bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lessons learnt from the Pietermaritzburg experience with damage control laparotomy for trauma
Authors: Weale Ross D , Kong V Y , Blodgett J M , Buitendag J , Ras A , Laing G , Bruce J L , Bekker W , Manchev V , Clarke D 
Published: June 2018

IntroductionThe modern concept of damage control surgery (DCS) for trauma was first introduced less than three decades ago. This audit aims to describe the spectrum and outcome of patients requiring DCS, to benchmark our experience against that reported from other centres and countries and to distil the pertinent teaching lessons from this experience.MethodsAll patients over the age of 15 years undergoing a laparotomy for trauma over the period from December 2012 to July 2016 were retrieved from the trauma registry of the Pietermaritzburg Metropolitan Trauma Service, South Africa. Physiological parameters and visceral injuries were assessed. Statistical analysis was performed using STATA V.15.0.ResultsA total of 562 patients underwent trauma laparotomy during the period under review. The mechanism was penetrating trauma in 81% of cases (453/562). A great proportion of trauma victims were male (503/562, 90%), with a mean age of 29.5±10.8. A total of 99 of these (18%) had a DCS procedure versus 463 (82%) non-DCS. Out of the 99 who required DCS, there were 32 mortalities (32%). The mean physiological parameters for the DCS patient demonstrated acidosis (pH 7.28±0.15) with a raised lactate (5.25 mmol/L±3.71). Our primary repair rates for enteric injuries were surprisingly high.ConclusionJust under 20% of trauma laparotomies require DCS. In this cohort of patients, the mortality rate is just under one-third. Further attention must be paid to refining the appropriate indications for DCS as the margin for error in such a cohort is very small and poor decision-making is difficult to correct. The major lesson from this analysis is that the decision to perform DCS must be made early and communicated appropriately to all those managing the patient.
Sex with a transgender or gender diverse person among patients attending a sexual health centre in Melbourne, Australia
Authors: Cleere Eoin F , Fairley Christopher K , McGrath Launcelot , Bradshaw Catriona S , Chen Marcus Y , Chow Eric P F 
Published: June 2018

Objectives
All males and females attending the Melbourne Sexual Health Centre (MSHC) from August 2017 were asked whether they had had sex with a transgender or gender diverse (TGD) person using computer-assisted self-interviewing (CASI). We aimed to verify the self-reported responses via chart review. The secondary aim of this study was to identify whether having sex with a TGD person was associated with STI risk.

Methods
This was a retrospective chart analysis of patients visiting MSHC between August and December 2017. Chart review was performed to verify the self-reported responses. Multivariable logistic regression was performed to examine the association between having sex with a TGD person and patients’ characteristics and STI risk.

Results
Of the 10 100 male and female consultations, the proportion who reported having sex with a TGD person was 111 (1.0%) and was higher among males (1.3%) than females (0.6%) (p=0.001). After chart review, we could verify 66.9% of the responses, more for males (75.2%) than females (45.2%) (p<0.001). Of the 6822 males, men aged ≥35 years (adjusted OR=2.2; 95% CI 1.1 to 4.1) were more likely to have sex with a TGD person compared with men aged ≤24 years, after adjusting for confounding factors. Sex with a TGD person was not associated with sexual orientation in males. Of the 3278 females, gay and bisexual females had 13.7-fold (95% CI 5.1 to 37.0) higher odds of having sex with a TGD person than heterosexual females. There was no association between chlamydia positivity and sex with a TGD person in both males and females.

