Somatic embryogenesis and plantlet regeneration from protoplast culture of Muscari neglectum Guss

A protocol has been developed for plant regeneration from protoplast culture of Muscari neglectum using regenerable embryogenic calli obtained from bulb culture on Murashige and Skoog medium (MS) plant growth regulators (PGR)-free or containing lower 1-naphthaleneacetic acid (NAA) and 6- benzylaminopurine (BA) concentrations and 30 g/l sucrose. Protoplasts were isolated directly from embryogenic calli, embedded in Ca-alginate beads and cultured with nurse cells in MS medium supplemented with 1 mg/l each of NAA and BA, 100 mg/l ascorbic acid and 0.5 M mannitol at 25°C in darkness. After 4 weeks of culture, microcalli appeared on the surface of the Ca-alginate beads. Growth of microcalli in the medium with nurse cells (33.3%) was much better than those in the medium without nurse cells (6.5%). Transferring beads onto MS medium supplemented with 0.1 mg/l BA increased the growth of embryogenic calli. Somatic embryo development was observed either on half strength MS medium PGR-free or with 1 mg/l abscisic acid at 25°C under continuous illumination with fluorescent light. Maturated embryos germinated and then converted to plantlets on half strength MS medium containing 1 mg/l BA after 3 months. The plantlets left in the medium produced bulbs after 5 months.Key words: Ca-alginate beads, Muscari neglectum, nurse culture, plantlet regeneration, protoplast culture, somatic embryogenesis

Identification and comparison of the yield and composition of essential oil constituents of four Eucalyptus species adapted to the climatic conditions of Khorramabad

Introduction: Eucalyptus has more than 400 species, while only a few species of this genus have been imported in Iran. In this study we aimed to investigate chemical compounds of the essential oils of Eucalyptus species adapted in Lorestan climate. Methods: In this study, the fresh young leaves of four different Eucalyptus species including E. suggrandis, E. globulus subsp. bicostata, E. nitens and E. globulus subsp. maidenii were collected in spring (the middle of May) in khorramabad, Iran. The powder of air-dried leaves of different species of Eucalyptus was subjected to hydro-distillation using a Clevenger-type apparatus. The chemical compositions of different essential oils were detected using gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC/MS) and determination of their retention time (RT), retention index (RI) and Mass Spectra. The obtained data were analyzed using SPSS software. Results: The results of this study indicated that there was significant difference (P&lt;0.01) among the yield and chemical compounds of the essential oils of studied species. The results showed that the yield of essential oil extracted from E. suggrandis, E. globulus bicostata, E. nitens and E. globulus maidenii were 1.12, 1.34, 2.57 and 5.38, respectively. Conclusion: The essential oil constituents of four Eucalyptus species plant were different in among of some compounds. E. globulus maidenii&nbsp; &nbsp;had most content of essential oil and 1.8-Cineole compound so it is necessary to identify quality and quantity characteristics of compounds available in this plant.</p

Coherent control of the cooperative branching ratio for nuclear x-ray pumping

Coherent control of nuclear pumping in a three level system driven by x-ray light is investigated. In single nuclei, the pumping performance is determined by the branching ratio of the excited state populated by the x-ray pulse. Our results are based on the observation that in ensembles of nuclei, cooperative excitation and decay leads to a greatly modified nuclear dynamics, which we characterize by a time-dependent cooperative branching ratio. We discuss prospects of steering the x-ray pumping by coherently controlling the cooperative decay. First, we study an ideal case with purely superradiant decay and perfect control of the cooperative emission. A numerical analysis of x-ray pumping in nuclear forward scattering with coherent control of the cooperative decay via externally applied magnetic fields is presented. Next, we provide an extended survey of nuclei suitable for our scheme, and propose proof-of-principle implementations already possible with typical M\"ossbauer nuclear systems such as $^{57}\mathrm{Fe}$. Finally, we discuss the application of such control techniques to the population or depletion of long-lived nuclear states.Comment: 11 pages, 8 figures; updated to the published versio

An international validation of the AO spine subaxial injury classification system.

PURPOSE To validate the AO Spine Subaxial Injury Classification System with participants of various experience levels, subspecialties, and geographic regions. METHODS A live webinar was organized in 2020 for validation of the AO Spine Subaxial Injury Classification System. The validation consisted of 41 unique subaxial cervical spine injuries with associated computed tomography scans and key images. Intraobserver reproducibility and interobserver reliability of the AO Spine Subaxial Injury Classification System were calculated for injury morphology, injury subtype, and facet injury. The reliability and reproducibility of the classification system were categorized as slight (ƙ = 0-0.20), fair (ƙ = 0.21-0.40), moderate (ƙ = 0.41-0.60), substantial (ƙ = 0.61-0.80), or excellent (ƙ = > 0.80) as determined by the Landis and Koch classification. RESULTS A total of 203 AO Spine members participated in the AO Spine Subaxial Injury Classification System validation. The percent of participants accurately classifying each injury was over 90% for fracture morphology and fracture subtype on both assessments. The interobserver reliability for fracture morphology was excellent (ƙ = 0.87), while fracture subtype (ƙ = 0.80) and facet injury were substantial (ƙ = 0.74). The intraobserver reproducibility for fracture morphology and subtype were excellent (ƙ = 0.85, 0.88, respectively), while reproducibility for facet injuries was substantial (ƙ = 0.76). CONCLUSION The AO Spine Subaxial Injury Classification System demonstrated excellent interobserver reliability and intraobserver reproducibility for fracture morphology, substantial reliability and reproducibility for facet injuries, and excellent reproducibility with substantial reliability for injury subtype

Development of Online Technique for International Validation of the AO Spine Subaxial Injury Classification System.

