Megahertz pulse trains enable multi-hit serial femtosecond crystallography experiments at X-ray free electron lasers.

The European X-ray Free Electron Laser (XFEL) and Linac Coherent Light Source (LCLS) II are extremely intense sources of X-rays capable of generating Serial Femtosecond Crystallography (SFX) data at megahertz (MHz) repetition rates. Previous work has shown that it is possible to use consecutive X-ray pulses to collect diffraction patterns from individual crystals. Here, we exploit the MHz pulse structure of the European XFEL to obtain two complete datasets from the same lysozyme crystal, first hit and the second hit, before it exits the beam. The two datasets, separated by <1 µs, yield up to 2.1 Å resolution structures. Comparisons between the two structures reveal no indications of radiation damage or significant changes within the active site, consistent with the calculated dose estimates. This demonstrates MHz SFX can be used as a tool for tracking sub-microsecond structural changes in individual single crystals, a technique we refer to as multi-hit SFX.

Massive X-ray screening reveals two allosteric drug binding sites of SARS-CoV-2 main protease

The coronavirus disease (COVID-19) caused by SARS-CoV-2 is creating tremendous health problems and economical challenges for mankind. To date, no effective drug is available to directly treat the disease and prevent virus spreading. In a search for a drug against COVID-19, we have performed a massive X-ray crystallographic screen of two repurposing drug libraries against the SARS-CoV-2 main protease (Mpro), which is essential for the virus replication and, thus, a potent drug target. In contrast to commonly applied X-ray fragment screening experiments with molecules of low complexity, our screen tested already approved drugs and drugs in clinical trials. From the three-dimensional protein structures, we identified 37 compounds binding to Mpro. In subsequent cell-based viral reduction assays, one peptidomimetic and five non-peptidic compounds showed antiviral activity at non-toxic concentrations. We identified two allosteric binding sites representing attractive targets for drug development against SARS-CoV-2.

Ultracompact 3D microfluidics for time-resolved structural biology.

To advance microfluidic integration, we present the use of two-photon additive manufacturing to fold 2D channel layouts into compact free-form 3D fluidic circuits with nanometer precision. We demonstrate this technique by tailoring microfluidic nozzles and mixers for time-resolved structural biology at X-ray free-electron lasers (XFELs). We achieve submicron jets with speeds exceeding 160 m s-1, which allows for the use of megahertz XFEL repetition rates. By integrating an additional orifice, we implement a low consumption flow-focusing nozzle, which is validated by solving a hemoglobin structure. Also, aberration-free in operando X-ray microtomography is introduced to study efficient equivolumetric millisecond mixing in channels with 3D features integrated into the nozzle. Such devices can be printed in minutes by locally adjusting print resolution during fabrication. This technology has the potential to permit ultracompact devices and performance improvements through 3D flow optimization in all fields of microfluidic engineering.

[Review of assessment methods used to evaluate feeding for children with pervasive developmental disorder]. / Revue des méthodes utilisées pour évaluer l'alimentation des enfants présentant un trouble envahissant du développement.

Current evaluations used by occupational therapists to assess and treat feeding problems derive mainly from the domain of dysphagia. The purpose of this article is to familiarize the reader with tools used, in research, for children with pervasive developmental disorders (PDD) and to determine if any of these meet the needs of occupational therapists. The following data bases were searched: Medline, CINAHL, HAPI and PsyINFO, using the terms pervasive developmental disorder, autism, Asperger syndrome, pervasive developmental disorder not otherwise specified, eating behavior, eating disorder, food preference, food selectivity, feeding disorders, picky eater and child. All articles published between 1980 and 2006 (n=27) were reviewed. A total of 20 studies met our selection criteria. Assessment methods are compared using the Disability Creation Model (DCP). The DCP is the Quebec alternative to the International Classification of Functioning, Disability and Health (ICF). None of the evaluation tools reviewed met all factors that may influence eating in children with PDD. Implications for research and practice in occupational therapy are discussed.

Effect of an oral stimulation program on sucking skill maturation of preterm infants.