Conclusion
When a question on TGD partners is asked as part of routine sexual history using CASI, the majority of responses could be verified. TGD partners were most commonly reported among males. These findings underscore the value of asking patients about sex with TGD partners.
A groove engineered ultralow frequency piezomems energy harvester with ultrahigh output voltage
Authors: Kordrostami Zoheir , Roohizadegan Sajjad 
Published: June 2018

In this paper, for the first time, a new design for a MEMS cantilever-based energy harvester (EH) has been proposed which takes advantage of two engineered piezoelectric layers. The output voltage of the EH has been increased by the aid of making grooves in the piezoelectric layers. By application of the grooves in the piezoelectric layers, the sensitivity of the cantilever as the vibration sensor or the EH has been improved. Results have shown that these grooves can increase the output voltage and decrease the resonance frequency which are desired changes in designing EHs. The single and double groove bimorph cantilevers have been compared and discussed. The position, length and depth of the grooves have been used as optimization parameters and consequently an optimal design has been proposed at the end of the paper. In the optimal design the top and the bottom piezoelectric layers have not covered the entire beam and have different lengths to produce maximum voltage. By means of groove engineering, we could rise the voltage from 5.395 V to 28.35 V which is considered a great improvement compared to other structures reported previously.
Dirac–Bergmann constraints in physics: Singular Lagrangians, Hamiltonian constraints and the second Noether theorem
Authors: Lusanna Luca 
Published: June 2018

There is a review of the main mathematical properties of system described by singular Lagrangians and requiring Dirac–Bergmann theory of constraints at the Hamiltonian level. The following aspects are discussed:(i)the connection of the rank and eigenvalues of the Hessian matrix in the Euler–Lagrange equations with the chains of first- and second-class constraints;(ii)the connection of the Noether identities of the second Noether theorem with the Hamiltonian constraints;(iii)the Shanmugadhasan canonical transformation for the identification of the gauge variables and for the search of the Dirac observables, i.e. the quantities invariant under Hamiltonian gauge transformations.
A novel fibroblast activation inhibitor attenuates left ventricular remodeling and preserves cardiac function in heart failure
Authors: Bradley Jessica M. , Spaletra Pablo , Li Zhen , Sharp Thomas E. , Goodchild Traci T. , Corral Laura G. , Fung Leah , Chan Kyle W. H. , Sullivan Robert W. , Swindlehurst Cathy A. , Lefer David J. 
Published: June 2018

Cardiac fibroblasts are critical mediators of fibrotic remodeling in the failing heart and transform into myofibroblasts in the presence of profibrotic factors such as transforming growth factor-β. Myocardial fibrosis worsens cardiac function, accelerating the progression to decompensated heart failure (HF). We investigated the effects of a novel inhibitor (NM922; NovoMedix, San Diego, CA) of the conversion of normal fibroblasts to the myofibroblast phenotype in the setting of pressure overload-induced HF. NM922 inhibited fibroblast-to-myofibroblast transformation in vitro via a reduction of activation of the focal adhesion kinase-Akt-p70S6 kinase and STAT3/4E-binding protein 1 pathways as well as via induction of cyclooxygenase-2. NM922 preserved left ventricular ejection fraction ( P < 0.05 vs. vehicle) and significantly attenuated transverse aortic constriction-induced LV dilation and hypertrophy ( P < 0.05 compared with vehicle). NM922 significantly ( P < 0.05) inhibited fibroblast activation, as evidenced by reduced myofibroblast counts per square millimeter of tissue area. Picrosirius red staining demonstrated that NM922 reduced ( P < 0.05) interstitial fibrosis compared with mice that received vehicle. Similarly, NM922 hearts had lower mRNA levels ( P < 0.05) of collagen types I and III, lysyl oxidase, and TNF-α at 16 wk after transverse aortic constriction. Treatment with NM922 after the onset of cardiac hypertrophy and HF resulted in attenuated myocardial collagen formation and adverse remodeling with preservation of left ventricular ejection fraction. Future studies are aimed at further elucidation of the molecular and cellular mechanisms by which this novel antifibrotic agent protects the failing heart. NEW & NOTEWORTHY Our data demonstrated that a novel antifibrotic agent, NM922, blocks the activation of fibroblasts, reduces the formation of cardiac fibrosis, and preserves cardiac function in a murine model of heart failure with reduced ejection fraction.
Simultaneous and opposing horizontal VOR adaptation in humans suggests functionally independent neural circuits
Authors: Gimmon Yoav , Migliaccio Americo A. , Todd Christopher J. , Figtree William V. C. , Schubert Michael C. 
Published: June 2018

