Intrinsic dichroism in amorphous and crystalline solids with helical light.

Amorphous solids do not exhibit long-range order due to the disordered arrangement of atoms. They lack translational and rotational symmetry on a macroscopic scale and are therefore isotropic. As a result, differential absorption of polarized light, called dichroism, is not known to exist in amorphous solids. Using helical light beams that carry orbital angular momentum as a probe, we demonstrate that dichroism is intrinsic to both amorphous and crystalline solids. We show that in the nonlinear regime, helical dichroism is responsive to the short-range order and its origin is explained in terms of interband multiphoton assisted tunneling. We also demonstrate that the helical dichroism signal is sensitive to chirality and its strength can be controlled and tuned using a superposition of OAM and Gaussian beams. Our research challenges the conventional knowledge that dichroism does not exist in amorphous solids and enables to manipulate the optical properties of solids.

Helical dichroism in enantiomeric solutions.

A novel chiroptical sensing technique was recently introduced that utilized the helical phase of the structured light as a chiral reagent instead of polarization of light to differentiate enantiopure chiral liquids. The unique advantage of this non-resonant, nonlinear technique is that the chiral signal can be scaled and tuned. In this paper, we extend this technique to enantiopure powders of alanine and camphor by dissolving them in solvents of varying concentrations. We show the differential absorbance of helical light to be an order of magnitude higher relative to conventional resonant linear techniques and is comparable to nonlinear techniques that use circularly polarized light. The origin of helicity dependent absorption is discussed in terms of induced multipole moments in nonlinear light-matter interaction. These results opens up new opportunities in using helical light as a primary chiral reagent in nonlinear spectroscopic techniques.

Early Clinical Prediction of Independent Outdoor Functional Walking Capacity in a Prospective Cohort of Traumatic Spinal Cord Injury Patients.

OBJECTIVE: The first objective was to identify a method for early prediction of independent outdoor functional walking 1 yr after a traumatic spinal cord injury using the motor and sensory function derived from the International Standards for Neurological Classification of Spinal Cord Injury assessment during acute care. Then, the second objective was to develop a clinically relevant prediction rule that would be accurate, easy to use, and quickly calculated in clinical setting. DESIGN: A prospective cohort of 159 traumatic spinal cord injury patients was analyzed. Bivariate correlations were used to determine the assessment method of motor strength and sensory function as well as the specific dermatomes and myotomes best associated with independent outdoor functional walking 1 yr after injury. An easy-to-use clinical prediction rule was produced using a multivariable linear regression model. RESULTS: The highest motor strength for a given myotome (L3 and L5) and preserved light touch sensation (dermatome S1) were the best predictors of the outcome. The proposed prediction rule displayed a sensitivity of 84.21%, a specificity of 85.54%, and a global accuracy of 84.91% for classification. CONCLUSIONS: After an acute traumatic spinal cord injury, accurately predicting the ability to walk is challenging. The proposed clinical prediction rule aims to enhance previous work by identifying traumatic spinal cord injury patients who will reach a mobility level that fosters social participation and quality of life in the chronic period after the injury. TO CLAIM CME CREDITS: Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME. CME OBJECTIVES: Upon completion of this article, the reader should be able to: (1) Revise the different motor and sensory function assessment methods used for prognostication of walking after an acute traumatic spinal cord injury; (2) Identify clinical factors that are significantly associated with functional walking 1 yr after a traumatic spinal cord injury; and (3) Accurately estimate the likelihood of reaching independent outdoor functional walking in the chronic phase after an acute traumatic spinal cord injury. LEVEL: Advanced. ACCREDITATION: The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The Association of Academic Physiatrists designates this Journal-based CME activity for a maximum of 1.0 AMA PRA Category 1 Credit(s)™. Physicians should only claim credit commensurate with the extent of their participation in the activity.

Clinical judgment is a cornerstone for validating and using clinical prediction rules: a head-to-head study on ambulation outcomes for spinal cord injured patients.