This study assessed the effect of an oral stimulation program on the maturation of sucking skills of preterm infants. Thirty-two preterm infants (13 males, 19 females), appropriate size for gestational age (gestational age at birth 28 wks, SD 1.2wks; birthweight 1002g, SD 251g), were randomly placed into experimental and control groups. The experimental group received a daily 15-minute oral stimulation program, consisting of stroking the peri- and intra-oral structures, for 10 days before the start of oral feedings. Sucking measures were monitored with a specially-designed nipple-bottle apparatus. Results indicate that the experimental group achieved full oral feedings 7 days sooner than the control group, and demonstrated greater overall intake (%), rate of milk transfer (mL/min), and amplitude of the expression component of sucking (mmHg). There was no difference in sucking stage maturation, sucking frequency, and amplitude of the suction component of sucking. Endurance, defined as ability to sustain the same sucking stage, sucking burst duration, and suction and expression amplitudes throughout a feeding session, was not significantly different between the two groups. The stimulation program enhanced the expression component of sucking, resulting in better oral feeding performance.

Impact of oral appliance therapy: are oral skills and growth maintained one year after termination of therapy?

To determine the impact of intraoral appliance (ISMAR) therapy on functional feeding skills and growth, children with cerebral palsy and moderate dysphagia were followed a full year after termination of one year of ISMAR therapy. Seventeen children, 6.6-15.4 years old (mean age = 10.2 +/- 3.0 years), were divided into two groups: group A (n = 9) continued to wear the appliance and group B (n = 8) no longer wore the appliance. Generalized estimating equations (GEE) were used to test differences between the two groups over time while accounting for the dependence for the repeated within-subject measurements. No significant differences were found in the 7 domains of functional feeding. Significant time x group interactions for weight (kg and z-score 0.01 < p < 0.05) were found. However, post hoc analyses showed that there were no significant differences in weight changes between the two groups at either 18 or 24 months of followup. These results suggest that during a one-year period of followup, maturation was equally effective as ISMAR therapy.

Feeding skills and growth after one year of intraoral appliance therapy in moderately dysphagic children with cerebral palsy.

We determined changes in functional feeding skills and growth after one year of intraoral appliance therapy in dysphagic children. Twenty children, 4.2-13.1 years of age (average 8.3 +/- 0.9 years), participated in this study. Children wore the appliance daily. Phase I of treatment (6 months) aimed primarily at stabilizing the mandible and phase II aimed at facilitating ingestive skills. A control period of 6 months preceded treatment. Functional feeding skills improved significantly during phase I beyond changes seen during the control period. Further significant improvement occurred in chewing during phase II. All children significantly gained weight (kg) during the control period, as well as during the two treatment phases. This weight gain was sufficient for children to maintain their growth trajectory. There was also significant growth in height (cm). This growth spurt was characterized by marginal catch-up. Jaw stabilization was a major contributor to the significant improvement in functional feeding skills. Weight gain cannot be attributed to intervention because it occurred during the control period and was the same in magnitude through both treatment phases. However, it permitted a period of growth in stature which previously had been described only after tube feeding.

"Whole body" mobility after one year of intraoral appliance therapy in children with cerebral palsy and moderate eating impairment.

The reciprocal influence of body postures on the oral structures, but also of the oral structures on body postures, has been proposed by clinicians and is taken into consideration when treating children with poor postural control and moderate to severe eating impairments. However, this relationship has not been rigorously investigated. The purpose of this study was to document the possible relationships among oral-motor, postural, and ambulatory control. Ambulatory skills [exclusive use of wheelchair (w/c) vs w/c and ambulation], postural control when sitting, "pathologic" reflexes, and lip and tongue posture were recorded before and after one year of therapy with an intraoral appliance (ISMAR) in 20 children with cerebral palsy and moderate eating impairment. Significant improvement occurred in sitting (head-trunk-foot control) following one year of ISMAR therapy. Ambulatory status also significantly improved above the level of maturation. Half of the children showed marked improvement in oral posture, i.e., their resting mouth posture was closed rather than open. These results support an hypothesis of interaction between oral structures and postural control of the "whole body." Further studies are needed to determine the controls of such a relationship.