The healthy vestibulo-ocular reflex (VOR) ensures that images remain on the fovea of the retina during head rotation to maintain stable vision. VOR behavior can be measured as a summation of linear and nonlinear properties although it is unknown whether asymmetric VOR adaptation can be performed synchronously in humans. The purpose of the present study is twofold. First, examine whether the right and left VOR gains can be synchronously adapted in opposing directions. Second, to investigate whether the adaptation context transfers between both sides. Three separate VOR adaptation sessions were randomized such that the VOR was adapted Up-bilaterally, Down-bilaterally, or Mixed (one side up, opposite side down). Ten healthy subjects completed the study. Subjects were tested while seated upright, 1 meter in front of a wall in complete dark. Each subject made active (self-generated) head impulse rotations for 15 min while viewing a gradually increasing amount of retinal slip. VOR training demand changed by 10% every 90 s. The VOR changed significantly for all training conditions. No significant differences in the magnitude of VOR gain changes between training conditions were found. The human VOR can be simultaneously driven in opposite directions. The similar magnitude of VOR gain changes across training conditions suggests functionally independent VOR circuits for each side of head rotation that mediate simultaneous and opposing VOR adaptations.NEW & NOTEWORTHY Our results indicate that humans have the adaptive capacity for concurrent and opposing directions of vestibulo-ocular reflex (VOR) motor learning. Context specificity of VOR adaptation is dependent on the error signal being unilateral or bilateral, which we illustrate via a lack of VOR gain transfer using unique adaptive demands.
Hyperexcitability of brain stem pathways in cerebral palsy
Authors: Smith A. T. , Gorassini M. A. 
Published: June 2018

Individuals with cerebral palsy (CP) experience impairments in the control of head and neck movements, suggesting dysfunction in brain stem circuitry. To examine if brain stem circuitry is altered in CP, we compared reflexes evoked in the sternocleidomastoid (SCM) muscle by trigeminal nerve stimulation in adults with CP and in age/sex-matched controls. Increasing the intensity of trigeminal nerve stimulation produced progressive increases in the long-latency suppression of ongoing SCM electromyography in controls. In contrast, participants with CP showed progressively increased facilitation around the same reflex window, suggesting heightened excitability of brain stem pathways. We also examined if there was altered activation of cortico-brain stem pathways in response to prenatal injury of the brain. Motor-evoked potentials (MEPs) in the SCM that were conditioned by a prior trigeminal afferent stimulation were more facilitated in CP compared with controls, especially in ipsilateral MEPs that are likely mediated by corticoreticulospinal pathways. In some participants with CP, but not in controls, a combined trigeminal nerve and cortical stimulation near threshold intensities produced large, long-lasting responses in both the SCM and biceps brachii muscles. We propose that the enhanced excitatory responses evoked from trigeminal and cortical inputs in CP are produced by heightened excitability of brain stem circuits, resulting in the augmented activation of reticulospinal pathways. Enhanced activation of reticulospinal pathways in response to early injury of the corticospinal tract may provide a compensated activation of the spinal cord or, alternatively, contribute to impairments in the precise control of head and neck functions. NEW & NOTEWORTHY This is the first study to show that in adults with spastic cerebral palsy, activation of brain stem circuits by cortical and/or trigeminal afferents produces excitatory responses in anterior neck muscles compared with inhibitory responses in age/sex-matched controls. This may reflect a more excitable reticulospinal tract in response to early brain injury to provide a compensated activation of postural muscles. On the other hand, a hyperexcitable brain stem may contribute to impairments in the precise control of head and neck functions.
Effects of pruritogens and algogens on rostral ventromedial medullary ON and OFF cells
Authors: Follansbee T. , Akiyama T. , Fujii M. , Davoodi A. , Nagamine M. , Iodi Carstens M. , Carstens E. 
Published: June 2018