STUDY DESIGN: Retrospective comparative study. OBJECTIVE: Clinical prediction rules (CPRs) are an effervescent topic in the medical literature. Recovering ambulation after a traumatic spinal cord injury (tSCI) is a priority for patients and multiple CPRs have been proposed for predicting ambulation outcomes. Our objective is to confront clinical judgment to an established CPR developed for patients with tSCI. SETTINGS: Level one trauma center specialized in tSCI and its affiliated rehabilitation center. METHOD: In this retrospective comparative study, six physicians had to predict the ambulation outcome of 68 patients after a tSCI based on information from the acute hospitalization. Ambulation was also predicted according to the CPR of van Middendorp (CPR-vM). The success rate of the CPR-vM and clinicians to predict ambulation was compared using criteria of 5% for defining clinical significance, and a level of statistical significance of 0.05 for bilateral McNemar tests. RESULTS: There was no statistical difference between the overall performance of physicians (success rate of 79%) and of the CPR-vM (81%) for predicting ambulation. The differences between the CPR-vM and physicians varied clinically and significantly with the level of experience, clinical setting, and field of expertise. CONCLUSION: Confronting CPRs with the judgment of a group of clinicians should be an integral part of the design and validation of CPRs. Head-to-head comparison of CPRs with clinicians is also a cornerstone for defining the optimal strategy for translation into the clinical practice, and for defining which clinician and specific clinical context would benefit from using the CPR.

Decreasing pressure injuries and acute care length of stay in patients with acute traumatic spinal cord injury.

OBJECTIVES: Identifying factors associated with the occurrence of pressure injuries (PI) during acute care and with longer length of stay (LOS), focusing on modifiable factors that can be addressed and optimized by the acute rehabilitation team. DESIGN: Prospective cohort study. SETTING: A single Level-1 trauma center specialized in SCI care. PARTICIPANTS: A cohort of 301 patients with acute TSCI was studied. OUTCOME MEASURES: The primary outcome was the occurrence of PI during acute care stay. The secondary outcome was acute care LOS. Bivariate and multivariate logistic or linear regression analyses were performed to determine the association between non-modifiable factors and outcomes (PI of any stage and acute LOS), whereas bivariate and hierarchical multivariate logistic or linear regression analyses were used for modifiable factors. RESULTS: When controlling for the level and severity of the TSCI, the occurrence of pneumonia (OR = 2.1, CI = 1.1-4.1) was significantly associated with the occurrence of PI. When controlling for the level and severity of the TSCI, the occurrence of medical complications (PI, urinary tract infection and pneumonia) and lesser daily therapy resulted in significantly longer acute care LOS (P < .001). CONCLUSIONS: Prevention of PI occurrence and the optimization of the acute care LOS represent crucial challenges of the acute rehabilitation team, as they are significantly associated with higher functional outcomes. Patients who develop pneumonia may benefit from more aggressive prevention strategies to reduce PI occurrence. Systematic protocols for the prevention of complications as well as greater volume of therapy interventions should be considered to optimize the acute care LOS.

Clinical Protocol for Identifying and Managing Bladder Dysfunction during Acute Care after Traumatic Spinal Cord Injury.

Bladder dysfunction is widespread following traumatic spinal cord injury (TSCI). Early diagnosis of bladder dysfunction is crucial in preventing complications, determining prognosis, and planning rehabilitation. We aim to suggest the first clinical protocol specifically designed to evaluate and manage bladder dysfunction in TSCI patients during acute care. A retrospective cohort study was conducted on 101 patients admitted for an acute TSCI between C1 and T12. Following spinal surgery, presence of voluntary anal contraction (VAC) was used as a criterion for removal of indwelling catheter and initiating trial of void (TOV). Absence of bladder dysfunction was determined from three consecutive post-void bladder scan residuals ≤200 mL without incontinence. All patients were reassessed 3 months post-injury using the Spinal Cord Independence Measure (SCIM). A total of 74.3% were diagnosed with bladder dysfunction during acute care, while 57.4% had a motor-complete TSCI. Three months later, 94.7% of them reported impaired bladder function. None of the patients discharged from acute care after a functional bladder was diagnosed reported impaired bladder function at the 3-month follow-up. A total of 95.7% patients without VAC had persisting impaired bladder function at follow-up. The proposed protocol is specifically adapted to the dynamic nature of neurogenic bladder function following TSCI. The assessment of VAC into the protocol provides major insight on the potential for reaching adequate bladder function during the subacute phase. Conducting TOV using bladder scan residuals in patients with VAC is a non-invasive and easy method to discriminate between a functional and an impaired bladder following acute TSCI.