Assessment of ingestive and oral praxis skills: children with cerebral palsy vs. controls.

Eating impairments (dysphagia) in children with cerebral palsy (CP) have been well documented. However, individual components of ingestion, such as the feeding skills of eating and drinking and their relationship to oral-motor planning skills (praxis), remain largely undetermined. The purpose of the present study was to examine functional feeding and oral praxis skills in a group of children with CP and mild eating impairment and to compare their skills with a group of age-matched controls. As well, interobserver reliabilities and concurrent validity of these tests were examined to determine their reliability and to what extent they may be measuring similar constructs. Twenty-seven children with CP and 21 age-matched controls, aged 4.0-16 years, participated in this study. Two oral praxis tests (OFMF and OPT) and two standard ingestive skills tests (GVA and FFAm) were administered to each child. Children with CP scored consistently and significantly lower on the OFMF than controls (p < 0.001); similar results were achieved on the OPT (p < 0.001). Children with CP had difficulty with items where there was a high demand for repetition and smooth sequencing. On the ingestive skills tests children with CP took significantly longer for chewing a hard solid food texture than controls (p < 0.001), and functional feeding skills were also significantly poorer than in controls. Interrater reliability coefficients for the OPT and OFMF were excellent (all ICCs > 0.90). There was high concurrent validity between the OPT and OFMF (r = 0.90, p < 0.0001). The correlations for the FFAm and GVA tests were somewhat weaker (r = -0.54, p < 0. 0001). Correlations were negative; as functional feeding scores increased (improved), chewing time decreased (improved). Excellent reliable and valid assessment instruments are available to the practicing clinician. They cover a wide range of oral-motor performance and, so, must be used judiciously and for the purpose that they have been developed.

The Innsbruck Sensorimotor Activator and Regulator (ISMAR): construction of an intraoral appliance to facilitate ingestive functions.

Oral sensorimotor therapy is practiced widely with children who have neuromotor impairments, such as cerebral palsy and eating problems. Although improvement in ingestive skills can be achieved in the short term (5 months), long-term effects (over 12 months) remain to be examined. Interventions with intraoral appliances are used in children with moderate impairments of the oral-motor system and offer an opportunity for long-term treatment. Instead of the daily oral sensorimotor exercises, which must be provided by a qualified therapist, the intraoral appliance is worn during the night, so that the "therapy" is initiated and controlled by the child. The purpose of this paper is to describe the appliance: its prescription, fabrication and therapeutic use. A case study illustrates that improvement in ingestive skills, efficiency of eating, and marked weight gain can be achieved.

Functional oral-motor skills: Do they change with age?

Dysphagia, a difficulty eating or drinking, appears to increase with age and is a concern for our growing elderly population. Mastication, tongue mobility, and lip closure are skills of the oral phase of ingestion, and have been shown to deteriorate with age. However, it is not clear whether these changes affect functional feeding. It is also unclear whether dysphagia is the result of the aging process itself, or whether it is secondary to disease. Therefore, the purpose of this study was to identify changes during the oral phase of ingestion in a group of healthy seniors. Functional feeding skills and oral praxis abilities were measured in 79 healthy adults aged 60-97 years. The Modified Functional Feeding Assessment (FFAm) subscale of the Multidisciplinary Feeding Profile (MFP) and the Oral Praxis Subtest (OPS) of the Southern California Sensory Integration Test were administered respectively. An interview followed to obtain information on denture wear, use of hearing aids and glasses, and types of foods avoided. Seniors maintained functional feeding skills throughout the four decades studied. These skills were not age-dependent, but depended on whether or not subjects wore full dentures. Even though all of the seniors maintained functional feeding skills, more seniors in the younger group (7th decade 60%, 8th decade 67%) had difficulty with a variety of food textures such as soft, hard, fibrous, and some with tough skins, than the older group (9th decade 40%, 10th decade 44%). Oral praxis abilities were correlated significantly with age, but not with hearing aid use. Overall, healthy seniors maintained their functional feeding and oral praxis skills. Good health and natural dentition appear to be excellent indicators for functional feeding ability.