STUDY DESIGN Global cross-sectional survey. OBJECTIVE To develop and refine the techniques for web-based international validation of fracture classification systems. METHODS A live webinar was organized in 2018 for validation of the AO Spine Subaxial Injury Classification System, consisting of 35 unique computed tomography (CT) scans and key images with subaxial spine injuries. Interobserver reliability and intraobserver reproducibility was calculated for injury morphology, subtype, and facet injury according to the classification system. Based on the experiences from this webinar and incorporating rater feedback, adjustments were made in the organization and techniques used and in 2020 a repeat validation webinar was performed, evaluating images of 41 unique subaxial spine injuries. RESULTS In the 2018 session, the AO Spine Subaxial Injury Classification System demonstrated fair interobserver reliability for fracture subtype (κ = 0.35) and moderate reliability for fracture morphology and facet injury (κ=0.45, 0.43, respectively). However, in 2020, the interobserver reliability for fracture morphology (κ = 0.87) and fracture subtype (κ = 0.80) was excellent, while facet injury was substantial (κ = 0.74). Intraobserver reproducibility for injury morphology (κ =0.49) and injury subtype/facet injury were moderate (κ = 0.42) in 2018. In 2020, fracture morphology and subtype reproducibility were excellent (κ =0.85, 0.88, respectively) while reproducibility for facet injuries was substantial (κ = 0.76). CONCLUSION With optimized webinar-based validation techniques, the AO Spine Subaxial Injury Classification System demonstrated vast improvements in intraobserver reproducibility and interobserver reliability. Stringent fracture classification methodology is integral in obtaining accurate classification results

The Influence of Regional Differences on the Reliability of the AO Spine Sacral Injury Classification System.

STUDY DESIGN Global cross-sectional survey. OBJECTIVE To explore the influence of geographic region on the AO Spine Sacral Classification System. METHODS A total of 158 AO Spine and AO Trauma members from 6 AO world regions (Africa, Asia, Europe, Latin and South America, Middle East, and North America) participated in a live webinar to assess the reliability, reproducibility, and accuracy of classifying sacral fractures using the AO Spine Sacral Classification System. This evaluation was performed with 26 cases presented in randomized order on 2 occasions 3 weeks apart. RESULTS A total of 8320 case assessments were performed. All regions demonstrated excellent intraobserver reproducibility for fracture morphology. Respondents from Europe (k = .80) and North America (k = .86) achieved excellent reproducibility for fracture subtype while respondents from all other regions displayed substantial reproducibility. All regions demonstrated at minimum substantial interobserver reliability for fracture morphology and subtype. Each region demonstrated >90% accuracy in classifying fracture morphology and >80% accuracy in fracture subtype compared to the gold standard. Type C morphology (p2 = .0000) and A3 (p1 = .0280), B2 (p1 = .0015), C0 (p1 = .0085), and C2 (p1 =.0016, p2 =.0000) subtypes showed significant regional disparity in classification accuracy (p1 = Assessment 1, p2 = Assessment 2). Respondents from Asia (except in A3) and the combined group of North, Latin, and South America had accuracy percentages below the combined mean, whereas respondents from Europe consistently scored above the mean. CONCLUSIONS In a global validation study of the AO Spine Sacral Classification System, substantial reliability of both fracture morphology and subtype classification was found across all geographic regions

The role of electrical stimulation for rehabilitation and regeneration after spinal cord injury

Electrical stimulation is used to elicit muscle contraction and can be utilized for neurorehabilitation following spinal cord injury when paired with voluntary motor training. This technology is now an important therapeutic intervention that results in improvement in motor function in patients with spinal cord injuries. The purpose of this review is to summarize the various forms of electrical stimulation technology that exist and their applications. Furthermore, this paper addresses the potential future of the technology

Variation in global treatment for subaxial cervical spine isolated unilateral facet fractures.

PURPOSE To determine the variation in the global treatment practices for subaxial unilateral cervical spine facet fractures based on surgeon experience, practice setting, and surgical subspecialty. METHODS A survey was sent to 272 members of the AO Spine Subaxial Injury Classification System Validation Group worldwide. Questions surveyed surgeon preferences with regard to diagnostic work-up and treatment of fracture types F1-F3, according to the AO Spine Subaxial Cervical Spine Injury Classification System, with various associated neurologic injuries. RESULTS A total of 161 responses were received. Academic surgeons use the facet portion of the AO Spine classification system less frequently (61.6%) compared to hospital-employed and private practice surgeons (81.1% and 81.8%, respectively) (p = 0.029). The overall consensus was in favor of operative treatment for any facet fracture with radicular symptoms (N2) and for any fractures categorized as F2N2 and above. For F3N0 fractures, significantly less surgeons from Africa/Asia/Middle East (49%) and Europe (59.2%) chose operative treatment than from North/Latin/South America (74.1%) (p = 0.025). For F3N1 fractures, significantly less surgeons from Africa/Asia/Middle East (52%) and Europe (63.3%) recommended operative treatment than from North/Latin/South America (84.5%) (p = 0.001). More than 95% of surgeons included CT in their work-up of facet fractures, regardless of the type. No statistically significant differences were seen in the need for MRI to decide treatment. CONCLUSION Considerable agreement exists between surgeon preferences with regard to unilateral facet fracture management with few exceptions. F2N2 fracture subtypes and subtypes with radiculopathy (N2) appear to be the threshold for operative treatment