Chiral discrimination by recollision enhanced femtosecond laser mass spectrometry.

Chiral molecules and their interactions are critical in a variety of chemical and biological processes. Circular dichroism (CD) is the most widely used optical technique to study chirality, often performed in a solution phase. However, CD has low-efficiency on the order of 0.01-1[Formula: see text]. Therefore, there is a growing need to develop high-efficiency chiroptical techniques, especially in gas-phase, to gain background-free in-depth insight into chiral interactions. By using mass spectrometry and strong-field ionization of limonene with elliptically polarized light, we demonstrate an efficient chiral discrimination method that produces a chiral signal of one to two orders of magnitude higher than the conventional CD. The chiral response exhibits a strong dependence on wavelength in the range of 1,300-2,400 nm, where the relative abundance of the ion yields alternates between the two enantiomers. The origin of enhanced enantio-sensitivity in intense laser fields is attributed to two mechanisms that rely on the recollision dynamics in a chiral system: (1) the excited ionic state dynamics mediated either by the laser field or by the recollision process, and (2) non-dipole effects that alter the electron's trajectories. Our results can serve as a benchmark for testing and developing theoretical tools involving non-dipole effects in strong-field ionization of molecules.

Effects of hypertonic saline solution on body weight and serum creatinine in patients with acute decompensated heart failure.

AIM: To test the safety and effectiveness of hypertonic saline solution (HSS + F) as a strategy for weight loss and prevention of further deterioration of renal function. METHODS: Patients admitted with acute decompensated heart failure (ADHF) who received HSS + F were included in the study. After a period of a standard ADHF treatment, our patients received an intravenous infusion of furosemide (250 mg) combined with HSS (150 mL of 3% NaCl) twice a day for a mean duration of 2.3 d. Our primary outcomes were weight loss and a change in serum creatinine per day of treatment. The parameters of the period prior to treatment with HSS + F were compared with those of the period with HSS + F. RESULTS: A total of 47 patients were included. The mean creatinine on admission was 155 µmol/L ± 65 µmol/L, the ejection fraction was 40% ± 17%. The experimental treatment (HSS + F) resulted in greater weight loss per day of treatment than the standard treatment (-1.4 kg/d ± 1.4 kg/d vs -0.4 kg/d ± 1.0 kg/d, P = 0.0168). Importantly, the change in creatinine was not significantly different. CONCLUSION: This study supports the effectiveness of HSS + F on weight loss in patients with ADHF. The safety profile, particularly with regard to renal function, leads us to believe that HSS + F may be a valuable option for those patients presenting with ADHF who do not respond to conventional treatment with intravenous furosemide alone.

Psychometric Properties of the Beach Center Family Quality of Life in French-Speaking Families With a Preschool-Aged Child Diagnosed With Autism Spectrum Disorder.

The Beach Center Family Quality of Life Scale (Beach Center FQOL) is used to evaluate and develop family-centered intervention services. However, its use with families of children with autism spectrum disorder (ASD) and in non-English speaking populations requires further investigation. The present study sought to assess the psychometric properties of a French translation of this scale on 452 parents of children aged 5 and under who were recently diagnosed with ASD. The resulting Satisfaction and Importance scales presented excellent internal consistency at the scale level and acceptable internal consistency at the subscale level. Theoretical model positing 5 dimensions of FQOL generally fit the data acceptably. Satisfaction ratings were found to be sensitive to changes and were negatively correlated with parenting stress.

Dyadic Adjustment Scale: a validation study among older French-Canadians living in relationships.

The principal objective of this study, the first of its kind to use this population, is to describe the factor analysis and validity of the Dyadic Adjustment Scale (EAD) among 895 French Canadian seniors living as couples. A confirmatory factor analysis was carried out using structural equation modeling. Results support Spanier's hierarchical model questionnaire (1976). Results also indicate evidence of validity and reliability satisfactorily set aside for the Affective Expression subscale having a lower Cronbach alpha coefficient. The results also indicate strong validity of the scale according to indices of convergent and discriminant validity. Finally, a discussion is presented addressing considerations to be taken into account for using the questionnaire among older couples.

