-opening polymerization process. The low amount of additive makes it possible to modify the printability of the resin only slightly, keep its resolution intact, and maintain the mechanical properties of the 3D object. The resin with additive was used in UV microfabrication and two-photon stereolithography setups and commercial 3D printers. The fabricated objects were shown to degrade in basic solvent as well in a homemade compost. The rate of degradation is nonetheless dependent on the size of the object. This feature was used to prepare 3D objects with support structures that could be easily solubilized.

Clinical predictive model of lumbar curve Cobb angle below selective fusion for thoracic adolescent idiopathic scoliosis: a longitudinal multicenter descriptive study.

PURPOSE: To implement a clinically applicable, predictive model for the lumbar Cobb angle below a selective thoracic fusion in adolescent idiopathic scoliosis. METHODS: A series of 146 adolescents with Lenke 1 or 2 idiopathic scoliosis, surgically treated with posterior selective fusion, and minimum follow-up of 5 years (average 7) was analyzed. The cohort was divided in 2 groups: if lumbar Cobb angle at last follow-up was, respectively, ≥ or < 10°. A logistic regression-based prediction model (PredictMed) was implemented to identify variables associated with the group ≥ 10°. The guidelines of the TRIPOD statement were followed. RESULTS: Mean Cobb angle of thoracic main curve was 56° preoperatively and 25° at last follow-up. Mean lumbar Cobb angle was 33° (20; 59) preoperatively and 11° (0; 35) at last follow-up. 53 patients were in group ≥ 10°. The 2 groups had similar demographics, flexibility of both main and lumbar curves, and magnitude of the preoperative main curve, p > 0.1. From univariate analysis, mean magnitude of preoperative lumbar curves (35° vs. 30°), mean correction of main curve (65% vs. 58%), mean ratio of main curve/distal curve (1.9 vs. 1.6) and distribution of lumbar modifiers were statistically different between groups (p < 0.05). PredictMed identified the following variables significantly associated with the group ≥ 10°: main curve % correction at last follow-up (p = 0.01) and distal curve angle (p = 0.04) with a prediction accuracy of 71%. CONCLUSION: The main modifiable factor influencing uninstrumented lumbar curve was the correction of main curve. The clinical model PredictMed showed an accuracy of 71% in prediction of lumbar Cobb angle ≥ 10° at last follow-up. LEVEL OF EVIDENCE IV: Longitudinal comparative study.

Subjective cognitive complaints and relations to objective cognitive performance among Lebanese patients with schizophrenia.

BACKGROUND: Patients with schizophrenia have a particularly low level of insight into their illness compared to people with other mental health disorders. The objectives of the study were to evaluate: 1) subjective cognitive complaints in individuals with schizophrenia in comparison with health controls, 2) the relation between subjective cognitive complaint (SCC) and objective cognitive performance in the patients group, and 3) factors related to cognitive complaint, such as depression, insight, autonomy, and psychological symptoms. METHODS: Cross-sectional study was conducted between July 2019 and March 2020 enrolled 120 patients with schizophrenia disorders, selected from the Psychiatric Hospital of the Cross (HPC) - Lebanon and 60 healthy controls. The Self-Assessment Scale of Cognitive Complaints in Schizophrenia (SASCCS) was used to measure people living with schizophrenia perception of their cognitive impairment, while the Brief Assessment of Cognition in Schizophrenia (BACS) was used to evaluate their cognitive functioning. RESULTS: A significant difference was found between schizophrenia patients and healthy controls in all neurocognition and SASCCS tests. The hierarchical regression analysis showed that the BACS total score (Beta = -.06, p = .04), the PANSS general psychopathology (Beta = .29, p = .003), higher depression (Beta = .75, p = .003) were significantly associated with higher SCC. However, higher autonomy (Beta = - 6.35, p = .001) was significantly associated with lower SCC. A Structural equation model showed that the two most contributing variables were general psychopathology (Standardized Beta (SB): .33, p < 0.001) and autonomy (SB: -.29, p < 0.001). CONCLUSION: A significant proportion of patients with schizophrenia could estimate their cognitive impairment. It also showed a positive correlation between depression and activity of daily living with SCC, suggesting that this aspect should be investigated alongside the clinical symptoms when a patient with schizophrenia presents with SCC.

