Morphological and molecular evidence confirms a new species, Riccia subcrinita YouL.Xiang & R.L.Zhu) and Riccia junghuhniana Nees & Lindenb. (Ricciaceae, Marchantiophyta) new to China

Riccia is the largest genus of complex thalloid liverworts (Marchantiopsida) with over 250 species currently accepted. Our recent investigation of Chinese liverworts found two interesting Riccia species, R. junghuhniana and Riccia subcrinita sp. nov. Riccia junghuhniana is currently known from Australia and Indonesia, while Riccia subcrinita is known only from China. Riccia subcrinita is similar to R. crinita, but differs in having smaller spores (56–71 µm in diameter), and spore distal surface and proximal surface alveoli without thick borders. The sequences of rbcL, rps4, and trnL-F, detailed descriptions, and illustrations of the Chinese specimens are provided. The range extension of R. junghuhniana suggests that more taxa of Riccia may have a wider distribution. The discovery of R. junghuhniana and the new species also suggests that a more intensive survey of Riccia diversity in China is necessary.

Spatiotemporally resolved measurements of electric field around a piezoelectric transformer using electric-field induced second harmonic (E-FISH) generation

When a piezoelectric transformer (PT) is actuated at its second harmonic frequency by a low input voltage, the generated electric field at the distal end can be sufficient to breakdown the surrounding gas, making them attractive power sources for non-equilibrium plasma generation. Understanding the potential and electric fields produced in the surrounding medium by the PT is important for effectively designing and using PT plasma devices. In this work, the spatiotemporally resolved characteristics of the electric field generated by a PT operating in open air have been investigated using the femtosecond electric field-induced second harmonic generation (E-FISH) method. Electric field components were determined by simultaneously conducting E-FISH measurements with the incident laser polarized in two orthogonal directions relative to the PT crystal. Results of this work demonstrate the spatial distribution of electric field around the PT’s output distal end and how it evolves as a function of time. Notably, the strongest electric field appears on the face of the PT’s distal surface, near the top and bottom edges and decreases by approximately 70% over 3 mm. The time delay between the PT’s input voltage and measured electric field indicates that there is an about 0.45 phase difference between the PT’s input voltage and output signal.

The effect of horizontal and vertical dimensions of the interproximal space on the existence of interdental papillae – A clinical study

The aim of the present study was to determine the existence of inter dental papilla according to the vertical dimension, horizontal dimension and the combined effects of the vertical and horizontal dimensions of the interproximal space on the existence of interdental papilla.182 interdental sites of 42 periodontitis patients undergoing open flap debridement were included in the study. The existence of interdental papilla was determined based on the Papilla Presence Index (PPI). The vertical dimension (VD) was measured from the alveolar crest to the contact point using UNC-15 probe. Horizontal dimension (HD) was measured from the mesial surface of the distal tooth and the distal surface of the mesial tooth at the level of the alveolar crest using castroviejocaliper. Statistical analysis was done by using independent ‘t’ test, Pearson’s Chi-square test and Trend Chi-square test. The existence of papilla was significantly higher in VD ≤ 5mm (91.5%) compared to VD > 5mm (9.8%) [p< 0.0001]. The existence of papilla was significantly higher in HD < 2mm (97%) compared to HD ≥ 2mm (1.2%) [p< 0.0001]. The contribution of both vertical dimension and horizontal dimension to the existence of papilla was about 61.6% and thus the existence of papilla may be influenced by various other factors (about 38.4%) which were not included in this study.The vertical and horizontal dimensions of the interproximal space gains significance in determining the existence of papilla and further research is needed to analyze the other factors influencing the papilla.

Isoetes baodongii (Isoetaceae), a New Basic Diploid Quillwort from China

Isoetes baodongii Y. F. Gu, Y. H. Yan & Yi J. Lu (Isoetaceae) is here described as a newly discovered, rare and endangered species of quillwort from eastern China. It has a basic diploid chromosome count of 2n = 22. Isoetes baodongii is similar to I. sinensis T. C. Palmer in its overall appearance and was previously misidentified as such. It differs from I. sinensis in its chromosome number and in megaspore ornamentation. In I. baodongii, both the proximal surface and distal surface of the megaspore are echinato-cristate, whereas in I. sinensis the proximal surface is echinate and the distal surface echinato-cristate. Microspores of I. baodongii have echinate ornamentation.