Rostroventromedial medulla (RVM) ON and OFF cells are thought to facilitate and inhibit spinal nociceptive transmission, respectively. However, it is unknown how ON and OFF cells respond to pruritic stimuli or how they contribute to descending modulation of spinal itch signaling. In pentobarbital sodium-anesthetized mice, single-unit recordings were made in RVM from ON and OFF cells identified by their respective increase or decrease in firing that occurred just before nocifensive hindlimb withdrawal elicited by paw pinch. Of RVM ON cells, 75% (21/28) were excited by intradermal histamine, 50% (10/20) by intradermal chloroquine, and 75% (27/36) by intradermal capsaicin. Most chemically responsive units also responded to a scratch stimulus applied to the injected hindpaw. Few ON cells responded to intradermal injection of vehicle (saline: 5/32; Tween 2/17) but still responded to scratching. For OFF cells, intradermal histamine and scratching inhibited 32% (6/19) with no effect of histamine in the remainder. Intradermal chloroquine inhibited 44% (4/9) and intradermal capsaicin inhibited 61% (11/18) of OFF cells. Few OFF cells were affected by vehicles (Tween: 1 inhibited, 7 unaffected; saline: 3 excited, 1 inhibited, 8 unaffected). Both ON and OFF cells that responded to one chemical usually also responded to others, whereas units unresponsive to the first-tested chemical tended not to respond to others. These results indicate that ascending pruriceptive signals activate RVM ON cells and inhibit RVM OFF cells. These effects are considered to facilitate and disinhibit spinal pain transmission, respectively. It is currently not clear if spinal itch transmission is similarly modulated.NEW & NOTEWORTHY The rostroventromedial medulla (RVM) contains ON and OFF cells that are, respectively, excited and inhibited by noxious stimuli and have descending projections that facilitate and inhibit spinal nociceptive transmission. Most RVM ON cells were excited, and OFF cells inhibited, by intradermal injection of the pruritogens histamine and chloroquine, as well as the algogen capsaicin. These results indicate that itchy stimuli activate RVM neurons that presumably give rise to descending modulation of spinal itch transmission.
Blunted cardiovascular responses to exercise in Parkinson’s disease patients: role of the muscle metaboreflex
Authors: Sabino-Carvalho Jeann L. , Teixeira André L. , Samora Milena , Daher Maurício , Vianna Lauro C. 
Published: June 2018

Patients with Parkinson’s disease (PD) exhibit attenuated cardiovascular responses to exercise. The underlying mechanisms that are potentially contributing to these impairments are not fully understood. Therefore, we sought to test the hypothesis that patients with PD exhibit blunted cardiovascular responses to isolated muscle metaboreflex activation following exercise. For this, mean blood pressure, cardiac output, and total peripheral resistance were measured using finger photoplethysmography and the Modelflow method in 11 patients with PD [66 ± 2 yr; Hoehn and Yahr score: 2 ± 1 a.u.; time since diagnosis: 7 ± 1 yr; means ± SD) and 9 age-matched controls (66 ± 3 yr). Measurements were obtained at rest, during isometric handgrip exercise performed at 40% maximal voluntary contraction, and during postexercise ischemia. Also, a cold pressor test was assessed to confirm that blunted cardiovascular responses were specific to exercise and not representative of generalized sympathetic responsiveness. Changes in mean blood pressure were attenuated in patients with PD during handgrip (PD: ∆25 ± 2 mmHg vs. controls: ∆31 ± 3 mmHg; P < 0.05), and these group differences remained during postexercise ischemia (∆17 ± 1 mmHg vs. ∆26 ± 1 mmHg, respectively; P < 0.01). Additionally, changes in total peripheral resistance were attenuated during exercise and postexercise ischemia, indicating blunted reflex vasoconstriction in patients with PD. Responses to cold pressor test did not differ between groups, suggesting no group differences in generalized sympathetic responsiveness. Our results support the concept that attenuated cardiovascular responses to exercise observed in patients with PD are, at least in part, explained by an altered skeletal muscle metaboreflex. NEW & NOTEWORTHY Patients with Parkinson’s disease (PD) presented blunted cardiovascular responses to exercise. We showed that cardiovascular response evoked by the metabolic component of the exercise pressor reflex is blunted in patients with PD. Furthermore, patients with PD presented similar pressor response during the cold pressor test compared with age-matched controls. Altogether, our results support the hypothesis that attenuated cardiovascular responses to exercise observed in patients with PD are mediate by an altered skeletal muscle metaboreflex.
Hyperoxia enhances slow-wave forebrain states in urethane-anesthetized and naturally sleeping rats
Authors: Hauer Brandon E. , Negash Biruk , Chan Kingsley , Vuong Wesley , Colbourne Frederick , Pagliardini Silvia , Dickson Clayton T. 
Published: June 2018