Feeding impairments in children: diagnosis and effective intervention.

The four main requirements for oral-motor development are stability and mobility of the ingestive system, rhythmicity, sensation, oral-motor efficiency and economy. Ingestion can be divided into oral, pharyngeal and esophageal stages. The main categories of pathology encountered in our swallowing and dysphagia clinic are encephalopathies (including cerebral palsy), genetic disorders (including chromosomal aberrations), syndromes associated with swallowing difficulty (e.g. Rett, Dandy-Walker, DiGeorge), head injuries, brain tumors, developmental delay and the oral deprivation syndrome (e.g. due to prolonged tube feeding on a preterm infant). The behavioral expression of the many different pathologies falls into three categories: (1) resistance to accepting food orally; (2) lack of energy and endurance to do the 'work' of eating; and (3) oral-motor disabilities resulting in an inability to produce the necessary motor skills for ingestion. Expect expression and exacerbation of feeding problems during periods of most active growth, i.e. from birth to 2 years and during the adolescent growth spurt. Identify the source of the feeding problem. Establish its pathology and note the clinical manifestations. Determine if the problem has a strictly physiologic origin or whether it may be exacerbated by the feeding interaction between child and feeder. Determine what diagnostic tests are needed and refer child for testing Formulate the treatment approach based on clinical observations and results of diagnostic tests. Teach and monitor treatment which can be given by caregivers. Set time limits for treatment and clearly state expected results. Evaluate progress by comparing outcome to stated treatment objectives. Refer children with more severe problems to a multidisciplinary treatment team.

Neonatal sucking and maternal feeding practices.

This study is the first to demonstrate an association between neonatal and later sucking ability, clinical signs of feeding ability and maternal feeding practices. Of 49 infants followed to a mean age of six weeks, 20 had some feeding problems (compensatory group), based on changes in feeding practices by their mothers, and 29 did not (non-compensatory group). Infants in the compensatory group performed less well on initial and follow-up sucking measures than infants in the non-compensatory group, indicating that they were feeding less efficiently from birth. Also, infants in the compensatory group ingested less during follow-up testing and were reported to be fed more frequently at home by their mothers than infants in the non-compensatory group. These findings strongly suggest that even among healthy infants, there may be more with problematic feeding abilities than have been previously recognized and that mothers are a reliable source of information about their infants' feeding abilities.

Effect of oral sensorimotor treatment on measures of growth and efficiency of eating in the moderately eating-impaired child with cerebral palsy.

Thirty-five children with cerebral palsy and moderate eating impairment were studied to determine the effect of oral sensorimotor treatment (OST) on eating efficiency and measures of growth (weight gain). After taking effects of maturation into account, 11 children who received OST (group A) exceeded their expected centile line by 1.7 percentile points after 10 weeks of treatment. Chewing exercises alone (group B) had no effect on weight gain. Although small decreases occurred in the time needed to eat three standard textures of food (solid, viscous, puree) in groups A and B, these were not significant. Children maintained their weight-for-age percentile line although at the lower end of expected norms. These children will be at risk of growth failure because of the increased energy demands once they enter their teenage growth spurt. The clinical implications of these findings are that prolonged mealtime and oral-motor therapies may be adequate through the childhood years. Thereafter, children's growth must be monitored carefully, and oral caloric supplementation is suggested to provide the necessary energy for growth.

Oral-motor skills following sensorimotor therapy in two groups of moderately dysphagic children with cerebral palsy: aspiration vs nonaspiration.