Cross-cultural adaptation and validation of the Arabic version of the BACS scale (the brief assessment of cognition in schizophrenia) among chronic schizophrenic inpatients.

BACKGROUND: Assessment of cognitive disorders in schizophrenia is becoming a part of clinical and research practice by using batteries that differ widely in their content. The Brief Assessment of Cognition in Schizophrenia (BACS) was developed to cover the main cognitive deficits of schizophrenia. The objective of this study was to assess concurrent validity of the Arabic version of the BACS with a standard neurocognitive battery of tests in Lebanese patients with schizophrenia and healthy controls. METHODS: A sample of 120 stable inpatients diagnosed with schizophrenia and 60 healthy controls received the Arabic version of the BACS in a first session, and a standard battery in a second session. RESULTS: Mean duration of completion for the BACS was 31.2 ± 5.4 min in patients with schizophrenia. All tests demonstrated significant differences between controls and patients (p < .01). Principal components analysis demonstrated that a one-factor solution best fits our dataset (64.8% of the variance). High Cronbach alpha was found (.85). The BACS composite scores were significantly correlated with the standard battery composite scores in patients (r = .73, p < .001) and healthy controls (r = .78, p < .001). Also, correlation analysis between the BACS sub-scores and the standard battery sub-scores showed significant results (p < .05). CONCLUSION: Results showed that the Arabic version of the BACS demonstrated high ability to discriminate patients with schizophrenia from healthy controls and it is a useful tool for assessing cognition in patients with schizophrenia and could be used in clinical practice in Lebanon.

Apolipoprotein E ϵ4 allele and neuropsychiatric symptoms among older adults in Central Africa (EPIDEMCA study).

OBJECTIVES: To evaluate the association between neuropsychiatric symptoms and apolipoprotein E (APOE) ϵ4 allele among older people in Central African Republic (CAR) and the Republic of Congo (ROC). DESIGN: Multicenter population-based study following a two-phase design. SETTING: From 2011 to 2012, rural and urban areas of CAR and ROC. PARTICIPANTS: People aged 65 and over. MEASUREMENTS: Following screening using the Community Screening Interview for Dementia, participants with low cognitive scores (CSI-D ≤ 24.5) underwent clinical assessment. Dementia diagnosis followed the DSM-IV criteria and Peterson's criteria were considered for Mild Cognitive Impairment (MCI). Neuropsychiatric symptoms were evaluated through the brief version of the Neuropsychiatric Inventory (NPI-Q). Blood samples were taken from all consenting participants before APOE genotyping was performed by polymerase chain reaction (PCR). Logistic regression models were used to evaluate the association between the APOE ϵ4 allele and neuropsychiatric symptoms. RESULTS: Overall, 322 participants had complete information on both neuropsychiatric symptoms and APOE status. Median age was 75.0 years and 81.1% were female. Neuropsychiatric symptoms were reported by 192 participants (59.8%) and at least 1 APOE ϵ4 allele was present in 135 (41.9%). APOE ϵ4 allele was not significantly associated with neuropsychiatric symptoms but showed a trend toward a protective effect in some models. CONCLUSION: This study is the first one investigating the association between APOE ϵ4 and neuropsychiatric symptoms among older people in sub-Saharan Africa (SSA). Preliminary findings indicate that the APOE ϵ4 allele was not associated with neuropsychiatric symptoms. Further research seems, however, needed to investigate the protective trend found in this study.

Prevention of surgical site infections in pediatric spines: a single-center experience.