Oxygen (O2) is a crucial element for physiological functioning in mammals. In particular, brain function is critically dependent on a minimum amount of circulating blood levels of O2 and both immediate and lasting neural dysfunction can result following anoxic or hypoxic episodes. Although the effects of deficiencies in O2 levels on the brain have been reasonably well studied, less is known about the influence of elevated levels of O2 (hyperoxia) in inspired gas under atmospheric pressure. This is of importance due to its typical use in surgical anesthesia, in the treatment of stroke and traumatic brain injury, and even in its recreational or alternative therapeutic use. Using local field potential (EEG) recordings in spontaneously breathing urethane-anesthetized and naturally sleeping rats, we characterized the influence of different levels of O2 in inspired gases on brain states. While rats were under urethane anesthesia, administration of 100% O2 elicited a significant and reversible increase in time spent in the deactivated (i.e., slow-wave) state, with concomitant decreases in both heartbeat and respiration rates. Increasing the concentration of carbon dioxide (to 5%) in inspired gas produced the opposite result on EEG states, mainly a decrease in the time spent in the deactivated state. Consistent with this, decreasing concentrations of O2 (to 15%) in inspired gases decreased time spent in the deactivated state. Further confirmation of the hyperoxic effect was found in naturally sleeping animals where it similarly increased time spent in slow-wave (nonrapid eye movement) states. Thus alterations of O2 in inspired air appear to directly affect forebrain EEG states, which has implications for brain function, as well as for the regulation of brain states and levels of forebrain arousal during sleep in both normal and pathological conditions. NEW & NOTEWORTHY We show that alterations of oxygen concentration in inspired air biases forebrain EEG state. Hyperoxia increases the prevalence of slow-wave states. Hypoxia and hypercapnia appear to do the opposite. This suggests that oxidative metabolism is an important stimulant for brain state.
Detecting multivariate cross-correlation between brain regions
Authors: Rodu Jordan , Klein Natalie , Brincat Scott L. , Miller Earl K. , Kass Robert E. 
Published: June 2018

The problem of identifying functional connectivity from multiple time series data recorded in each of two or more brain areas arises in many neuroscientific investigations. For a single stationary time series in each of two brain areas statistical tools such as cross-correlation and Granger causality may be applied. On the other hand, to examine multivariate interactions at a single time point, canonical correlation, which finds the linear combinations of signals that maximize the correlation, may be used. We report here a new method that produces interpretations much like these standard techniques and, in addition, 1) extends the idea of canonical correlation to 3-way arrays (with dimensionality number of signals by number of time points by number of trials), 2) allows for nonstationarity, 3) also allows for nonlinearity, 4) scales well as the number of signals increases, and 5) captures predictive relationships, as is done with Granger causality. We demonstrate the effectiveness of the method through simulation studies and illustrate by analyzing local field potentials recorded from a behaving primate. NEW & NOTEWORTHY Multiple signals recorded from each of multiple brain regions may contain information about cross-region interactions. This article provides a method for visualizing the complicated interdependencies contained in these signals and assessing them statistically. The method combines signals optimally but allows the resulting measure of dependence to change, both within and between regions, as the responses evolve dynamically across time. We demonstrate the effectiveness of the method through numerical simulations and by uncovering a novel connectivity pattern between hippocampus and prefrontal cortex during a declarative memory task.