The purpose of this study was to determine the effect of oral sensorimotor treatment on oral-motor skills and measures of growth in moderately eating impaired children with cerebral palsy who were stratified by state of aspiration/nonaspiration. Twenty-seven children aged 2.5-10.0 years participated in this study (aspiration: n = 7, nonaspiration: n = 20). Weight and skinfold measures were taken. Children were observed at lunch time and six domains of feeding were examined: spoon feeding, biting, chewing, cup drinking, straw drinking, swallowing, and drooling. Children underwent 10 weeks of control and 10 weeks of sensorimotor treatment, 5-7 minutes/day, 5 days/week. Treatment compliance for the entire group was 67%. Children who aspirated had significantly poorer oral-motor skills in spoon feeding, biting, chewing, and swallowing than children who did not aspirate. There was significant improvement in eating: spoon feeding (fewer abnormal behaviors, p < 0.03), chewing (more normal behaviors, p < 0.003), and swallowing (more normal behaviors, p < 0.008). There were no significant changes in drinking skills. Children as a group maintained their pretreatment weight-age percentile but did not show any catch-up growth. Children showed adequate energy reserves as measured by skinfold thicknesses. Improvement in oral-motor skills may help these children to ingest food more competently (i.e., less spillage). However, their weight remains at the lowest level of age norms.

Campo electromagnético pulsatil en el tratamiento de pseudoartrosis y defectos oseos / Pulsed electromagnetic fields in the treatment of pseudoarthrosis and bone defects

Se realizó un estudio clínico en 2 grupos de pacientes con alteraciones de la continuidad ósea incluidos pacientes con pseudoartrosis ydefectos óseos, a los cuales se les aplicó el campo electromagnético pulsátil a nivel de la región afectada como tratamiento coadyuvante para evaluar los efectos de éste en la inducción de la osteogénesis. El universo de trabajo estuvo formado por 19 pacientes de ambos sexos cuyas edades variaron desde 5 a 72 años. Se obtuvo un éxito de 88,8 por ciento. Se valoraron las características de la respuesta osteogénica (AU)

Campo electromagnetico pulsatil en el tratamiento de pseudoartrosis y defectos oseos / Pulsed electromagnetic fields in the treatment of pseudoarthrosis and bone defects

Se realizo un estudio clinico en 2 grupos de pacientes con alteraciones de la continuidad osea incluidos pacientes con pseudoartrosis ydefectos oseos, a los cuales se les aplico el campo electromagnetico pulsatil a nivel de la region afectada como tratamiento coadyuvante para evaluar los efectos de este en la induccion de la osteogenesis. El universo de trabajo estuvo formado por 19 pacientes de ambos sexos cuyas edades variaron desde 5 a 72 anos. Se obtuvo un exito de 88,8 por ciento. Se valoraron las caracteristicas de la respuesta osteogenica

Effect of oral sensorimotor treatment on measures of growth, eating efficiency and aspiration in the dysphagic child with cerebral palsy.

Twenty-seven children (mean age 5.1 years) with cerebral palsy and moderate eating impairment were studied to determine frequency of aspiration and the effect of 10 and 20 weeks of oral sensorimotor therapy on eating efficiency and measures of growth (weight, skinfold thickness). The eating efficiency of the children did not change markedly in response to oral sensorimotor therapy. Children maintained their centile rank in weight-for-age and skinfold-for-age measurements. However, there was no catch-up growth. The findings suggest that eating efficiency is not a good estimator of treatment outcome, but rather a diagnostic indicator of the severity of eating impairment. Monitoring of these children's growth is essential in order to provide nutritional rehabilitation as soon as their eating skills can no longer keep up with growth demands.

Classification of eating impairments based on eating efficiency in children with cerebral palsy.

Eating impairments in children with cerebral palsy (CP) may vary widely from mild to severe. Accurate diagnosis of the severity of eating has been hampered by the lack of a classification system which would permit stratification of this wide range of problems into mild, moderate, and severe. We propose such a classification system based on measures of (1) growth: weight, height, and skinfold thickness and (2) eating skills: eating efficiency and oral-motor skills. One hundred children, 54 boys and 46 girls from 2 to 16 years, who had various degrees of CP and eating impairments, were studied. Classification, treatment effectiveness, as well as the implications for growth monitoring, based on this classification system are discussed. system are discussed.