PURPOSE: To describe the potential issues in the methodology of surgical site infection (SSI) prevention and how it was investigated and corrected in a single institution. METHODS: A pediatric orthopedic unit experienced an increase of SSI, concerning up to 10% of scoliosis surgery cases from 2011 to 2013. An institutional procedure of multimodal and interdisciplinary risk evaluation was initiated, including a review of the literature, a morbi-mortality meeting, internal and external audits concerning the hygiene conditions in the operating room, the antibiotic prophylaxis, patients, and sterile material pathways. Several preventive actions were implemented, including the improvement of air treatment in the operating room, wound irrigation with 2L of saline before closure, application of topic vancomycine in the wound, verification of doses and timing of antibiotics injection, and use of waterproof bandages. We compared the rates of spine SSI before (retrospective group, 2011-2013) and after the implementation of various preventive measures (prospective group, 2014-2018). RESULTS: SSI occurred in 12 patients (6 idiopathic and 6 neuromuscular) out of 120 operated on (93 idiopathic, 18 neuromuscular, 9 others) in the retrospective group and 2 (both neuromuscular) out of 196 (150 idiopathic, 33 neuromuscular,13 others) in the prospective group (10% vs 1%, odds ratio=9.7, p=0.001). The groups were comparable for age, etiology, duration of surgery, body mass index, American Society of Anesthesiologists score, number of levels fused, and blood loss (p>0.2). CONCLUSION: The systematic analysis of SSI allowed for the understanding of the failures and correcting them. The current process is effectively preventing SSI. LEVEL OF EVIDENCE: 3: prospective series with case-control analysis.

Surgical increase in thoracic kyphosis predicts increase of cervical lordosis after thoracic fusion for adolescent idiopathic scoliosis.

PURPOSE: The modification of cervical lordosis (CL) after adolescent idiopathic scoliosis (AIS) surgery is influenced by the correction of thoracic hypokyphosis. The quantification of the increase of CL as a function of the increase of thoracic kyphosis (TK) has never been calculated. METHODS: A total of 92 consecutive AIS patients who underwent a posterior thoracic selective fusion, corrected by simultaneous translation on 2 rods technique, with minimum 24-month follow-up, were analyzed from a prospective database. We evaluated global sagittal kyphosis and lordosis. CL was divided by the horizontal line in proximal (PCL) and distal cervical lordosis (DCL), likewise TK in proximal (PTK) and distal TK (DTK), and lumbar lordosis (LL) in proximal (PLL) and distal LL (DLL). RESULTS: The mean TK gain was 16°, 14° and 28° in the whole cohort, normokyphosis group and hypokyphosis group, respectively. The mean DCL gain was, respectively, 9°, 7° and 20° and the mean CL gain 8°, 5° and 21°. There was a strong correlation between TK gain and CL gain (coefficient = 0.86) and between TK gain and DCL gain (coefficient = 0.74). The regression equation was defined as DCLgain = - 3 + 0.75 × TKgain (p < 0.0001) corresponding on average to 60% of the TK gain. CONCLUSION: 60% of the TK gain was transferred to DCL gain. Correlations reflect the geometrical equivalence between PTK and DCL. The use of sagittal global measurements shows that DCL is equivalent to PTK and can be expressed as a function of pelvic parameters (DCL = PT + LL-PI). DCL must be considered to optimize the postoperative sagittal alignment of the spine.

Proximal junctional kyphosis is a rebalancing spinal phenomenon due to insufficient postoperative thoracic kyphosis after adolescent idiopathic scoliosis surgery.