Marital functioning and psychological distress among older couples over an 18-month period.

Many authors have underlined the existence of a negative association between marital functioning and psychological distress. However, little is known about the direction of this association over time among older couples. This study examined the relation over time between psychological distress and marital functioning among 394 community-dwelling couples. The authors conducted dyadic data analyses to determine whether marital functioning at baseline (T1) predicted psychological distress 18 months later (T2), and inversely. The results for women suggested that marital and psychological functioning may each predict the other. The results for men showed that marital problems lead to more psychological distress. The authors found some significant partner effects: In both genders, the marital functioning of one spouse influenced the marital functioning of the other. Men's marital functioning at baseline significantly predicted women's psychological distress at T2. The authors conducted analyses also to determine how 6 patterns of change in marital functioning between times were associated with changes in psychological distress, and inversely. Changes characterized by an increase in psychological distress over time in at least 1 spouse were associated with a decrease in marital functioning. These findings underlined the importance for clinicians and researchers to pay closer attention to the association between these variables.

Brain lesions and IQ: recovery versus decline depends on age of onset.

A growing literature suggests that early lesions are associated with poorer IQ outcome. Those studies covered a restricted age range in pediatric populations only and did not control for important moderator variables. The present investigation studied IQ change in brain-lesioned children and adults (age 0 to 84 years). Altogether, 725 cases with a documented unilateral focal lesion were gathered from hospital charts and from published cases in the literature, including 240 with repeated IQ testing. Multiple regression analyses isolated the contribution of age at lesion onset to IQ change. Important mediator variables included were lesion side, site, volume, etiology, and so on. An early lesion was significantly associated with poorer postlesion IQ in time and with decline of IQ in time. Later onset lesions were associated with better postlesion IQ and recovery in time. The so-called Kennard principle is refuted, with regard to IQ.

Healthcare utilization following cognitive-behavioral treatment for panic disorder with agoraphobia.

The aim of this study was to examine the overall changes in healthcare services utilization after providing an empirically supported cognitive-behavioral treatment for panic disorder with agoraphobia. Data on healthcare utilization were collected for a total of 84 adults meeting DSM-IV criteria. Participants were completers of a cognitive-behavioral treatment for panic disorder with agoraphobia. Data on utilization of healthcare services and medication were obtained from semi-structured interviews from baseline to 1-year after treatment. Results of the Friedman non-parametric analysis reveal a significant decrease in overall and mental health-related costs following treatment. This study shows a significant reduction in healthcare costs following cognitive behavior therapy for panic disorder with agoraphobia. More studies are needed to examine the potential long-term cost-offset effect of empirically supported treatments for panic disorder.

Predictors of intellectual function after a unilateral cortical lesion: study of 635 patients from infancy to adulthood.

This study investigated potential predictors of intellectual outcome in 417 children and 218 adults who had sustained a unilateral cortical lesion. Of these, 295 cases were collected from the scientific literature and 340 from medical records at seven hospitals in Canada Different sets of predictors emerged for the Wechsler Verbal and Performance IQ values, accounting for differing variances (i.e., 12.4% and 20.1%, respectively). The volume of the lesion was the factor that explained the most variance (i.e., 4.95% and 11.7%, respectively). Age at lesion onset was significantly and positively correlated with verbal intelligence scores. This variable, considered independently or in interaction with other predictors, did not account for a large portion of the variance explained in intelligence. This refutes the commonly held notion that early onset of the insults results in a better prognosis.

Conflict, social support, and relationship quality: an observational study of heterosexual, gay male, and lesbian couples' communication.

Data from 42 heterosexual, 46 gay male, and 33 lesbian couples were used to assess the contribution of conflict and support discussions to relationship quality. Couples completed questionnaires, and videotaped discussions were coded for levels of negative and positive behaviors. Correlations showed that behaviors were associated with relationship quality in the expected directions. Hierarchical linear modeling analyses assessed the unique contributions of individual and dyadic behaviors to the variability of relationship quality. The findings indicated that, beyond the contribution of individual negative behaviors in the conflict task, the variables of dyadic positive behaviors in the conflict task, individual positive behaviors in the support task, and perceived help accounted for unexplained variance in relationship quality. There were no differences between types of couples on levels of behaviors or on their contributions to relationship quality.