Accessory medial cuneiform bone in a child: unreported site and review of literature

<p>Accessory ossicles of the foot are not uncommon finding in foot radiographs which has confused radiologists and orthopedic surgeons from time immemorial. Occasionally these bones are symptomatic, hindering daily activities of patients. We present a case report of an eleven years old girl with a symptomatic accessory medial cuneiform on the dorsal aspect of left foot. The child was evaluated radiologically and after a trial of failed conservative treatment, she was operated upon. Intraoperatively a superficial nerve on dorsum of this accessory ossicle was found, and the extra bone was excised. This accessory bone was found to be related to medial cuneiform bone at its dorsal and distal surface making to suggest its name as "Os cuneo-I metatarsale-I dorsale". Detailed radiological evaluation is mandatory for identification and exact anatomical localization of the extra bone before proceeding to excision, when non operative treatment fails to relieve the symptoms.</p><p><strong> </strong></p>

Prediction of maxillary canine impaction using eruption pathway and angular measurement on panoramic radiographs

ABSTRACT Objectives To compare the normal eruption pattern and angulation in impacted maxillary canines using panoramic radiographs to predict maxillary canine impaction. Materials and Methods Patients aged 6 to 15 years were classified into the normal eruption group (n = 229) and the impaction group (n = 191). At least two panoramic radiographs were taken in the normal eruption group during the eruption process of the maxillary canine. The growth pattern of the maxillary canine was analyzed using an XY coordinate system, with the tip of the maxillary lateral incisor as the origin and the tooth's long axis as the Y-axis and measurement of the relative position of the crown tip and angulation of the maxillary canine. Results The crown tips of normally erupted maxillary canines were intensively distributed along the distal surface of the maxillary lateral incisor, while those of impacted canines were widely distributed. The angulations of the normally erupted canines increased as eruption increased along the lateral incisor and then decreased at the cervical point of the lateral incisor. The angulations of the impacted canines were scattered, with no uniform pattern. Conclusions While using the normal eruption path of the maxillary canine and the pattern of change in angulation based on the distal surface of the maxillary lateral incisor, early intervention or regular follow-up is needed to prevent maxillary canine impaction.

A multidisciplinary approach for external cervical resorption: A case report with 5-year follow-up

Introduction: External cervical resorption (ECR) is a physiological or pathological event usually detected on radiographic examination, since there are no symptoms in its initial and intermediate phases. Objectives: This case is an important finding because the early detection of this lesion allowed an effective multidisciplinary approach to be carried out. Case Report: Radiography was taken in a 55-year-old male and revealed a radiolucent area on the distal surface of the permanent mandibular left first molar, suggesting ECR with impaired pulpal vitality. Based on the clinical and radiographic examinations, a multidisciplinary approach was established involving endodontic treatment, periodontal surgery and indirect restoration that provided an option for preserve the affected tooth. The early diagnosis of ECR was essential for the successful treatment in order to maintain the satisfactory function for five-year follow-up. Conclusion: Despite the procedures performed, the idiopathic etiology of the lesion contributed to the appearance of recurrences; however, monitoring and maintenance of the affected tooth proved to be important for the longevity of the treatment.

Modified Spring for Uprighting Mesioangular Impacted Molars

Uprighting molar that is mesially angulated improves its periodontal status, coupled with bone deposition at the distal surface. 1 , 2 It also provides adequate support to its occlusal antagonist and maintains a stable occlusal pattern. Various methods for uprighting molars using springs, nickel-titanium superelastic wires, and miniscrews have been elucidated in literature. 3 - 5 This article presents a modification of spring fabricated of nickel-titanium that is effective in uprighting mesially angulated molars with minimal invasiveness. The proposed advantage of using this spring was that buccal flaring of the angulated molar was not observed due to the mild distalizing force applied against the molar by the tugging action of the spring.

The postcranial skeleton of Cerrejonisuchus improcerus (Crocodyliformes: Dyrosauridae) and the unusual anatomy of dyrosaurids

Dyrosauridae is a clade of neosuchian crocodyliforms that diversified in terrestrial and aquatic environments across the Cretaceous-Paleogene transition. The postcranial anatomy of dyrosaurids has long been overlooked, obscuring both their disparity and their locomotive adaptations. Here we thoroughly describe of the postcranial remains of an unusually small dyrosaurid, Cerrejonisuchus improcerus, from the middle-late Paleocene Cerrejón Formation of Colombia, and we provide a wealth of new data concerning the postcranial anatomy of the key dyrosaurids: Congosaurus bequaerti and Hyposaurus rogersii. We identify a series of postcranial autapomorphies in Cerrejonisuchus improcerus (an elliptic-shaped odontoid laterally wide, a ulna possessing a double concavity, a fibula bearing a widely flattened proximal end, a pubis showing a large non-triangular distal surface) as well as functionally-important traits such as a relatively long ulna (85% of the humerus’ length), short forelimb (83% of hindlimb’s length), or thoracic vertebra bearing comparatively large lateral process (with widened parapophysis and diapophysis) along with strongly arched thoracic ribs allowing a more sturdy and cylindrical rib cage. These indicate a more terrestrial lifestyle for Cerrejonisuchus compared to the derived members of the clade. We also built a dataset of 187 traits on 27 taxa, that extensively samples the cranial and postcranial architectures of exemplar crocodyliforms. We analyze these data in via Principal Coordinate Analysis (PCoA) to visualize the postcranial morphospace occupation of Dyrosauridae, Thalattosuchia, and Crocodylia. Our data reveal the existence of a distinctive postcranial anatomy for Dyrosauridae that is markedly distinct from that of crocodylians. As a result, modern crocodylians are probably not good functional analog for extinct crocodyliformes. Postcranial data should also be more widely used in phylogenetic and disparity analyses of Crocodyliformes.