PURPOSE: Many authors tried to explain proximal junctional kyphosis (PJK) after adolescent idiopathic scoliosis (AIS) surgery by looking for risk factors. Latest publications focus on sagittal alignment. Each healthy adolescent has a specific thoracic kyphosis (TK) depending on their pelvic parameters and lumbar lordosis (LL). The objective of this work is to determine if the difference between TK at follow-up (TKFU) and the patient-specific TK (PSTK) plays a role in PJK occurrence after AIS surgery. The secondary objective was to find other risk factors. METHODS: We analyzed retrospectively 570 thoracic AIS who underwent a posterior thoracic fusion from nine centers. The series was separated in two groups: with and without PJK. PSTK was calculated with the formula PSTK = 2(PT + LL-PI). TK Gap was the difference between TKFU and PSTK. Logistic regression was utilized to test the impact of TK Gap and other known risk factors on PJK occurrence. RESULTS: Univariate analysis showed 15 factors significantly different between the groups. In a multivariate analysis, three factors had a strong significant influence on PJK: TKFU, TK Gain and TK Gap. Four additional factors affected the rate of PJK: Posterior translation on two rods, preoperative TK, preoperative LL and number of instrumented vertebrae. CONCLUSION: PJK is related to the insufficient TK at follow-up, compared to the specific TK that every patient should have according to their pelvic parameters. PJK incidence is significantly reduced by a strong gain in TK and a thoracic selective fusion which leaves the proximal lumbar vertebrae free. LEVEL OF EVIDENCE I: Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding.

Exploring the implementation and underlying mechanisms of centralized referral systems to access specialized health services in Quebec.

BACKGROUND: In 2016, Quebec, a Canadian province, implemented a program to improve access to specialized health services (Accès priorisé aux services spécialisés (APSS)), which includes single regional access points for processing requests to such services via primary care (Centre de répartition des demandes de services (CRDS)). Family physicians fill out and submit requests for initial consultations with specialists using a standardized form with predefined prioritization levels according to listed reasons for consultations, which is then sent to the centralized referral system (the CRDS) where consultations with specialists are assigned. We 1) described the APSS-CRDS program in three Quebec regions using logic models; 2) compared similarities and differences in the components and processes of the APSS-CRDS models; and 3) explored contextual factors influencing the models' similarities and differences. METHODS: We relied on a qualitative study to develop logic models of the implemented APSS-CRDS program in three regions. Semi-structured interviews with health administrators (n = 9) were conducted. The interviews were analysed using a framework analysis approach according to the APSS-CRDS's components included in the initially designed program, Mitchell and Lewis (2003)'s logic model framework, and Chaudoir and colleagues (2013)'s framework on contextual factors' influence on an innovation's implementation. RESULTS: Findings show the APSS-CRDS program's regional variability in the implementation of its components, including its structure (centralized/decentralized), human resources involved in implementation and operation, processes to obtain specialists' availability and assess/relay requests, as well as monitoring methods. Variability may be explained by contextual factors' influence, like ministerial and medical associations' involvement, collaborations, the context's implementation readiness, physician practice characteristics, and the program's adaptability. INTERPRETATION: Findings are useful to inform decision-makers on the design of programs like the APSS-CRDS, which aim to improve access to specialists, the essential components for the design of these types of interventions, and how contextual factors may influence program implementation. Variability in program design is important to consider as it may influence anticipated effects, a next step for the research team. Results may also inform stakeholders should they wish to implement similar programs to increase access to specialized health services via primary care.

Precise Alkoxyamine Design to Enable Automated Tandem Mass Spectrometry Sequencing of Digital Poly(phosphodiester)s.

A major step towards reliable reading of information coded in the sequence of long poly(phosphodiester)s was previously achieved by introducing an alkoxyamine spacer between information sub-segments. However, MS/MS decoding had to be performed manually to safely identify useful fragments of low abundance compared to side-products from the amide-based alkoxyamine used. Here, alternative alkoxyamines were designed to prevent side-reactions and enable automated MS/MS sequencing. Different styryl-TEMPO spacers were prepared to increase radical delocalization and stiffness of the structure. Their dissociation behavior was investigated by EPR and best results were obtained with spacers containing in-chain benzyl ring, with no side-reaction during synthesis or sequencing. Automated decoding of these polymers was performed using the MS-DECODER software, which interprets fragmentation data recorded for each sub-segment and re-align them in their original order based on location tags.